• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.231-235
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• 1988

Population changes of aerobic bacteria, yeasts, and lactic acid bacteria ware investigated during the fermentation of Kimchis containing 0, 1, 2, 4, and 6% garlic at $21^{\circ}C$. The numbers of aerobic bacteria increased during the first 2 days and decreased thereafter. The higher the garlic concentration of the Kimchis was, the smaller the increase of the aerobic bacterial population was during the initial periods of the fermentations. Garlic concentrations that showed the largest population difference between them after 2-days fermentation were 1% and 2%. The population of lactic acid bacteria also increased only during the first 2 days and was held thereafter. Lactic acid bacterial population increased more at higher garlic concentrations during the initial period of the fermentations and major microorganisms contributed to the increase were Lactobacillus brevis and low acid-producing lactbacilli. Changes of yeasts at the different garlic concentrations during the fermentations were not apparent.

• Animal Bioscience
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• v.34 no.4
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• pp.613-620
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• 2021

Objective: This study aimed at studying the potential use of Flemingia (Flemingia macrophylla) as a protein source fodder to improve nutrients digestibility and ruminal fermentation efficiency in beef cattle. Methods: Four, Thai native beef cattle were randomly assigned in a 4×4 Latin square design. Four levels of Flemingia hay meal (FHM) were used to replace soybean meal (SBM) in the concentrate mixtures in four dietary treatments replacing levels at 0%, 30%, 60%, and 100% of SBM. Results: The experimental findings revealed that replacements did not effect on intake of rice straw, concentrate and total dry matter (DM) intake (p>0.05). However, the apparent digestibilities of DM, organic matter, crude protein, acid detergent fiber, and neutral detergent fiber were linearly increased up to 100% replacement levels. Moreover, the production of total volatile fatty acids, and propionate concentration were enhanced (p<0.05) whereas the concentration of acetate was reduced in all replacement groups. Consequently, the CH4 production was significantly lower when increasing levels of FHM for SBM (p<0.05). Furthermore, rumen bacterial population was additionally increased (p<0.05) while protozoal population was clearly decreased (p<0.05) in all replacement groups up to 100%. In addition, microbial nitrogen supply and efficiency of microbial nitrogen synthesis were enhanced (p<0.05), as affected by FHM replacements. Conclusion: The findings under this experiment suggest that 100% FHM replacement in concentrate mixture enhanced rumen fermentation efficiency, nutrients digestibilities, bacterial population, microbial protein synthesis, and subsequently reduced CH4 production in beef cattle fed on rice straw.

• Journal of Microbiology and Biotechnology
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• v.21 no.7
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• pp.739-745
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• 2011

During the production of grape wine, the formation of thick leathery pellicle/bacterial cellulose (BC) at the airliquid interface was due to the bacterium, which was isolated and identified as Gluconacetobacter hansenii UAC09. Cultural conditions for bacterial cellulose production from G. hansenii UAC09 were optimized by central composite rotatable experimental design. To economize the BC production, coffee cherry husk (CCH) extract and corn steep liquor (CSL) were used as less expensive sources of carbon and nitrogen, respectively. CCH and CSL are byproducts from the coffee processing and starch processing industry, respectively. The interactions between pH (4.5-8.5), CSL (2-10%), alcohol (0.5-2%), acetic acid (0.5-2%), and water dilution rate to CCH ratio (1:1 to 1:5) were studied using response surface methodology. The optimum conditions for maximum BC production were pH (6.64), CSL (10%), alcohol (0.5%), acetic acid (1.13%), and water to CCH ratio (1:1). After 2 weeks of fermentation, the amount of BC produced was 6.24 g/l. This yield was comparable to the predicted value of 6.09 g/l. This is the first report on the optimization of the fermentation medium by RSM using CCH extract as the carbon source for BC production by G. hansenii UAC09.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1808-1819
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• 2017

Knowledge on the functional characteristics and temporal variation of anaerobic bacterial populations is important for better understanding of the microbial process of two-stage anaerobic reactors. However, owing to the high diversity of anaerobic bacteria, close attention should be prioritized to the frequently abundant bacteria that were defined as core bacteria and putatively functionally important. In this study, using MiSeq sequencing technology, the core bacterial community of 98 operational taxonomic units (OTUs) was determined in a two-stage upflow blanket filter reactor treating pharmaceutical wastewater. The core bacterial community accounted for 61.66% of the total sequences and accurately predicted the sample location in the principal coordinates analysis scatter plot as the total bacterial OTUs did. The core bacterial community in the first-stage (FS) and second-stage (SS) reactors were generally distinct, in that the FS core bacterial community was indicated to be more related to a higher-level fermentation process, and the SS core bacterial community contained more microbes in syntrophic cooperation with methanogens. Moreover, the different responses of the FS and SS core bacterial communities to the temperature shock and influent disturbance caused by solid contamination were fully investigated. Co-occurring analysis at the Order level implied that Bacteroidales, Selenomonadales, Anaerolineales, Syneristales, and Thermotogales might play key roles in anaerobic digestion due to their high abundance and tight correlation with other microbes. These findings advance our knowledge about the core bacterial community and its temporal variability for future comparative research and improvement of the two-stage anaerobic system operation.

• Toxicological Research
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• v.28 no.2
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• pp.117-122
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• 2012

Flavonoids, which form a major component in Houttuynia cordata Thunb., display a wide range of pharmacological activities. The expression of plant flavonoids is partly regulated by fermentation. Therefore, we studied the effects of fermentation on H. cordata in order to identify the strains present during the fermentation process, and to determine whether fermented H. cordata could be used as a probiotic. Our results showed that all 6 of the bacterial strains isolated from fermented H. cordata (FHC) belonged to the genus Bacillus. As expected, fermenting H cordata also increased the flavonoid content as increases were observed in the levels of rutin, quercitrin, and quercetin. To test the effects of fermentation, we treated LPS-stimulated RAW264.7 cells with non-fermented H. cordata extracts (HCE) or FHC extracts (FHCE). Compared to the HCE-treated cells, the FHCE-treated cells showed increased viability. No cytotoxic effects were detected in the FHCE-treated groups in the 2 cell lines used in the study, namely, RAW264.7 and RBL-2H3. FHCE-treated HepG2 cells showed decreased growth, compared to HCE-treated HepG2 cells. These results indicate that the fermented H. cordata predominantly contained Bacillus strains. Furthermore, FHCE are able to prevent LPS-induced inflammatory effects and inhibit the growth of HepG2 cells.

• Korean journal of food and cookery science
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• v.27 no.5
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• pp.577-587
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• 2011

In this study, lotus leaf was added to a Takju (Korean milky rice wine) preparation to evaluate its effects on physicochemical and fermentation properties. For rapid saccharification Takju was stored at 25$^{\circ}C$ for 2 days and then temperature was switched to 18$^{\circ}C$ to mature the wine for 21 days. From the start of fermentation to 2-days, the pH of Takju decreased rapidly and acidity increased. Maltose, a byproduct of starch saccharification, increased for 2 days then rapidly decreased. Glucose fluctuated for 7 days and of the 21-days fermentation. The ethanol production rate was highest during the first 7 days, then slowed. Total viable yeast and lactic acid bacterial counts increased rapidly for 2 days and then decreased gradually thereafter. Leuconostoc spp. grew rapidly for 1 day and sharply disappeared with decreasing pH. DPPH radical scavenging activity was significantly higher for Takju prepared with lotus leaf than without. The overall acceptance of Takju tended to increase when it was prepared with lotus leaf.

• Korean journal of food and cookery science
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• v.19 no.4
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• pp.521-528
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• 2003

This research was conducted to find the effects of the addition of kugija to the quality and conservativeness of Nabak kimchi. Kugija extract was prepared by boiling kugija fruits, at different ratios (1, 3, 5 and 7%; w/v) in water for 30 minutes. The changes in the sensory and microbiological properties of the Nabak kimchi were measured for 25 days, following the preparation at a uniform temperature of 10$^{\circ}C$, and compared to a control (distilled water without kugija). For the properties of acceptability, the Nabak kimchi treated with 3% kugija was evaluated as being best during the whole fermentation. The number of total cell counts and number of lactic acid microorganisms gradually increased to a maximum, and then decreased. It was the maximum for controlling and 1 % treatment on day 2, forand 3, 5 and 7% treatment on day 7. (Eds note: the highlighted sentence needs c1arification\ulcorner)This experimental study revealed the effect of kugija extract in enhancing the eating qualities on Nabak kimchi and retarding the fermentation over the initial seven days. The optimum levels of kugija extract on Nabak kimchi obtained through experiments was between 1 and 3% of the water content. Although 3% gave a better color, the fermentation-retarding effect and savory taste. The application of kugija extract could be domestically applied to improve the eating quality and the preservation of traditionally prepared Nabak kimchi.

• The Korean Journal of Food And Nutrition
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• v.26 no.2
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• pp.249-257
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• 2013

This study is being performed to confirm the container effects during the fermentation processes of kimchi. Kimchi fermentation was prepared in the laboratory with four different types of containers; namely, a traditional Onggi vessel (Korean traditional clay pot, TOV), plastic airtight covered Onggi vessel (PAOV), plastic covered vessel (PCV) and plastic airtight covered vessel (PACV). The kimchi fermentation in the different containers was followed by taking samples at 48 hour intervals for 10 days. In all fermentation containers, the pH changes of kimchi were decreased with fermentation days, while salt content was the same for all types of containers. The number of lactic acid bacteria in kimchi were $1.09{\times}10^8$ $CFU/m{\ell}$ at first. But the TOV, PAOV, PCV, and PACV after fermentation for 10 days were $1.42{\times}10^{10}$, $9.13{\times}10^9$, $4.93{\times}10^9$ and $7.46{\times}10^9$ $CFU/m{\ell}$, respectively. The kimchi fermented in the TOV with the most dominant bacterial species were the following 5 strains: Bacillus subtilis, B. licheniformis, B. safensis, Lactobacillus brevis and B. pumilus. The use of different types of containers therefore influenced the number of L. brevis and the four Bacillus species. in kimchi, and may influence the characteristics of the fermented kimchi products. The TOV offered the greatest L. brevis numbers and suggested that it could be the best suited for preparing traditional kimchi fermentation.

• Journal of Microbiology and Biotechnology
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• v.34 no.8
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• pp.1727-1737
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• 2024

The quality of tobacco is directly affected by macromolecular content, fermentation is an effective method to improve biochemical properties. In this study, we utilized CBHA (cellobiohydrolase A) glycosylase, which was expressed by Pichia pastoris, as an additive for fermentation. The contents of main chemical components of tobacco leaves after fermentation were determined, and the changes of microbial community structure and abundance in tobacco leaves during fermentation were analyzed. The relationship between chemical composition and changes in microbial composition was investigated, and the function of bacteria and fungi in fermentation was predicted to identify possible metabolic pathways. After 48 h of CBHA fermentation, the contents of starch, cellulose and total nitrogen in tobacco leaf decreased by 17.60%, 28.91% and 16.05%, respectively. The microbial community structure changed significantly, with Aspergillus abundance decreasing significantly, while Filobasidum, Cladosporium, Bullera, Komagataella, etc., increased in CBHA treated group. Soluble sugar was most affected by microbial community in tobacco leaves, which was negatively correlated with starch, cellulose and total nitrogen. During the fermentation process, the relative abundance of metabolism-related functional genes increased, and the expressions of cellulase and endopeptidase also increased. The results showed that the changes of bacterial community and dominant microbial community on tobacco leaves affected the content of chemical components in tobacco leaves, and adding CBHA for fermentation had a positive effect on improving the quality of tobacco leaves.

• Journal of Life Science
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• v.22 no.2
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• pp.232-238
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• 2012

Kumjungsansung-Makgeolli$^{(R)}$ is a traditional Korean rice wine that is fermented from traditional nuruk and rice. In this study, we performed the PCR-denaturing gradient gel electrophoresis (DGGE) analysis targeting the 16S and 28S rRNA genes to characterize bacterial and fungal diversity during Makgeolli fermentation. The predominant bacteria in the PCR-DGGE profile during Makgeolli fermentation were Lactobacillus spp. (Lactobacillus curvatus, L. kisonensis, L. plantarum, L. sakei, and L. gasseri), Pediococcus spp. (P. acidilactici, P. parvulus, P. agglomerans, and P. pentosaceus), Pantoea spp. (P. agglomerans and P. ananatis), and Citrobacter freundii; these were identified on the base of analysis of 16S rRNA gene sequences. The dominant bacterium during Makgeolli fermentation was L. curvatus. The predominant fungi in PCR-DGGE profile during Makgeolli fermentation were Pichia kudriavzevii, Saccharomyces cerevisiae, Asidia idahoensis, Kluyveromyces marxianus, Saccharomycopsis fibuligera, and Torulaspora delbrueckii, and these were identified on the basis of analysis of 28S rRNA gene sequences. The dominant fungal species during Makgeolli fermentation changed from P. kudriavzevii at 0-2 days incubation to S. cerevisiae at 3-6 days incubation. This study suggests that PCR-DGGE analysis could be a suitable tool for the understanding of microbial diversity and structure during Makgeolli fermentation.