Occurrence of Biosurfactant Producing Bacillus spp. in Diverse Habitats.

Krushi Hingurao,Sanket J Joshi,Anuradha Nerurkar,Harish Suthar,Amit Kumar Yadav

doi:10.5402/2013/652340

Abstract

Diversity among biosurfactant producing Bacillus spp. from diverse habitats was studied among 77 isolates. Cluster analysis based on phenotypic characteristics using unweighted pair-group method with arithmetic averages (UPGMAs) method was performed. Bacillus isolates possessing high surface tension activity and five reference strains were subjected to amplified 16S rDNA restriction analysis (ARDRA). A correlation between the phenotypic and genotypic characterization of Bacillus spp. is explored. Most of the oil reservoir isolates showing high surface activity clustered with B. licheniformis and B. subtilis, the hot water spring isolates clustered in two ingroups, while the petroleum contaminated soil isolates were randomly distributed in all the three ingroups. Present work revealed that diversity exists in distribution of Bacillus spp. from thermal and hydrocarbon containing habitats where majority of organisms belonged to B. licheniformis and B. subtilis group. Isolate B. licheniformis TT42 produced biosurfactant which reduced the surface tension of water from 72 mNm−1 to 28 mNm−1, and 0.05 mNm−1 interfacial tension against crude oil at 80°C. This isolate clustered with B. subtilis and B. licheniformis group on the basis of ARDRA. These findings increase the possibility of exploiting the Bacillus spp. from different habitats and their possible use in oil recovery.

Highlights

Bacillus spp. are main workhorses for biotechnological applications. eir products are in the GRAS list of US Food and Drug Administration (USFDA) and are regarded harmless [1,2,3]. ey produce a variety of products namely. extracellular enzymes, biopolymers, biosurfactants, biopesticides, and so forth from renewable resources and are ecofriendly
Samples from various habitats were subjected to enrichment for facultative, sporulating, and Gram-positive rods. e isolates were checked for biosurfactant production ability on blood agar plate [11]
ampli ed 16S rDNA restriction analysis (ARDRA). ree biosurfactant producing isolates, TT42 and TT21 belonging to the ingroup II and HTO representing ingroup III showing surface activity between 28–35 mNm−1 (Table 3) and ve reference strains B. licheniformis, B. subtilis, B. cereus, B. pumilus, and B. megaterium were subjected to ARDRA by restriction enzymes Hae III, Hha I, and Msp I, and dendrogram based on restriction patterns of these three restriction enzymes was constructed (Figure 1)

Summary

Introduction

Bacillus spp. are main workhorses for biotechnological applications. eir products are in the GRAS list (generally regarded as safe) of US Food and Drug Administration (USFDA) and are regarded harmless [1,2,3]. ey produce a variety of products namely. extracellular enzymes, biopolymers, biosurfactants, biopesticides, and so forth from renewable resources and are ecofriendly. Biosurfactants are biologically produced surface-active compounds which are versatile process chemicals, and those from Bacillus spp. possess the property of functionality under extreme conditions of pH, temperature, and salinity [4, 5]. E lipopeptide biosurfactants produced by B. subtilis and B. licheniformis are highly potent due to their surface tension reducing ability. Surfactin and lichenysin are two wellstudied lipopeptide biosurfactants produced by B. subtilis and B. licheniformis, respectively. Similarity exists in the 25 kb, operons encoding for the surfactin and lichenysin and in their chemical structure [9] Their genomes are useful for comparative and evolutionary studies among species within subtilis-licheniformis group. Potent biosurfactant producing Bacillus species from natural habitats like oil reservoir have been reported; the diversity of these in various habitats has not been studied. ISRN Biotechnology the biosurfactant producing Bacillus spp. and a distinct distribution among the species known to produce powerful biosurfactants mainly B. licheniformis and B. subtilis based on the information obtained from phenotypic characterization and ampli ed 16S rDNA restriction analysis (ARDRA) band patterns

Materials and Methods

Results

Discussion

Conclusions