Screening chemical modulators of benzoic acid derivatives to improve lipid accumulation in Schizochytrium limacinum SR21 with metabolomics analysis

Abstract

Background Schizochytrium sp. is a marine fungus with great potential as an alternative commercial source of lipids rich in polyunsaturated fatty acids (PUFAs). To further increase lipid accumulation in Schizochytrium sp., the effect of exogenous additives has become one of the hotspots of current research. Although benzoic acid derivatives showed positive effects on lipid accumulation in Schizochytrium , the biochemical mechanism needs further investigation. Results Four benzoic acid derivatives (sodium benzoate, p -aminobenzoic acid, p -methyl benzoic acid and folic acid) were screened and evaluated for their effect on lipid accumulation in Schizochytrium limacinum SR21. The lipid yield was increased by 56.84% with p -aminobenzoic acid ( p -ABA) at a concentration of 200 mg/L among the four tested chemical modulators. The metabolomics analysis showed that 200 mg/L p -ABA was optimal for promoting glucose catabolism in glycolysis with an increase in the mevalonate pathway and a weakening of the tricarboxylic acid (TCA) cycle. Moreover, p -ABA increased NADPH generation by enhancing the pentose phosphate pathway (PPP), ultimately redirecting the metabolic flux to lipid synthesis. Fed-batch fermentation further proved that p -ABA could significantly increase the yield of lipid by 30.01%, reaching 99.67 g/L, and the lipid content was increased by 35.03%, reaching 71.12%. More importantly, the yields of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were increased by 33.28% and 42.0%, respectively. Conclusion The addition of p -ABA could promote the synthesis of tetrahydrofolate, enhancing NADPH, which ultimately promoted the flow of carbon flux to lipid synthesis. These findings provide a valuable strategy for improving the lipid accumulation in Schizochytrium by additives.

An emerging simple and effective approach to increase the productivity of thraustochytrids microbial lipids by regulating glycolysis process and triacylglycerols’ decomposition

“…HX-308, a gas chromatography–mass spectrometry (GC–MS) method combined with multivariate analyses was used to determine the changes in metabolites in the presence of different concentrations of orlistat. The sample derivatization process was in accordance with a previously reported method [ 15 ], with some modifications. The above sample was mixed with 25 μL of an internal standard (Adonitol, 0.2 mg/mL) and dried with a nitrogen blower.…”

“…These small-molecule drugs that act as activators or inhibitors are called chemical modulators. Many microorganisms that lack genetic engineering tools have benefited from chemical modulators in their lipid production [ 15 ]. The biosynthesis of microbial lipids relies on a powerful supply of adenosine triphosphate (ATP), acetyl-CoA, and nicotinamide adenine dinucleotide (NADPH), and the availability of substrates is the key to balance growth and lipid production as these two processes compete with each other [ 16 ].…”

Application of Metabolomics in Fungal Research

“…In contrast, benzoic acid derivatives such as sodium benzoate, p-aminobenzoic acid, and p-methylbenzoic acid all promote lipid synthesis in Penicillium sr21 . Furthermore, 200 mg/L p-aminobenzoic acid even promoted glucose catabolism during glycolysis, increased the mevalonate pathway, weakened the tricarboxylic acid cycle, and promoted the production of tetrahydrofolate and NADPH [ 31 ]. The antibacterial polycationic peptide ε-poly-l-lysine (ε-PL) enhances the freeze–thaw tolerance of industrial yeast by promoting cell membrane-associated fatty-acid synthesis before freeze–thaw and promoting alglucan biosynthesis and glycerophospholipid metabolism after freeze–thaw [ 32 ].…”

Role of dietary Schizochytrium sp. in improving disease resistance of zebrafish through metabolic and microbial analysis

“…The original GC-MS data were conducted as previous reports [27]. Each peak was identi ed by alignment with the mass spectra from the NIST 2.2 (National Institute of Standards and Technology, USA) library.…”