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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 μg/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 °C, pH 7 and 2 μg/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 °C, pH 7 and 2 μg/mL initial MC-LR) and analyze the structure of bacterial community for the first time. • RSM was used to optimize MC-LR biodegradation conditions by YFMCD4 for the first time. • Varying temperatures, pH and MC-LR concentrations influenced MC-LR biodegradation. • Structure of YFMCD4 was analyzed by high-throughput pyrosequencing technology. • mlrA and mlrD homologues genes were amplified from YFMCD4. [ABSTRACT FROM AUTHOR]

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In order to enhance the role of Al in the materials, Al-substituted MnAlO catalysts were synthesized via the hydrothermal-redox method at different calcination temperatures for acetone oxidation. There were Al-substituted α-MnO 2 and amorphous aluminum oxide existed with homogeneous dispersion of elements in the catalysts. The surface property, reaction rate, CO 2 yield and water resistance of MnAlO catalysts were greatly affected by calcination temperatures. MnAlO-450 catalyst exhibited the best catalytic performance (acetone conversion of 90% at 165 °C) with CO 2 yield higher than 99.7%, which was mainly related to the weaker Mn–O bond strength, lower temperature reducibility and abundant Lewis acid sites. The acetone conversion of MnAlO-450 increased by as much as 16% in the presence of 1 vol% H 2 O compared to that in the absence of H 2 O at T 50 (the temperature for 50% conversion of acetone). The acceleration consumption of ethanol as the main by-product by H 2 O improved the catalytic performance. This work would shed light on the Al substitution based catalysts for OVOC oxidation with highly efficient and water resistance. [Display omitted] • MnAlO catalysts are facilely prepared by a one-step hydrothermal-redox method. • The surface property and catalytic activity are affected by calcination temperatures. • MnAlO-450 exhibits excellent catalytic performance and water resistance. • The accelerated consumption of ethanol by H 2 O promotes the acetone oxidation. • PTR-MS and GC-MS results reveal the reaction route of acetone oxidation. [ABSTRACT FROM AUTHOR]