Tayel Ahmed A, Gharieb Mohamed M, Zaki Hanaa R, Elguindy Nihal M
Genetic Engineering and Biotechnology Research Institute, University of Sadat City, El-Sadat City, Egypt; Faculty of Fisheries and Aquaculture Sciences, Kafrelsheikh University, Kafrelsheikh, Egypt.
Botany Department, Faculty of Science, Menoufia University, Shibin Al Kawm, Al Minufiyah, Egypt.
Int J Biol Macromol. 2016 Feb;83:277-81. doi: 10.1016/j.ijbiomac.2015.11.072. Epub 2015 Nov 29.
Water pollution is among the most hazardous problems that threaten human health worldwide. Chitosan is a marvelous bioactive polymer that could be produced from fungal mycelia. This study was conducted to produce chitosan from Cunninghamella elegans and to use it for water pollutants elimination, e.g. heavy metals and waterborne microorganisms, and to investigate its antibacterial mode of action against Escherichia coli. The produced fungal chitosan had a deacetylation degree of 81%, a molecular weight of 92.73 kDa and a matched FT-IR spectrum with standard shrimp chitosan. Fungal chitosan exhibited remarkable antimicrobial activity against E. coli, Staphylococcus aureus and Candida albicans. Chitosan was proved as an effective metal adsorbent, toward the examined metal ions, Cu2+, Zn2+ and Pb2+, and its adsorption capacity greatly increased with the increasing of metal concentration, especially for Cu and Zn. The scanning electron micrographs, of treated E. coli cells with fungal chitosan, indicated that the cells began to lyse and combine after 3h of exposure and chitosan particles attached to the combined cells and, after 12 h from exposure, the entire bacterial cell walls were fully disrupted and lysed. Therefore, fungal chitosan could be recommended, as a bioactive, renewable, ecofriendly and cost effective material, for overcoming water pollution problems, from chemical and microbial origins.
水污染是全球范围内威胁人类健康的最危险问题之一。壳聚糖是一种神奇的生物活性聚合物，可以从真菌菌丝体中产生。本研究旨在从雅致小克银汉霉中生产壳聚糖，并将其用于消除水污染物，如重金属和水传播微生物，并研究其对大肠杆菌的抗菌作用模式。所生产的真菌壳聚糖的脱乙酰度为81%，分子量为92.73 kDa，其傅里叶变换红外光谱与标准虾壳聚糖匹配。真菌壳聚糖对大肠杆菌、金黄色葡萄球菌和白色念珠菌表现出显著的抗菌活性。壳聚糖被证明是一种有效的金属吸附剂，对所检测的金属离子Cu2+、Zn2+和Pb2+具有吸附作用，并且其吸附能力随着金属浓度的增加而大大提高，尤其是对铜和锌。用真菌壳聚糖处理大肠杆菌细胞的扫描电子显微镜照片表明，暴露3小时后细胞开始裂解并结合，壳聚糖颗粒附着在结合的细胞上，暴露12小时后，整个细菌细胞壁被完全破坏并裂解。因此，真菌壳聚糖作为一种生物活性、可再生、生态友好且具有成本效益的材料，可被推荐用于克服化学和微生物来源的水污染问题。
