Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
Division of Agronomy, ICAR- Indian Agricultural Research Institute, New Delhi, 110012, India.
World J Microbiol Biotechnol. 2020 Mar 4;36(3):44. doi: 10.1007/s11274-020-02818-1.
The present study is an attempt to understand the impact of bioinoculants, Azotobacter chroococcum (A), Bacillus megaterium (B), Pseudomonas fluorescens (P), on (a) soil and plant nutrient status, (b) total resident and active bacterial communities, and (c) genes and transcripts involved in nitrogen cycle, during cultivation of Cajanus cajan. In terms of available macro- and micro-nutrients, triple inoculation of the bioinoculants (ABP) competed well with chemical fertilizer (CF). Their 'non-target' effects were assessed in terms of the abundance and activity of the resident bacterial community by employing denaturing gradient gel electrophoresis (DGGE). The resident bacterial community (16S rRNA gene) was stable, while the active fraction (16S rRNA transcripts) was influenced (in terms of abundance) by the treatments. Quantification of the genes and transcripts involved in N cycle by qPCR revealed an increase in the transcripts of nifH in the soil treated with ABP over CF, with an enhancement of 3.36- and 1.57- fold at flowering and maturity stages of plant growth, respectively. The bioinoculants shaped the resident microflora towards a more beneficial community, which helped in increasing soil N turnover and hence, soil fertility as a whole.
本研究旨在探讨生物菌剂（固氮菌 A、巨大芽孢杆菌 B、荧光假单胞菌 P）对绿豆（Cajanus cajan）栽培过程中（a）土壤和植物养分状况、（b）总常驻和活性细菌群落、以及（c）与氮循环相关的基因和转录本的影响。在可用的大量和微量养分方面，三种生物菌剂（ABP）的接种效果可与化肥（CF）相媲美。通过变性梯度凝胶电泳（DGGE）评估其“非目标”效应，评估常驻细菌群落的丰度和活性。常驻细菌群落（16S rRNA 基因）稳定，而活性部分（16S rRNA 转录物）受到处理的影响（在丰度方面）。通过 qPCR 定量参与 N 循环的基因和转录本表明，ABP 处理的土壤中 nifH 转录本增加，在植物生长的开花和成熟阶段分别增加了 3.36 倍和 1.57 倍。生物菌剂使常驻微生物群向更有益的群落发展，这有助于增加土壤氮周转，从而整体提高土壤肥力。
