以吡啶为目标污染物,考察从焦化废水处理系统中分离的12株高效吡啶降解菌对吡啶的降解性能和生物膜形成特性,以期为在废水处理系统中构建降解型生物膜提供理论参考。结果表明:12株菌都具有较高的吡啶降解活性,其中代表性菌株Pseudomonas sp.ZX01和Arthrobacter sp.ZX07降解吡啶的最适温度是35°C,最适pH是7.0,在初始吡啶浓度为100～2000 mg/L的范围内,降解率均达到100%。不同菌株的生物膜形成能力差异明显,胞外蛋白分泌量、胞外多糖分泌量和由鞭毛参与的游动能力与各株菌的生物膜形成能力之间存在显著的正相关关系。 

【背景】 煤化工企业排放的废水中含有大量难降解、高毒性的有机污染物，采用以高效降解菌为基础的生物强化技术对其进行处理，是一种经济可行的策略；而促进高效降解菌在载体材料表面的生物膜形成，有助于提升生物膜法废水处理系统的效能。【目的】 探究一株吡啶高效降解菌 Pseudomonas sp.ZX08 的生物膜形成过程和特性，识别不同的环境因子如温度、 pH、 Na+、 K+、Ca2+、 Mg2+等对其生物膜形成的影响规律，为实现人工调控其在实际废水处理系统中的成膜过程提供理论依据。【方法】 采用改良的微孔板生物膜培养与定量方法，以单因子影响实验测定不同条件下菌株在 12 孔板内的生物膜形成量和浮游态细菌量；采用激光共聚焦显微镜(confocal laser scanning microscope，CLSM)观察和分析生物膜的结构特征。【结果】 Pseudomonas sp. ZX08 菌株具有良好的吡啶降解性能，且生物膜形成能力较强， CLSM 观察到其在载体表面形成的生物膜可达到 40-50 mm；生物膜外层的活细胞比例更高，分泌的胞外蛋白也更多。 ZX08 菌株的生物膜形成量具有明显的周期性变化特征， 12 h、48 h 的生物膜量是相对峰值。 ZX08 生物膜形成的最适温度是 25 °C，最适 pH范围是 7.0-9.0；较高浓度的 NaCl (>0.6 mol/L)和 KCl (>0.4 mol/L)均对 ZX08的生物膜形成有显著的抑制作用；一定范围内(0-16 mmol/L) Ca2+浓度的提高可以促进 ZX08 在 12 孔板底部固-液界面生物膜的形成，浓度更高时则显著抑制生物膜的形成；一定范围内(0-16 mmol/L) Mg2+浓度的提高对 ZX08 生物膜形成有促进作用，但促进幅度不大。【结论】 吡啶降解菌 Pseudomonas sp. ZX08 的生物膜形成能力较强，未来在实际废水处理系统中应用时需要综合考虑各种环境因子对其生物膜形成的影响。

Microbial community structure is affected by both natural processes and human activities. In coastal area, anthropegenetic activity can usually lead to the discharge of the effluent from wastewater treatment plant (WWTP) to sea, and thus the water quality chronically turns worse and marine ecosystem becomes unhealthy. Microorganisms play key roles in pollutants degradation and ecological restoration; however, there are few studies about how the WWTP effluent disposal influences coastal microbial communities. In this study, sediment samples were collected from two WWTP effluent-receiving areas (abbreviated as JX and SY) in Hangzhou Bay. First, based on the high-throughput sequencing of 16S rRNA gene, microbial community structure was analyzed. Secondly, several statistical analyses were conducted to reveal the microbial community characteristics in response to the effluent disposal. Using PCoA, the significant difference of in microbial community structure was determined between JX and SY; using RDA, water COD and temperature, and sediment available phosphate and ammonia nitrogen were identified as the key environmental factors for the community difference; using LDA effect size analysis, the most distinctive microbes were found and their correlations with environmental factors were investigated; and according to detrended beta-nearest-taxon-index, the sediment microbial communities were found to follow “niche theory”. An interesting and important finding was that in SY that received more and toxic COD, many distinctive microbes were related to the groups that were capable of degrading toxic organic pollutants. This study provides a clear illustration of eco-environmental deterioration under the long-term human pressure from the view of microbial ecology.

Current technologies could identify the abundance and functions of specific microbes, and evaluate their individual effects on microbial ecology. However, these microbes interact with each other, as well as environmental factors, in the form of complex network. Determination of their combined ecological influences remains a challenge. In this study, we developed a tripartite microbial-environment network (TMEN) analysis method that integrates microbial abundance, metabolic function, and environmental data as a tripartite network to investigate the combined ecological effects of microbes. Applying TMEN to analyzing the microbial-environment community structure in the sediments of Hangzhou Bay, one of the most seriously polluted coastal areas in China, we found that microbes were well-organized into 4 bacterial communities and 9 archaeal communities. The total organic carbon, sulfate, chemical oxygen demand, salinity, and nitrogen-related indexes were detected as crucial environmental factors in the microbial-environmental network. With close interactions with these environmental factors, Nitrospirales and Methanimicrococcu were identified as hub microbes with connection advantage. Our TMEN method could close the gap between lack of efficient statistical and computational approaches and the booming of large-scale microbial genomic and environmental data. Based on TMEN, we discovered a potential microbial ecological mechanism that crucial species with significant influence on the microbial community ecology would possess one or two of the community advantages for enhancing their ecological status and essentiality, including abundance advantage and connection advantage.

The coastal area of the East China Sea has experienced rapid urbanization and industrialization in China since 1980s, resulting in severe pollution of its environments. Antibiotic resistance genes (ARGs) are regarded as a kind of emerging pollutant with potential high risk. The sediment samples were collected from Hangzhou Bay (HB), Xiangshan Bay (XB), and Taizhou Bay (TB) to investigate the spatial occurrence and distribution of 27 ARGs and class I integron–integrase gene (intI1) in the coastal area of the East China Sea. The PCR results showed the frequent presence of 11 ARGs and intI1 in the sediments of the three bays. The qPCR results further showed that sulfonamide resistance was the most prevalent ARG type and antibiotic target replacement and protection were the most important resistance mechanisms in the sediments. Regarding the subtype of ARGs, sulI, tetW, and dfrA13 were the most abundant ARGs, in which sulI was higher in TB (based on both the absolute and relative abundances) and dfrA13 was higher in HB (based on the relative abundances). The network analysis revealed that intI1 had significant correlations with tetC, sulI, sulII, and blaPSE-1. Oil was the key connected factor, which had positive connections with sulI, sulII, and blaPSE-1. In addition, the joint effect of heavy metals and nutrients & organic pollutants might be crucial for the fate of ARGs in the coastal sediments.