Halomonas sp. BS4, A biosurfactant producing halophilic bacterium isolated from solar salt works in India and their biomedical importance

Abstract

Halophilic bacteria were isolated from Thamaraikulam solar salt works in India. After routine biosurfactant screening by various methods, the biosurfactant producing bacteria, Halomonas sp BS4 was confirmed by 16 S rRNA sequencing. The growth optimization of Halomonas sp BS4 revealed their optimum growth at 8% NaCl and 6-8 pH in the growth medium. Further the partially purified biosurfactants were characterized by TLC, FTIR and GC-MS analysis. GC-MS results revealed that, the partial purified biosurfactants contain 1, 2-Ethanediamine N, N, N', N'-tetra, 8-Methyl-6-nonenamide, (Z)-9-octadecenamide and a fatty acid derivative. Pharmacological screening of antibacterial, antifungal, antiviral and anticancer assays revealed that, the biosurfactant extracted from Halomonas sp BS4 effectively controlled the human pathogenic bacteria and fungi an aquaculturally important virus, WSSV. The biosurfactant also suppressed the proliferation of mammary epithelial carcinoma cell by 46.77% at 2.5 μg concentration. Based on these findings, the present study concluded that, there is a possibility to develop eco-friendly antimicrobial and anticancer drugs from the extremophilic origin.

Keywords: Antimicrobial activity; Biosurfactants; Halomonas; White spot syndrome virus (WSSV).

Figure 1

Graphical phylogenetic tree analysis of Halomonas sp. BS4 based on 16S rRNA gene sequence data compare with other sp.

Figure 2

Growth optimization of Halomonas sp BS4 isolated from solar salt works grown in NaCl concentrations (a) and pH (b). The values are significantly differed each other’s (F = 78.88; P < = 0.001- Figure 2a) and (F = 48.36; P < = 0.001- Figure 2b) – Two Way ANOVA.

Figure 3

Functional group analysis of Halomonas sp BS4 yield biosurfactants by Fourier Transmission Infra Red (FTIR) spectroscopic analysis.

Figure 4

PCR detection of haemolymph samples ofPenaeus monodonafter injection with various percentages of biosurfactant incubated with WSSV. Statistical differences (P < 0.01) between treated and control groups are indicated by a-f superscripts; error bars are standard errors- One way ANOVA.

Figure 5

Anti tumor activity performed in tumor mammary epithelial carcinoma cell lines with various percentages of Halomonas BS4 yield biosurfactants. Statistical differences (P < 0.001) between treated and control groups are indicated by a-f superscripts and asterisks indicates non significant; error bars are standard errors- One way ANOVA.