Biodegradation of microcystin-LR using acclimatized bacteria isolated from different units of the drinking water treatment plant
Biodegradation of microcystin-LR using acclimatized bacteria isolated from different units of the drinking water treatment plant
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DOI：
10.1016/j.envpol.2018.07.008
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发表时间：
2018-11-01
影响因子：
8.9
通讯作者：
Galvez-Cloutier, Rosa
中科院分区：
文献类型：
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作者：
Kumar, Pratik;Hegde, Krishnamoorthy;Galvez-Cloutier, Rosa
在富含微胱氨酸-亮氨酸(MC-LR)的环境中，从饮用水处理厂(DWTP)的不同单元(包括预臭氧单元(POU)、沉淀单元的出水-污泥混合物(ESSU)和过滤单元的表层砂层水样(TSFU))中分离出的细菌群落分别驯化，以评价MC-LR的生物降解性。驯化的TSFU菌群的降解率最高，为97.2+/-8.7%，其次是驯化的POU和驯化的ESSU，降解率分别为72.1+/-6.4%和86.2+/-7.3%。与驯化细菌群落相比，未驯化细菌群落对TSFU、ESSU和POU的降解率分别为71.1+/-7.37%、86.7+/-3.19%和94.35+/-10.63%。然而，驯化条件下的生物降解率是未驯化条件下的1.5倍。MC-LR降解的质谱学研究描述了环状MC-LR的水解线性化以及与降低毒性有关的包括AddA分子在内的小肽片段的形成(定性毒性分析)。以紫花苜蓿根瘤菌为生物指示剂，进一步定量证实了这一点。驯化的TSFU细菌群落由新的MC-LR降解菌、金杆菌属组成。经16S rRNA测序证实为脆性假单胞菌。(C)2018爱思唯尔有限公司。保留所有权利。
Bacterial community isolated from different units of a Drinking Water Treatment Plant (DWTP) including pre-ozonation unit (POU), the effluent-sludge mixture of the sedimentation unit (ESSU) and top-sand layer water sample from the filtration unit (TSFU) were acclimatized separately in the microcystinleucine arginine (MC-LR)-rich environment to evaluate MC-LR biodegradation. Maximum biodegradation efficiency of 97.2 +/- 8.7% was achieved by the acclimatized-TSFU bacterial community followed by 72.1 +/- 6.4% and 86.2 +/- 7.3% by acclimatized-POU and acclimatized-ESSU bacterial community, respectively. Likewise, the non-acclimatized bacterial community showed similar biodegradation efficiency of 71.1 +/- 7.37%, 86.7 +/- 3.19% and 94.35 +/- 10.63% for TSFU, ESSU and POU, respectively, when compared to the acclimatized ones. However, the biodegradation rate increased 1.5-folds for acclimatized versus non acclimatized conditions. The mass spectrometry studies on MC-LR degradation depicted hydrolytic linearization of cyclic MC-LR along with the formation of small peptide fragments including Adda molecule that is linked to the reduced toxicity (qualitative toxicity analysis). This was further confirmed quantitatively by using Rhizobium meliloti as a bioindicator. The acclimatized-TSFU bacterial community comprised of novel MC-LR degrading strains, Chryseobacterium sp. and Pseudomonas fragi as confirmed by 16S rRNA sequencing. (C) 2018 Elsevier Ltd. All rights reserved.