Biocontrol efficacy and plant growth promoting activity of Bacillus altitudinis isolated from Darjeeling hills, India

Abstract

A total of 18 bacterial isolates were obtained from the rhizosphere of Sechium edule growing in the lower foothills of Darjeeling, India. The bacterial isolates were tested for PGPR traits in vitro such as phosphate solubilization, HCN, siderophore, IAA, chitinase, protease production as well as inhibition of pthytopathogens. Of all the bacterial isolates, one bacterium designated as BRHS/S-73 was found to possess all the tested characters which was identified on the basis of 16S rRNA gene sequence analysis as Bacillus altitudinis and was selected for in vivo studies. A significant improvement in growth measured in terms of increase in root length, shoot length, and increase in root and shoot biomass was observed when seeds of Vigna radiata, Cicer arietinum, and Glycine max were bacterized prior to sowing in field condition. Besides, the bacterium could also solubilize soil phosphate. Apart form growth promotion, root rot disease of Vigna radiata caused by Thanatephorus cucumeris was also significantly reduced by 74% when the bacterium was applied to the rhizosphere prior to pathogen challenge. The biocontrol efficacy of the bacterium was found to be 66.6% even after 30 days of pathogen inoculation. Activities of key defense related enzymes such as phenylalanine ammonia lyase, peroxidase, β-1,3-glucanase, and chitinase in both roots and leaves of treated plants were also enhanced. Results clearly suggest that B. altitudinis (BRHS/S-73) is a potential PGPR which can be used as efficient microorganism for enhancement of plant growth and suppression of fungal disease.

Isolation and characterization of Bacillus altitudinis JSCX-1 as a new potential biocontrol agent against Phytophthora sojae in soybean [Glycine max (L.) Merr.]

“…1). Recently, reports of B. altitudinis having the ability to promote growth and suppress root fungal pathogens, such as Macrophomina phaseolina and Thanatephorus cucumeris, were described (Gopalakrishnan et al 2011;Sunar et al 2015), indicating that B. altitudinis was a promising BCA for controlling fungal diseases. In our study, B. altitudinis JSCX-1 showed significant biocontrol activity in in vivo and in vitro assays (Figs.…”

Ameliorating effects of chicken feathers in plant growth promotion activity by a keratinolytic strain of Bacillus subtilis PF1

“…Various plant growthpromoting factors such as indole acetic acid (IAA), phosphate solubilization and nitrogen fixation, and bio-control attributes like production of HCN, siderophore, hydrolytic enzymes and antibiotics have been previously reported for Bacillus sp. (Senthilkumar et al 2009, Kumar et al 2012, Sunar et al 2013.…”

Describing Paenibacillus mucilaginosus strain N3 as an efficient plant growth promoting rhizobacteria (PGPR)

“…Since then there are limited reports describing strains of Paenibacillus as PGPR. Strains of Paenibacillus have not received comparable importance as efficient PGPR as strains of Acinetobacter, Agrobacterium, Arthobacter, Azotobacter, Sinorhizobium, Azospirillum, Burkholderia, Bradyrhizobium, Rhizobium, Frankia, Serratia, Thiobacillus, Pseudomonads, and Bacillus have received (Jacobson, Pasternak, & Glick, 1994;Sunar, Dey, Chakraborty, & Chakraborty, 2013;Vessey, 2003). However, over the period of last 10 years, few strains of Paenibacillus were rediscovered as nitrogen fixers which helped them to prove superiority over other extensively studied PGPR.…”