An efficient process for co-production of γ-aminobutyric acid and probiotic Bacillus subtilis cells

Abstract

This study was to establish an integrated process for the co-production of c-aminobutyric acid (GABA) and live probiotics. Six probiotic bacteria were screened and Bacillus subtilis ATCC 6051 showed the highest GABAproducing capacity. The optimal temperature and initial pH value for GABA production in B. subtilis were found to be 30°C and 8.0, respectively. A variety of carbon and nitrogen sources were tested, and potato starch and peptone were the preferred carbon and nitrogen sources for GABA production, respectively. The concentrations of carbon source, nitrogen source and substrate (sodium L-glutamate) were then optimized using the response surface methodology. The GABA titer and concentration of viable cells of B. subtilis reached 19.74 g/L and 6.0 9 10 8 cfu/mL at 120 h. The GABA titer represents the highest production of GABA in B. subtilis. This work thus demonstrates a highly efficient co-production process for GABA and probiotic B. subtilis cells.

The Fatty-Acid Hydratase Activity of the Most Common Probiotic Microorganisms

“…In addition, Lactobacillus reuteri produces (R)-(4) and (S)-(6) with very low (10% ee) and modest (78% ee) enantiopurity, respectively. Similarly, Lactobacillus salivarius transforms oleic acid into (R)-(4) possessing modest enantiopurity (80% ee) and into 10-ketostearic acid (5). The latter ketone can result from either the hydration of oleic acid followed by the oxidation of the formed 10-hydroxystearic acid or through a multistep oxidation of oleic acid, not necessarily involving the transformation of 10-hydroxystearic acid (Figure 3).…”

“…The growth of the probiotics market has fostered the biochemical studies of these species, especially those regarding the microorganism-human being interaction. Despite this fact, their use as biocatalysts for industrial biotransformation is restricted to a limited number of applications [3][4][5][6][7][8][9][10][11][12]. Among the most known probiotic bacteria, those belonging to the genus Lactobacillus and Bifidobacterium turned out to be the most promising for industrial purposes.…”

“…Two possible biosynthetic pathways involved in the Lactobacillus salivarius mediated transformation of oleic acid into 10-HSA (4) and 10-KSA(5).…”

Identification of new glutamate decarboxylases from Streptomyces for efficient production of γ-aminobutyric acid in engineered Escherichia coli

“…The activities of StGAD, SsGAD, ScGAD and GadB were examined through in vitro reactions based on the Berthelot method with some modifications [ 3 , 37 ]. The 2.0-mL reaction mixture consisted of 200 mM Na 2 HPO 4 -citric acid buffer (pH 5.2 for StGAD, pH 3.8 for SsGAD, pH 4.2 for ScGAD and pH 4.0 for GadB), 50 mM L-MSG, 0.01 mM PLP, and 50–100 μL of purified enzyme.…”

Role of Probiotic Bacilli in Developing Synbiotic Food: Challenges and Opportunities

“…Specifically, probiotic Bacilli can metabolize different prebiotic compounds that promote the healthiness of the host organism in which they reside using different mechanisms; these mechanisms include: pathogen obstruction due to antagonism and competition, pH level preservation, and defense of intestinal mucosal barrier and its functions (Ilinskaya et al, 2017;Davani-Davari et al, 2019;Seifert et al, 2019). In addition, probiotic Bacilli have been related to the production of many health-promoting factors for the host organism, for instance, vitamins and small molecules such as aminobutyric acid (GABA; Gu et al, 2015;Wang et al, 2019;Ren et al, 2020); this four-carbon non-proteinogenic amino acid is well-known for its diverse biological functions such as anxiety inhibition, sleep promotion, blood pressure reduction, diabetes treatment, and immune enhancement (Li et al, 2016;Wang et al, 2019).…”