Zhuang Mei, Sanganyado Edmond, Xu Liang, Zhu Jianming, Li Ping, Liu Wenhua
Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Science, Shantou University, Shantou 515063, China.
School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China.
Microorganisms. 2020 Feb 9;8(2):233. doi: 10.3390/microorganisms8020233.
Estuaries and coastal environments are often regarded as a critical resource for the bioremediation of organic pollutants such as azo dyes due to their high abundance and diversity of extremophiles. Bioremediation through the activities of azoreductase, laccase, and other associated enzymes plays a critical role in the removal of azo dyes in built and natural environments. However, little is known about the biodegradation genes and azo dye degradation genes residing in sediments from coastal and estuarine environments. In this study, high-throughput sequencing (16S rRNA) of sediment DNA was used to explore the distribution of azo-dye degrading bacteria and their functional genes in estuaries and coastal environments. Unlike laccase genes, azoreductase (), and naphthalene degrading genes were ubiquitous in the coastal and estuarine environments. The relative abundances of most functional genes were higher in the summer compared to winter at locations proximal to the mouths of the Hanjiang River and its distributaries. These results suggested inland river discharges influenced the occurrence and abundance of azo dye degrading genes in the nearshore environments. Furthermore, the genes had a significant negative relationship with total organic carbon, Hg, and Cr ( < 0.05). This study provides critical insights into the biodegradation potential of indigenous microbial communities in nearshore environments and the influence of environmental factors on microbial structure, composition, and function which is essential for the development of technologies for bioremediation in azo dye contaminated sites.
河口和沿海环境因其丰富多样的极端微生物，常被视为生物修复偶氮染料等有机污染物的关键资源。通过偶氮还原酶、漆酶及其他相关酶的活性进行生物修复，在人工环境和自然环境中去除偶氮染料方面发挥着关键作用。然而，对于沿海和河口环境沉积物中存在的生物降解基因和偶氮染料降解基因，我们知之甚少。在本研究中，利用沉积物DNA的高通量测序（16S rRNA）来探究河口和沿海环境中偶氮染料降解细菌及其功能基因的分布。与漆酶基因不同，偶氮还原酶（）和萘降解基因在沿海和河口环境中普遍存在。在靠近汉江入海口及其支流的位置，夏季大多数功能基因的相对丰度高于冬季。这些结果表明内河排放影响了近岸环境中偶氮染料降解基因的出现和丰度。此外，这些基因与总有机碳、汞和铬呈显著负相关（<0.05）。本研究为近岸环境中本地微生物群落的生物降解潜力以及环境因素对微生物结构、组成和功能的影响提供了关键见解，这对于开发偶氮染料污染场地的生物修复技术至关重要。
