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Various challenges facing the industrial production of bio-based lactic acid (LA) such as cost of raw materials and nitrogen sources, as well as contamination risk by mesophilic and neutrophilic producers, should be overcome for the commercial production. This study aimed to investigate the feasibility of corn steep water (CSW) as a raw material for LA production using a newly thermo-alkali-tolerant lactic acid bacterium. The physicochemical characteristics of CSW were investigated. The high carbohydrates, proteins, amino acids, vitamins, essential elements, minerals, and non-protein nitrogenous compounds content confirmed that the CSW is a promising substrate for LA production. Out of 67 bacterial isolates, Enterococcus faecium WH51-1 was selected based on its tolerance to high temperatures and inhibitory compounds (sodium metabisulfate, sodium chloride, sodium acetate, and formic acid). Fermentation factors including sugar concentration, temperature, inoculum size, and neutralizing agents were optimized for LA production. Lactic acid concentration of about 44.6 g/L with a high yield (0.89 ± 0.02 g/g) was obtained using 60 g/L of CSW sugar, inoculum size 10% (v/v), 45 °C, and sodium hydroxide or calcium carbonate as a neutralizing agent. These results demonstrated the potential of strain WH51-1 for LA production using CSW effluent as raw material.
Mohamed Selim; Salem Salem; Amr Fouda; Mamdouh El-Gamal; Mohamed Abdel-Rahman. Use of Corn-Steep Water Effluent as a Promising Substrate for Lactic Acid Production by Enterococcus faecium Strain WH51-1. Fermentation 2021, 7, 111 .
AMA StyleMohamed Selim, Salem Salem, Amr Fouda, Mamdouh El-Gamal, Mohamed Abdel-Rahman. Use of Corn-Steep Water Effluent as a Promising Substrate for Lactic Acid Production by Enterococcus faecium Strain WH51-1. Fermentation. 2021; 7 (3):111.
Chicago/Turabian StyleMohamed Selim; Salem Salem; Amr Fouda; Mamdouh El-Gamal; Mohamed Abdel-Rahman. 2021. "Use of Corn-Steep Water Effluent as a Promising Substrate for Lactic Acid Production by Enterococcus faecium Strain WH51-1." Fermentation 7, no. 3: 111.
Endophytic bacteria colonize plants and live inside them for part of or throughout their life without causing any harm or disease to their hosts. The symbiotic relationship improves the physiology, fitness, and metabolite profile of the plants, while the plants provide food and shelter for the bacteria. The bacteria-induced alterations of the plants offer many possibilities for biotechnological, medicinal, and agricultural applications. The endophytes promote plant growth and fitness through the production of phytohormones or biofertilizers, or by alleviating abiotic and biotic stress tolerance. Strengthening of the plant immune system and suppression of disease are associated with the production of novel antibiotics, secondary metabolites, siderophores, and fertilizers such as nitrogenous or other industrially interesting chemical compounds. Endophytic bacteria can be used for phytoremediation of environmental pollutants or the control of fungal diseases by the production of lytic enzymes such as chitinases and cellulases, and their huge host range allows a broad spectrum of applications to agriculturally and pharmaceutically interesting plant species. More recently, endophytic bacteria have also been used to produce nanoparticles for medical and industrial applications. This review highlights the biotechnological possibilities for bacterial endophyte applications and proposes future goals for their application.
Ahmed Eid; Amr Fouda; Mohamed Abdel-Rahman; Salem Salem; Albaraa Elsaied; Ralf Oelmüller; Mohamed Hijri; Arnab Bhowmik; Amr Elkelish; Saad Hassan. Harnessing Bacterial Endophytes for Promotion of Plant Growth and Biotechnological Applications: An Overview. Plants 2021, 10, 935 .
AMA StyleAhmed Eid, Amr Fouda, Mohamed Abdel-Rahman, Salem Salem, Albaraa Elsaied, Ralf Oelmüller, Mohamed Hijri, Arnab Bhowmik, Amr Elkelish, Saad Hassan. Harnessing Bacterial Endophytes for Promotion of Plant Growth and Biotechnological Applications: An Overview. Plants. 2021; 10 (5):935.
Chicago/Turabian StyleAhmed Eid; Amr Fouda; Mohamed Abdel-Rahman; Salem Salem; Albaraa Elsaied; Ralf Oelmüller; Mohamed Hijri; Arnab Bhowmik; Amr Elkelish; Saad Hassan. 2021. "Harnessing Bacterial Endophytes for Promotion of Plant Growth and Biotechnological Applications: An Overview." Plants 10, no. 5: 935.
The incidence of Extended-spectrum β-lactamase (ESBL)-encoding genes (bla CTX-M and bla TEM) among Gram-negative multidrug-resistant pathogens collected from three different countries was investigated. Two hundred and ninety-two clinical isolates were collected from Egypt (n = 90), Saudi Arabia (n = 162), and Sudan (n = 40). Based on the antimicrobial sensitivity against 20 antimicrobial agents from 11 antibiotic classes, the most resistant strains were selected and identified using the Vitek2 system and 16S rRNA gene sequence analysis. A total of 85.6% of the isolates were found to be resistant to more than three antibiotic classes. The ratios of the multidrug-resistant strains for Egypt, Saudi Arabia, and Sudan were 74.4%, 90.1%, and 97.5%, respectively. Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa showed inconstant resistance levels to the different classes of antibiotics. Escherichia coli and Klebsiella pneumoniae had the highest levels of resistance against macrolides followed by penicillins and cephalosporin, while Pseudomonas aeruginosa was most resistant to penicillins followed by classes that varied among different countries. The isolates were positive for the presence of the bla CTX-M and bla TEM genes. The bla CTX-M gene was the predominant gene in all isolates (100%), while bla TEM was detected in 66.7% of the selected isolates. This work highlights the detection of multidrug-resistant bacteria and resistant genes among different countries. We suggest that the medical authorities urgently implement antimicrobial surveillance plans and infection control policies for early detection and effective prevention of the rapid spread of these pathogens.
Khaled Azab; Mohamed Abdel-Rahman; Hussien El-Sheikh; Ehab Azab; Adil Gobouri; Mohamed Farag. Distribution of Extended-Spectrum β-Lactamase (ESBL)-Encoding Genes among Multidrug-Resistant Gram-Negative Pathogens Collected from Three Different Countries. Antibiotics 2021, 10, 247 .
AMA StyleKhaled Azab, Mohamed Abdel-Rahman, Hussien El-Sheikh, Ehab Azab, Adil Gobouri, Mohamed Farag. Distribution of Extended-Spectrum β-Lactamase (ESBL)-Encoding Genes among Multidrug-Resistant Gram-Negative Pathogens Collected from Three Different Countries. Antibiotics. 2021; 10 (3):247.
Chicago/Turabian StyleKhaled Azab; Mohamed Abdel-Rahman; Hussien El-Sheikh; Ehab Azab; Adil Gobouri; Mohamed Farag. 2021. "Distribution of Extended-Spectrum β-Lactamase (ESBL)-Encoding Genes among Multidrug-Resistant Gram-Negative Pathogens Collected from Three Different Countries." Antibiotics 10, no. 3: 247.
Lignocellulosic and algal biomass are promising substrates for lactic acid (LA) production. However, lack of xylose utilization and/or sequential utilization of mixed-sugars (carbon catabolite repression, CCR) from biomass hydrolysates by most microorganisms limits achievable titers, yields, and productivities for economical industry-scale production. This study aimed to design lignocellulose-derived substrates for efficient LA production by a thermophilic, xylose-utilizing, and inhibitor-resistant Bacillus coagulans Azu-10. This strain produced 102.2 g/L of LA from 104 g/L xylose at a yield of 1.0 g/g and productivity of 3.18 g/L/h. The CCR effect and LA production were investigated using different mixtures of glucose (G), cellobiose (C), and/or xylose (X). Strain Azu-10 has efficiently co-utilized GX and CX mixture without CCR; however, total substrate concentration (>75 g/L) was the only limiting factor. The strain completely consumed GX and CX mixture and homoferemnatively produced LA up to 76.9 g/L. On the other hand, fermentation with GC mixture exhibited obvious CCR where both glucose concentration (>25 g/L) and total sugar concentration (>50 g/L) were the limiting factors. A maximum LA production of 50.3 g/L was produced from GC mixture with a yield of 0.93 g/g and productivity of 2.09 g/L/h. Batch fermentation of GCX mixture achieved a maximum LA concentration of 62.7 g/L at LA yield of 0.962 g/g and productivity of 1.3 g/L/h. Fermentation of GX and CX mixture was the best biomass for LA production. Fed-batch fermentation with GX mixture achieved LA production of 83.6 g/L at a yield of 0.895 g/g and productivity of 1.39 g/L/h.
Mohamed Abdel-Rahman; Saad Hassan; Hassan Alrefaey; Tamer Elsakhawy. Efficient Co-Utilization of Biomass-Derived Mixed Sugars for Lactic Acid Production by Bacillus coagulans Azu-10. Fermentation 2021, 7, 28 .
AMA StyleMohamed Abdel-Rahman, Saad Hassan, Hassan Alrefaey, Tamer Elsakhawy. Efficient Co-Utilization of Biomass-Derived Mixed Sugars for Lactic Acid Production by Bacillus coagulans Azu-10. Fermentation. 2021; 7 (1):28.
Chicago/Turabian StyleMohamed Abdel-Rahman; Saad Hassan; Hassan Alrefaey; Tamer Elsakhawy. 2021. "Efficient Co-Utilization of Biomass-Derived Mixed Sugars for Lactic Acid Production by Bacillus coagulans Azu-10." Fermentation 7, no. 1: 28.
The textile and leather industry produces large amounts of wastewater that contains high levels of chemicals and other pollutants, incorporated during the processing stages. We evaluated the efficacy of green synthesized iron oxide (α-Fe2O3) and magnesium oxide (MgO) nanoparticles (NPs) for wastewater treatment of crude textile and tannery effluents. Green synthesis of α-Fe2O3-NPs and MgO-NPs was conducted using the newly obtained Aspergillus carbonarious strain D-1. The optimization of the physicochemical parameters for the biosynthesis of NPs, including incubation periods, contact time, pH, temperature, and precursor concentrations, were assessed. The characterization of NPs obtained under optimal conditions was evaluated using UV–visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) patterns, dynamic light scattering (DLS), and Fourier Transform Infrared (FT-IR) Spectroscopy. The optimal concentration for efficient textile/tannery wastewater decolorization was determined to be 100 mg NPs after eight hours for α-Fe2O3-NPs and after four hours for MgO-NPs. Under these conditions, chemical oxygen deman (COD), pH value, total dissolved solids (TDS), total suspended solids (TSS), and conductivity were greatly reduced as compared to control for crude textile wastewater. GC–MS analysis of NPs-treated textile wastewater revealed that some major compounds were greatly diminished, bio-transformed, or completely degraded. MgO and α-Fe2O3 NPs exhibited a high capacity to reduce the COD of tannery wastewater by 97.5% and 95.0%, respectively. Hematite NPs exhibited higher removal capacity for TDS, TSS, and conductivity compared to MgO-NPs. MgO and hematite NPs exhibited high capacities to remove Cr, with MgO redcing Cr by 87.06 and hematite NPs reducing Cr by 75.4%. MgO-NPs were more effective than α-Fe2O3-NPs at removing Pb, Ni, and Cd.
Amr Fouda; Saad El-Din Hassan; Mohamed Ali Abdel-Rahman; Mohamed M.S. Farag; Amr Shehal-Deen; Asem A. Mohamed; Sultan M. Alsharif; Ebrahim Saied; Saad A. Moghanim; Mohamed Salah Azab. Catalytic degradation of wastewater from the textile and tannery industries by green synthesized hematite (α-Fe2O3) and magnesium oxide (MgO) nanoparticles. Current Research in Biotechnology 2021, 3, 29 -41.
AMA StyleAmr Fouda, Saad El-Din Hassan, Mohamed Ali Abdel-Rahman, Mohamed M.S. Farag, Amr Shehal-Deen, Asem A. Mohamed, Sultan M. Alsharif, Ebrahim Saied, Saad A. Moghanim, Mohamed Salah Azab. Catalytic degradation of wastewater from the textile and tannery industries by green synthesized hematite (α-Fe2O3) and magnesium oxide (MgO) nanoparticles. Current Research in Biotechnology. 2021; 3 ():29-41.
Chicago/Turabian StyleAmr Fouda; Saad El-Din Hassan; Mohamed Ali Abdel-Rahman; Mohamed M.S. Farag; Amr Shehal-Deen; Asem A. Mohamed; Sultan M. Alsharif; Ebrahim Saied; Saad A. Moghanim; Mohamed Salah Azab. 2021. "Catalytic degradation of wastewater from the textile and tannery industries by green synthesized hematite (α-Fe2O3) and magnesium oxide (MgO) nanoparticles." Current Research in Biotechnology 3, no. : 29-41.
Effective lactic acid (LA) production from lignocellulosic biomass materials is challenged by several limitations related to pentose sugar utilization, inhibitory compounds, and/or fermentation conditions. In this study, a newly isolated Bacillus coagulans strain Azu-10 was obtained and showed homofermentative LA production from xylose with optimal fermentation conditions at 50 °C and pH 7.0. Growth of strain Azu-10 and LA-fermentation efficiency were evaluated in the presence of various lignocellulose-derived inhibitors (furans, carboxylic acids, and phenols) at different concentrations. Furanic lignocellulosic-derived inhibitors were completely detoxified. The strain has exhibited high biomass, complete xylose consumption, and high LA production in the presence of 1.0‒4.0 g/L furfural and 1.0‒5.0 g/L of hydroxymethyl furfural, separately. Moreover, strain Azu-10 exhibited high LA production in the presence of 5.0–15.0 g/L acetic acid, 5.0 g/L of formic acid, and up to 7.0 g/L of levulinic acid, separately. Besides, for phenolic compounds, p-coumaric acid was most toxic at 1.0 g/L, while syringaldehyde or p-hydroxybenzaldehyde, and vanillin at 1.0 g/L did not inhibit LA fermentation. The present study provides an interesting potential candidate for the thermophilic LA fermentation from lignocellulose-derived substrates at the industrial biorefinery level.
Mohamed Abdel-Rahman; Saad Hassan; Amr Fouda; Ahmed Radwan; Mohammed Barghoth; Salha Desouky. Evaluating the Effect of Lignocellulose-Derived Microbial Inhibitors on the Growth and Lactic Acid Production by Bacillus coagulans Azu-10. Fermentation 2021, 7, 17 .
AMA StyleMohamed Abdel-Rahman, Saad Hassan, Amr Fouda, Ahmed Radwan, Mohammed Barghoth, Salha Desouky. Evaluating the Effect of Lignocellulose-Derived Microbial Inhibitors on the Growth and Lactic Acid Production by Bacillus coagulans Azu-10. Fermentation. 2021; 7 (1):17.
Chicago/Turabian StyleMohamed Abdel-Rahman; Saad Hassan; Amr Fouda; Ahmed Radwan; Mohammed Barghoth; Salha Desouky. 2021. "Evaluating the Effect of Lignocellulose-Derived Microbial Inhibitors on the Growth and Lactic Acid Production by Bacillus coagulans Azu-10." Fermentation 7, no. 1: 17.
Different fermentation strategies were investigated for improving lactic acid (LA) production by homofermentative LA-producing strain, Enterococcus hirae ds10. Batch mode with initial sugar molasses of 69.53 g/L achieved LA production of 36.79 g/L with a yield of 0.91 g/g and productivity of 1.02 g/L/h; however, 52% of sugar molasses was only consumed. Otherwise, in batch mode with high cell density (HCD), strain ds10 consumed more substrate achieving LA production at 49.49 g/L at yield (0.91 g/g) and low LA productivity (0.41 g/L/h). Subsequently, one-pulse and multi-pulse fed-batch strategies with/without HCD were provided better sugar utilization and higher LA production but low LA productivity was obtained. Interestingly, the repeated batch fermentation was conducted for 16 runs and achieved the highest LA of 61.76 g/L after 30 h at a higher initial sugar concentration of 85.87 g/L with an improvement of LA productivity at 2.06 g/L/h and yield at 0. 97 g/g.
Mohamed Ali Abdel-Rahman; Saad El-Din Hassan; Hassan M.A. Alrefaey; Ehab F. El-Belely; Tamer Elsakhawy; Amr Fouda; Salha G. Desouky; Sadat M.R. Khattab. Subsequent improvement of lactic acid production from beet molasses by Enterococcus hirae ds10 using different fermentation strategies. Bioresource Technology Reports 2020, 13, 100617 .
AMA StyleMohamed Ali Abdel-Rahman, Saad El-Din Hassan, Hassan M.A. Alrefaey, Ehab F. El-Belely, Tamer Elsakhawy, Amr Fouda, Salha G. Desouky, Sadat M.R. Khattab. Subsequent improvement of lactic acid production from beet molasses by Enterococcus hirae ds10 using different fermentation strategies. Bioresource Technology Reports. 2020; 13 ():100617.
Chicago/Turabian StyleMohamed Ali Abdel-Rahman; Saad El-Din Hassan; Hassan M.A. Alrefaey; Ehab F. El-Belely; Tamer Elsakhawy; Amr Fouda; Salha G. Desouky; Sadat M.R. Khattab. 2020. "Subsequent improvement of lactic acid production from beet molasses by Enterococcus hirae ds10 using different fermentation strategies." Bioresource Technology Reports 13, no. : 100617.
Enterococcus mundtii QU25, a non-dairy lactic acid bacterium of the phylum Firmicutes, is capable of simultaneously fermenting cellobiose and xylose, and is described as a promising strain for the industrial production of optically pure l-lactic acid (≥ 99.9%) via homo-fermentation of lignocellulosic hydrolysates. Generally, Firmicutes bacteria show preferential consumption of sugar (usually glucose), termed carbon catabolite repression (CCR), while hampering the catabolism of other sugars. In our previous study, QU25 exhibited apparent CCR in a glucose-xylose mixture phenotypically, and transcriptional repression of the xylose operon encoding initial xylose metabolism genes, likely occurred in a CcpA-dependent manner. QU25 did not exhibit CCR phenotypically in a cellobiose-xylose mixture. The aim of the current study is to elucidate the transcriptional change associated with the simultaneous utilization of cellobiose and xylose. To this end, we performed RNA-seq analysis in the exponential growth phase of E. mundtii QU25 cells grown in glucose, cellobiose, and/or xylose as either sole or co-carbon sources. Our transcriptomic data showed that the xylose operon was weakly repressed in cells grown in a cellobiose-xylose mixture compared with that in cells grown in a glucose-xylose mixture. Furthermore, the gene expression of talC, the sole gene encoding transaldolase, is expected to be repressed by CcpA-mediated CCR. QU25 metabolized xylose without using transaldolase, which is necessary for homolactic fermentation from pentoses using the pentose-phosphate pathway. Hence, the metabolism of xylose in the presence of cellobiose by QU25 may have been due to 1) sufficient amounts of proteins encoded by the xylose operon genes for xylose metabolism despite of the slight repression of the operon, and 2) bypassing of the pentose-phosphate pathway without the TalC activity. Accordingly, we have determined the targets of genetic modification in QU25 to metabolize cellobiose, xylose and glucose simultaneously for application of the lactic fermentation from lignocellulosic hydrolysates.
Yuh Shiwa; Haruko Fujiwara; Mao Numaguchi; Mohamed Ali Abdel-Rahman; Keisuke Nabeta; Yu Kanesaki; Yukihiro Tashiro; Takeshi Zendo; Naoto Tanaka; Nobuyuki Fujita; Hirofumi Yoshikawa; Kenji Sonomoto; Mariko Shimizu-Kadota. Transcriptome profile of carbon catabolite repression in an efficient l-(+)-lactic acid-producing bacterium Enterococcus mundtii QU25 grown in media with combinations of cellobiose, xylose, and glucose. PLOS ONE 2020, 15, e0242070 .
AMA StyleYuh Shiwa, Haruko Fujiwara, Mao Numaguchi, Mohamed Ali Abdel-Rahman, Keisuke Nabeta, Yu Kanesaki, Yukihiro Tashiro, Takeshi Zendo, Naoto Tanaka, Nobuyuki Fujita, Hirofumi Yoshikawa, Kenji Sonomoto, Mariko Shimizu-Kadota. Transcriptome profile of carbon catabolite repression in an efficient l-(+)-lactic acid-producing bacterium Enterococcus mundtii QU25 grown in media with combinations of cellobiose, xylose, and glucose. PLOS ONE. 2020; 15 (11):e0242070.
Chicago/Turabian StyleYuh Shiwa; Haruko Fujiwara; Mao Numaguchi; Mohamed Ali Abdel-Rahman; Keisuke Nabeta; Yu Kanesaki; Yukihiro Tashiro; Takeshi Zendo; Naoto Tanaka; Nobuyuki Fujita; Hirofumi Yoshikawa; Kenji Sonomoto; Mariko Shimizu-Kadota. 2020. "Transcriptome profile of carbon catabolite repression in an efficient l-(+)-lactic acid-producing bacterium Enterococcus mundtii QU25 grown in media with combinations of cellobiose, xylose, and glucose." PLOS ONE 15, no. 11: e0242070.
Liquid microbial inoculants have recently received great attention due to their vital roles for sustainable agricultural practices. However, long-term conservation under ambient temperature conditions and deleterious environmental factors might negatively impact microbial cell survival and limit their efficacy in the field. Thus, developing efficient liquid formulation providing prolonged survival of rhizobia in the final product and after an application is crucial. Therefore, this study investigates the effect of various additives on the long-term survival of rhizobia stored in liquid cultures at room temperature (25 °C) for 12 months. Various yeast sucrose media amended with polyvinylpyrrolidone (PVP) or gum arabic as colloidal agents in combination with ectoine (as a compatible solute) and/or glycerol were evaluated. A dramatic decline in viable cell count was obtained in formulas amended only with PVP from Log 8.5 to Log 5 in the first six months and then to Log 1.5 after 12 months. In contrast, rhizobia stored at PVP-based formulas amended with 10 mg L‒1 ectoine exhibited almost constant survival level till the end of the storage period. The same trend was obtained using formulas based on gum arabic as a colloidal dispersing agent; however, less decline in cell count using a formula containing gum arabic alone as compared to using PVP. On the other hand, PVP based formulas exhibited higher viscosity compared with another formula. Increased viscosity till the 8th month of storage was achieved in the presence of ectoine indicating the increase of exopolymeric substances production. Electrophoretic protein pattern of rhizobial cells (stored for 12 months) exhibited several low molecular weight protein bands in cells stored in PVP based formula with ectoine as compared to the other treatments. Thus, the amendment of the liquid formulation of rhizobia bioinoculant with PVP plus ectoine not only improved cell survival but also enhanced the culture viscosity and consequently ameliorate the colonization and performance of rhizobial inoculants.
Tamer Elsakhawy; Azza Ghazi; Mohamed Ali Abdel-Rahman. Developing Liquid Rhizobium Inoculants with Enhanced Long-Term Survival, Storage Stability, and Plant Growth Promotion Using Ectoine Additive. Current Microbiology 2020, 78, 282 -291.
AMA StyleTamer Elsakhawy, Azza Ghazi, Mohamed Ali Abdel-Rahman. Developing Liquid Rhizobium Inoculants with Enhanced Long-Term Survival, Storage Stability, and Plant Growth Promotion Using Ectoine Additive. Current Microbiology. 2020; 78 (1):282-291.
Chicago/Turabian StyleTamer Elsakhawy; Azza Ghazi; Mohamed Ali Abdel-Rahman. 2020. "Developing Liquid Rhizobium Inoculants with Enhanced Long-Term Survival, Storage Stability, and Plant Growth Promotion Using Ectoine Additive." Current Microbiology 78, no. 1: 282-291.
In the current work, date wastes were used for lactic acid (LA) production under thermo-alkaline conditions to overcome some fermentation challenges. Amongst 27 bacterial isolates that produced LA from date juice, isolate D-218 exhibited better growth stability and LA production under various stressed conditions. This isolate was characterized as Bacillus coagulans D-218 using physiological and molecular identification methods. In batch fermentation mode, strain D-218 could not completely utilize 80 g/L of the total sugar and produced only 45.8 ± 2.8 g/L of LA at LA productivity of 0.214 g/L.h and high residual sugar (29.2 g/L) was unutilized in the fermentation media. Different repeated batch fermentations with different initial sugar concentrations and gradual increase in sugar concentrtions were conducted to maximize LA productivity. Starting with 60 g/L of total sugar, four runs of repeated batch fermentations were conducted that enhanced the LA productivity (70%) to 0.49 g/L.h. Another 9 runs were initiated with 40 g/L which further improved LA productivity that reached up to 0.77 g/L.h. Surprisingly, initiating fermentations with 20 g/L of total sugar successfully attained long-term fermentation (18 runs) with high LA yield and productivity without carbon loss of initiated startup sugar of date waste. In this process, strain D-218 could completely consume 80 g/L sugars with high LA production titer (72.9 ± 0.56 g/L), yield (0.92 g/g), and productivity (0.71 g/L.h). This study is the first to exploit date waste in a cost-effective system for high-titer lactic acid production under thermo-alkaline conditions (pH 9.0; 50 °C) and to report repeated batch fermentation for LA production from date wastes.
Mahmoud Ali Gaber; Mohamed Ali Abdel-Rahman; Saad El-Din Hassan; Mohamed Salah Azab. Efficient biorefinery process for lactic acid production from date wastes with alleviating substrate inhibition effect using thermo-alkaline repeated batch fermentation. Biomass Conversion and Biorefinery 2020, 11, 1053 -1066.
AMA StyleMahmoud Ali Gaber, Mohamed Ali Abdel-Rahman, Saad El-Din Hassan, Mohamed Salah Azab. Efficient biorefinery process for lactic acid production from date wastes with alleviating substrate inhibition effect using thermo-alkaline repeated batch fermentation. Biomass Conversion and Biorefinery. 2020; 11 (3):1053-1066.
Chicago/Turabian StyleMahmoud Ali Gaber; Mohamed Ali Abdel-Rahman; Saad El-Din Hassan; Mohamed Salah Azab. 2020. "Efficient biorefinery process for lactic acid production from date wastes with alleviating substrate inhibition effect using thermo-alkaline repeated batch fermentation." Biomass Conversion and Biorefinery 11, no. 3: 1053-1066.
Microbial bioconversion of agro-industrial wastes to green chemicals has become an important objective in industrial biotechnology for lowering the product costs. Therefore, in this work, beet molasses was used as a potential raw material for lactic acid (LA) production by a newly isolated bacterium, Enterococcus faecium S6. The pretreatment of molasses with EDTA has exhibited the highest effectiveness for bioconversion to LA. The optimal medium components and culture conditions were established. Supplementation of molasses by yeast extract (YE) and ammonium chloride have achieved LA production of 11.90 g/L at a yield of 0.71 g/g-consumed sugars and a productivity of 0.33 g/L/h. Various approaches were used for the optimization of relevant factors affecting l-LA production in batch fermentations. Using classical “one-factor-at-a-time” approach, the optimal factors were as follows: sugar concentration, 40 g/L; pH, 7.0; 40 °C; and inoculum size, 10% (v/v) achieving LA at 29.7 g/L. The effects of these five fermentation parameters were further investigated by response surface methodology (RSM) to maximize LA production. The optimized fermentation conditions by RSM were as follows: sugar concentration, 65 g/L; YE, 0.625 g/L; temperature, 42 °C; pH, 6.75; and inoculum size, 9.5% (v/v) that achieved LA production of 41.5 g/L. Further improvements were achieved using repeated batch fermentation that has conducted for 16 runs. Using seed culture pre-adapted to the actual fermentation conditions in repeated batch fermentation led to enhanced LA production with a shorter process time compared to batch fermentation. These results achieved a maximum LA of 64.7 g/L with high yield (0.94 g/g of consumed sugars) and productivity (2.16 g/L/h). This study presented a cost-effective and long-term fermentative production of LA from beet molasses. Graphical abstract
Hassan M. A. Alrefaey; Mohamed Ali Abdel-Rahman; Saad El-Din Hassan; Mohamed Nour El-Din; Mohamed Salah Azab. Sequential optimization of the fermentation factors with integrating seed culture adaptation for increased biorefinery of beet molasses to lactic acid. Biomass Conversion and Biorefinery 2020, 11, 1013 -1028.
AMA StyleHassan M. A. Alrefaey, Mohamed Ali Abdel-Rahman, Saad El-Din Hassan, Mohamed Nour El-Din, Mohamed Salah Azab. Sequential optimization of the fermentation factors with integrating seed culture adaptation for increased biorefinery of beet molasses to lactic acid. Biomass Conversion and Biorefinery. 2020; 11 (3):1013-1028.
Chicago/Turabian StyleHassan M. A. Alrefaey; Mohamed Ali Abdel-Rahman; Saad El-Din Hassan; Mohamed Nour El-Din; Mohamed Salah Azab. 2020. "Sequential optimization of the fermentation factors with integrating seed culture adaptation for increased biorefinery of beet molasses to lactic acid." Biomass Conversion and Biorefinery 11, no. 3: 1013-1028.
This study addresses the impacts of metabolites from different microbial taxa on the fabrication and multifunctional biological properties of spherical silver nanoparticles (Ag-NPs). Three microbial taxa, a bacterial (Bacillus cereus A1-5), actinomycetes (Streptomyces noursei H1-1), and fungal (Rhizopus stolonifer A6-2) strains were used for Ag-NPs biosynthesis, whereas Streptomyces noursei is demonstrated for the first time. These isolates were identified using either 16S rRNA or ITS gene sequencing. Characterization of Ag-NPs was done using color change analysis, Uv-Vis spectroscopy, FT-IR spectroscopy, XRD, TEM, SEM-EDX, DLS, and Zeta potential analysis. All biosynthesized NPs exhibited spherical shape with different sizes ranged from 6‒50 nm, 6-30 nm and 6-40 nm for NPs obtained by A1-5, H1-1 and A6-2, respectively. The crystalline center cubic face of Ag-NPs was confirmed using XRD at 2θ values 38.08o, 44.27o, 64.41o and 77.36o. FT-IR analysis revealed varied intense absorption peaks for biomolecules required for NPs synthesize by each microbial strain. The stability of spherical Ag-NPs was confirmed due to highly DLS negative surface charge of ‒17.5mV, ‒18.9mV, and ‒15.6mV for NPs synthesized by strains A1-5, H1-1, and A6-2, respectively. Ag-NPs exhibited a broadspectrum of antibacterial activity against Gram-positive and Gram-negative bacteria with varied effectiveness. They also exhibited a cytotoxic effect against cancer cell line (caco-2) in a dose-dependent pattern with IC50 of 8.9 ± 0.5, 5.6 ± 3.0, 11.2 ± 0.5 μg/ml for NPs synthesized by strains A1-5, H1-1, and A6-2, respectively. Moreover, these spherical Ag-NPs showed larvicidal activity against the 3rd instar larvae of the dengue vector Aedes aegypti.
Sultan M. Alsharif; Salem S. Salem; Mohamed Ali Abdel-Rahman; Amr Fouda; Ahmed Eid; Saad El-Din Hassan; Mohamed A. Awad; Asem A. Mohamed. Multifunctional properties of spherical silver nanoparticles fabricated by different microbial taxa. Heliyon 2020, 6, e03943 .
AMA StyleSultan M. Alsharif, Salem S. Salem, Mohamed Ali Abdel-Rahman, Amr Fouda, Ahmed Eid, Saad El-Din Hassan, Mohamed A. Awad, Asem A. Mohamed. Multifunctional properties of spherical silver nanoparticles fabricated by different microbial taxa. Heliyon. 2020; 6 (5):e03943.
Chicago/Turabian StyleSultan M. Alsharif; Salem S. Salem; Mohamed Ali Abdel-Rahman; Amr Fouda; Ahmed Eid; Saad El-Din Hassan; Mohamed A. Awad; Asem A. Mohamed. 2020. "Multifunctional properties of spherical silver nanoparticles fabricated by different microbial taxa." Heliyon 6, no. 5: e03943.
We previously reported that Aeromonas hydrophila exhibited the highest prevalence rate amongst 182 bacterial strains isolated from naturally diseased Nile tilapia (Oreochromis niloticus) collected from El-Abassa Fish Farm, Egypt (Hassan et al., Egypt. J. Aquac., 10, 23–43, 2020). The overuse of antibiotics for controlling diseases has led to acquired antibiotics resistance of aquatic bacteria, besides the developments of human, aquatic animal and environmental risks arising from residual antibiotics. Therefore, the evaluation of safe alternative phytotherapies is of great importance. This study was conducted to evaluate and compare growth performance and immune potentiating activities of moringa (Moringa oleifera) leaves extract (Moringa LE) and pomegranate (Punica granatum) peel extract (Pomegranate PE) on Nile tilapia against infection with a pathogenic bacterium, Aeromonas hydrophila. A total of 150 Oreochromis niloticus were randomly divided into 5 groups to be fed at 3% of body weight with isonitrogenous/isoenergetic diets supplemented with Moringa LE at 0.15 and 0.25% kg−1 or Pomegranate PE at of 0.3 and 0.5% kg−1, separately. Growth performance was significantly affected by Moringa LE as compared with the control group without supplementation of plant extract, while Pomegranate PE levels did not affect growth performance. Maximum average daily gains, specific growth rate, albumin, globulin, total protein, A/G ratio, alanine amino transaminase (ALT), aspartate amino transaminase (AST), cholesterol, triglyceride, creatinine, urea, and lysozyme were analyzed. Antioxidant enzymes of catalase and superoxide dismutase were also evaluated in liver tissues. After feeding experiment, the results indicated that the addition of Moringa LE and Pomegranate PE improved lipid profile, liver and kidney functions, immune response towards the emerging bacterial diseases. Besides this, feeding the fishes on diets supplemented with Moringa LE at concentration 0.25% kg−1 showed the best growth performance, and improved immunity. Moreover, it exhibited the highest protection against bacterial infection with Aeromonas hydrophila achieving the lowest mortality rate of 10% as compared to 80% of mortality rate at the control group.
Walid Monir; Mohamed Ali Abdel-Rahman; Saad El-Din Hassan; El Sayed Mansour; Somayah M.M. Awad. Pomegranate peel and moringa-based diets enhanced biochemical and immune parameters of Nile tilapia against bacterial infection by Aeromonas hydrophila. Microbial Pathogenesis 2020, 145, 104202 .
AMA StyleWalid Monir, Mohamed Ali Abdel-Rahman, Saad El-Din Hassan, El Sayed Mansour, Somayah M.M. Awad. Pomegranate peel and moringa-based diets enhanced biochemical and immune parameters of Nile tilapia against bacterial infection by Aeromonas hydrophila. Microbial Pathogenesis. 2020; 145 ():104202.
Chicago/Turabian StyleWalid Monir; Mohamed Ali Abdel-Rahman; Saad El-Din Hassan; El Sayed Mansour; Somayah M.M. Awad. 2020. "Pomegranate peel and moringa-based diets enhanced biochemical and immune parameters of Nile tilapia against bacterial infection by Aeromonas hydrophila." Microbial Pathogenesis 145, no. : 104202.
In this study, the production of lactic acid (LA) from beet molasses, a by-product of the beet sugar industry was investigated using newly isolated potential lactic acid bacteria. Isolate ds10 was selected amongst 138 bacterial isolates obtained from natural sources. This isolate was identified as Enterococcus hirae ds10 based on morphological, biochemical and molecular characteristics using 16S rRNA sequence. Direct utilization of molasses achieved low LA production at 2.01 g L‒1. Different molasses’ pretreatment methods were investigated. Molasses treated with EDTA were considered as the best substrate achieving effective LA production at 11.39 ± 2.07 g L‒1. Furthermore, medium constituent was optimized, where supplementation of 0.5% (w/v) ammonium chloride and 0.05% (w/v) yeast extract exhibited the best fermentation medium. Further optimization of fermentation factors was performed by using one-factor-at-a-time (OFAT) and response surface Minitab 18 software approaches. OFAT technique achieved the maximum LA production of 25.4 ± 0.42 g L‒1 after 24 h at sugar molasses conc., 4% (w/v); inoculum size, 10% (v/v); pH, 8.0; and temperature, 40 °C. Whereas, response surface Minitab 18 software approach resulted in a 60% increase in LA production achieving 40.69 g L‒1 at 60 g L‒1 sugar concentration, 0.625 g L‒1 yeast extract, 40 °C, pH 8 and 9.5% inoculum size. The optimization strategy in this study could achieve a 20-fold increase in LA production as compared to initial production.
Mohamed A. Abdel-Rahman; Saad E. D. Hassan; Mohamed N. El-Din; Mohamed S. Azab; Ehab F. El-Belely; Hassan M. A. Alrefaey; Tamer Elsakhawy. One-factor-at-a-time and response surface statistical designs for improved lactic acid production from beet molasses by Enterococcus hirae ds10. SN Applied Sciences 2020, 2, 1 -14.
AMA StyleMohamed A. Abdel-Rahman, Saad E. D. Hassan, Mohamed N. El-Din, Mohamed S. Azab, Ehab F. El-Belely, Hassan M. A. Alrefaey, Tamer Elsakhawy. One-factor-at-a-time and response surface statistical designs for improved lactic acid production from beet molasses by Enterococcus hirae ds10. SN Applied Sciences. 2020; 2 (4):1-14.
Chicago/Turabian StyleMohamed A. Abdel-Rahman; Saad E. D. Hassan; Mohamed N. El-Din; Mohamed S. Azab; Ehab F. El-Belely; Hassan M. A. Alrefaey; Tamer Elsakhawy. 2020. "One-factor-at-a-time and response surface statistical designs for improved lactic acid production from beet molasses by Enterococcus hirae ds10." SN Applied Sciences 2, no. 4: 1-14.
Nile-Tilapia (Oreochromis niloticus) aquaculture represents one of the most important cultivation species in Egypt. However, Tilapia fish farming is challenged by some problems. Of those, the presence of bacterial pathogens resulting in high fish mortalities and huge economic losses. Thus, the current investigation aimed to isolate, identify, and characterize the pathogenic bacteria from Nile tilapia fish farm in El-Abassa village, Egypt and to investigate their antibiotic susceptibility as a primary step for controlling diseases. 182 bacterial isolates were obtained from one hundred Tilapia fish samples. The microbiological and biochemical analysis of the examined fish indicated the presence of only 5 bacterial genera. Three of them are Gram-negative bacteria (representing 86.26% of total isolates) including Aeromonas spp. (46.70 %), Pseudomonas spp. (23.08 %), and Vibrio spp. (16.48 %). While two genera are Gram-positive bacteria (representing 13.74% of the total isolates) including Streptococcus spp. (8.79 %) and Staphylococcus spp. (4.95 %). This indicates that Gram-negative bacteria are the main cause of high fish mortalities in the studied area while Aeromonas hydrophila exhibited the highest prevalence in infected tilapia. Antibiogram test revealed high levels of resistance expressed by all isolates to ampicillin, amoxicillin, and erythromycin. On the other hand, norfloxacin was effective against all isolated bacteria followed by ciprofloxacin; therefore, norfloxacin should be recommended as a supplement in fish fed-diets to control the bacterial infection. Establishing effective control methods for pathogenic isolates would greatly enhance fish production.
Saad Hassan; Mohamed Abdel-Rahman; El Sayed Mansour; Walid Monir. Isolation, phenotypic characterization and antibiotic susceptibility of prevalent bacterial pathogens implicating the mortality of cultured Nile tilapia, Oreochromis niloticus. Egyptian Journal for Aquaculture 2020, 10, 23 -43.
AMA StyleSaad Hassan, Mohamed Abdel-Rahman, El Sayed Mansour, Walid Monir. Isolation, phenotypic characterization and antibiotic susceptibility of prevalent bacterial pathogens implicating the mortality of cultured Nile tilapia, Oreochromis niloticus. Egyptian Journal for Aquaculture. 2020; 10 (1):23-43.
Chicago/Turabian StyleSaad Hassan; Mohamed Abdel-Rahman; El Sayed Mansour; Walid Monir. 2020. "Isolation, phenotypic characterization and antibiotic susceptibility of prevalent bacterial pathogens implicating the mortality of cultured Nile tilapia, Oreochromis niloticus." Egyptian Journal for Aquaculture 10, no. 1: 23-43.
In this work, a non‐sterile (open) continuous fermentation (OCF) process with no‐carbon loss was developed to improve lactic acid (LA) productivity and operational stability from the co‐utilization of lignocellulose‐derived sugars by thermophilic Enterococcus faecium QU 50. The effects of different sugar mixtures on LA production were firstly investigated in conventional OCF at 50oC, pH 6.5 and dilution rate of 0.20 h−1. Xylose consumption ratio was greatly lower than glucose in fermentations with glucose/xylose mixtures, indicating apparent carbon catabolite repression (CCR). However, CCR could be efficiently eliminated by feeding solutions containing cellobiose/xylose mixture. In OCF at dilution rate ca. 0.10 h−1, strain QU 50 produced 42.6 g L−1 of l‐LA with a yield of 0.912 g g−1‐consumed sugars, LA yield of 0.655 g g−1 based on mixed sugar‐loaded, and a productivity of 4.31 g L−1 h−1 from simulated energy cane hydrolyzate. In OCF with high cell density by cell recycling, simultaneous and complete co‐utilization of sugars was achieved with stable LA production at 60.1±3.25 g L−1 with LA yield of 0.944 g g−1‐consumed sugar and LA productivity of 6.49±0.357 g L−1 h−1. Besides, a dramatic increase in LA yield of 0.927 g g−1 based on mixed sugar‐loaded with prolonged operational stability for at least 500 h (>20 days) was established. This robust system demonstrates an initial green step with a no‐carbon loss under energy‐saving toward the feasibility of sustainable LA production from lignocellulosic sugars.
Mohamed Ali Abdel‐Rahman; Jiaming Tan; Yukihiro Tashiro; Takeshi Zendo; Kenji Sakai; Kenji Sonomoto. Non‐carbon loss long‐term continuous lactic acid production from mixed sugars using thermophilic Enterococcus faecium QU 50. Biotechnology and Bioengineering 2020, 117, 1673 -1683.
AMA StyleMohamed Ali Abdel‐Rahman, Jiaming Tan, Yukihiro Tashiro, Takeshi Zendo, Kenji Sakai, Kenji Sonomoto. Non‐carbon loss long‐term continuous lactic acid production from mixed sugars using thermophilic Enterococcus faecium QU 50. Biotechnology and Bioengineering. 2020; 117 (6):1673-1683.
Chicago/Turabian StyleMohamed Ali Abdel‐Rahman; Jiaming Tan; Yukihiro Tashiro; Takeshi Zendo; Kenji Sakai; Kenji Sonomoto. 2020. "Non‐carbon loss long‐term continuous lactic acid production from mixed sugars using thermophilic Enterococcus faecium QU 50." Biotechnology and Bioengineering 117, no. 6: 1673-1683.
Various challenges of lactic acid (LA) fermentations including substrate cost and pre-treatments, medium cost, and contamination risk as a result of utilizing neutral pH and mesophilic conditions have been occurred. Therefore, this study focused on development of consolidated bioprocess for LA production from organic wastes under in harsh conditions. A newly isolated thermos-alkali-tolerant lactic acid bacterium, Enterococcus durans BP130, was firstly used for direct LA production from banana peels (BP). Increasing the solid concentration of BP from 4.0% to 6.7% [w-dry matter/v] have resulted in increased fermentation efficiency with the highest LA production (16.0 g L−1) at 6.7% [w-dry matter/v]. Besides, co-fermentation of BP and food waste (FW) materials resulted in 38% improvements in LA concentration and 35% in LA productivity at 0.5:1 of BP:FW (w/w). Increasing of food waste concentrations could replace the nutritional components of the media and achieved increased LA production. Without any nutrients supplementation, food waste substituted the medium components and resulted in 14.3 g L−1 of LA produced using mixed substrates of FW: BP at 3:1 (w/w). The highest LA concentration of 28.8 g L−1 LA with a yield of 0.85 g g−1-consumed sugar and productivity of 0.60 g L−1 h−1 was achieved in batch fermentation using CaCO3 as a neutralizing agent. This study introduced effective mixed waste-based biorefinery process for direct LA production in an inexpensive fermentation system.
Saad El-Din Hassan; Mohamed Ali Abdel-Rahman; Mohamed M. Roushdy; Mohamed Salah Azab; Mahmoud Ali Gaber. Effective biorefinery approach for lactic acid production based on co-fermentation of mixed organic wastes by Enterococcus durans BP130. Biocatalysis and Agricultural Biotechnology 2019, 20, 101203 .
AMA StyleSaad El-Din Hassan, Mohamed Ali Abdel-Rahman, Mohamed M. Roushdy, Mohamed Salah Azab, Mahmoud Ali Gaber. Effective biorefinery approach for lactic acid production based on co-fermentation of mixed organic wastes by Enterococcus durans BP130. Biocatalysis and Agricultural Biotechnology. 2019; 20 ():101203.
Chicago/Turabian StyleSaad El-Din Hassan; Mohamed Ali Abdel-Rahman; Mohamed M. Roushdy; Mohamed Salah Azab; Mahmoud Ali Gaber. 2019. "Effective biorefinery approach for lactic acid production based on co-fermentation of mixed organic wastes by Enterococcus durans BP130." Biocatalysis and Agricultural Biotechnology 20, no. : 101203.
This study aimed to achieve effective lactic acid (LA) production from waste materials. From natural sources on banana peels-containing media, 253 bacterial isolates were obtained. Isolate FW26 was selected for LA production from untreated banana peels (no pre-treatment) at pH 9.0 and 50 °C. It was identified as Enterococcus faecium strain FW26 using 16S rRNA sequencing. The optimal solid-to-liquid ratio was 1:10 (w/v) achieving LA at 15.9 g L−1. Utilization of co-substrates achieved positive synergistic effects. Fermentation of banana peels and food wastes mixture (1:1.5, w/w) exhibited 21.4% improvements in LA concentration. Exclusion of medium components achieved comparable LA fermentation to that obtained with medium supplementation. Furthermore, controlling of fermentation pH showed 81% improvements in LA concentration achieving 33.3 ± 2.6 g L−1 with yield of 0.84 g g−1-consumed sugar. This indicates the potentiality of strain FW26 for LA production by direct utilization of untreated mixed wastes without medium supplementation under thermo-alkaline condition.
Mohamed Ali Abdel-Rahman; Saad El-Din Hassan; Mohamed M. Roushdy; Mohamed Salah Azab; Mahmoud Ali Gaber. Free-nutrient supply and thermo-alkaline conditions for direct lactic acid production from mixed lignocellulosic and food waste materials. Bioresource Technology Reports 2019, 7, 100256 .
AMA StyleMohamed Ali Abdel-Rahman, Saad El-Din Hassan, Mohamed M. Roushdy, Mohamed Salah Azab, Mahmoud Ali Gaber. Free-nutrient supply and thermo-alkaline conditions for direct lactic acid production from mixed lignocellulosic and food waste materials. Bioresource Technology Reports. 2019; 7 ():100256.
Chicago/Turabian StyleMohamed Ali Abdel-Rahman; Saad El-Din Hassan; Mohamed M. Roushdy; Mohamed Salah Azab; Mahmoud Ali Gaber. 2019. "Free-nutrient supply and thermo-alkaline conditions for direct lactic acid production from mixed lignocellulosic and food waste materials." Bioresource Technology Reports 7, no. : 100256.
Potential high bio-deterioration of certain microorganisms due to their metabolic activities on organic materials causes serious problems in the conservation of cultural heritage. This study focuses on establishing an efficient conservation strategy against microbial deterioration using biosynthesized nanoparticle (NPs). Isolation, identification, and characterization of microorganisms involved in deterioration of archaeological manuscript dating back to 17th century (1677 A.D) were conducted. Eleven bacterial species and fifteen fungal species were obtained and identified using 16S rRNA and ITS sequences, respectively. All strains exhibited potent cellulolytic activity. Bacillus subtilis strain (B3) and Penicillium chrysogenum strain (F9) achieved the highest cellulolytic activity amongst obtained bacterial and fungal strains. Paper models conservation effect of biosynthesized silver and zinc oxide NPs against strain (B3) and strain (F9) was evaluated. Microbial growth inhibition, color change according to CIE L*a*b* color space, fourier transform infrared spectroscopy (FT-IR) were assessed. Furthermore, morphology and the elemental component of paper models were analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Silver NPs achieved better results than zinc oxide NPs for paper preservation. Application of 1.0 or 2.0 mM silver NPs exhibited the best preservation effect on the paper models achieving 100% microbial inhibition (bacteria and fungi, respectively). Moreover, NPs-treated paper models showed slight color change and exhibited similar structural analysis as original papers. These results showed the potentiality of this green strategy to be applied for conservation of cellulose-constructed cultural heritage.
Amr Fouda; Gomaa Abdel-Maksoud; Mohamed Ali Abdel-Rahman; Salem S. Salem; Saad El-Din Hassan; Mohamad Abdel-Haleem El-Sadany. Eco-friendly approach utilizing green synthesized nanoparticles for paper conservation against microbes involved in biodeterioration of archaeological manuscript. International Biodeterioration & Biodegradation 2019, 142, 160 -169.
AMA StyleAmr Fouda, Gomaa Abdel-Maksoud, Mohamed Ali Abdel-Rahman, Salem S. Salem, Saad El-Din Hassan, Mohamad Abdel-Haleem El-Sadany. Eco-friendly approach utilizing green synthesized nanoparticles for paper conservation against microbes involved in biodeterioration of archaeological manuscript. International Biodeterioration & Biodegradation. 2019; 142 ():160-169.
Chicago/Turabian StyleAmr Fouda; Gomaa Abdel-Maksoud; Mohamed Ali Abdel-Rahman; Salem S. Salem; Saad El-Din Hassan; Mohamad Abdel-Haleem El-Sadany. 2019. "Eco-friendly approach utilizing green synthesized nanoparticles for paper conservation against microbes involved in biodeterioration of archaeological manuscript." International Biodeterioration & Biodegradation 142, no. : 160-169.
Optically pure lactic acid (LA) is an important chemical platform that has a wide range of industrial and biotechnological applications. Improved parameters for cost effective LA production are of great interest for industrial developments. In the present study, an alkaliphilic lactic acid bacterium, BoM 1-2, was selected among 369 newly obtained bacterial isolates. It was characterized using API 50 CHL kit and identified asEnterococcus hiraeBoM 1-2 by 16S rRNA gene sequence analysis. Efficient polymer-gradeL-lactic acid production was achieved at pH 9.0 and 40°C. In batch fermentation strategy using 20 g L−1glucose, 19.6 g L−1lactic acid was obtained with volumetric productivity of 2.18 g L−1 h−1. While using 100 g L−1glucose, 96.0 g L−1lactic acid was obtained with volumetric productivity of 1.07 g L−1 h−1.The highest lactic acid concentration of 180.6 g L−1was achieved in multipulse fed batch strategy with volumetric productivity of 0.65 g L−1 h−1. To achieve higher productivity, repeated fermentation processes were applied using the two different strategies. In the first strategy, the lactic acid productivity was increased from 1.97 g L−1 h−1to 4.48 g L−1 h−1when the total of 10 repeated runs were carried out using 60 g L−1glucose, but lactic acid productivity decreased to 2.95 g L−1 h−1using 100 g L−1glucose. In second strategy, repeated fermentation coupled with gradual increase in glucose concentration from 40 to 100 g L−1was conducted for 24 runs. A dramatic increase in LA productivity up to 39.9 g L−1 h−1(18-fold compared to first run) was achieved using 40 g L−1glucose while volumetric productivity ranging between 24.8 and 29.9 g L−1 h−1was achieved using 60–100 g L−1glucose.
Mohamed Ali Abdel-Rahman; Saad El-Din Hassan; Mohamed Salah Azab; Abdullah-Al- Mahin; Mahmoud Ali Gaber. High Improvement in Lactic Acid Productivity by New Alkaliphilic Bacterium Using Repeated Batch Fermentation Integrated with Increased Substrate Concentration. BioMed Research International 2019, 2019, 1 -13.
AMA StyleMohamed Ali Abdel-Rahman, Saad El-Din Hassan, Mohamed Salah Azab, Abdullah-Al- Mahin, Mahmoud Ali Gaber. High Improvement in Lactic Acid Productivity by New Alkaliphilic Bacterium Using Repeated Batch Fermentation Integrated with Increased Substrate Concentration. BioMed Research International. 2019; 2019 ():1-13.
Chicago/Turabian StyleMohamed Ali Abdel-Rahman; Saad El-Din Hassan; Mohamed Salah Azab; Abdullah-Al- Mahin; Mahmoud Ali Gaber. 2019. "High Improvement in Lactic Acid Productivity by New Alkaliphilic Bacterium Using Repeated Batch Fermentation Integrated with Increased Substrate Concentration." BioMed Research International 2019, no. : 1-13.