State Key Lab of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen, 518055, China.
Cas Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Environ Res. 2022 Dec;215(Pt 2):114348. doi: 10.1016/j.envres.2022.114348. Epub 2022 Sep 19.
Nitrate pollution is an important cause of eutrophication and ecological disruption. Recently, element sulfur-based denitrification (ESDeN) has attracted increasing attention because of its non-carbon source dependence, low sludge yield, and cost-effectiveness. Although the denitrification performance of sulfur autotrophic denitrifying bacteria at different temperatures has been widely studied, there are still many unknown factors about the adaptability and the shaping of microbial community. In this study, we comprehensively understood the shaping of ESDeN microbial communities under different temperature conditions. Results revealed that microbial communities cultivated at temperatures ranging from 10 °C to 35 °C could be classified as high-temperature (35 °C), middle-temperature (30, 25 and 20 °C), and low-temperature (15 and 10 °C) communities. Dissolved oxygen in water was an important factor that, in combination with temperature, shaped microbial community structure. According to network analysis, the composition of keystone taxa was different for the three groups of communities. Some bacteria that did not have sulfur compound oxidation function were identified as the "keystone species". The abundances of carbon, nitrogen, and sulfur metabolism of the three microbial communities were significantly changed, which was reflected in that the high-temperature and middle-temperature communities were dominated by dark oxidation of sulfur compounds and dark sulfide oxidation, while the low-temperature community was dominated by chemoheterotrophy and aerobic chemoheterotrophy. The fact that the number of microorganisms with dark oxidation of sulfur compounds capacity was quite higher than that of microorganisms with dark sulfur oxidation capacity suggested that the sulfur bioavailability at different temperatures, especially low temperature, was the main challenge for the development of efficient ESDeN process. This study provided a biological basis for developing a high-efficiency ESDeN process to cope with temperature changes in different seasons or regions.
硝酸盐污染是水体富营养化和生态破坏的一个重要原因。近年来，由于其不依赖碳源、产泥量低、成本效益高，基于元素硫的反硝化（ESDeN）技术受到越来越多的关注。虽然硫自养反硝化细菌在不同温度下的反硝化性能已经得到了广泛的研究，但对于微生物群落的适应性和形成机制仍有许多未知因素。在本研究中，我们全面了解了不同温度条件下 ESDeN 微生物群落的形成。结果表明，在 10-35°C 温度范围内培养的微生物群落可分为高温（35°C）、中温（30、25 和 20°C）和低温（15 和 10°C）群落。水中溶解氧是与温度一起塑造微生物群落结构的重要因素。根据网络分析，三组群落的关键类群组成不同。一些没有硫化合物氧化功能的细菌被鉴定为“关键种”。三组微生物群落的碳、氮和硫代谢组成发生了显著变化，这反映在高温和中温群落主要以硫化合物的暗氧化和暗硫化氧化为主，而低温群落主要以化能异养和需氧化能异养为主。具有硫化合物暗氧化能力的微生物数量明显高于具有暗硫氧化能力的微生物数量，这表明不同温度（尤其是低温）下的硫生物可利用性是开发高效 ESDeN 工艺的主要挑战。本研究为开发高效 ESDeN 工艺以应对不同季节或地区的温度变化提供了生物学基础。
