Characterization of Solibacillus silvestris strain AM1 that produces amyloid bioemulsifier

Abstract

Solibacillus silvestris AM1 was the first strain from the genus to be reported for the production of a functional amyloid and its potential use as a surface active agent, a thermostable glycoprotein amyloid bioemulsifier BE-AM1 capable of influencing environment and biofilm formation. Phylogenetic analysis based on 16S rRNA gene, molecular characterization studies on the basis of DNA-DNA hybridization and chemotaxonomic fatty acid methyl ester (FAME) analysis showed that S. silvestris AM1 as a strain matches with the type strain S. silvestris HR3-23. But strain AM1 differs from the type strain HR3-23 in carbon substrate utilization studies along with amyloid bioemulsifier production ability with potential industrial and environmental applications. S. silvestris AM1 exhibited bioemulsifier production at wide range of factors like pH and NaCl concentrations, while temperature influenced the bioemulsifier production indirectly (since it affected the growth). Bioemulsifier production was observed even at oligotrophic conditions (0.5 mg ml ) seen usually in its native environment. In this study, we have characterized the amyloid producing S. silvestris AM1 taxonomically and also analyzed 16S rDNA of 103 sequences of Solibacillus sp. available, which indicated the possibility of new species in this genus and can be studied for industrially and environmentally important biomolecules.

Analysis of Nutritional Factors Influencing the Biosynthesis of Amyloid Bioemulsifier Be-Am1 Applicable in Food Industry

“…This will be the first study to analyse the effect of factors influencing the production of industrially important functional amyloid protein from bacterial source having potential in environmental remediation and microbial interaction. ARTICLE INFO medium (composition given in Table 1) showing enhanced thermos-stability (Markande & Nerurkar, 2016a;Markande et al, 2013;Markande et al, 2018). The production of amphipathic BE-AM1 was analysed by emulsification assay.…”

“…Galactose is a major carbohydrate that S. silvestris AM1 utilizes (Markande et al, 2018). Growth and production of BE-AM1 in cell bound and cell free form was checked in different concentrations of Galactose (1, 5, 10, 15 mg/ml) in ZM salt solution.…”

“…It was reported to be able to produce amyloid BE-AM1 only in ZM medium but differed in many utilization aspects from type strain HR3-23 T (Markande et al, 2013;Markande et al, 2018;. As given in materials and methods, thirteen macro and micronutrients as salts in ZM medium make up around 3.4%.…”

“…BE-AM1 production by S. silvestris AM1 was consistent in pH and NaCl concentrations variations, but was affected by temperature variation due its influence on bacterial growth. BE-AM1 production was also seen at oligotrophic conditions mimicking natural environments (Markande et al, 2018). Thus as the objective of present study were to elucidate the nutritive factors influencing the production of amyloid bioemulsifier BEAM1 using statistical methods like Plackett Burman and Response surface methodology.…”

“…For therapeutic intervention of neurodegenerative disease, a way to alter is to influence the microbial partners and their products like amyloid proteins nutritionally (Friedland and Chapman, 2017). Solibacillus silvestris AM1 was recently reported to be differing in biochemical and utilization properties from the type strain HR3-23T (Markande, et al, 2018). S. silvestris AM1 was reported previously for the production of amyloid bioemulsifiers BE-AM1 having the ability to produce stable emulsions in aliphatic and aromatic hydrocarbons (Markande et al, 2013).…”