Zhang Lujie, Zhao Xue, Wang Jieying, He Liyuan, Ren Chengjie, Wang Jun, Guo Yaoxin, Wang Ninglian, Zhao Fazhu
Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Northwest University, Xi'an 710127, China.
College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China.
Microorganisms. 2024 Aug 16;12(8):1689. doi: 10.3390/microorganisms12081689.
The life strategies of bacterial communities determine their structure and function and are an important driver of biogeochemical cycling. However, the variations in these strategies under different soil resource conditions remain largely unknown. We explored the bacterial life strategies and changes in structure and functions between Antarctic soils and forest (temperate, subtropical, and tropical) soils. The results showed that the weighted mean rRNA operon copy number in temperate soils was 19.5% lower than that in Antarctic soils, whereas no significant differences were observed among Antarctic, subtropical, and tropical soils. An unexpected result was that bacterial communities in Antarctic soils tended to be copiotrophs, such as Actinobacteriota and Bacteroidota, whereas those in temperate soils tended to be oligotrophs, such as Acidobacteriota and Chloroflexi. Functional predictions showed that in comparison to copiotrophs in Antarctic soils, temperate-inhabiting oligotrophic bacteria exhibited an 84.2-91.1% lower abundance of labile C decomposition genes (hemicellulose, cellulose, monosaccharides, and disaccharides), whereas a 74.4% higher abundance of stable C decomposition (lignin). Genes involved in N cycling (nitrogen fixation, assimilatory nitrate reduction, and denitrification) were 24.3-64.4% lower in temperate soils than in Antarctic soils. Collectively, our study provides a framework for describing the life strategies of soil bacteria, which are crucial to global biogeochemical cycles.
细菌群落的生活策略决定了它们的结构和功能，是生物地球化学循环的重要驱动力。然而，在不同土壤资源条件下这些策略的变化仍 largely 未知。我们探究了南极土壤与森林（温带、亚热带和热带）土壤之间细菌的生活策略以及结构和功能的变化。结果表明，温带土壤中加权平均 rRNA 操纵子拷贝数比南极土壤低 19.5%，而南极、亚热带和热带土壤之间未观察到显著差异。一个意外的结果是，南极土壤中的细菌群落倾向于成为富养菌，如放线菌门和拟杆菌门，而温带土壤中的细菌群落则倾向于成为贫养菌，如酸杆菌门和绿弯菌门。功能预测表明，与南极土壤中的富养菌相比，栖息在温带的贫养菌中不稳定碳分解基因（半纤维素、纤维素、单糖和二糖）的丰度低 84.2 - 91.1%，而稳定碳分解（木质素）的丰度高 74.4%。参与氮循环（固氮、同化硝酸盐还原和反硝化）的基因在温带土壤中比在南极土壤中低 24.3 - 64.4%。总体而言，我们的研究提供了一个描述土壤细菌生活策略的框架，这对全球生物地球化学循环至关重要。
