Biomolecular Characterization of Bacillus tequilensis A1C1 Isolated from Soil and Chromatographic Analysis of D-serine in its Cellular Fraction

Abstract

The bacteria isolated from the pomace dumping soil site (bacteria id A1C1) showed maximum growth (O.D600 = 1.97±0.4 X 109 cells/ml) within 48h in the minimal salt media supplemented with L-serine. The isolated strain was identified as ‘Bacillus tequilensis’ through 16sRNA sequencing. The strain was quantified for D-serine content by using RP-HPLC. The D-serine concentration was calculated as 0.919±0.02 nM in the bacterial cellular fraction by using a standard curve plot and linear curve equation. Further, recovery % was also calculated for the spiked samples which vary from 85-90%. The study’s peculiarity reflects the fact that the isolated strain was explored for the first time to detect the presence of serine enantiomers. The biochemical features also showed 70% similarity to the standard strain Bacillus tequilensis 10bT. The optimum growth parameters were recorded as 37℃±0.5, 150±0.5 RPM, and 7±0.5pH. The strain was Gram-positive and synthesized endospores. Morphological results showed its rod shape, large, irregular, and off-white-coloured colonies. A1C1 was also tested for the production of secondary metabolites and enzymes. A1C1 showed positive results for indole production, lactose fermentation, protease, and gelatinase whereas, negative results for catalase, MR-VP, citrate utilization, cellulase, amylase, and pectinase. Further, the strain was assayed for PGPR attributes and showed a negative phosphate solubilization index and IAA production. The antibacterial assay showed 5% and 2% efficacy of the extracellular fraction against MTCC 40 and MTCC 11949 respectively. These results demonstrate that Bacillus tequilensis A1C1 has antibacterial activity, the potential to secrete extracellular enzymes, and D-serine content in the intracellular fraction of the cultivated cells.