Effect of Adding Bifidobacterium animalis BZ25 on the Flavor, Functional Components and Biogenic Amines of Natto by Bacillus subtilis GUTU09

Abstract

Natto is a high-value fermented soybean produced by B. subtilis. However, B. subtilis produces a pungent amine odor. This study compared the volatile organic compounds (VOCs), free amino acids (FAAs) and biogenic amines (BAs), nattokinase (NK) of natto made by two-strain fermentation with Bifidobacterium animalis BZ25 and Bacillus subtilis GUTU09 (NMBB) and that of natto made by single-strain fermentation with Bacillus subtilis GUTU09 (NMB). Compared with NMB, volatile amine substances disappeared, ketones and aldehydes of NMBB were reduced, and alcohols increased. Besides that, the taste activity value of other bitter amino acids was lowered, and BA content was decreased from 255.88 mg/kg to 238.35 mg/kg but increased NK activity from 143.89 FU/g to 151.05 FU/g. Correlation analysis showed that the addition of BZ25 reduced the correlation between GUTU09 and BAs from 0.878 to 0.808, and pH was changed from a positive correlation to a negative one. All these results showed that the quality of natto was improved by two-strain co-fermentation, which laid a foundation for its potential industrial application.

Effect of Soy Protein Products on Growth and Metabolism of Bacillus subtilis, Streptococcus lactis, and Streptomyces clavuligerus

“…Figure 5 reveals the correlation between the nutritional components of the soy protein products, the cell growth of BSNK-5, and NK synthesis. It has been reported that the pH influences bacterial growth and enzyme synthesis [35]. There As shown in Figure 4C, the content of CA increased in the first 72 h and then stabilized from 72 h to 144 h. CA had the highest stability at a neutral pH, and the decomposition rate was significantly higher at acidic and alkaline pHs [33].…”

“…Figure 5 reveals the correlation between the nutritional components of the soy protein products, the cell growth of BSNK-5, and NK synthesis. It has been reported that the pH influences bacterial growth and enzyme synthesis [35]. There was a negative correlation between the pH and bacteria density.…”

High-Efficiency Fermentation of Nattokinase by Recombinant PSP2 Using Oyster Protein Hydrolysate as a Substrate

“…Suwanmanon et al reported enzymatic activity of 130.9 FU/mL under optimized fermentation conditions [ 25 ]. Zhang Q increased the activity of the nattokinase enzyme from 143.89 to 151.05 FU/mL after two-bacteria fermentation [ 26 ]. These results indicate that the level of nattokinase activity in this study is higher than that in previous studies.…”

Comparative metabolomics reveal histamine biodegradation mechanism by salt stressed Bacillus subtilis JZXJ-7

“…B.cereus, B.polymyxa, B.lichemiformis and B.amyloliquefaciens isolated from salted fish products have also shown a greater capacity to degrade histamine, cadaverine and putrescine [13] . In addition, salt stress may activate cross-protection, thereby supporting metabolic regulation of these bacteria, such as upregulate the amine oxidase gene and increasing efflux pump expression to efficiently efflux many types of toxic substances [14,29] .…”

“…such as B.cereus, B.polymyxa, B.lichemiformis and B.amyloliquefaciens isolated from salted fish products have a profound capacity to degrade histamine, cadaverine and putrescine [13] . Zhang et al [14] reported that B. haynesii isolated from fermented foods can significantly upregulate the amine oxidase gene family (biogenic amine degrading enzymes) to degrade biogenic amines during food fermentation. B. subtilis is a versatile Gram-positive bacterium capable of adapting to a wide variety of stress conditions such as heat, hyperosmosis and hosphate deprivation.…”