Su Tongfu, Liu Haohao, Zhang Chaohui, Shang Di, Wang Chaojiang, Qiu Liyou
College of Sciences, Henan Agricultural University, Zhengzhou, China.
Key Laboratory of Enzyme Engineering of Agricultural Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Henan Agricultural University, Zhengzhou, China.
Front Microbiol. 2020 Nov 11;11:592034. doi: 10.3389/fmicb.2020.592034. eCollection 2020.
In this study, Taisui TS-2007S, a previously unidentified biological object discovered in soil in China, was identified. TS-2007S was shown to contain abundant carbohydrates but a scarcity of protein, fat, and minerals. The exopolymers of TS-2007S showed FT-IR spectra that were similar to those of xanthan gum (XG) but that were dissimilar to those of polyvinyl alcohol (PVA). The NMR spectra of TS-2007S exopolymers in DO were similar to those of PVA but differed from those of xanthan gum. Unlike PVA, TS-2007S exopolymers and xanthan gum were not soluble in dimethyl sulfoxide (DMSO). Furthermore, the exopolymers contained many monosaccharide components, including fucose, rhamnose, mannose, and glucuronic acid in a molar ratio of 87.90:7.49:4.45:0.15. The exopolymers also included traces of glucuronic acid, galactose, and xylose. Taken together, these results suggest that the exopolymers are microbial extracellular polymeric substances (EPSs). The microbial community structure in TS-2007S showed that the predominant bacterial, archaeal, and fungal phyla were Proteobacteria, Euryarchaeota, and Ascomycota at high relative abundances of 90.77, 97.15, and 87.43%, respectively, different from those observed in water and soil environments. Based on these results, we strongly propose that TS-2007S should be defined as a microbial mat formed in soil.
在本研究中，对在中国土壤中发现的一种此前未鉴定的生物对象——太岁TS - 2007S进行了鉴定。结果表明，TS - 2007S含有丰富的碳水化合物，但蛋白质、脂肪和矿物质含量稀少。TS - 2007S的胞外聚合物的傅里叶变换红外光谱（FT - IR）与黄原胶（XG）相似，但与聚乙烯醇（PVA）不同。TS - 2007S胞外聚合物在氘代氧（DO）中的核磁共振光谱与PVA相似，但与黄原胶不同。与PVA不同，TS - 2007S胞外聚合物和黄原胶不溶于二甲基亚砜（DMSO）。此外，胞外聚合物含有许多单糖成分，包括岩藻糖、鼠李糖、甘露糖和葡萄糖醛酸，摩尔比为87.90:7.49:4.45:0.15。胞外聚合物还含有痕量的葡萄糖醛酸、半乳糖和木糖。综合这些结果表明，胞外聚合物是微生物胞外聚合物（EPSs）。TS - 2007S中的微生物群落结构表明，主要的细菌、古菌和真菌门类分别是变形菌门、广古菌门和子囊菌门，相对丰度较高，分别为90.77%、97.15%和87.43%，与在水和土壤环境中观察到的不同。基于这些结果，我们强烈建议将TS - 2007S定义为在土壤中形成的微生物垫。
