Abstract

Bioremediation is an essential feature of microorganisms concerning contaminations in soil and water. The use of microorganisms has been proved to be an effective treatment of industrially released effluents comprising of heavy metals, such as chromium (VI). In the current study, seasonal variations were observed in the concentrations of chromium(VI) as the samples from selected locations showed an increase in mean concentration during the summer compared to the low mean during winter, suggesting excessive evaporation in the summer leading to the heavy metal accumulation. Among the 35 isolates obtained from tannery effluent contaminated wastewater sources the 3 unique strains identified as Streptococcus pyogenes strain APRRJVITS10, Pseudomonas putida strain APRRJVITS11, and Bacillus thuringiensis strain APRRJVITS15, showed tolerance toward chromium(VI) and the maximum tolerance for each strain was 1250 ppm. The media optimization through shake flask methods showed chromium(VI) (in 100 ml LB broth) removal of 47.82%, 48.11%, and 49.93% by S. pyogenes, P. putida, and B. thuringiensis respectively. Further, Pseudomonas putida showed chromium(VI) (in 1500 ml LB broth) removal of 50.48% in optimized conditions, proving to be highly potential for treating effluent wastewater for chromium(VI) removal.

摘要

生物修复是微生物在土壤和水中污染的基本特征。微生物的使用已被证明是一种有效处理工业排放的含有重金属如铬 (VI) 的流出物。在目前的研究中，观察到铬 (VI) 浓度的季节性变化，因为来自选定地点的样本显示，与冬季的低平均值相比，夏季的平均浓度有所增加，这表明夏季蒸发过度导致重金属积累。在从制革厂污水污染的废水源中获得的 35 个分离株中，3 个独特的菌株被鉴定为化脓性链球菌菌株 APRRJVITS10、恶臭假单胞菌菌株 APRRJVITS11 和苏云金芽孢杆菌菌株 APRRJVITS15 显示出对铬 (VI) 的耐受性，每个菌株的最大耐受性为 1250 ppm。通过摇瓶方法进行的培养基优化表明，化脓性链球菌、恶臭假单胞菌和苏云金芽孢杆菌分别去除了 47.82%、48.11% 和 49.93% 的铬 (VI)（在 100 ml LB 肉汤中） 。此外，恶臭假单胞菌在优化条件下表现出 50.48% 的铬 (VI) 去除率（在 1500 ml LB 肉汤中），证明在处理废水以去除铬 (VI) 方面具有很高的潜力。