Isolation of phytase-producing bacteria from Himalayan soils and their effect on growth and phosphorus uptake of Indian mustard (Brassica juncea)

Abstract

Phytase-producing bacteria (PPB) is being investigated as plant growth promoting rhizobacteria (PGPR) to improve the phosphorus (P) nutrition and growth of plants grown in soil with high phytate content. Phytate is dominant organic P forms in many soils and must be hydrolyzed to be available for plants. Indian mustard (Brassica juncea) is a plant with economic importance in agriculture and phytoremediation, therefore biotechnological tools to improve growth and environmental stress tolerance are needed. In this study, we isolated and characterized PPB from Himalayan soils and evaluated their effect on growth and P uptake by B. juncea under greenhouse conditions. Sixty five PPB were isolated and based on phytate hydrolysis, three efficient PPB were chosen and identified as Acromobacter sp. PB-01, Tetrathiobacter sp. PB-03 and Bacillus sp. PB-13. Selected PPB showed ability to grow at wide range of pH, temperature and salt concentrations as well as to harbour diverse PGPR activities, such as: solubilization of insoluble Ca-phosphate (193-642 μg ml(-1)), production of phytohormone indole acetic acid (5-39 μg ml(-1)) and siderophore. Tetrathiobacter sp. PB-03 and Bacillus sp. PB-13 showed 50 and 70 % inhibition of phytopathogen Rhizoctonia solani, respectively. Greenhouse potting assay also showed that the bacterization of B. juncea seeds with Tetrathiobacter sp. PB-03 and Bacillus sp. PB-13 significantly increased the biomass and P content in 30 days old seedlings. This study reveals the potential of PPB as PGPR to improve the growth of B. juncea.

Beneficial microbiomes: Biodiversity and potential biotechnological applications for sustainable agriculture and human health

“…This is produced by bacteria [95], fungi [96], and plants [97] with tremendous diversity in various agro-climatic and environmental conditions. Four classes of phytases, namely, (HAPhy), (BPPhy), (PAPhy), and (CPhy), have been reported in the literature based on catalytic and sequence features [98].…”

“…Several applications of phytases and phytaseproducing microbes have been reported leading to tremendous opportunities in using these microbes for beneficial purposes. Bacterial isolates and their consortiums for PGP have been well documented in several reports [95,100]. Although microbes promote the growth of plants by different means, the presence of enough organic phosphorus (as phytate) in soil increases the significance of phytate-hydrolyzing microbes in soil for efficient utilization of this source of phosphorus by plants as it is a major element determining proper health of plant.…”

“…has been resulted in improved growth of plants. Studies on potential PGP attributes in phytase-positive bacterial isolates have revealed multiple attributes of PGP including the production of plant growth hormones and siderophores, solubilization of phosphorus, and inhibition of plant pathogenic fungal growth [95,100]. These attributes with additional phytase production potential make these microbes more useful as they also reduce the use of phosphorus fertilizers, thereby decreasing environmental phosphorus pollution and contribute toward sustainable agriculture.…”

Production and characterization of a neutral phytase of Penicillium oxalicum EUFR-3 isolated from Himalayan region

“…For efficient industrial application, a phytase which has high production, good activity at 37 °C, high activity and stability at broad pH range and ability to tolerate the high temperature are desirable characteristics. Therefore, most of the research on phytase has been focused on isolation and characterization of novel phytase with desirable characteristics from different sources (Huang et al 2009;Kalsi et al 2016;Kumar et al 2013;Mullaney et al 2010). Penicillium oxalicum has been reported as a promising phytase producing fungi with reports on characterization, heterogeneous expression and engineering of phytase from this fungi are available (Lee et al 2007;Lee et al 2015;Zhao et al 2010).…”

An insight into protein sequences of PTP-like cysteine phytases

“…Phytases are widely distributed among plants and microbial cells (Hegeman and Grabau 2001;Kumar et al 2013;Singh et al 2014;Lei et al 2013). To develop a suitable phytase for above applications and better understand the catalytic mechanism of diverse groups of phytases, large number of such organisms has been studied in detail for their phytase gene sequences and biochemical properties.…”