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Book Chapter
Ismail, M. M., M. Hassan, and T. M. Essam, "Biological Testing and Toxicity Bioassays in Biodegradation: Toward Better Process Control", Toxicity and Biodegradation Testing, New York, NY, Springer New York, pp. 185 - 205, 2018, 2017. Abstract

The main purpose of bioremediation processes is to eliminate or even to reduce the risk of the toxic pollutants to reach safe and acceptable limits. Although environmental pollutants have complex nature and composition, most of the performed studies reported the application of methods for biodegradation of pollutants and xenobiotics in environment, especially wastewater, as a black box without considering sequestered risks. In this sense, chemical analysis alone is not sufficient for complete assessment of water quality while biological toxicity assays can estimate the effect of wastewater on the biota and assess the actual direct and sequestered environmental risks. This was the main driving force to teamwork in our lab to adopt, develop, and optimize biological testing methods and bioassays for better process control and real monitoring of the bioremediation efficiency. Several methods and bioassays were used such as BOD5 and algal toxicity (to assess the degree of wastewater toxicity), Artemia toxicity (to assess impact on the aquatic creatures), phytotoxicity (to assess the impact on terrestrial plants). Also endocrine disruptors’ assays and cytotoxicity (to assess the impact on mammalians and humans) were optimized. The authors discuss and transfer the knowledge and the step by step experience gained with these methods and bioassays. Moreover, this chapter elaborates all necessary practical tricks and precautions required to achieve accurate and reproducible measurements.

Conference Paper
Hassan, M., R. Samir, T. Essam, and S. Megahed, "Biomonitoring of algal-bacterial system for wastewater treatment: Assessment towards better process control", 1st International Conference on Bioresource Technology for Bioenergy, Bioproducts & Environmental Sustainability, Spain, Oct 2016.
Hassan, M., T. Essam, and S. Megahed, "Community shift of water microbiome in an algal-bacterial based photo- bioreactor for wastewater treatment", 9th Probiotics, Prebiotics & New Foods, Nutraceuticals and Botanicals for Nutrition & Human and Microbiota Health, Rome, Italy, 10 September , 2017.
Hassan, M., A. Yassin, T. Essam, and A. Salama, "Optimization of biosurfactant production using organic pollutants biodegrading bacterial isolates", 2nd International Conference on Advanced basic and Applied sciences, Ain Sokhna, Egypt, April 2014.
Hassan, M., A. Yassin, T. Essam, and A. Salama, "Optimized bio-surfactant production by organic pollutants biodegrading bacterial isolates", 3rd FUE International Conference of Pharmaceutical Sciences, Egypt, Feb 2015.
Hassan, M., A. Yassin, T. Essam, and A. Salama, "Screening of relevant biodegrading bacterial isolates for the production of biosurfactants", 3rd International Scientific Conference of the Faculty of Pharmacy, Cairo University, Egypt, April 2012.
Journal Article
Hassan, M., T. Essam, A. Mira, and S. Megahed, "Biomonitoring detoxification efficiency of an algal-bacterial microcosm system for treatment of coking wastewater: Harmonization between Chlorella vulgaris microalgae and wastewater microbiome", Science of The Total Environment, vol. 677, pp. 120 - 130, 2019. AbstractWebsite

Nowadays, due to worldwide water shortage, water utilities are forced to re-evaluate treated wastewater. Consequently, wastewater treatment plants need to conduct biomonitoring. Coking wastewater (CWW) has toxic, mutative and carcinogenic components with threatening effect on the environment. CWW was selected as a model for complex highly toxic industrial wastewater that should be treated. CWW from Egypt was treated in a nine-liter photobioreactor using an algal-bacterial system. The photobioreactor was operated for 154 days changing different parameters (toxic load and light duration) for optimization. Optimized conditions achieved significant reduction (45%) in the operation cost. The algal-bacterial system was monitored using chemical assays (chemical oxygen demand and phenol analysis), bioassays (phytotoxicity, Artemia-toxicity, cytotoxicity, algal-bacterial ratio and settleability) and Illumina-MiSeq sequencing of 16S rRNA gene. The algal-bacterial system detoxified (in terms of phytotoxicity, cytotoxicity and Artemia-toxicity) CWW introduced as influent through all phases. A significant difference was recorded in the microbial diversity between influent and effluent samples. Four phyla dominated influent samples; Proteobacteria (77%), Firmicutes (11%), Bacteroidetes (5%) and Deferribacteres (3%) compared to only two in effluent samples; Proteobacteria (66%) and Bacteroidetes (26%). The significant relative-abundance of versatile aromatic degraders (Comamonadaceae and Pseudomonadaceae families) in influent samples conformed to the nature of CWW. Microbial community shifted and promoted the activity of catabolically versatile and xenobiotics degrading families (Chitinophagaceae and Xanthomonadaceae). Co-culture of microalgae had a positive effect on the biodegrading bacteria that was reflected by enhanced treatment efficiency, significant increase in relative abundance of bacterial genera with cyanide-decomposing potential and negative effect on waterborne pathogens.

Hassan, M., T. Essam, and S. Megahed, "Illumina sequencing and assessment of new cost-efficient protocol for metagenomic-DNA extraction from environmental water samples", Brazilian Journal of Microbiology, vol. 49, issue 1, pp. 1-8, 2018.