Zhang Xin, Li Hua-Jun, Jiang Lei, Wang Jing, He Ruo
Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China.
Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China.
Appl Microbiol Biotechnol. 2023 May;107(9):3099-3111. doi: 10.1007/s00253-023-12472-w. Epub 2023 Mar 18.
Methanotrophs are able to metabolize volatile organic sulfur compounds (VOSCs), excrete organic carbon during CH oxidation, and influence microbial community structure and function of the ecosystem. In return, microbial community structure and environmental factors can affect the growth metabolism of methanotrophs. In this study, Methylomonas koyamae and Hyphomicrobium methylovorum were used for model organisms, and methanethiol (MT) was chosen for a typical VOSC to investigate the synergy effects under VOSC stress. The results showed that when Hyphomicrobium methylovorum was co-cultured with Methylomonas koyamae in the medium with CH used as the carbon source, the co-culture had better MT tolerance relative to Methylomonas koyamae and oxidized all CH within 120 h, even at the initial MT concentration of 2000 mg m. The optimal co-culture ratios of Methylomonas koyamae to Hyphomicrobium methylovorum were 4:1-12:1. Although MT could be converted spontaneously to dimethyl disulfide (DMDS), HS, and CS in air, faster losses of MT, DMDS, HS, and CS were observed in each strain mono-culture and the co-culture. Compared with Hyphomicrobium methylovorum, MT was degraded more quickly in the Methylomonas koyamae culture. During the co-culture, the CH oxidation process of Methylomonas koyamae could provide carbon and energy sources for the growth of Hyphomicrobium methylovorum, while Hyphomicrobium methylovorum oxidized MT to help Methylomonas koyamae detoxify. These findings are helpful to understand the synergy effects of Methylomonas koyamae and Hyphomicrobium methylovorum under MT stress and enrich the role of methanotrophs in the sulfur biogeochemical cycle. KEY POINTS: • The co-culture of Methylomonas and Hyphomicrobium has better tolerance to CHSH. • Methylomonas can provide carbon sources for the growth of Hyphomicrobium. • The co-culture of Methylomonas and Hyphomicrobium enhances the removal of CH and CHSH.
甲烷营养菌能够代谢挥发性有机硫化合物（VOSCs），在甲烷氧化过程中分泌有机碳，并影响生态系统的微生物群落结构和功能。作为回报，微生物群落结构和环境因素会影响甲烷营养菌的生长代谢。在本研究中，选用小山甲基单胞菌（Methylomonas koyamae）和食甲基生丝微菌（Hyphomicrobium methylovorum）作为模式生物，并选择甲硫醇（MT）作为典型的VOSC来研究VOSC胁迫下的协同效应。结果表明，当食甲基生丝微菌与小山甲基单胞菌在以甲烷作为碳源的培养基中共同培养时，相对于小山甲基单胞菌，该共培养物对甲硫醇具有更好的耐受性，并且即使在初始甲硫醇浓度为2000 mg/m³的情况下，也能在120小时内将所有甲烷氧化。小山甲基单胞菌与食甲基生丝微菌的最佳共培养比例为4:1至12:1。尽管甲硫醇在空气中可自发转化为二甲基二硫醚（DMDS）、硫化氢（HS）和二硫化碳（CS），但在每种菌株的单培养和共培养中，均观察到甲硫醇、二甲基二硫醚、硫化氢和二硫化碳的更快损失。与食甲基生丝微菌相比，甲硫醇在小山甲基单胞菌培养物中降解更快。在共培养过程中，小山甲基单胞菌的甲烷氧化过程可为食甲基生丝微菌的生长提供碳源和能源，而食甲基生丝微菌氧化甲硫醇以帮助小山甲基单胞菌解毒。这些发现有助于理解小山甲基单胞菌和食甲基生丝微菌在甲硫醇胁迫下的协同效应，并丰富甲烷营养菌在硫生物地球化学循环中的作用。要点：• 甲基单胞菌和生丝微菌的共培养物对甲硫醇具有更好的耐受性。• 甲基单胞菌可为生丝微菌的生长提供碳源。• 甲基单胞菌和生丝微菌的共培养增强了甲烷和甲硫醇的去除。
