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Malaysia is the second largest palm oil producer and exporter globally. When crude palm oil is produced in both plantations and oil processing mills, a large amount of oil palm empty fruit bunch (OPEFB) is simultaneously produced as a waste product. Here, we describe the preparation of hydrolysate from OPEFB. After OPEFB was hydrothermally treated at 180–200 °C, the resultant liquid phase was subjected to high-performance liquid chromatography analysis, while the solid phase was used for acidic and enzymatic hydrolysis. Hemicellulose yield from the acid-treated solid phase decreased from 153 mg/g-OPEFB to 27.5 mg/g-OPEFB by increasing the hydrothermal treatment temperature from 180 to 200 °C. Glucose yield from the enzyme-treated solid phase obtained after hydrothermal treatment at 200 °C was the highest (234 ± 1.90 mg/g-OPEFB, 61.7% production efficiency). In contrast, xylose, mannose, galactose, and arabinose yields in the hydrolysate prepared from the solid phase hydrothermally treated at 200 °C were the lowest. Thus, we concluded that the optimum temperature for hydrothermal pretreatment was 200 °C, which was caused by the low hemicellulose yield. Based on these results, we have established an effective method for preparing OPEFB hydrolysates with high glucose content.
Hironaga Akita; Mohd Yusoff; Shinji Fujimoto. Preparation of Oil Palm Empty Fruit Bunch Hydrolysate. Fermentation 2021, 7, 81 .
AMA StyleHironaga Akita, Mohd Yusoff, Shinji Fujimoto. Preparation of Oil Palm Empty Fruit Bunch Hydrolysate. Fermentation. 2021; 7 (2):81.
Chicago/Turabian StyleHironaga Akita; Mohd Yusoff; Shinji Fujimoto. 2021. "Preparation of Oil Palm Empty Fruit Bunch Hydrolysate." Fermentation 7, no. 2: 81.
The influence of biomass cellulosic content on biochar nanopore structure and adsorption capacity in aqueous phase was scarcely reported. Commercial cellulose (100% cellulose), oil palm frond (39.5% cellulose), and palm kernel shell (20.5% cellulose) were pyrolyzed AT 630 °C, characterized and tested for the adsorption of iodine and organic contaminants. The external surface area and average pore size increased with cellulosic content, where commercial cellulose formed biochar with external surface area of 95.4 m2/g and average pore size of 4.1 nm. The biochar from commercial cellulose had the largest adsorption capacities: 371.40 mg/g for iodine, 86.7 mg/L for tannic acid, 17.89 mg/g for COD and 60.35 mg/g for colour, while biochar from palm kernel shell had the least adsorption capacities. The cellulosic content reflected the differences in biochar nanopore structure and adsorption capacities, signifying the suitability of highly cellulosic biomass for producing biochar to effectively treat wastewater.
Abubakar Abdullahi Lawal; Mohd Ali Hassan; Mohd Rafein Zakaria; Mohd Zulkhairi Mohd Yusoff; Mohd Nor Faiz Norrrahim; Mohd Noriznan Mokhtar; Yoshihito Shirai. Effect of oil palm biomass cellulosic content on nanopore structure and adsorption capacity of biochar. Bioresource Technology 2021, 332, 125070 .
AMA StyleAbubakar Abdullahi Lawal, Mohd Ali Hassan, Mohd Rafein Zakaria, Mohd Zulkhairi Mohd Yusoff, Mohd Nor Faiz Norrrahim, Mohd Noriznan Mokhtar, Yoshihito Shirai. Effect of oil palm biomass cellulosic content on nanopore structure and adsorption capacity of biochar. Bioresource Technology. 2021; 332 ():125070.
Chicago/Turabian StyleAbubakar Abdullahi Lawal; Mohd Ali Hassan; Mohd Rafein Zakaria; Mohd Zulkhairi Mohd Yusoff; Mohd Nor Faiz Norrrahim; Mohd Noriznan Mokhtar; Yoshihito Shirai. 2021. "Effect of oil palm biomass cellulosic content on nanopore structure and adsorption capacity of biochar." Bioresource Technology 332, no. : 125070.
Most palm oil mills adopted conventional ponding system, including anaerobic, aerobic, facultative and algae ponds, for the treatment of palm oil mill effluent (POME). Only a few mills installed a bio-polishing plant to treat POME further before its final discharge. The present study aims to determine the quality and toxicity levels of POME final discharge from three different mills by using conventional chemical analyses and fish (Danio rerio) embryo toxicity (FET) test. The effluent derived from mill A which installed with a bio-polishing plant had lower values of BOD, COD and TSS at 45 mg/L, 104 mg/L, and 27 mg/L, respectively. Only mill A nearly met the industrial effluent discharge standard for BOD. In FET test, effluent from mill A recorded low lethality and most of the embryos were malformed after hatching (half-maximal effective concentration (EC50) = 20%). The highest toxicity was observed from the effluent of mill B and all embryos were coagulated after 24 h in samples greater than 75% of effluent (38% of half-maximal lethal concentration (LC50) at 96 h). The embryos in the effluent from mill C recorded high mortality after hatching, and the survivors were malformed after 96 h exposure (LC50 = 26%). Elemental analysis of POME final discharge samples showed Cu, Zn, and Fe concentrations were in the range of 0.10–0.32 mg/L, 0.01–0.99 mg/L, and 0.94–4.54 mg/L, respectively and all values were below the effluent permissible discharge limits. However, the present study found these metals inhibited D. rerio embryonic development at 0.12 mg/L of Cu, and 4.9 mg/L of Fe for 96 h-EC50. The present study found that bio-polishing plant installed in mill A effectively removing pollutants especially BOD and the FET test was a useful method to monitor quality and toxicity of the POME final discharge samples.
Yuya Hashiguchi; Mohd Rafein Zakaria; Maeda Toshinari; Mohd Zulkhairi Mohd Yusoff; Yoshihito Shirai; Mohd Ali Hassan. Ecotoxicological assessment of palm oil mill effluent final discharge by zebrafish (Danio rerio) embryonic assay. Environmental Pollution 2021, 277, 116780 .
AMA StyleYuya Hashiguchi, Mohd Rafein Zakaria, Maeda Toshinari, Mohd Zulkhairi Mohd Yusoff, Yoshihito Shirai, Mohd Ali Hassan. Ecotoxicological assessment of palm oil mill effluent final discharge by zebrafish (Danio rerio) embryonic assay. Environmental Pollution. 2021; 277 ():116780.
Chicago/Turabian StyleYuya Hashiguchi; Mohd Rafein Zakaria; Maeda Toshinari; Mohd Zulkhairi Mohd Yusoff; Yoshihito Shirai; Mohd Ali Hassan. 2021. "Ecotoxicological assessment of palm oil mill effluent final discharge by zebrafish (Danio rerio) embryonic assay." Environmental Pollution 277, no. : 116780.
Nitrogen stress condition is believed to increase the production of lipid in microalgae, but the synthesis of both lipid and carbohydrate is less known. Therefore, the effect of nitrogen stress condition on the synthesis of lipid and carbohydrate of Tetradesmus obliquus UPSI-JRM02 was studied in a 2 L bioreactor system. The highest lipid and carbohydrate yields achieved under nitrogen stress condition were 37% and 23%, respectively. Nitrogen stress condition induced the accumulation of carbohydrate at early stage but started to reduce on day 4 when the carbon shifted towards lipid production. The fatty acid profile produced under nitrogen stress condition was composed of 54% polyunsaturated fatty acid (PUFA), 43% saturated fatty acid (SFA) and 3% monounsaturated fatty acid (MUFA). The biofuel properties of T. obliquus obtained under the nitrogen stress condition was within the range of biodiesel standard and is most suitable for the usage in cold country.
Syafiqah Md Nadzir; Norjan Yusof; Norazela Nordin; Azlan Kamari; Mohd Zulkhairi Mohd Yusoff. PRODUCTION OF LIPID AND CARBOHYDRATE IN Tetradesmus obliquus UPSI-JRM02 UNDER NITROGEN STRESS CONDITION. Jurnal Teknologi 2021, 83, 27 -35.
AMA StyleSyafiqah Md Nadzir, Norjan Yusof, Norazela Nordin, Azlan Kamari, Mohd Zulkhairi Mohd Yusoff. PRODUCTION OF LIPID AND CARBOHYDRATE IN Tetradesmus obliquus UPSI-JRM02 UNDER NITROGEN STRESS CONDITION. Jurnal Teknologi. 2021; 83 (2):27-35.
Chicago/Turabian StyleSyafiqah Md Nadzir; Norjan Yusof; Norazela Nordin; Azlan Kamari; Mohd Zulkhairi Mohd Yusoff. 2021. "PRODUCTION OF LIPID AND CARBOHYDRATE IN Tetradesmus obliquus UPSI-JRM02 UNDER NITROGEN STRESS CONDITION." Jurnal Teknologi 83, no. 2: 27-35.
Malaysia is one of the largest producers and exporters of palm oil, thus, a large amount of palm oil mill effluent (POME) is generated through this process. POME contributes to environmental pollution if it is not properly treated. This complex effluent consists of colloidal matters and mainly organic components with more than 90% water. Thus, it is useful to be used as a substrate for fermentative processes, including biohydrogen production. Biohydrogen from POME is a renewable source that can potentially serve as an alternative to substitute fossil fuels. The abundance of POME and the rising price of fossil fuels in the global market create a demand for this source of energy. However, the complexity of the substituents in POME makes the optimisation of this effluent as a substrate in dark fermentation a challenge. This review article explores the important parameters that need to be considered for optimal biohydrogen production, such as the bioreactor operational parameters and the microbial consortium. Besides, the potential of metabolic engineering as a tool to overcome the limitations of the microbial strains to metabolise POME for increased biohydrogen production was also reviewed. However, further research and development are needed to increase the biohydrogen yield on par with commercial demand.
Fatin Sakinah Rosman; Mohd Zulkhairi Mohd Yusoff; Mohd Rafein Zakaria; Toshinari Maeda; Mohd Ali Hassan. Dark Fermentative Biohydrogen Production from Palm oil Mill Effluent: Operation Factors and Future Progress of Biohydrogen Energy. Pertanika Journal of Science and Technology 2020, 28, 1 .
AMA StyleFatin Sakinah Rosman, Mohd Zulkhairi Mohd Yusoff, Mohd Rafein Zakaria, Toshinari Maeda, Mohd Ali Hassan. Dark Fermentative Biohydrogen Production from Palm oil Mill Effluent: Operation Factors and Future Progress of Biohydrogen Energy. Pertanika Journal of Science and Technology. 2020; 28 (S2):1.
Chicago/Turabian StyleFatin Sakinah Rosman; Mohd Zulkhairi Mohd Yusoff; Mohd Rafein Zakaria; Toshinari Maeda; Mohd Ali Hassan. 2020. "Dark Fermentative Biohydrogen Production from Palm oil Mill Effluent: Operation Factors and Future Progress of Biohydrogen Energy." Pertanika Journal of Science and Technology 28, no. S2: 1.
In order to meet the growing demand for adsorbents to treat wastewater effectively, there has been increased interest in using sustainable biomass feedstocks. In this present study, the dermal tissue of oil palm frond was pyrolyzed with superheated steam at 500 °C to produce nanoporous biochar as bioadsorbent. The effect of operating conditions was investigated to understand the adsorption mechanism and to enhance the adsorption of phenol and tannic acid. The biochar had a microporous structure with a Brunauer-Emmett-Teller surface area of 422 m2/g containing low polar groups. The adsorption capacity of 62.89 mg/g for phenol and 67.41 mg/g for tannic acid were obtained using 3 g/L biochar dosage after 8 h of treatment at solution pH of 6.5 and temperature of 45 °C. The Freundlich model had the best fit to the isotherm data of phenol (R2 of 0.9863), while the Langmuir model best elucidated the isotherm data of tannic acid (R2 of 0.9632). These indicated that the biochar-phenol interface was associated with a heterogeneous multilayer sorption mechanism, while the biochar-tannic acid interface had a nonspecific monolayer sorption mechanism. The residual concentration of 26.3 mg/L phenol and 23.1 mg/L tannic acid was achieved when treated from 260 mg/L three times consecutively with 1 g/L biochar dosage, compared to a reduction to 72.3 mg/L phenol and 69.9 mg/L tannic acid using 3 g/L biochar dosage in a single treatment. The biochar exhibited effective adsorption of phenol and tannic acid, making it possible to treat effluents that contain varieties of phenolic compounds.
Abubakar Abdullahi Lawal; Mohd Ali Hassan; Mohamed Abdillah Ahmad Farid; Tengku Arisyah Tengku Yasim-Anuar; Mohd Hafif Samsudin; Mohd Zulkhairi Mohd Yusoff; Mohd Rafein Zakaria; Mohd Noriznan Mokhtar; Yoshihito Shirai. Adsorption mechanism and effectiveness of phenol and tannic acid removal by biochar produced from oil palm frond using steam pyrolysis. Environmental Pollution 2020, 269, 116197 .
AMA StyleAbubakar Abdullahi Lawal, Mohd Ali Hassan, Mohamed Abdillah Ahmad Farid, Tengku Arisyah Tengku Yasim-Anuar, Mohd Hafif Samsudin, Mohd Zulkhairi Mohd Yusoff, Mohd Rafein Zakaria, Mohd Noriznan Mokhtar, Yoshihito Shirai. Adsorption mechanism and effectiveness of phenol and tannic acid removal by biochar produced from oil palm frond using steam pyrolysis. Environmental Pollution. 2020; 269 ():116197.
Chicago/Turabian StyleAbubakar Abdullahi Lawal; Mohd Ali Hassan; Mohamed Abdillah Ahmad Farid; Tengku Arisyah Tengku Yasim-Anuar; Mohd Hafif Samsudin; Mohd Zulkhairi Mohd Yusoff; Mohd Rafein Zakaria; Mohd Noriznan Mokhtar; Yoshihito Shirai. 2020. "Adsorption mechanism and effectiveness of phenol and tannic acid removal by biochar produced from oil palm frond using steam pyrolysis." Environmental Pollution 269, no. : 116197.
The aquatic ecosystem is continuously threatened by the infiltration and discharge of anthropogenic wastewaters. This issue requires the unending improvement of monitoring systems to become more comprehensive and specific to targeted pollutants. This review intended to elucidate the overall aspects explored by researchers in developing better water pollution monitoring tools in recent years. The discussion is encircled around three main elements that have been extensively used as the basis for the development of monitoring methods, namely the dissolved compounds, bacterial indicator, and nucleic acids. The latest technologies applied in wastewater and surface water mapped from these key players were reviewed and categorized into physicochemical and compound characterizations, biomonitoring, and molecular approaches in taxonomical and functional analyses. Overall, researchers are continuously rallying to enhance the detection of causal source for water pollution through either conventional or mostly advanced approaches focusing on spectrometry, high-throughput sequencing, and flow cytometry technology among others. From this review’s perspective, each pollution evaluation technology has its own advantages and it would be beneficial for several aspects of pollutants assessments to be combined and established as a complementary package for better aquatic environmental management in the long run.
Nurhasliza Zolkefli; Siti Suhailah Sharuddin; Mohd Zulkhairi Mohd Yusoff; Mohd Ali Hassan; Toshinari Maeda; Norhayati Ramli. A Review of Current and Emerging Approaches for Water Pollution Monitoring. Water 2020, 12, 3417 .
AMA StyleNurhasliza Zolkefli, Siti Suhailah Sharuddin, Mohd Zulkhairi Mohd Yusoff, Mohd Ali Hassan, Toshinari Maeda, Norhayati Ramli. A Review of Current and Emerging Approaches for Water Pollution Monitoring. Water. 2020; 12 (12):3417.
Chicago/Turabian StyleNurhasliza Zolkefli; Siti Suhailah Sharuddin; Mohd Zulkhairi Mohd Yusoff; Mohd Ali Hassan; Toshinari Maeda; Norhayati Ramli. 2020. "A Review of Current and Emerging Approaches for Water Pollution Monitoring." Water 12, no. 12: 3417.
This study aims to elucidate the mechanism of carbon partitioning towards starch and triacylglycerol (TAG) under nitrogen stress. Whole-transcriptome analysis was performed using RNA sequencing before being validated with qRT-PCR. The strain, Chlorella vulgaris UPSI-JRM01, exhibited a two-stage response to nitrogen stress: i) carbohydrate accumulation, plastid protein degradation and amino acid biosynthesis; and ii) lipid accumulation, carbohydrate degradation and DNA damage. In the first stage, the genes responsible for plastid protein degradation (CD4A), amino acid biosynthesis (arg, GLSN, AHCY, win1), carbon fixation (RuBisCO, GapC, fba, TK) and starch synthesis (SS, SBE2) were upregulated. In the second stage, the upregulation of genes responsible for starch degradation (SP), glycolysis (PFO, PK, ACS), fatty acid biosynthesis (FabH, accD) and TAG accumulation (DGAT2) were observed. By contrast, the components of photosystem I (PsbD, PsbC, PsbB), photosystem II (PsaA), cytochrome b6/f (PetA, PetG) and F-type ATPase (beta, alpha) were downregulated. The results suggested that nitrogen stress triggered high starch accumulation before the carbon was partitioned towards triacylglycerol (TAG) for long-term energy storage by two different pathways: chloroplastic TAG synthesis and glycerolipid metabolism. The starch build-up functions served as a rapid response to nitrogen stress, whereas subsequent lipid accumulation benefited the long-term storage of energy. This research provides in-depth understanding of the metabolic changes triggered by nitrogen stress.
Norazela Nordin; Norjan Yusof; Toshinari Maeda; Nurul Asyifah Mustapha; Mohd Zulkhairi Mohd Yusoff; Raja Farhana Raja Khairuddin. Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis. Biomass and Bioenergy 2020, 138, 105600 .
AMA StyleNorazela Nordin, Norjan Yusof, Toshinari Maeda, Nurul Asyifah Mustapha, Mohd Zulkhairi Mohd Yusoff, Raja Farhana Raja Khairuddin. Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis. Biomass and Bioenergy. 2020; 138 ():105600.
Chicago/Turabian StyleNorazela Nordin; Norjan Yusof; Toshinari Maeda; Nurul Asyifah Mustapha; Mohd Zulkhairi Mohd Yusoff; Raja Farhana Raja Khairuddin. 2020. "Mechanism of carbon partitioning towards starch and triacylglycerol in Chlorella vulgaris under nitrogen stress through whole-transcriptome analysis." Biomass and Bioenergy 138, no. : 105600.
Advances in biochar production and modification have extended the applications of biochar to wastewater treatment. However, not all feedstocks produced porous biochar at a moderate temperature suitable for wastewater treatment. In this study, biochar was produced from oil palm frond using steam pyrolysis at 500 °C and pulverized to granular and micro-fine particles. Both biochar particles were characterized and applied as adsorbents for treating final discharge of palm oil mill effluent. The effluent was also filtered and treated to examine the effect of suspended solids on adsorption capacity. The biochar had Brunauer-Emmett-Teller surface area of 406.6 m2 g−1. Pulverization eliminated the residual macropores in granular biochar, created new external surface area, and exposed constricted nanopores, which resulted in increasing the surface area to 457.7 m2 g−1. The adsorption capacity decreased from 24.6 to 6.1 mg g−1 for chemical oxygen demand and 49.0 to 10.9 Pt–Co g−1 for color by increasing the dosage of micro-fine biochar from 5 to 30 g L−1. The total suspended solids affected the adsorption capacity of granular biochar by blocking residual macropores that provide access to adsorption sites in micropores and mesopores. At 30 g L−1, the micro-fine biochar exhibited an effective reduction of chemical oxygen demand from 224 to 41.6 mg g−1 and color from 344 to 15 Pt–Co g−1 making the wastewater suitable for reuse in palm oil mills and safe for discharge into the aquatic environment.
Abubakar Abdullahi Lawal; Mohd Ali Hassan; Mohamed Abdillah Ahmad Farid; Tengku Arisyah Tengku Yasim-Anuar; Mohd Zulkhairi Mohd Yusoff; Mohd Rafein Zakaria; Ahmad Muhaimin Roslan; Mohd Noriznan Mokhtar; Yoshihito Shirai. Production of biochar from oil palm frond by steam pyrolysis for removal of residual contaminants in palm oil mill effluent final discharge. Journal of Cleaner Production 2020, 265, 121643 .
AMA StyleAbubakar Abdullahi Lawal, Mohd Ali Hassan, Mohamed Abdillah Ahmad Farid, Tengku Arisyah Tengku Yasim-Anuar, Mohd Zulkhairi Mohd Yusoff, Mohd Rafein Zakaria, Ahmad Muhaimin Roslan, Mohd Noriznan Mokhtar, Yoshihito Shirai. Production of biochar from oil palm frond by steam pyrolysis for removal of residual contaminants in palm oil mill effluent final discharge. Journal of Cleaner Production. 2020; 265 ():121643.
Chicago/Turabian StyleAbubakar Abdullahi Lawal; Mohd Ali Hassan; Mohamed Abdillah Ahmad Farid; Tengku Arisyah Tengku Yasim-Anuar; Mohd Zulkhairi Mohd Yusoff; Mohd Rafein Zakaria; Ahmad Muhaimin Roslan; Mohd Noriznan Mokhtar; Yoshihito Shirai. 2020. "Production of biochar from oil palm frond by steam pyrolysis for removal of residual contaminants in palm oil mill effluent final discharge." Journal of Cleaner Production 265, no. : 121643.
Conventional aerobic treatment of facultatively treated palm oil mill effluent (POME) containing phenolic compounds such as phenol, encounters difficulty because of microbial inhibition. In this study, adsorption of phenol in facultatively treated POME was proposed as a solution for mitigating the inhibition. Low-cost biochars produced from oil palm frond using nitrogen or steam pyrolysis at 600 °C were characterized and investigated for efficient and effective removal of phenol. Nitrogen and steam pyrolysis yielded mesoporous biochars with Brunauer–Emmett–Teller surface area of 368.4 m2/g and 461.3 m2/g respectively. Within 8 h, steam-derived biochar attained equilibrium capacity of 59.6 mg/L in distilled water, which decreased to 18.5 mg/L in facultatively treated POME. Steam-derived biochar exhibited slightly higher adsorption capacity for phenol in facultatively treated POME due to higher surface area, wider nanopore size distribution, a larger volume of mesopores and a stronger affinity for phenol. More than 90% of phenol was removed using 16–20 g/L dosage, yielding a facultatively treated POME with 0% inhibition to aerobic microbial growth. Overall, low-cost biochar produced from oil palm frond can be used as an efficient and effective adsorbent for adsorbing phenol in facultatively treated POME to enhance the performance of aerobic treatment system.
Abubakar Abdullahi Lawal; Mohd Ali Hassan; Mohamed Abdillah Ahmad Farid; Tengku Arisyah Tengku Yasim-Anuar; Mohd Zulkhairi Mohd Yusoff; Mohd Rafein Zakaria; Ahmad Muhaimin Roslan; Mohd Noriznan Mokhtar; Yoshihito Shirai. One-step steam pyrolysis for the production of mesoporous biochar from oil palm frond to effectively remove phenol in facultatively treated palm oil mill effluent. Environmental Technology & Innovation 2020, 18, 100730 .
AMA StyleAbubakar Abdullahi Lawal, Mohd Ali Hassan, Mohamed Abdillah Ahmad Farid, Tengku Arisyah Tengku Yasim-Anuar, Mohd Zulkhairi Mohd Yusoff, Mohd Rafein Zakaria, Ahmad Muhaimin Roslan, Mohd Noriznan Mokhtar, Yoshihito Shirai. One-step steam pyrolysis for the production of mesoporous biochar from oil palm frond to effectively remove phenol in facultatively treated palm oil mill effluent. Environmental Technology & Innovation. 2020; 18 ():100730.
Chicago/Turabian StyleAbubakar Abdullahi Lawal; Mohd Ali Hassan; Mohamed Abdillah Ahmad Farid; Tengku Arisyah Tengku Yasim-Anuar; Mohd Zulkhairi Mohd Yusoff; Mohd Rafein Zakaria; Ahmad Muhaimin Roslan; Mohd Noriznan Mokhtar; Yoshihito Shirai. 2020. "One-step steam pyrolysis for the production of mesoporous biochar from oil palm frond to effectively remove phenol in facultatively treated palm oil mill effluent." Environmental Technology & Innovation 18, no. : 100730.
Microorganisms are progressively adopted as reliable and specific bioindicators of pollution, with Alcaligenaceae and Chromatiaceae being recently proposed to indicate contamination in river water due to palm oil mill effluent (POME) final discharge. This study was conducted to evaluate the reliability of these bacteria to act as specific bioindicators by assessing their detections in correlation with environmental factors in rivers polluted by POME final discharge when compared to by other pollution sources. By using the Illumina MiSeq high throughput sequencing platform, bacterial diversities and compositions were compared among unpolluted (upstream) river, polluted rivers due to POME final discharge and other rivers polluted by mining, chemical and automotive industries. To correlate between bacterial compositions and metabolisms in rivers subjected to different pollutants sources, the viability and the ratio of the high and low nucleic acids (HNA/LNA) bacterial cells were also compared by using a double staining assay based on flow cytometry. Interestingly, Alcaligenaceae and Chromatiaceae were found only in POME final discharge polluted rivers (>0.15%) but were not detected in rivers polluted by other pollutants. Higher bacterial cell viability was detected in rivers polluted by POME final discharge (86–91%) as compared to the other polluted rivers (15–80%). From the viable fractions of the bacterial cells, higher HNA cells (91–93%) were quantified in the POME final discharge receiving rivers but with only 5–18% in the other rivers. These trends indicated that the nutrients carried by the POME final discharge enhanced the growth of bacteria in the receiving river water that might include Alcaligenaceae and Chromatiaceae. These results suggested that either Alcaligenaceae or Chromatiaceae or both were unique in the POME final discharge polluted rivers but not in the others. They could function as specific and reliable bacterial bioindicators relevant for the establishment of a complementary monitoring system for POME pollutant discharge.
Nurhasliza Zolkefli; Norhayati Ramli; Noor Shaidatul Lyana Mohamad-Zainal; Nurul Asyifah Mustapha; Mohd Zulkhairi Mohd Yusoff; Mohd Ali Hassan; Toshinari Maeda. Alcaligenaceae and Chromatiaceae as pollution bacterial bioindicators in palm oil mill effluent (POME) final discharge polluted rivers. Ecological Indicators 2020, 111, 106048 .
AMA StyleNurhasliza Zolkefli, Norhayati Ramli, Noor Shaidatul Lyana Mohamad-Zainal, Nurul Asyifah Mustapha, Mohd Zulkhairi Mohd Yusoff, Mohd Ali Hassan, Toshinari Maeda. Alcaligenaceae and Chromatiaceae as pollution bacterial bioindicators in palm oil mill effluent (POME) final discharge polluted rivers. Ecological Indicators. 2020; 111 ():106048.
Chicago/Turabian StyleNurhasliza Zolkefli; Norhayati Ramli; Noor Shaidatul Lyana Mohamad-Zainal; Nurul Asyifah Mustapha; Mohd Zulkhairi Mohd Yusoff; Mohd Ali Hassan; Toshinari Maeda. 2020. "Alcaligenaceae and Chromatiaceae as pollution bacterial bioindicators in palm oil mill effluent (POME) final discharge polluted rivers." Ecological Indicators 111, no. : 106048.
Mumtazah Ibrahim; Norjan Yusof; Hanisom Abdullah; Mohd Zulkhairi Mohd Yusoff; Mohd Ali Hassan. Efficient feeding strategy to enhance the start-up of anaerobic ammonium oxidation process in an anaerobic up-flow biofilm column reactor. Desalination and Water Treatment 2020, 183, 253 -267.
AMA StyleMumtazah Ibrahim, Norjan Yusof, Hanisom Abdullah, Mohd Zulkhairi Mohd Yusoff, Mohd Ali Hassan. Efficient feeding strategy to enhance the start-up of anaerobic ammonium oxidation process in an anaerobic up-flow biofilm column reactor. Desalination and Water Treatment. 2020; 183 ():253-267.
Chicago/Turabian StyleMumtazah Ibrahim; Norjan Yusof; Hanisom Abdullah; Mohd Zulkhairi Mohd Yusoff; Mohd Ali Hassan. 2020. "Efficient feeding strategy to enhance the start-up of anaerobic ammonium oxidation process in an anaerobic up-flow biofilm column reactor." Desalination and Water Treatment 183, no. : 253-267.
Palm oil mill effluent (POME) contains complex and highly biodegradable organic matters so discharging it without appropriate treatment may lead to environmental problems. POME final discharge quality is normally determined based on conventional chemical detection such as by biological oxygen demand (BOD) and chemical oxygen demand (COD). The novelty of the present study is that the toxicity effects of the POME final discharge samples were evaluated based on whole effluent toxicity (WET) and toxicity identification evaluation (TIE) tests using Daphnia magna. The toxicity unit (TU) values were recorded to be in the range from TU = 1.1–11 obtained from WET, and the TIE manipulation tests suggested that a substantial amount of toxic compounds was contained in the POME final discharge. Phenol, 2,6-bis (1,1-dimethylethyl)- and heavy metals such as Cu and Zn were detected in all the effluents and were recognized as being the main toxicants in the POME final discharge. GC/MS analyses also successfully identified cyclic volatile methyl siloxanes; cyclotetrasiloxane, octamethyl- (D4), cyclopentasiloxane, decamethyl- (D5), cyclohexasiloxane, dodecamethyl- (D6). D4 was detected at 0.0148–0.0357 mg/L, which could be potentially toxic. The palm oil industry used only water in the form of steam to process the fruits, and the presence of these compounds might be derived from the detergents and grease used in palm oil mill cleaning and maintenance operations. An appropriate treatment process is thus required to eliminate these toxicants from the POME final discharge. It is recommended that two approaches, chemical-based monitoring as well as biological toxicity-based monitoring, should be utilized for achieving an acceptable quality of POME final discharge in the future.
Yuya Hashiguchi; Mohd Rafein Zakaria; Toshinari Maeda; Mohd Zulkhairi Mohd Yusoff; Mohd Ali Hassan; Yoshihito Shirai. Toxicity identification and evaluation of palm oil mill effluent and its effects on the planktonic crustacean Daphnia magna. Science of The Total Environment 2019, 710, 136277 .
AMA StyleYuya Hashiguchi, Mohd Rafein Zakaria, Toshinari Maeda, Mohd Zulkhairi Mohd Yusoff, Mohd Ali Hassan, Yoshihito Shirai. Toxicity identification and evaluation of palm oil mill effluent and its effects on the planktonic crustacean Daphnia magna. Science of The Total Environment. 2019; 710 ():136277.
Chicago/Turabian StyleYuya Hashiguchi; Mohd Rafein Zakaria; Toshinari Maeda; Mohd Zulkhairi Mohd Yusoff; Mohd Ali Hassan; Yoshihito Shirai. 2019. "Toxicity identification and evaluation of palm oil mill effluent and its effects on the planktonic crustacean Daphnia magna." Science of The Total Environment 710, no. : 136277.
The study aims to investigate the effect of photo-autotrophic cultural conditions on the productivity and biomass composition of Chlorella vulgaris. The following five photo-autotrophic cultural conditions were investigated: light intensity (4000, 10,500, 17,000, 23,000, 30,000 lux), temperature (25, 28, 32, 35, 40 °C), pH (6, 7, 8, 9, 10), CO2 (0.03, 2.5, 5, 7.5, 10%) and NO3− (0, 250, 500, 750, 1000 mg/L). Results indicate that lipid and protein yields were increased by 3.19 fold and decreased by 1.47 fold, respectively, under NO3− deficiency (0 mg/L). Meanwhile, carbohydrate yield was increased by 1.39 fold in 5% CO2. Further cultivation with parameters of the highest biomass productivity (10,500 lux, 28 °C, pH 8, 5% CO2 and 500 mg/L NO3−) achieved the maximum biomass productivity of 0.468 g/L/day. Moreover, cultivation with parameters of the highest lipid yield (23,500 lux, 40 °C, pH 8, 0.03% CO2 and 0 mg/L NO3−) achieved the maximum lipid yield of 43.70%. The major fatty acid methyl ester compositions produced were C20:0 (39.08%) and C16:0 (37.15%), producing biodiesel with high cetane number and oxidative stability. These promising results provide a comprehensive comparison regarding the effect of photo-autotrophic cultural conditions on microalgae biomass and its potential application as a biofuels feedstock.
Norazela Nordin; Norjan Yusof; Syafiqah Md Nadzir; Mohd Zulkhairi Mohd Yusoff; Mohd Ali Hassan. Effect of photo-autotrophic cultural conditions on the biomass productivity and composition of Chlorella vulgaris. Biofuels 2019, 1 -11.
AMA StyleNorazela Nordin, Norjan Yusof, Syafiqah Md Nadzir, Mohd Zulkhairi Mohd Yusoff, Mohd Ali Hassan. Effect of photo-autotrophic cultural conditions on the biomass productivity and composition of Chlorella vulgaris. Biofuels. 2019; ():1-11.
Chicago/Turabian StyleNorazela Nordin; Norjan Yusof; Syafiqah Md Nadzir; Mohd Zulkhairi Mohd Yusoff; Mohd Ali Hassan. 2019. "Effect of photo-autotrophic cultural conditions on the biomass productivity and composition of Chlorella vulgaris." Biofuels , no. : 1-11.
The global waste generation keeps increasing over the years and it requires innovative solutions to minimize its impacts on environmental quality and public health. A strategic plan must be ascertained to overcome the future challenges of Municipal solid waste (MSW) locally and globally. Universiti Putra Malaysia (UPM) coined an initiative to demonstrate a showcase pilot plant for green energy production from MSW. The data was obtained from the survey and actual sampling within the UPM compound shows that UPM has generated 5.0–7.0 t/d of MSW generated consist of 30–35% organic fraction. Restaurants are the main source of the organic fraction. Upon separation, the organic fractions were digested into biogas. At a maximum conversion of the organic fraction, 715 kWh of electricity might be generated from the 2.2 t/d of organic waste generated in UPM. In this study, organic components from UPM were proposed to be subsequently used as a substrate via anaerobic digestion to produce green energy in the form of electricity or flammable fuels.
Ahmad Aiman Zulkifli; Mohd Zulkhairi Mohd Yusoff; Latifah Abd Manaf; Mohd Rafein Zakaria; Ahmad Muhaimin Roslan; Hidayah Ariffin; Yoshihito Shirai; Mohd Ali Hassan. Assessment of Municipal Solid Waste Generation in Universiti Putra Malaysia and Its Potential for Green Energy Production. Sustainability 2019, 11, 3909 .
AMA StyleAhmad Aiman Zulkifli, Mohd Zulkhairi Mohd Yusoff, Latifah Abd Manaf, Mohd Rafein Zakaria, Ahmad Muhaimin Roslan, Hidayah Ariffin, Yoshihito Shirai, Mohd Ali Hassan. Assessment of Municipal Solid Waste Generation in Universiti Putra Malaysia and Its Potential for Green Energy Production. Sustainability. 2019; 11 (14):3909.
Chicago/Turabian StyleAhmad Aiman Zulkifli; Mohd Zulkhairi Mohd Yusoff; Latifah Abd Manaf; Mohd Rafein Zakaria; Ahmad Muhaimin Roslan; Hidayah Ariffin; Yoshihito Shirai; Mohd Ali Hassan. 2019. "Assessment of Municipal Solid Waste Generation in Universiti Putra Malaysia and Its Potential for Green Energy Production." Sustainability 11, no. 14: 3909.
Escherichia coli has approximately 4300 open reading frames and about 178 of them are annotated as pseudogenes. The existence of the pseudogenes in E. coli had raised the question of whether they contribute to any cell function. Recently, several pseudogenes have been studied; however, these genes are still considered rare and tend to be ignored as so-called junk. Our recent study has shown several pseudogenes in E. coli are essential in hydrogen metabolism. ydfW is one of the pseudogenes associated with hydrogen metabolism. Here, we found carbon dioxide and nitrate in the fermentation medium of mutant ydfW suggesting that this strain may induce nitrate pathways. The Fdh-N complex is comprised of FdnG, FdnH, and FdnI subunits which correspond to the nitrate-nitrite pathway. This finding is supported by transcription analysis that shows formate dehydrogenase (fdnG) and nitrate reductase (narG) are significantly induced (25- and 18-fold, respectively). FdnG and NarG play a significant role in the reduction of nitrate into nitrite; hence, their genes are induced by the build-up of nitrate. Based on in silico docking analysis, we predict that YdfW is covalently bound to the Fdh-N complex in the cytoplasm. Hence, deletion of ydfW is expected has influenced the nitrate-nitrite pathway. Subsequently, the situation will affect the hydrogen production in E. coli.
Marahaini Mokhtar; Mohd Zulkhairi Mohd Yusoff; Mohd Shukuri Mohamad Ali; Nurul Asyifah Mustapha; Thomas K. Wood; Toshinari Maeda. Pseudogene YdfW in Escherichia coli decreases hydrogen production through nitrate respiration pathways. International Journal of Hydrogen Energy 2019, 44, 16212 -16223.
AMA StyleMarahaini Mokhtar, Mohd Zulkhairi Mohd Yusoff, Mohd Shukuri Mohamad Ali, Nurul Asyifah Mustapha, Thomas K. Wood, Toshinari Maeda. Pseudogene YdfW in Escherichia coli decreases hydrogen production through nitrate respiration pathways. International Journal of Hydrogen Energy. 2019; 44 (31):16212-16223.
Chicago/Turabian StyleMarahaini Mokhtar; Mohd Zulkhairi Mohd Yusoff; Mohd Shukuri Mohamad Ali; Nurul Asyifah Mustapha; Thomas K. Wood; Toshinari Maeda. 2019. "Pseudogene YdfW in Escherichia coli decreases hydrogen production through nitrate respiration pathways." International Journal of Hydrogen Energy 44, no. 31: 16212-16223.
The production of renewable energy from agro-food waste possesses a lot of advantages over conventional methods. This study aimed at enhancing the hydrogen and methane production from co-digestion of food waste and chicken manure by adding different inoculums: aeration tank sludge (ATS), return activated sludge (RAS) and palm oil mill effluent sludge (POME). One-stage anaerobic fermentation for hydrogen and methane production was carried out in a 150 mL serum bottle at 35ºC with initial pH of 7. The effects of different combination ratios (food waste and chicken manure) were also examined. The microbial community was determined using next-generation sequencing (NGS) of 16S ribosomal RNA technique. Based on the results, the co-digestion of food waste, chicken manure using a combination ratio of 50:50 (v/v) with RAS without heat treatment gave the highest biogas yield at 120.97 NmL/g COD. The highest percentages of hydrogen and methane produced were 53.35% and 52.85%, respectively. Clostridium sp. was detected in the biohydrogen production phase with methanogens responsible for biomethane production. Thus, the heat treatment of inoculums was seen as unsuitable for producing biomethane as it inhibits methanogens.
Mohd Faiz Mat Saad; Nor Aini Abdul Rahman; Mohd Zulkhairi Mohd Yusoff. Hydrogen and Methane Production from Co-digestion of Food Waste and Chicken Manure. Polish Journal of Environmental Studies 2019, 28, 2805 -2814.
AMA StyleMohd Faiz Mat Saad, Nor Aini Abdul Rahman, Mohd Zulkhairi Mohd Yusoff. Hydrogen and Methane Production from Co-digestion of Food Waste and Chicken Manure. Polish Journal of Environmental Studies. 2019; 28 (4):2805-2814.
Chicago/Turabian StyleMohd Faiz Mat Saad; Nor Aini Abdul Rahman; Mohd Zulkhairi Mohd Yusoff. 2019. "Hydrogen and Methane Production from Co-digestion of Food Waste and Chicken Manure." Polish Journal of Environmental Studies 28, no. 4: 2805-2814.
A one-step self-sustained carbonization of coconut shell biomass, carried out in a brick reactor at a relatively low temperature of 300–500°C, successfully produced a biochar-derived adsorbent with 308 m2/g surface area, 2 nm pore diameter, and 0.15 cm3/g total pore volume. The coconut shell biochar qualifies as a nano-adsorbent, supported by scanning electron microscope images, which showed well-developed nano-pores on the surface of the biochar structure, even though there was no separate activation process. This is the first report whereby coconut shell can be converted to biochar-derived nano-adsorbent at a low carbonization temperature, without the need of the activation process. This is superior to previous reports on biochar produced from oil palm empty fruit bunch.
Mohd Hafif Samsudin; Mohd Ali Hassan; Juferi Idris; Norhayati Ramli; Mohd Zulkhairi Mohd Yusoff; Izzudin Ibrahim; Mohd Ridzuan Othman; Ahmad Amiruddin Mohd Ali; Yoshihito Shirai. A one-step self-sustained low temperature carbonization of coconut shell biomass produced a high specific surface area biochar-derived nano-adsorbent. Waste Management & Research: The Journal for a Sustainable Circular Economy 2019, 37, 551 -555.
AMA StyleMohd Hafif Samsudin, Mohd Ali Hassan, Juferi Idris, Norhayati Ramli, Mohd Zulkhairi Mohd Yusoff, Izzudin Ibrahim, Mohd Ridzuan Othman, Ahmad Amiruddin Mohd Ali, Yoshihito Shirai. A one-step self-sustained low temperature carbonization of coconut shell biomass produced a high specific surface area biochar-derived nano-adsorbent. Waste Management & Research: The Journal for a Sustainable Circular Economy. 2019; 37 (5):551-555.
Chicago/Turabian StyleMohd Hafif Samsudin; Mohd Ali Hassan; Juferi Idris; Norhayati Ramli; Mohd Zulkhairi Mohd Yusoff; Izzudin Ibrahim; Mohd Ridzuan Othman; Ahmad Amiruddin Mohd Ali; Yoshihito Shirai. 2019. "A one-step self-sustained low temperature carbonization of coconut shell biomass produced a high specific surface area biochar-derived nano-adsorbent." Waste Management & Research: The Journal for a Sustainable Circular Economy 37, no. 5: 551-555.
Pseudogenes in the Escherichia coli genome are assumed to be non-functional. In this study, Keio collection BW25113∆yqiG and YqiG-producing strain (BW25113/pCA24N-YqiG) were used to evaluate the importance of pseudogene yqiG in hydrogen metabolism. Our results show pseudogene protein YqiG was identified as an essential protein in the production of biohydrogen from glucose. The mutant yqiG decreased biohydrogen production from 37 µmol mg−1 protein to 6 µmol mg−1 protein compared to the wild-type strain, and glucose consumption was reduced by 80%. Through transcriptional analysis, we found that the yqiG mutation represses pflB transcription tenfold; pflB encodes pyruvate-formate lyase, one of the key enzymes in the anaerobic metabolism of E. coli. Moreover, production of YqiG stimulated glycolysis and increased biohydrogen productivity 1.5-fold compared to that of the wild-type strain. Thus, YqiG is important for the central glycolysis reaction and is able to influence hydrogen metabolism activity in E. coli.
Muhammad Azman Zakaria; Mohd Zulkhairi Mohd Yusoff; Mohd Rafein Zakaria; Mohd Ali Hassan; Thomas K. Wood; Toshinari Maeda. Pseudogene product YqiG is important for pflB expression and biohydrogen production in Escherichia coli BW25113. 3 Biotech 2018, 8, 435 .
AMA StyleMuhammad Azman Zakaria, Mohd Zulkhairi Mohd Yusoff, Mohd Rafein Zakaria, Mohd Ali Hassan, Thomas K. Wood, Toshinari Maeda. Pseudogene product YqiG is important for pflB expression and biohydrogen production in Escherichia coli BW25113. 3 Biotech. 2018; 8 (10):435.
Chicago/Turabian StyleMuhammad Azman Zakaria; Mohd Zulkhairi Mohd Yusoff; Mohd Rafein Zakaria; Mohd Ali Hassan; Thomas K. Wood; Toshinari Maeda. 2018. "Pseudogene product YqiG is important for pflB expression and biohydrogen production in Escherichia coli BW25113." 3 Biotech 8, no. 10: 435.
Polyhydroxyalkanoate (PHA) is a linear polyester produced through the fermentation of sugar or lipid. Biosynthesis of PHA comprises three enzymes known as acetyl-CoA acetyltransferase (phaA), acetoacetyl-CoA reductase (phaB) and PHA synthase (phaC). Comamonas sp. is one of the strains commonly used for PHA production. In order to develop higher PHA production from bacterial respond strategy, PHA biosynthesis operon of Comamonas sp. EB172 was introduced into Escherichia coli BW25113 through a pGEM-T vector. E. coli was chosen due to the complete genome information available and the absence of depolymerisation gene, phaZ. In this study, the deletion of several single genes, which are frdC, gltA, and pta, was found to be associated with PHA metabolism activity in E. coli BW25113. P1 transduction was performed to construct multiple genes knockout. The engineered strain, E. coli BW25113 frdCgltApta::kan/pGEM’-phaCABCo, yielded the highest PHA production at 64 wt.% with 1.4 fold higher than that of control strain of E. coli BW25113/pGEM’-phaCABCo. This strain is potential for industrial application for higher PHA production from E. coli.
Nurhajirah Mohamed Biran; Mohd Zulkhairi Mohd Yusoff; Toshinari Maeda; Mohd Rafein Zakaria; Lian-Ngit Yee; Mohd Ali Hassan. Triple knockout of frdC gltA and pta genes enhanced pHA production in Escherichia coli. Asia Pacific Journal of Molecular Biology and Biotechnology 2018, 11 -18.
AMA StyleNurhajirah Mohamed Biran, Mohd Zulkhairi Mohd Yusoff, Toshinari Maeda, Mohd Rafein Zakaria, Lian-Ngit Yee, Mohd Ali Hassan. Triple knockout of frdC gltA and pta genes enhanced pHA production in Escherichia coli. Asia Pacific Journal of Molecular Biology and Biotechnology. 2018; ():11-18.
Chicago/Turabian StyleNurhajirah Mohamed Biran; Mohd Zulkhairi Mohd Yusoff; Toshinari Maeda; Mohd Rafein Zakaria; Lian-Ngit Yee; Mohd Ali Hassan. 2018. "Triple knockout of frdC gltA and pta genes enhanced pHA production in Escherichia coli." Asia Pacific Journal of Molecular Biology and Biotechnology , no. : 11-18.