Akram A. Aboseidah

Bio: Akram A. Aboseidah is an academic researcher from Suez University. The author has contributed to research in topics: Fermentation & Biohydrogen. The author has an hindex of 5, co-authored 13 publications receiving 57 citations.

ACC deaminase containing endophytic bacteria ameliorate salt stress in Pisum sativum through reduced oxidative damage and induction of antioxidative defense systems.

Abstract: Approximately 6% of the world's total land area and 20% of the irrigated land are affected by salt stress. Egypt is one such country affected by salt-stress problems. This paper focuses on the role of isolated bacteria, such as Bacillus subtilis and Pseudomonas fluorescens, in alleviating the harmful effects of salt stress. The results show that the irrigation of plants with different concentrations of saline water (0, 75, and 150 mM NaCl) leads to significantly decreased growth criteria, photosynthetic pigments (i.e., chl a, chl b, and carotenoids), and membrane stability index (MSI) values. Moreover, malondialdehyde (MDA), glutathione content, endogenous proline, the antioxidant defense system, 1-aminocyclopropane-1-carboxylic acid (ACC) content, ACC synthase (ACS), ACC oxidase (ACO), and Na+ content were significantly increased under NaCl-stress exposure. On the contrary, treatment with endophytic bacteria significantly increased the resistance of pea plants to salt stress by increasing the enzymatic antioxidant defenses (i.e., superoxide dismutase, catalase, peroxidase, and glutathione reductase), non-enzymatic antioxidant defenses (i.e., glutathione), osmolyte substances such as proline, and antioxidant enzyme gene expression. As a result, endophytic bacteria's use was significantly higher compared to control values for indole-3-acetic acid (IAA), gibberellic acid GA3, MSI, and photosynthetic pigments. The use of endophytic bacteria significantly decreased Na+ accumulation while, at the same time, promoting K+ uptake. In conclusion, the induction of endophytic bacterium-induced salt tolerance in pea plants depends primarily on the effect of endophytic bacteria on osmoregulation, the antioxidant capacity, and ion uptake adjustment by limiting the uptake of Na+ and, alternatively, increasing the accumulation of K+ in plant tissue.

Characterization and optimization of lipase activity produced by Pseudomonas monteilli 2403-KY120354 isolated from ground beef

Abstract: A total of 56 Gram negative bacterial isolates were recovered from twenty ground beef samples and were screened for their potentiality to produce lipase. Forty four bacterial isolates were recorded as positive producers for lipase on tween as carbon source in solid medium. Also, the highly producer isolates were screened for lipase activity in submerged culture using olive oil as carbon and the most active isolate was 2043 which gave an activity of 20.0 ± 0.29 U/ml. The bacterial isolate 2403 was identified phenotypically according to Bergey’s Manual and genotypically using 16S rRNA genes analysis as Pseudomonas monteilli. Effect of some different factors on lipase activity were studied and the maximum lipase activity was achieved at reaction medium of pH 6 and incubated at 40°C for 60 min. Also, addition of Ba2+ in the reaction medium enhanced the lipase activity, while the other tested metals reduced the enzyme activity. Key words: Food contamination, lipase activity, olive oil, cultural conditions, Pseudomonas.

Application of Langmuir and Freundlich Isotherm Models on Biosorption of Pb2+ by Freez-dried Biomass of Pseudomonas aeruginosa

Abstract: TODAY, the pollution of soil and aquatic environment by lead metal ion results from the discharged industrial waste water represents serious environmental problem. Biosorption is an ecofriendly technology that uses microbial biomasses to bind heavy metals on their surfaces by physicochemical pathways from waste water. Seventy-two bacterial isolates resistant to lead metal ion were recovered from 30 sewage water samples collected from different streets of Faisal district in Suez Governorate, Egypt. Interestingly, the isolate number 2103 was selected among them as the most highly resistant to high concentrations of Pb2+. This isolate was characterized morphologically, biochemically and identified by 16S rRNA gene sequencing as Pseudomonas aeruginosa and deposited in the GenBank database under the accession number KY712434. Studying the effects of contact time and pH on Pb2+ biosorption by the freeze-dried biomass of Pseudomonas aeruginosa 2103 revealed that the maximum biosorption was achieved within 30min at pH 6. The maximum adsorption capacity (qmax) of Pb2+ removal by the freeze-dried biomass of Pseudomonas aeruginosa 2103 was 114.94mg/g. The regression coefficients (R2) were 0.8847 and 0.9751 from the Langmuir and Freundlich isotherm models, respectively, so the biosorption of Pb2+ onto the biomass of Pseudomonas aeruginosa 2103 has been found to fits Freundlich isotherm model better than Langmuir isotherm model.

Evaluation of Antibacterial and Antibiofilm Activity of New Antimicrobials as an Urgent Need to Counteract Stubborn Multidrug-resistant Bacteria

Abstract: The biggest problem in the world today is antimicrobial resistance, which undermines human health and increases morbidity and mortality associated with life-threatening serious diseases. Scientists from different fields are therefore examining plants for their antimicrobial use in the face of multidrug-resistant bacteria with a new eye. So, the aim of this research to find a new antibacterial from five aqueous extracts of Nigella sativa, Ziziphus spina-christi, Rosmarinus officinalis, Origanum majorana, and Allium sativum medicinal plants tested against the most multidrug-resistant bacterial isolates from clinical specimens which were Klebsiella pneumoniae (Gram-negative), Escherichia coli (Gram-negative), Pseudomonas aeruginosa (Gram-negative), Staphylococcus aureus (Gram-positive) and Methicillin-resistant Staphylococcus aureus (Gram-positive). Also, to investigate the antibiofilm activity of the most potent extract. From all tested plants, the total extract of Z. spina-christi appeared a strong antibacterial effect against all tested MDR-strains. Besides, its polyphenol fraction showed a stronger effect. Furthermore, the total extract MIC ranged between 3.125-12.5 mg/ml with MBC was 3.125-25 mg/ml against previous strains. While, polyphenol fraction MIC and MBC were about 0.3121.25 mg/ml and 0.312-2.5 mg/ml, respectively. In contrast to the antibacterial strength of polyphenol fraction, the antibiofilm effect was weaker than the total extract antibiofilm effect, where at 1⁄2 MIC, the reduction of biofilm was about 78.18%, 81.9% and 99.48% against S. aureus, MRSA and P. aeruginosa, respectively. While, in the case of polyphenol fraction, the biofilm reduction effect against previous strains was 63.82%, 59.97%, and 87.95%, respectively.

Enhancement of glycerol production by UV-mutagenesis of the marine yeast Wickerhamomyces anomalus HH16: kinetics and optimization of the fermentation process

Abstract: The current study aims to enhance glycerol production using UV-mutagenesis of the marine yeast Wickerhamomyces anomalus HH16 isolated from marine sediment collected from South Sinai Governorate, Egypt. Besides optimization of the culture conditions and analyzing the kinetic parameters of growth and glycerol biosynthesis by the mutant strain were studied. The marine yeast isolate HH16 was selected as the front runner glycerol-producer among all tested isolates, with glycerol yield recorded as 66.55 gl−1. The isolate was identified based on the phenotypic and genotypic characteristics of W. anomalus. The genotypic characterization based on the internal transcribed spacer (ITS) sequence was deposited in the GenBank database with the accession number MK182824. UV-mutagenesis of W. anomalus HH16 by its exposure to UV radiation (254 nm, 200 mW cm−2) for 5 min; increased its capability in the glycerol production rate with 16.97% (80.15 g l−1). Based on the kinetic and Monod equations, the maximum specific growth rate (μmax) and maximum specific glycerol production rate (vmax) by the mutant strain W. anomalus HH16MU5 were 0.21 h−1 and 0.103 g g−1, respectively. Optimization of the fermentation parameters such as nitrogen source, salinity and pH has been achieved. The maximum glycerol production 86.55 g l−1 has been attained in a fermentation medium composed of 200 g l−1 glucose, 1 g l−1 peptone, 3 g l−1 yeast extract, and 58.44 g l−1 NaCl, this medium was adjusted at pH 8 and incubated for 3 days at 30° C. Moreover, results indicated the ability of this yeast to produce glycerol (73.33 g l−1) using a seawater based medium. These findings suggest the applicability of using the yeast isolate W. anomalus HH16MU5 as a potential producer of glycerol for industrial purposes.

Quantification of biofilm in microtiter plates: overview oftesting conditions and practical recommendations for assessmentof biofilm production by staphylococci.

Abstract: The details of all steps involved in the quantification of biofilm formation in microtiter plates are described. The presented protocol incorporates information on assessment of biofilm production by staphylococci, gained both by direct experience as well as by analysis of methods for assaying biofilm production. The obtained results should simplify quantification of biofilm formation in microtiter plates, and make it more reliable and comparable among different laboratories.

Plants’ Physio-Biochemical and Phyto-Hormonal Responses to Alleviate the Adverse Effects of Drought Stress: A Comprehensive Review

Abstract: Water, a necessary component of cell protoplasm, plays an essential role in supporting life on Earth; nevertheless, extreme changes in climatic conditions limit water availability, causing numerous issues, such as the current water-scarce regimes in many regions of the biome. This review aims to collect data from various published studies in the literature to understand and critically analyze plants’ morphological, growth, yield, and physio-biochemical responses to drought stress and their potential to modulate and nullify the damaging effects of drought stress via activating natural physiological and biochemical mechanisms. In addition, the review described current breakthroughs in understanding how plant hormones influence drought stress responses and phytohormonal interaction through signaling under water stress regimes. The information for this review was systematically gathered from different global search engines and the scientific literature databases Science Direct, including Google Scholar, Web of Science, related studies, published books, and articles. Drought stress is a significant obstacle to meeting food demand for the world’s constantly growing population. Plants cope with stress regimes through changes to cellular osmotic potential, water potential, and activation of natural defense systems in the form of antioxidant enzymes and accumulation of osmolytes including proteins, proline, glycine betaine, phenolic compounds, and soluble sugars. Phytohormones modulate developmental processes and signaling networks, which aid in acclimating plants to biotic and abiotic challenges and, consequently, their survival. Significant progress has been made for jasmonates, salicylic acid, and ethylene in identifying important components and understanding their roles in plant responses to abiotic stress. Other plant hormones, such as abscisic acid, auxin, gibberellic acid, brassinosteroids, and peptide hormones, have been linked to plant defense signaling pathways in various ways.

Production of optically pure lactic acid by microbial fermentation: a review

Abstract: Biotransformation of organic wastes into value-added products is gaining interest owing to waste management issues, exhaustion of fossil fuels and the demand for biodegradable plastics. Lactic acid is widely used for polymers, foods, beverages, medicines, cosmetics and clothing. However, the major obstacle in large-scale fermentation of lactic acid is achieving enhanced yield, productivity and optical purity with cheap resources. Therefore, we review methods and recovery techniques for production of microbial lactic acid using cheap fermentative substrates. New strategies allow to alleviate limitations associated with substrate inhibition, product inhibition, undesirable by-products, sensitivity to toxic compounds, inefficient utilization of mixed sugars and overuse of neutralizing agents. Efficient utilization of mixed sugars can be achieved with simultaneous saccharification and fermentation using mixed cultures, isolating carbon catabolic repression-negative strains and altering the metabolic pathway. Lactic acid productivity can be improved by co-culture, maintaining high cell density and periodically removing end-products accumulated in the fermentation medium. Inhibition by toxic compounds can be eliminated by using engineered feedstock which releases less inhibitors, by using inhibitor-tolerant microbes and by development of genetically engineered strains. Fed-batch fermentation was found to be better than other operation modes due to less substrate inhibition.