Pérez-Hernández Valentín, Hernández-Guzmán Mario, Luna-Guido Marco, Navarro-Noya Yendi E, Romero-Tepal Elda M, Dendooven Luc
Laboratory of Soil Ecology, Department of Chemistry and Biochemistry, Instituto Tecnológico de Tuxtla-Gutiérrez, Tecnológico Nacional de México, Tuxtla Gutiérrez, Chiapas 29050, Mexico.
Laboratory of Soil Ecology, Cinvestav, Mexico City 07360, Mexico.
Microorganisms. 2021 Jun 15;9(6):1297. doi: 10.3390/microorganisms9061297.
We studied three soils of the former lake Texcoco with different electrolytic conductivity (1.9 dS m, 17.3 dS m, and 33.4 dS m) and pH (9.3, 10.4, and 10.3) amended with young maize plants and their neutral detergent fibre (NDF) fraction and aerobically incubated in the laboratory for 14 days while the soil bacterial community structure was monitored by means of 454-pyrosequencing of their 16S rRNA marker gene. We identified specific bacterial groups that showed adaptability to soil salinity, i.e., in soil amended with young maize plants and in soil amended with NDF. An increase in soil salinity (17.3 dS m, 33.4 dS m) showed more bacterial genera enriched than soil with low salinity (1.9 dS m). Functional prediction showed that members of Alfa-, Gamma-, and Deltaproteobacteria, which are known to adapt to extreme conditions, such as salinity and low nutrient soil content, were involved in the lignocellulose degradation, e.g., and as cellulose degraders, and and as lignin degraders. This research showed that the taxonomic annotation and their functional prediction both highlighted keystone bacterial groups with the ability to degrade complex C-compounds, such as lignin and (hemi)cellulose, in the extreme saline-alkaline soil of the former Lake of Texcoco.
我们研究了特斯科科湖旧址的三种土壤,其具有不同的电导率(1.9 dS/m、17.3 dS/m和33.4 dS/m)和pH值(9.3、10.4和10.3),分别用嫩玉米植株及其中性洗涤纤维(NDF)组分进行改良,并在实验室中进行好氧培养14天,同时通过对其16S rRNA标记基因进行454焦磷酸测序来监测土壤细菌群落结构。我们鉴定出了对土壤盐分具有适应性的特定细菌类群,即在添加嫩玉米植株的土壤和添加NDF的土壤中。土壤盐分增加(17.3 dS/m、33.4 dS/m)时,富集的细菌属比低盐度土壤(1.9 dS/m)更多。功能预测表明,已知能适应极端条件(如盐分和低养分土壤含量)的α-、γ-和δ-变形菌门成员参与了木质纤维素的降解,例如,[具体菌名1]和[具体菌名2]作为纤维素降解菌,[具体菌名3]和[具体菌名4]作为木质素降解菌。这项研究表明,分类注释及其功能预测都突出了在前特斯科科湖极端盐碱土壤中具有降解木质素和(半)纤维素等复杂碳化合物能力的关键细菌类群。