Aerobic biodegradation biodegradation of microcystin-LR by an indigenous bacterial mixed culture isolated in Taiwan
Aerobic biodegradation biodegradation of microcystin-LR by an indigenous bacterial mixed culture isolated in Taiwan
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DOI：
10.1016/j.ibiod.2017.04.011
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发表时间：
2017-10-01
影响因子：
4.8
通讯作者：
Lee, Jiunn-Fwu
中科院分区：
文献类型：
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作者：
Tsao, Sha;Wei, Da-Jiun;Lee, Jiunn-Fwu
微囊藻毒素(MC)广泛存在于湖泊、池塘、水库等富营养化水体中。MCS是肝脏毒素，当饮用MC污染的水时，会产生高风险的肝癌和癌症。由于MC污染的水体可以构成许多饮用水系统的正常组成部分，因此对MC-LR类化合物进行积极的处理已经成为一个世界性的重要问题。这项研究的目的是开发一种方法，通过生物降解去除高浓度的MC-LRs(ppm水平)，使用在台湾分离的本地细菌混合培养物。利用该培养基生物降解系统，MC-LR的降解率可达99%，16天后MC-LR的最终浓度为0.324微克L-1。在前4天，MC-LR生物降解的拟一级速率常数为876微克L-1天(-1)。根据丰富度指数和Shannon-Wiener多样性指数，生物降解过程中的细菌多样性在第一阶段(0-4天)有所下降，在第二阶段(5-16天)又有所增加。在混合培养物中鉴定出的细菌种类包括鞘氨醇单胞菌、假黄单胞菌、亚微生物菌、鞘氨醇杆菌、根瘤菌、类杆菌。和不动杆菌属，所有这些似乎都是。在MC-LR的生物降解中起着重要的作用。基因mlrB和mlrC编码参与MC-LR生物降解的不同方面的蛋白质，被发现存在于混合培养物中，并能够作为台湾水库MC-LR生物降解过程的生物标志物。(C)2017爱思唯尔有限公司。保留所有权利。
Microcystins (MCs) are commonly found in eutrophicated waterbodies such as lakes, ponds and reservoirs. MCs are hepatotoxins and create a high risk of liver tumors and cancer when MC-polluted water is drunk. Since MC-polluted waterbodies can form a normal part of many drinkiing water system, aggressive treatment to remove MC-LR type compounds has become an important issue worldwide. The objective of this study was to develop a method for the removal of high concentrations of MC-LRs (ppm level) by biodegradation using an indigious bacterial mixed culture isolated in Tawian. Using this culture based biodegradation system, MC-LR removal of >99% is able to be achieved with the final concentration of MC-LR being measured to be 0.324 mu g L-1 after 16 days. The pseudo-first rate constant of the MC-LR biodegradation was 876 mu g L-1 day(-1) during the first 4 days. The bacterial biodiversity during biodegradation was found to decrease during the first stage (Day 0-4) and then increased again during the second stage (Day 5-16), based on the Richness Index and Shannon-Wiener Diversity Index. The bacterial species identified in the mixed culture included Sphingomonas spp., Pseudoxanthomonas spp., Hyphomicrobium aestuarii, Sphingobium spp., Rhizobium spp., Steroidobacter spp. and Acinetobacter spp, all of which seem to. play important roles in MC-LR biodegradation. The genes mlrB and mlrC, which encodes proteins involved in various aspects of MC-LR biodegradation, were found to be present in the mixed cultures and are capable of being used as a biomarker for the MC-LR biodegradation process in Taiwanese reservoirs. (C) 2017 Elsevier Ltd. All rights reserved.