Optimization of microcystin biodegradation by bacterial community YFMCD4 using response surface method

The increasing production of microcystin-LR (MC-LR) causing animal and human health issues is found in eutrophic water bodies, marine habitats and desert environments. The health threat posed by MC-LR has led to the establishment of World Health Organization's water guideline value of 1 mu g/mL. Combating this has increased the search for cost-effective approach to degrade MC-LR. The study aimed to optimize the MC-degrading environmental factors of bacterial community YFMCD4. Response surface methodology (RSM) was employed to evaluate the influence of varying temperatures, pH and initial MC-LR concentration on the biodegradation efficiency of MC-LR by bacterial community YFMCD4. The optimal MC-LR biodegradation environmental factors were found to be 30 degrees C, pH 7 and 2 mu g/mL initial MC-LR. The biodegradation rate reached 100% after 10 h. YFMCD4 mainly consisted of genera Alacligenes, Sphingobacterium and Pseudomonas using High-throughput pyrosequencing technology. The mlrA gene encoding MlrA enzyme considered most important for MC-LR biodegradation was obtained from YFMCD4. Data demonstrated that the bacterial structure and biodegradation efficiency of YFMCD4 varied with the change of environmental factors including temperature, pH and MC-LR concentrations. RSM is considered a good method to examine the optimal biodegradation environmental conditions for MC-LR. To date, RSM and High-throughput pyrosequencing technology are employed to optimize the biodegradation conditions (30 degrees C, pH 7 and 2 mu g/mL initial MC-LR) and analyze the structure of bacterial community for the first time. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study aimed to optimize the MC-degrading environmental factors of bacterial community YFMCD4, finding that the optimal conditions for MC-LR biodegradation were 30 degrees C, pH 7, and 2 mu g/mL initial MC-LR concentration. High-throughput pyrosequencing technology revealed that YFMCD4 primarily consisted of Alacligenes, Sphingobacterium, and Pseudomonas genera, with the mlrA gene encoding MlrA enzyme being crucial for MC-LR biodegradation. The use of Response Surface Methodology (RSM) was considered effective in determining the best biodegradation environmental conditions for MC-LR.