• Journal of Applied Biological Chemistry
• /
• v.66
• /
• pp.353-358
• /
• 2023

Barley (Hordeum vulgare) belongs to the Poaceae family. This study compared the polyphenol and flavonoid levels of unfermented and fermented barley sprouts using spectrophotometric assays. The findings indicated that fermentation greatly boosted the flavonoid content but caused only a slight increase in the polyphenol content. However, this does not imply that fermentation has no effects whatsoever on the polyphenol content of barley sprouts. This was due to the fact that some flavonoids cannot be detected by the wavelength used to calculate the overall polyphenol concentration. Both samples were subjected to high-performance liquid chromatography analysis and detected the flavonoids lutonarin, saponarin, isoorientin, isovitexin, and tricin-all of which have bioactive properties-most notably known for their antioxidant activity. These results augment the ongoing phytochemical profiling research and can possibly valorize the already thriving barley industry.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.3
• /
• pp.307-316
• /
• 2022

Yeasts play an important role in spontaneous fermentation of traditional alcoholic beverages. Our previous study revealed that a mixed-consortia of both Saccharomyces and non-Saccharomyces yeasts were responsible for fermentation of khadi, a popular, non-standardized traditional beverage with an immense potential for commercialization in Botswana. Functional characterization of isolated fermenting yeasts from mixed consortia is an indispensable step towards the selection of potential starter cultures for commercialization of khadi. In this study, we report the characterization of 13 khadi isolates for the presence of brewing-relevant phenotypes such as their fermentative capacity, ability to utilize a range of carbon sources and their ability to withstand brewing-associated stresses, as a principal step towards selection of starter cultures. Khadi isolates such as Saccharomyces cerevisiae, Saccharomycodes ludwigii and Candida ethanolica showed good brewing credentials but Lachancea fermentati emerged as the isolate with the best brewing attributes with a potential as a starter culture. However, we were then prompted to investigate the potential of L. fermentati to influence the fruity aromatic flavor, characteristic of khadi. The aroma components of 18 khadi samples were extracted using headspace solid phase micro-extraction (HS-SPME) and identified using a GC-MS. We detected esters as the majority of volatile compounds in khadi, typical of the aromatic signature of both khadi and L. fermentati associated fermentations. This work shows that L. fermentati has potential for commercial production of khadi.

• Journal of Korean Medicine for Obesity Research
• /
• v.18 no.2
• /
• pp.64-73
• /
• 2018

Objectives: This study investigated the effect on microbial ecology, fermentation characteristics and anti-obesity of Platycodon grandiflorum (PG) fermentation with salt. Methods: PG was fermented for four weeks with 2.5% salt and the characteristics of fermented PG were performed by measuring pH, total sugar content, viable bacteria number and microbial profiling. Also, we measured total polyphenol, flavonoid and the percent of inhibition of lipase activity and lipid accumulation. Results: Salt added to PG for fermentation had an effect on pH, total sugar, total and the number of lactic acid bacteria. Total sugar and pH were reduced and number of total and lactic acid bacteria were increased after fermentation. The majority of bacteria for fermentation were Lactobacillus plantarum, Leuconostoc psedomesenteroides and Lactococcus lactis subspecies lactis regardless of salt addition. However, microbial compositions were altered by added salt and additional bacteria including Weissella koreensis, W. viridescens, Lactobacillus sakei and Lactobacillus cuvatus were found in fermented PG with salt. Total flavonoid was increased in fermented PG and lipid accumulation on HepG2 cells treated with fermented PG was reduced regardless of salt addition. Moreover, fermented PG without salt suppressed lipase activity. Conclusions: Addition of salt for PG fermentation had influence on fermentation characteristics including pH and sugar content as well as number of bacteria and microbial composition. In addition, fermented PG showed anti-obesity effect by increasing flavonoid content and inhibition of lipase activity and lipid accumulation.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.6
• /
• pp.1150-1156
• /
• 2017

Understanding phosphorus metabolism in photosynthetic organisms is important as it is closely associated with enhanced crop productivity and pollution management for natural ecosystems (e.g., algal blooming). Accordingly, we exploited highly time-resolved metabolic responses to different levels of phosphate deprivation in Chlamydomonas reinhardtii, a photosynthetic model organism. We conducted non-targeted primary metabolite profiling using gas-chromatography time-of-flight mass spectrometric analysis. Primarily, we systematically identified main contributors to degree-wise responses corresponding to the levels of phosphate deprivation. Additionally, we systematically characterized the metabolite sets specific to different phosphate conditions and their interactions with culture time. Among them were various types of fatty acids that were most dynamically modulated by the phosphate availability and culture time in addition to phosphorylated compounds.

• Journal of Microbiology and Biotechnology
• /
• v.34 no.8
• /
• pp.1653-1659
• /
• 2024

Starter cultures used during the fermentation of malt wort can increase the sensory characteristics of the resulting beverages. This study aimed to explore the aroma composition and flavor recognition of malt wort beverages fermented with lactic acid bacteria (Levilactobacillus brevis WiKim0194) isolated from kimchi, using metabolomic profiling and electronic tongue and nose technologies. Four sugars and five organic acids were detected using high-performance liquid chromatography, with maltose and lactic acid present in the highest amounts. Additionally, e-tongue measurements showed a significant increase in the sourness (AHS), sweetness (ANS), and umami (NMS) sensors, whereas bitterness (SCS) significantly decreased. Furthermore, 20 key aroma compounds were identified using gas chromatography-mass spectrometry and 15 key aroma flavors were detected using an electronic nose. Vanillin, citronellol, and β-damascenone exhibited significant differences in the flavor profile of the beverage fermented by WiKim0194, which correlated with floral, fruity, and sweet notes. Therefore, we suggest that an appropriate starter culture can improve sensory characteristics and predict flavor development in malt wort beverages.

• Journal of Korean Medicine for Obesity Research
• /
• v.18 no.2
• /
• pp.96-105
• /
• 2018

Objectives: The aim of this study was to examine the effect of Asparagus cochinchinensis (AC) and fermented AC (fAC) on microorganisms and efficacies. Methods: AC was fermented for four weeks without using any bacterial strains. Then we investigated fermentation characteristics including potential of hydrogen (pH), total sugar, microbial profiling and antioxidant compound contents such as total polyphenol and total flavonoid. The anti-obesity effects of AC and fAC were evaluated by using Oil Red O staining in 3T3-L1 adipocyte. Also anti-diabetic effects of them were evaluated by using 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) uptake in C2C12 skeletal muscle cell. Results: Both pH and total sugar of fAC were decreased significantly compared to unfermented AC. And the abundance of total bacteria and lactic acid bacteria increased during fermentation, especially Lactobacillus plantarum. Also fermentation of AC increased the content of total polyphenol. On the metabolic aspects, we found that AC and fAC suppressed fat accumulation. Conclusions: After four weeks of fermentation, AC increased concentrations of active compounds, altered microbial composition, and inhibited fat accumulation such as triglyceride. These results indicate that fermentation of AC might be a beneficial therapeutic approach for obesity.

• Journal of Ginseng Research
• /
• v.42 no.1
• /
• pp.57-67
• /
• 2018

Background: Ginseng contains many small metabolites such as amino acids, fatty acids, carbohydrates, and ginsenosides. However, little is known about the relationships between microorganisms and metabolites during the entire ginseng fermentation process. We investigated metabolic changes during ginseng fermentation according to the inoculation of food-compatible microorganisms. Methods: Gas chromatography mass spectrometry (GC-MS) datasets coupled with the multivariate statistical method for the purpose of latent-information extraction and sample classification were used for the evaluation of ginseng fermentation. Four different starter cultures (Saccharomyces bayanus, Bacillus subtilis, Lactobacillus plantarum, and Leuconostoc mesenteroide) were used for the ginseng extract fermentation. Results: The principal component analysis score plot and heat map showed a clear separation between ginseng extracts fermented with S. bayanus and other strains. The highest levels of fructose, maltose, and galactose in the ginseng extracts were found in ginseng extracts fermented with B. subtilis. The levels of succinic acid and malic acid in the ginseng extract fermented with S. bayanus as well as the levels of lactic acid, malonic acid, and hydroxypruvic acid in the ginseng extract fermented with lactic acid bacteria (L. plantarum and L. mesenteroide) were the highest. In the results of taste features analysis using an electronic tongue, the ginseng extracts fermented with lactic acid bacteria were significantly distinguished from other groups by a high index of sour taste probably due to high lactic acid contents. Conclusion: These results suggest that a metabolomics approach based on GC-MS can be a useful tool to understand ginseng fermentation and evaluate the fermentative characteristics of starter cultures.

• Journal of Korean Medicine for Obesity Research
• /
• v.15 no.2
• /
• pp.123-130
• /
• 2015

Objectives: Samjung-hwan (SJH), a well-known traditional fermented herb formula recorded in Dongui Bogam, has been commonly used for prolonging life for four hundred years in Eastern Asia. However, fermented SJH has not been investigated in terms of microbial ecology until present time. Methods: SJH was fermented for five weeks and fermentation characteristics during SJH fermentation were performed including pH, acidity and microbial profiling. Also, we measured total polyphenol and total flavonoid contents and 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. In order to select starter candidate, several lactic acid bacteria were isolated from fermented SJH. Results: pH of fermented SJH was decreased from 4.7 to 3.0 and acidity was increased from 0.45% to 1.72%. Also, fermented SJH increased antioxidant indicator such as total polyphenol and total flavonoid as well as DPPH free radical scavenging activity. Lactobacillus brevis was increased, Pseudanabaena sp. was decreased, and Lactococcus lactis subsp. lactis was stable during 5-week fermentation of SJH. L. brevis and L. plantarum were isolated from fermented SJH. Conclusions: Fermented SJH for four weeks had optimal effect on antioxidant and fermentation characteristics such as pH, acidity and microbial profile. Further studies are required to develop starter and analyze functional compounds in oder to produce standardized SJH.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.7
• /
• pp.1242-1251
• /
• 2016

The ethanol production of Trichoderma reesei was improved by genome shuffling in our previous work. Using RNA-Seq, the transcriptomes of T. reesei wild-type CICC40360 and recombinant strain HJ48 were compared under fermentation conditions. Based on this analysis, we defined a set of T. reesei genes involved in ethanol production. Further expression analysis identified a series of glycolysis enzymes, which are upregulated in the recombinant strain HJ48 under fermentation conditions. The differentially expressed genes were further validated by qPCR. The present study will be helpful for future studies on ethanol fermentation as well as the roles of the involved genes. This research reveals several major differences in metabolic pathways between recombinant strain HJ48 and wild-type CICC40360, which relates to the higher ethanol production on the former, and their further research could promote the development of techniques for increasing ethanol production.

• Journal of Ginseng Research
• /
• v.41 no.3
• /
• pp.379-385
• /
• 2017

In this study, white ginseng was used as the raw material, which was fermented with Paecilomyces hepiali through solid culture medium, to produce ginsenosides with modified chemical composition. The characteristic chemical markers of the products thus produced were investigated using rapid resolution liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (RRLC-QTOF-MS). Chemical profiling data were obtained, which were then subjected to multivariate statistical analysis for the systematic comparison of active ingredients in white ginseng and fermented ginseng to understand the beneficial properties of ginsenoside metabolites. In addition, the effects of these components on biological activity were investigated to understand the improvements in the phagocytic function of macrophages in zebrafish. According to the established RRLC-QTOF-MS chemical profiling, the contents in ginsenosides of high molecular weight, especially malonylated protopanaxadiol ginsenosides, were slightly reduced due to the fermentation, which were hydrolyzed into rare and minor ginsenosides. Moreover, the facilitation of macrophage phagocytic function in zebrafish following treatment with different ginseng extracts confirmed that the fermented ginseng is superior to white ginseng. Our results prove that there is a profound change in chemical constituents of ginsenosides during the fermentation process, which has a significant effect on the biological activity of these compounds.