Enhanced production of anteiso-branched chain fatty acids rich bacterial oil using Lentibacillus salarius strain BPIITR under furan aldehydes induced oxidative stress

Abstract

Monomethyl branched-chain fatty acids (mBCFAs) are highly valuable compounds in the oleochemical industry, with diverse industrial applications including pharmaceuticals, biofuels and lubricants. In the current study, the medium components of L. salarius BPIITR were statistically optimized to produce mBCFAs-rich lipid, yielding up to 227.16 ± 16.2 mg/g dcw. The supplementation of 2-methyl butyric acid increased the lipid content to 276.42 ± 7.46 mg/g dcw, with anteiso fatty acids up to 87.59 ± 1.56 % w/w of the total lipid. The addition of 5-hydroxymethyl furfural (5-HmF) and furfural induced oxidative stress, resulting in the synthesis of lipids rich in anteiso-mBCFAs. Furfural supplementation led to a lipid accumulation of 256.49 ± 7.91 mg/g dcw, whereas with 5-HmF, it increased to 284.75 ± 8.98 mg/g dcw. Furthermore, the elongation of mBCFAs from C15:0 to C17:0 was significantly affected during oxidative stress. This study suggests that under oxidative stress conditions, the synthesis of anteiso fatty acids is favored over iso-fatty acids in L. salarius BPIITR. Additionally, value-added products such as trehalose and furan carboxylic acids were identified as potential co-products in this study, with trehalose reaching up to 255.84 ± 8.04, 163.65 ± 20.94, and 217.46 mg/g dcw in the presence of 2-methylbutyric acid, furfural, and 5-HmF, respectively. The concentration of 2-furan carboxylic acid and 2,5-furan dicarboxylic acids in the fermentation broth reached up to 4.37 ± 0.28 g/L and 2.48 ± 0.35 g/L, respectively. The utilization of short-chain fatty acids and furan aldehydes not only provided a cost-effective carbon source but also modulated the metabolic flux towards specific mBCFAs rich bacterial oil production.