Optimized Production of GABA and γ-PGA in a Turmeric and Roasted Soybean Mixture Co-fermented by <i>Bacillus subtilis</i> and <i>Lactobacillus plantarum</i>

Abstract

A turmeric and roasted soybean flour mixture (TRSF) was successfully fermented in solid-state using Bacillus subtilis HA and Lactobacillus plantarum K154. The co-fermentation was optimized using the turmeric mixture Food products made from soybeans, such as tofu, soy sauce, and soybean paste, have been consumed in Asia for a long time. InWestern countries, soy protein is used in processed products such as sausages, hamburgers, breads and pastries (Fukushima, 1981).Soy products are recognized as healthy foods rich in protein and low in saturated fats, which also contain bioactive compounds such as isoflavones and saponins (Messina, 2010). Fermented soy products are popular in Asian cuisines; however, they generally require a long processing time. Nevertheless, soybean fermentation using Bacillus subtilis can be achieved in a short time, and the products generated are rich in polypeptides and peptones, resulting in easy digestion and absorption. Examples of such products are the Japanese natto and Korean chungkookjang. Fermented soybean products have been reported to have antihypertensive (Shin et al., 2001), antioxidant (Wang et al., 2008, fibrinolytic (Kim et al., 2006) and anticancer (Zhao et al., 2013) activities. However, the strong smell and taste of these fermented products is a barrier for their generalized consumption (Park et al., 2012). Therefore, improving the organoleptic qualities of fermented soy products is desirable. A co-fermentation with B. subtilis MC31 andLactobacillus sakei 83 was reported to enhance the GABA contentand flavor of chungkookjang .The lactic acid bacteria (LAB) used to make fermented food products generate functional compounds such as oligosaccharides and peptides in addition to lactic acid (Leroy and De Vuyst, 2004).One of the functional compounds that can be generated by fermentation with LAB is γ-aminobutyric acid (GABA), a nonprotein amino acid that acts as an inhibitory neurotransmitter and that also exhibits hypotensive effects (Dhakal et al., 2012). In LAB, GABA acts as a defense against acidic environments and as an alternative energy source (Kook et al., 2010a). Fermentation with B. subtilis generates mucilage containing γ-polyglutamic acid (γ-PGA) and fructan, which give the sticky consistency to natto (Nagai et al., 1994;Park et al., 2012). γ-PGA is a biodegradable, water soluble and edible biopolymer, which can be composed of either the L or D isomer of glutamic acid or both. γ-PGA is a promising biological material that could be used in medicine as a drug delivery agent, in food as an encapsulating agent and fat replacement, and in skin care products as a humectant (Ogunleye et al., 2015). γ-PGA has also been used as a bitterness relieving agent in Japan (Murase et al., 2000). Moreover, γ-PGA exhibits immuneboosting and anticancer activities. However, the production cost of γ-PGA is still high; hence, more research on the microbial production of this biopolymer is needed (Kim et al., 2014b;Ogunleye et al., 2015).In this study, the solid-state fermentation of a turm...

Fortification of Mucilage and GABA in <i>Hovenia dulcis</i> Extract by Co-fermentation with <i>Bacillus subtilis</i> HA and <i>Lactobacillus plantarum</i> EJ2014

“…Free amino acids in the co-fermented culture broth were determined using HPLC, revealing the complete conversion of glutamic acid to GABA after 5 days of fermentation. The initial glutamic acid content of 20.01 mg/mL in the broth containing 5% skim milk decreased to zero after 5 days, whereas the GABA content increased from none at the beginning to 16.08 mg/mL, which is higher than that reported for a co-fermentation of a soybean/turmeric mixture (Lim et al, 2016).…”

“…Fermentation of plant products can enrich them with bioactive compounds, enhancing their health benefits (Lim et al, 2016).…”

“…γ-PGA has been efficiently produced in mucilage by solid-state fermentation using B. subtilis and L. plantarum (Park et al, 2012;Lim et al, 2016). Thus, alkaline fermentation could be applied to enhance the content of this metabolite in natural products.…”

Production of Gamma-Aminobutyric Acid from Lactic Acid Bacteria: A Systematic Review

“…plantarum K154. It was found that, in the final stage of fermentation, GABA accumulation from co-fermentation was higher, up to 1.78% more than that of the single-fermented system [112]. B. subtilis HA and Lb.…”

Higher production of γ-aminobutyric acid in Toxicodendron vernicifluum extract by co-fermentation using yeast and lactic acid bacteria

“…천연소재로 GABA는 현미 100 g 당 4-8 mg, 발아현미 10-100 mg으로 자연에서 얻을 수 있는 GABA는 제한적이 며, 젖산균을 이용한 발효물에서 250 mg 이상의 GABA를 함유한다는 연구가 보고되었다 (Hwang, 2011;Mody 등, 1994;Park, 2012). 울금을 이용한 B. subtilis HA와 L. plantarum K154의 혼합발효에서 1.78% GABA 생산이 보고 되었으며 (Lim, 2014), 녹각 추출물을 이용한 L. plantarum EJ2014의 발효에서 1.4%, Leuconostoc mesenteroides SM와 Lactobacillus plantarum K154 균주의 혼합발효에서는 1.23% 의 GABA가 생산되었다고 보고되었다 (Kwon, 2016;Song, Fig. 6.…”