Search

BACKGROUND: The quality of commercial soy sauce is variable at present. Technical work is needed to improve the quality and flavor of soy sauce, especially in China. Material is a factor for influencing soy sauce characters in fermentation. RESULTS: Germinated soybean sauce (fermented by germinated soybean) had a gamma aminobutyric acid (GABA) concentration of 6.83 μg mL−1, whereas a control (a soy sauce fermented by soybean) had a GABA concentration of less than 2.42 μg mL−1. Germinated soybean sauce also contained significantly higher levels of isoflavones, total polyphenol, and amino acid nitrogen than the control soy sauce. Microbial diversity results showed that Bacillus was the dominant bacteria in germinated soy sauce compared with the control. Aldehydes, alcohols, esters, and phenols were the major flavor components of germinated soybean sauce. CONCLUSION: A soy sauce with high levels of GABA, isoflavones, and total polyphenol was developed using germinated soybean. Stenotrophomonas, the typical pathogen found in the control, was reduced dramatically and replaced by Bacillus during fermentation with the germinated soybean. The germinated soybean sauce exhibited a better aroma and taste than the control. Soy sauce fermented by soybeans that germinated for 48 h exhibited greater advantages than soy sauce that germinated for 24 and 72 h. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Kazakh cheese is a traditional dairy product in Xinjiang, China. To study the function and potential probiotic characteristics of yeast in Kazakh cheese and its contribution to cheese fermentation, we screened the γ-aminobutyric acid (GABA)-producing yeasts Pichia kudriavzevii 1-21, Kluyveromyces marxianus B13-5, Saccharomyces cerevisiae DL6-20, and Kluyveromyces lactis DY1-10. We investigated the potential probiotic properties of these strains and their use in cheese fermentation (cheeses designated CSP, CSM, CSS, and CSI, respectively); a control with no added yeast was designated CS. The results showed that the 4 yeast strains all showed high self-polymerization (2- and 24-h autoaggregation capacity of >80 and 90%, respectively), hydrophobicity (40-92% variation, low hydrophobicity in xylene, but within the range of probiotics), and the ability to survive the gastrointestinal tract (survival rate >75% after simulation), indicating the probiotic ability of the strains in vitro. The GABA production capacity of the CSM cheese increased (to 95.6 mg/100 g), but its protein content did not change significantly, and amino acid degradation was obvious. The GABA production capacity of the CSS cheese decreased (to 450 mg/kg); its protein content declined, and its amino acid content increased. Except for water and protein, we found no obvious differences in most physical and chemical indicators. Kluyveromyces marxianus B13-5 helped to form the desired texture. Multivariate statistical analysis showed that fermentation of the cheese with the 4 yeasts improved the production of esters and alcohols. The CSS cheese had good aroma production performance, because S. cerevisiae DL6-20 produced high concentrations of isoamyl alcohol, hexanoic acid ethyl ester, benzyl alcohol, octanoic acid ethyl ester, 3-hydroxy-2-butanone, and hexanoic acid; the content of 2-methyl-propanoic acid was low. Compared with the CSP cheese, the CSI and CSM cheeses had a fruitier aroma and a milder odor, but the CSI and CSM cheeses had high concentrations of ethyl acetate, butanoic acid, ethyl ester, 3-methyl-1-butanol-acetate, ethyl hexanoate, ethyl octanoate, acetic acid 2-phenylethyl ester, and ethyl lactate; concentrations of 3-methyl-butanoic acid, propanoic acid, acetic acid, and butanoic acid were low. The CSP cheese had stronger acid-producing ability. The order of fragrance production performance was CSS > CSI, CSM > CSP > CS. Research into the fermentation mechanisms of GABA-producing yeast in cheese will provide a theoretical basis for the quality control and industrial production of Kazakh cheese., (Copyright © 2021 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Background: Post-herpetic neuralgia (PHN) is the most common complication of herpes zoster and is defined as pain that lasts for one month or more after the outbreak itself heals. While the annual incidence of herpes zoster is approximately 3-5%, 9-34% of these patients will develop PHN. Approximately 30-50% of these cases last for more than a year but some cases can persist for 10 years or more. To date, the economic burden of PHN in China has not been studied. The first-line topical therapy for PHN is application of lidocaine-medicated plasters (LMPs) which have shown good efficacy and tolerability. Furthermore, LMPs were added to China's National Health Insurance List in 2019, thereby significantly relieving the financial burden on patients. A cost-effectiveness analysis was performed on LMPs compared with pregabalin in the treatment of PHN to provide a reference for the basis for clinical treatments and health decisions in patients with PHN., Methods: A Markov model was built according to the PHN disease characteristics. The efficacy data were extracted from a randomized controlled trial conducted in China, and the transition probability, utility value, and medical cost of each state in the model were collected through a systematic review of the literature and public databases. The outcome measure was cost per quality-adjusted life year (QALY) gained. The incremental cost-effectiveness ratios (ICERs) were calculated. Sensitivity analysis was conducted to confirm the robustness of the model., Results: In the base case analysis, treatment for a 6-month period with pregabalin and lidocaine plasters led to a mean QALY gain of 0.34012 and 0.42543, respectively, and mean incremental costs of 5,720 Chinese Yuan (CNY) and 3690 CNY, respectively. The ICER of treatment with 5% lidocaine plaster was negative, indicating that lidocaine plasters had absolute advantage. Monte Carlo simulation resulted in an estimate of 90% probability that the 5% lidocaine plaster treatment was cost-effective., Conclusions: Within the Chinese medical and health system, LMPs can reduce the economic burden of patients with PHN. LMPs are more cost-effective and more efficient in absolute terms compared to the first-line treatment systemic drug pregabalin in the treatment of PHN.

The ability of immune defense and resistance to physiological stress is crucial to animal health and survival. This study investigated the regulation of γ-aminobutyric acid (GABA) on metabolic homeostasis and its enhancement of hepatopancreas health in juvenile Chinese mitten crab (Eriocheir sinensis) under food deprivation. Juvenile crabs of 400 individuals were divided into four treatment groups: a control group without injection, and injections with a phosphate-buffered saline solution, 100 μmol GABA/mL and 1000 μmol GABA/mL, respectively. Hypoglycemia was induced by fasting, whereas the GABA treatment regulated hemolymph glucose homeostasis. The quantitative real-time PCR (qRT-PCR) results showed that the GABA treatment significantly up-regulated the mRNA expression levels of crustacean hyperglycemic hormone (CHH) and pyruvate kinase (PK). In contrast, the expression of E. sinensis insulin-like peptide (EsILP) was significantly down-regulated in the cranial ganglia, thoracic ganglia and hepatopancreas. Moreover, acid phosphatase (ACP), alkaline phosphatase (AKP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were significantly increased in the hepatopancreas by the GABA treatment. Furthermore, the hemocyanin content in serum was significantly increased with the GABA injection, and the glutathione (GSH) content, total superoxide dismutase (T-SOD) activity and catalase (CAT) activity in the hepatopancreas showed a similar increasing trend with the dose elevation of GABA. Therefore, these results indicate that GABA can effectively maintain the hemolymph glucose homeostasis by regulating the levels of glucose metabolism-related hormones and key enzymes to promote the degradation and utilization of hepatopancreas glycogen. Meanwhile, GABA can improve the hepatopancreas function and immune status of juvenile E. sinensis under fasting stress. The treatment with GABA may provide a clue to guide health management in crab farming., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Soil alkalization affects apple production in northwest China. Autophagy is a highly conserved degradative protein pathway in eukaryotes. Autophagy in plants can be activated by various abiotic factors. We previously identified the positive role of the autophagy-related gene MdATG18a in drought, nitrogen deficiency and resistance to Diplocarpon mali infection in apple. However, it is still unclear whether ATG18a is related to alkaline stress. In this study, we used hydroponic culture to simulate alkaline stress and found that the overexpression of MdATG18a significantly improved the tolerance of apple to alkaline stress. The overexpression of MdATG18a increased biomass, photosynthetic rate and antioxidant capacity of transgenic plants compared with wild-type plants under alkaline stress. The overexpression of MdATG18a promoted γ-aminobutyric acid (GABA) shunt via an increase in glutamate (GABA precursor) and GABA contents and upregulation of GABA shunt-related genes. In addition, the overexpression of MdATG18a significantly upregulated the expression of other core ATG genes and increased the formation of autophagosomes under alkaline stress. In conclusion, these results suggest that the overexpression of MdATG18a in apple enhances alkaline tolerance and the GABA shunt, which may be owing to the increase in autophagic activity., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Salt stress is a serious abiotic stress that caused crop growth inhibition and yield decline. Previous studies have reported on the the synthesis of gamma-aminobutyric acid (GABA) and its relationship with plant resistance under various abiotic stress. However, the relationship between exogenous GABA alleviating plant salt stress damage and ion flux, amino acid synthesis, and key enzyme expression remains largely unclear. We investigated plant growth, Na + transportation and accumulation, reactive oxygen species (ROS) metabolism and evaluated the effect of GABA on amino acids, especially SlGADs gene expression and the endogenous GABA content of tomato (Solanum lycopersicum L.) seedlings treated with or without 5 mmol·L - 1 GABA under 175 mmol·L - 1 NaCl stress., Results: Exogenous application of GABA significantly reduced the salt damage index and increased plant height, chlorophyll content and the dry and fresh weights of tomato plants exposed to NaCl stress. GABA significantly reduced Na + accumulation in leaves and roots by preventing Na + influx in roots and transportation to leaves. The transcriptional expression of SlGAD1-3 genes were induced by NaCl stress especially with GABA application. Among them, SlGAD1 expression was the most sensitive and contributed the most to the increase in glutamate decarboxylase (GAD) activity induced by NaCl and GABA application; Exogenous GABA increased GAD activity and amino acid contents in tomato leaves compared with the levels under NaCl stress alone, especially the levels of endogenous GABA, proline, glutamate and eight other amino acids. These results indicated that SlGADs transcriptional expression played an important role in tomato plant resistance to NaCl stress with GABA application by enhancing GAD activity and amino acid contents. GABA significantly alleviated the active oxygen-related injury of leaves under NaCl stress by increasing the activities of antioxidant enzymes and decreasing the contents of active oxygen species and malondialdehyde., Conclusion: Exogenous GABA had a positive effect on the resistance of tomato seedlings to salt stress, which was closely associated with reducing Na + flux from root to leaves, increasing amino acid content and strengthening antioxidant metabolism. Endogenous GABA content was induced by salt and exogenous GABA at both the transcriptional and metabolic levels.