Background: Mangrove sediment microbes are increasingly attracting scientific attention due to their demonstrated capacity for diverse bioremediation activities, encompassing a wide range of environmental contaminants. Materials and methods: The microbial communities of five Avicennia marina mangrove sediment samples collected from Al Rayyis White Head, Red Sea (KSA), were characterized using Illumina amplicon sequencing of the 16S rRNA genes. Results: Our study investigated the microbial composition and potential for organohalide bioremediation in five mangrove sediments from the Red Sea. While Proteobacteria dominated four microbiomes, Bacteroidetes dominated the fifth. Given the environmental concerns surrounding organohalides, their bioremediation is crucial. Encouragingly, we identified phylogenetically diverse organohalide-respiring bacteria (OHRB) across all samples, including Dehalogenimonas, Dehalococcoides, Anaeromyxobacter, Desulfuromonas, Geobacter, Desulfomonile, Desulfovibrio, Shewanella and Desulfitobacterium. These bacteria are known for their ability to dechlorinate organohalides through reductive dehalogenation. PICRUSt analysis further supported this potential, predicting the presence of functional biomarkers for organohalide respiration (OHR), including reductive dehalogenases targeting tetrachloroethene (PCE) and 3-chloro-4-hydroxyphenylacetate in most sediments. Enrichment cultures studies confirmed this prediction, demonstrating PCE dechlorination by the resident microbial community. PICRUSt also revealed a dominance of anaerobic metabolic processes, suggesting the microbiome’s adaptation to the oxygen-limited environment of the sediments. Conclusion: This study provided insights into the bacterial community composition of five mangrove sediments from the Red Sea. Notably, diverse OHRB were detected across all samples, which possess the metabolic potential for organohalide bioremediation through reductive dehalogenation pathways. Furthermore, PICRUSt analysis predicted the presence of functional biomarkers for OHR in most sediments, suggesting potential intrinsic OHR activity by the enclosed microbial community.

This study aimed to isolate potent thermophilic and amylolytic bacteria from a hot spring of Pharaoh’s bath, Sinai, Egypt, and screen its degradative activity. The amylolytic activity was further optimized using a statistical full factorial design followed by response surface methodology. A thermophilic bacterium was isolated from the hot spring of Pharaoh’s Bath, Sinai, Egypt. The isolate produced amylase, cellulase, and caseinase and was identified by 16S rRNA gene sequencing as Parageobacillus thermoglucosidasius Pharon1 (MG965879). A growth medium containing 1% soluble starch was found to optimize the amylase production. Dinitrosalycalic acid method (DNS) was used to estimate the amount of reducing sugar produced. Statistical full factorial and response surface designs were employed to optimize physical variables affecting the α-amylase production and determine the significant interactions of the studied variables during the fermentation process. According to the results obtained by the response optimizer, the maximum amylase activity reached 76.07 U/mL/ min at 54.1°C, pH 5.6 after 98.5 h incubation under aerobic conditions. Moreover, the produced enzyme was thermostable and retained most of its activity when exposed to a high temperature of 100°C for 120 min. Maximum enzyme activity was attained when the enzyme was incubated at 70°C for 30 min. This is the first report of the production of thermostable α-amylase by the potent thermophilic Parageobacillus thermoglucosidasius. The enzyme endured extreme conditions of temperature and pH which are important criteria for commercial and industrial applications.

This study aimed to biosynthesize zinc oxide nanoparticles (ZnO-NPs) using extracts from various seaweeds, including Ulva lactuca, Ulva intestinalis (Chlorophyta), and Sargassum muticum (Phaeophyceae). The biosynthesized ZnO-NPs were characterized using UV spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and zeta potential analysis. Their antimicrobial activity was assessed using the disk diffusion method, revealing significant efficacy against two bacterial species (Klebsiella pneumoniae and Escherichia coli) and two fungal species (Candida albicans and Aspergillus niger). Additionally, the antioxidant potential of the ZnO-NPs was evaluated based on the total antioxidant capacity, ferric reducing antioxidant power, and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assays. The antioxidant activity of the ZnO-NPs was confirmed using the three antioxidant assays. The ZnO-NPs of U. lactuca recorded the highest antioxidant activity. The cytotoxicity of the ZnO-NPs was tested on different cell lines using the MTT assay. The ZnO-NPs of U. lactuca showed very weak cytotoxic effects on WI 38 (84.98 ± 4.6 µg/mL) and 23, and this result confirmed its safety on normal cells. The ZnO-NPs of U. lactuca showed moderate cytotoxic effects on the HepG-2 (46.66 ± 2.8 µg/mL) and MCF-7 (30.60 ± 2.1 µg/mL) cell lines. In an in vivo study, the ZnO-NPs of U. lactuca showed a decrease in tumor volume, weight, and serum malondialdehyde in experimental mice, while the total antioxidant capacity of the serum was increased. Histopathological changes in ZnO-NPs indicated a reduction in tumor size, a lower number of mitosis divisions, and a rise in apoptosis correlated with the ZnO-NPs of the U. lactuca-treated groups. In conclusion, biosynthesized ZnO-NPs from seaweed showed potent antimicrobial, antioxidant, and antitumor activities, which can be used in the pharmaceutical industry.

The present study evaluated ethanol, methanol, ethyl acetate, hexane, chloroform and acetone extracts of five green and red seaweed species from Abu-Qir bay, Alexandria, Egypt for their antimicrobial, antioxidant activities and cytotoxicity against four cell lines. Chloroform extracts of Ulva lactuca and Ulva fasciata exhibited the highest inhibition zones against the tested pathogenic bacteria (Klebsiella pneumoniae and Proteus mirabilis) and fungi (Aspergillus flavus, Aspergillus fumingatus and Aspergillus niger) as measured by disc diffusion method. The extracts of U. lactuca and U. fasciata showed the highest antioxidant activity (IC50 6.32±0.29 mg/ml and 6.61±0.27 mg/ml, respectively), using DPPH (2, 2- diphenyl-1- picrylhydrazyl) scavenging method and total antioxidant capacity assay (2.13 and 1.51 mg ascorbic acid equivalent /gram dry weight, respectively). Cytotoxicity test using MTT assay showed that U. lactuca extract had strong activity against MCF-7 and Hela cell lines (IC50 10.83±1.0, 12.43±1.3 μg/ml, respectively), while U. fasciata had strong activity against PC3 and HePG2 cell lines (IC50 12.99±1.2, 16.75±1.5 μg/ml, respectively). The most active purified antimicrobial fractions of U. lactuca and U. fasciata extracts were analyzed by Gas Chromatography Mass Spectroscopy as Di-isooctyl Phthalate (390.56 g/mol molecular weight) and Butylated Hydroxytoluene (220.356 g/mol), respectively. The studied seaweeds have distinct active metabolites being a promising source of antimicrobial and antiproliferative compounds that can be used effectively in pharmaceutical drug industry.

Aim This research aimed to monitor pharmaceutical water system by sampling water from all treatment stages, identify bacterial isolates from each phase and determine the most suitable methods to control them. Methods and results Water samples were collected and examined from pharmaceutical water system in a pharmaceutical factory in Giza, Egypt during twelve months, once per month, (from December 2017 to November 2018) from fifteen points covering all stages of the treatment process starting from wells, pretreatment points; treatment points ending with purified points which are the main source of water used in all pharmaceutical process. Two hundred and sixteen water samples were collected and examined, 156 isolates were selected according to morphological characteristics. VITEK system 2 (BioMérieux) was used for identification of all isolates resulting to 24 different identified bacteria. Antibiotic assay test using disc diffusion methods were carried out using seven antibiotics from different groups. Several disinfectants were also examined for efficacy against the isolates to control microorganisms in water treatment stage and manufacturing area. The effect of different preservatives (parabens, acids and alcohols) in various pharmaceutical formulas was also tested on bacterial isolates, 63% of formulas were effective against all bacterial isolates. Conclusion Ciprofloxacin was the most effective antibiotic, mixture of 0.45% peracetic acid plus 2.2% of hydrogen peroxide (Minnacare 1%) was maximally effective disinfectant, and Cronobacter sakazakii was the most resistant microorganism against 22.7% of tested preservatives. Impact of study Controlling pharmaceutical manufacturing operation from pathogenic bacteria that affect quality of drugs.