Diversity of Multi-Trait Plant Growth-Promoting Culturable Bacteria from Natural Geothermal Springs

Abstract

Natural geothermal springs are extreme ecological niches harboring a variety of microbial resources with potential roles in agriculture. The objective of the current study was to investigate the functional microbial diversity of Tattapani and Sohna hot springs. A total of 19 best bacterial strains were selected based on multifunctional plant growth-promoting (PGP) properties. The majority of selected bacterial strains possessed antagonistic activity and were able to solubilize zinc (2.58- 6.00 ZSI), potassium (2.11- 4.00 KSI), phosphate (3.00 PSI) and silicate (1.50- 4.00 SiSI) under in-vitro conditions. Out of selected strains 84% and 73% strains showed siderophore (20.08 to 70.15% siderophore units) and Indole-3-acetic acid production (20.50 − 37.15 μg ml−1), respectively. 16S rDNA sequencing of selected strains showed the predominance of Bacillaceae (44%), Pseudomonadaceae (22%), Moraxellaceae (11%), Enterobacteriaceae (11%), Paracoccaceae (6%) and Acidithiobacillaceae (6%). The outcome of the current investigation shows that multitrait plant growth-promoting bacteria could be isolated from the hot springs and may have a potential impact on crop production of problematic soils. Therefore, these potential strains can be further harnessed for preparation of bioformulations for the sustainable agriculture.