Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, Valladolid University, Dr. Mergelina, s/n, Valladolid, Spain.
Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, the Netherlands.
J Environ Manage. 2019 Feb 1;231:1091-1099. doi: 10.1016/j.jenvman.2018.11.017. Epub 2018 Nov 14.
Methane bioconversion into products with a high market value, such as ectoine or hydroxyectoine, can be optimized via isolation of more efficient novel methanotrophic bacteria. The research here presented focused on the enrichment of methanotrophic consortia able to co-produce different ectoines during CH metabolism. Four different enrichments (Cow3, Slu3, Cow6 and Slu6) were carried out in basal media supplemented with 3 and 6% NaCl, and using methane as the sole carbon and energy source. The highest ectoine accumulation (∼20 mg ectoine g biomass) was recorded in the two consortia enriched at 6% NaCl (Cow6 and Slu6). Moreover, hydroxyectoine was detected for the first time using methane as a feedstock in Cow6 and Slu6 (∼5 mg g biomass). The majority of the haloalkaliphilic bacteria identified by 16S rRNA community profiling in both consortia have not been previously described as methanotrophs. From these enrichments, two novel strains (representing novel species) capable of using methane as the sole carbon and energy source were isolated: Alishewanella sp. strain RM1 and Halomonas sp. strain PGE1. Halomonas sp. strain PGE1 showed higher ectoine yields (70-92 mg ectoine g biomass) than those previously described for other methanotrophs under continuous cultivation mode (∼37-70 mg ectoine g biomass). The results here obtained highlight the potential of isolating novel methanotrophs in order to boost the competitiveness of industrial CH-based ectoine production.
将甲烷生物转化为具有高市场价值的产品，如章鱼胺或羟乙基章鱼胺，可以通过分离更高效的新型甲烷氧化菌来优化。本研究集中于富集能够在 CH 代谢过程中共生产不同章鱼胺的甲烷氧化菌共生物。在补充有 3%和 6%NaCl 的基础培养基中，使用甲烷作为唯一的碳源和能源，进行了四种不同的富集（Cow3、Slu3、Cow6 和 Slu6）。在 6%NaCl 富集的两种共生物（Cow6 和 Slu6）中，章鱼胺积累量最高（约 20mg 章鱼胺 g 生物质）。此外，首次在 Cow6 和 Slu6 中使用甲烷作为原料检测到羟乙基章鱼胺（约 5mg g 生物质）。在两种共生物中，通过 16S rRNA 群落分析鉴定的大多数耐盐嗜碱细菌以前没有被描述为甲烷氧化菌。从这些富集物中，分离出了两种能够以甲烷为唯一碳源和能源的新型菌株（代表新物种）：Alishewanella sp. strain RM1 和 Halomonas sp. strain PGE1。Halomonas sp. strain PGE1 比其他甲烷氧化菌在连续培养模式下（约 37-70mg 章鱼胺 g 生物质）的产章鱼胺产量更高（70-92mg 章鱼胺 g 生物质）。本研究结果突出了分离新型甲烷氧化菌以提高基于 CH 的工业章鱼胺生产竞争力的潜力。
