Microbial diversity and soil physiochemical characteristic of higher altitude
Microbial diversity and soil physiochemical characteristic of higher altitude
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DOI：
10.1371/journal.pone.0213844
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发表时间：
2019-03-15
期刊：
影响因子：
3.7
通讯作者：
Goel, Reeta
中科院分区：
文献类型：
--
作者：
Kumar, Saurabh;Suyal, Deep Chandra;Goel, Reeta
海拔高度是影响土壤生态系统生物多样性和土壤理化性质的主要因素。为了了解海拔对喜马拉雅寒漠地区土壤理化性质和细菌多样性的影响，研究了高海拔甘戈特里土壤生态系统，并与中高海拔坎大哈土壤进行了比较。土壤理化分析表明，海拔高度与土壤pH、有机质和全氮含量呈正相关。土壤矿质养分和土壤磷与海拔高度呈负相关。基于RT-PCR的分析显示，高海拔地区细菌和重氮营养丰度下降。宏基因组研究表明，在高海拔土壤中，Proteobacteria、Acidobacteria和Actinobacteria是优势菌门，Bacteroidetes和Fermicutes在低海拔土壤中占优势菌门。革兰氏阴性菌与革兰氏阳性菌比例较高，表明革兰氏阴性菌在高海拔地区选择性增殖，革兰氏阳性菌数量减少。此外，高海拔地区α变形菌较多，β变形菌较多。高海拔地区的噬细胞菌、黄杆菌和拟杆菌（Bacteroides， CFB）丰度也较高。Gangotri土壤中存在许多未分类的序列，表明在高海拔地区存在新的细菌多样性。此外，通过本地设计的扩散室分离细菌，发现细菌的存在，这些细菌在西印度喜马拉雅（西印度喜马拉雅）的不可培养研究中有记录，但从未从WIH中培养过。然而，多种功能自由的重氮营养菌仅从高海拔甘戈特里土壤中分离出来。分子鉴定鉴定为腐殖质节杆菌、隐短芽孢杆菌、曼德利假单胞菌和helmantic假单胞菌。因此，本研究记录了高海拔地区的细菌和嗜冷重氮营养多样性，为探索低温细菌对农业生产力的影响，实现山地农业的可持续发展奠定了基础。
Altitude is the major factor affecting both biodiversity and soil physiochemical properties of soil ecosystems. In order to understand the effect of altitude on soil physiochemical properties and bacterial diversity across the Himalayan cold desert, high altitude Gangotri soil ecosystem was studied and compared with the moderate altitude Kandakhal soil. Soil physiochemical analysis showed that altitude was positively correlated with soil pH, organic matter and total nitrogen content. However soil mineral nutrients and soil phosphorus were negatively correlated to the altitude. RT-PCR based analysis revealed the decreased bacterial and diazotrophic abundance at high altitude. Metagenomic study showed that Proteobacteria, Acidobacteria and Actinobacteria were dominant bacteria phyla at high altitude soil while Bacteroidetes and Fermicutes were found dominant at low altitude. High ratio of Gram-negative to Gram positive bacteria at Gangotri suggests the selective proliferation of Gram negative bacteria at high altitude with decrease in Gram positive bacteria. Moreover, Alphaproteobacteria was found more abundant at high altitude while the opposite was true for Betaproteobacteria. Abundance of Cytophaga, Flavobacterium and Bacteroides (CFB) were also found comparatively high at high altitude. Presence of many taxonomically unclassified sequences in Gangotri soil indicates the presence of novel bacterial diversity at high altitude. Further, isolation of bacteria through indigenously designed diffusion chamber revealed the existence of bacteria which has been documented in unculturable study of WIH (Western Indian Himalaya) but never been cultivated from WIH. Nevertheless, diverse functional free-living psychrotrophic diazotrophs were isolated only from the high altitude Gangotri soil. Molecular characterization revealed them as Arthrobacter humicola, Brevibacillus invocatus, Pseudomonas mandelii and Pseudomonas helmanticensis. Thus, this study documented the bacterial and psychrophilic diazotrophic diversity at high altitude and is an effort for exploration of low temperature bacteria in agricultural productivity with the target for sustainable hill agriculture.