Isolation of gene conferring salt tolerance from halophilic bacteria of Lunsu, Himachal Pradesh, India

Abstract

Background Halophiles offer an attractive source of genes conferring salt tolerance. Halobacillus trueperi SS1 strain of Lunsu, Himachal Pradesh, India, a strict halophile, was exploited to isolate and clone the genes for salt tolerance. The genomic library of BamH1 digest of H. trueperi SS1 was constructed in pUC19, and recombinants were screened for salt tolerance on an LB medium containing ampicillin (100 μg/ml) and NaCl (0 to 1.5 M). Results One recombinant clone named as salt-tolerant clone (STC) conferred salt tolerance to host Escherichia coli/DH5α, which showed growth in the LB medium supplemented with ampicillin and 1.2 M NaCl. Restriction digestion and PCR analysis revealed the presence of an insert of approximately 2000 bp in the STC. DNA sequencing of the 2-kb insert on both strands yielded a sequence of 2301 nucleotides. Protein BLAST analysis of 2301-bp sequence of H. trueperi SS1 present in STC showed 97% identity to multidrug transport ATP binding/permease protein of Halobacillus karajensis. The insert contained in STC was subcloned into pGEX4T2 vector, and the recombinant clone STC/pGEX4T2 conferred salt tolerance to the bacterial host E. coli. Conclusions The present study led to the isolation of salt tolerance gene encoding a putative multidrug transport ATP binding/permease protein from H. trueperi SS1. The salt tolerance gene can be subcloned for transferring salt tolerance traits into agricultural crop plants for cultivation in saline and coastal lands.

Bacterial diversity changes in response to an altitudinal gradient in arid and semi-arid regions and their effects on crops growth

“…Abiotic stresses resistance of the isolates was measured by screening the resistance to alkaline conditions (pH = 10) (Wiegert et al, 2001), salinity stress (final concentration of 100 mM NaCl) (Gupta et al, 2020), osmotic stress (25% polyethylene glycol Mn6000 PEG) (Vardharajula et al, 2011), and thermal stress (cold stress at 15 • C and heat stress at 60 • C) (Merkel and Perry, 1977;Graumann et al, 1996;Mukhtar et al, 2020). Muller Hinton media was used as the basic growth culture media for all the experiments, and the incubation period was 15 h, and plates were kept under dark conditions.…”

Isolation and characterization of salt-tolerant bacteria with plant growth-promoting activities from saline agricultural fields of Haryana, India

“…The salttolerant bacteria with PGPR activities may prove beneficial in the management of salt-affected agricultural fields for crop improvement. Alternatively, halophilic bacteria and their genes can be mined for salt-tolerant PGPR activities or salt tolerance traits can be transferred to crop plants [51][52][53].…”