Inoculation of Ensifer fredii strain LP2/20 immobilized in agar results in growth promotion and alteration of bacterial community structure of Chinese kale planted soil

Abstract

In our former research, we succeeded in using agar, alginate, and perlite as immobilization materials to maintain long-term survival of the inoculant, Ensifer fredii LP2/20, in a controlled glasshouse. Therefore the information on the establishment and activity of the inoculant to promote plant growth under field conditions, the effects of the inoculant on the soil microbial communities and specific microbial taxa, and the association between the inoculant and soil elements merit further studies. Here, we found that agar was the most suitable material that supported the establishment of the inoculant under field conditions. RNA-based analysis showed that E. fredii LP2/20 immobilized in agar was still metabolically active at day 50 after being introduced into soil. Inoculation of E. fredii LP2/20 immobilized in agar conferred the highest plant dry weight (up to 89.94%) and all plant elements including total N (9.55%), P (17.94%), K (68.42%), Ca (39.77%), Mg (30.76%), Fe (29.85%), and Zn (22.44%). Inoculation of E. fredii LP2/20 immobilized in agar increased soil chemicals including soil organic matter (99.02%), total N (272.48%), P (31.75%), K (52.74%), Fe (51.06%), and Zn (63.10%). High-throughput next-generation sequencing of bacterial 16S rRNA amplicons showed that the Proteobacteria, Acidobacteria, Bacteroidetes, and Firmicutes were dominant phyla in Chinese kale field soil. Inoculation of E. fredii LP2/20 significantly affected the soil bacterial community structure by decreasing total bacterial richness and diversity. The numbers of alpha- and gamma-Proteobacteria were significantly increased while the number of delta-Proteobacteria was significantly decreased due to E. fredii LP2/20 establishment. Soil total P, K, and Ca and soil pH were the important factors that shaped the soil bacterial community composition.

Insights into Bacterial Communities and Diversity of Mangrove Forest Soils along the Upper Gulf of Thailand in Response to Environmental Factors

“…The members of Proteobacteria are metabolically diverse and can sustain a wide range of ecosystems because they harbor intricate groups of genes responsible for stress resistance, then enhancing their adaptive capabilities and survival that are attributes of dominant groups [ 20 , 63 ]. Proteobacteria , Bacteroidetes , and Chloroflexi , which are usually the dominant taxa in mangrove and terrestrial environments, are consistently important contributors to biogeochemical processes, such as nitrogen fixation, ammonification, nitrification, denitrification, carbon fixation, carbon degradation, phosphate solubilization, sulfite reduction as well as nitrogen, phosphorus, and iron acquisition [ 64 , 65 , 66 , 67 ]. The high amount of Firmicutes contributed to the activity of sulfur-oxidizing bacteria which detoxified sulfide to reduce pollution in the mangrove ecosystem [ 68 ].…”

Comparative Analysis of the Cultured and Total Bacterial Community in the Wheat Rhizosphere Microbiome Using Culture-Dependent and Culture-Independent Approaches

“…were also identified as promising PGPRs. Consistent with our findings, there are numerous reports describing the PGP activities of Ensifer sp., many of which are N 2 fixers ( 48 , 49 ); however, there is currently little evidence for Dyadobacter spp. acting as PGPR ( 50 ).…”

Maize edible-legumes intercropping systems for enhancing agrobiodiversity and belowground ecosystem services

“…A Principal Coordinate Analysis (PCoA) was conducted to identify fungal and bacterial contributors to beta diversity variation. The shared microbial communities among sample types, cropping systems, and sampling locations were visualized using Venn diagrams generated with the Venn Counts function in the limma package (linear models for microarray data) 2 , 40 . Permutational Multivariate Analysis of Variance (PERMANOVA), with each smallholder farm being treated as strata, was employed to compare fungal and bacterial populations across cropping systems, sample types, and studied locations.…”