• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.779-786
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• 2012

Rhodiola sachalinensis fermentates by lactic acid bacteria were prepared using the adsorption process, and were investigated for changes of the main compounds and anti-oxidative activities during the adsorption and fermentation process. While the R. sachalinensis extract (RSE), which did not go through the adsorption process, showed little change in pH during fermentation and a significant reduction in the number of lactic acid bacteria, the pre-preparatory adsorption process was found to be helpful for promoting fermentation and for maintenance of bacterial numbers. The contents of total phenolic compounds mostly decreased during the adsorption process, but showed an increasing tendency to rebound during the fermentation process. The contents of salidroside and p-tyrosol in the RSE were 1153.3 mg% and 185.0 mg% respectively, and they did not significantly change after treatment with acid clay or bentonite as adsorbents, which were 1093.0 and 190.5 mg% by acid clay, and 882.2 and 157.3 mg% by bentonite. When the extract was fermented after treatment with acid clay or bentonite, the salidroside contents were decreased by 282.7 and 505.0 mg% respectively, but the p-tyrosol contents were increased by 714.0 and 522.4 mg% respectively. Compared to the DPPH radical scavenging activity of the RSE (66.8%) at the conc. of 0.1%, that of the fermented RSE, which went through adsorption process with acid clay or bentonite, was significantly increased to 79.4 and 72.7% respectively at the same concentration (p<0.05). Though fermentation by lactic acid bacteria was suppressed in the RSE, the results suggested that the adsorption process may promote fermentation without any change in the content of major active compounds. It is expected that fermentation by lactic acid bacteria could improve the antioxidant activity and various associated functionalities of R. sachalinensis.

• Journal of Environmental Health Sciences
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• v.23 no.3
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• pp.40-49
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• 1997

In Korea, naked barley and tapioca are main raw materials for the production of fermentation ethyl alcohol, and one million drums bf 95% fermentation ethyl alcohol is produced per year by use of them. Stillage of alcoholic fermentation is mostly digested by methane fermentation process, and methane gas occured if methane fermentation process is recovered and mixed with fuel to decrease 25-30% for total fuel used in factories. In the anaerobic digestion process of naked barley stillage, supplement of nutrients is necessary to slove the problems caused by inhibitory materials contained if stillage and deficiency of nutrients. Therefore, the objective of this study was to examine why the anaerobic digesters using the naked barley distillery wastewater have shown the poor digestability frequently and how to control it. As the poor digestion was supposed to be occurred by the lack of iron as trace nutrient, the experiments were carried out to find out the optimum dosage and the way of addition of iron and to assess the quantitative evaluation of the type of iron in digesters. Initially, bottle test as batch digesters and lab-scaled continuous flow digesters were used in order to determine the digestion characteristics with tapioca and naked barley distillery wastewater. According to the results of batch tests, the poor digestion was caused by volatile fatty acids and could be improved by adding of calcium. The activity of the methanogenic bacteria were increased remarkably when the iron was added to the digester in the form of mixture with substrates.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.5
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• pp.340-344
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• 2000

Microbial oxidation of D-sorbitol to L-sorbose by Acetobacter suboxydans is of commercial importance since it is the only biochemical process in vitamin C synthesis. The main bottleneck in the batch oxidation of sorbitol to sorbose is that the process is severely inhibited by sorbitol. Suitable fed-batch fermentation designs can eliminate the inherent substrate inhibition and improve sorbose productivity. Fed-batch sorbose fermentations were conducted by using two nutrient feeding strategies. For fed-batch fermentation with pulse feeding, highly concentrated sorbitor (600g/L) along with other nutrients were fed intermittently in four pulses of 0.5 liter in response to the increased DO signal. The fed-batch fermentation was over in 24h with a sorbose productivity of 13.40g/L/h and a final sorbose concentration of 320.48g/L. On the other hand, in fed-batch fermentation with multiple feeds, two pulse feeds of 0.5 liter nutrient medium containing 600g/L sorbitol was followed by the addition of 1.5 liter nutrient medium containing 600g/L sorbitol at a constant feed rate of 0.36L/h till the full working capacity of the reactor. The fermentation was completed in 24h with an enhanced sorbose productivity of 15.09g/L/h and a sorbose concentration of 332.60g/L. The sorbose concentration and productivity obtained by multiple feeding of nutrients was found to be higher than that obtained by pulse feeding and was therefore a better strategy for fed-batch sorbose fermentation.

• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.863-870
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• 2024

Meju, a fermented soybean brick, is a key component in soybean foods like doenjang and ganjang, harboring a variety of microorganisms, including bacteria and fungi. These microorganisms significantly contribute to the nutritional and sensory characteristics of doenjang and ganjang. Amplicon-based next-generation sequencing was applied to investigate how the microbial communities of meju fermented at low and high temperatures differ and how this variation affects the microbial communities of doenjang, a subsequently fermented soybean food. Our metagenomic data showed distinct patterns depending on the fermentation temperature. The microbial abundance in the bacterial community was increased under both temperatures during the fermentation of meju and doenjang. Weissella was the most abundant genus before the fermentation of meju, however, it was replaced by Bacillus at high temperature-fermented meju and lactic acid bacteria such as Weissella and Latilactobacillus at low temperature-fermented meju. Leuconostoc, Logiolactobacillus, and Tetragenococcus gradually took over the dominant role during the fermentation process of doenjang, replacing the previous dominant microorganisms. Mucor was dominant in the fungal community before and after meju fermentation, whereas Debaryomyces was dominant under both temperatures during doenjang fermentation. The dominant fungal genus of doenjang was not affected regardless of the fermentation temperature of meju. Strong correlations were shown for specific bacteria and fungi linked to specific fermentation temperatures. This study helps our understanding of meju fermentation process at different fermentation temperatures and highlights different bacteria and fungi associated with specific fermentation periods which may influence the nutritional and organoleptic properties of the final fermented soybean foods doenjang.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.9
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• pp.1359-1365
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• 2010

This study investigated effects of types of added sugar on alcohol fermentation of oriental melon. According to the results, pH was not significantly different according to types of added sugar and fermentation process. Total acidity increased with fermentation process in all groups by recording around 1.4% at the ninth day of fermentation. For sugar content, its initial level was $22^{\circ}Brix$, and alcohol fermented oriental melon fluids added by sucrose, fructose and glucose recorded similar levels or $6.6{\sim}6.8^{\circ}Brix$ while the fluids added by honey and fructo-oligosaccharide showed a slightly higher level or $8.1^{\circ}Brix$ at the ninth day of fermentation. Although free sugar content was different in the early phase of fermentation according to types of added sugar such as sucrose, fructose and glucose, it reduced with fermentation process to nearly non-detection at the ninth day of fermentation. As organic acids, lactic acid and acetic acid were observed in all phases of fermentation and their contents became higher gradually with fermentation process. Alcohol content showed the highest level in alcohol fermented oriental melon fluid added by sucrose by recording 12.80% and was relatively low in the fluids added by fructose and oligosaccharide. For alcohol, acetaldehyde, n-propanol and iso- amylalcohol contents were not significantly different according to types of added sugar and methanol content was the lowest in the fluid added by fructose by recording 84.99 ppm.

• Korean Journal of Microbiology
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• v.11 no.4
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• pp.167-174
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• 1973

This study included two parts of investigation, the microfloral changes during the brewing process with the changes of pH, total acidity, temperature and alcoholic contents, as well as determination of survival times of major enteric pathogens in Takju. 1. Maximum number of Saccharomyces cerevisiae was $4.3{\times}10^7$ per milliliter on the 5th day of fermentation and gradually decreased. Saccharomyces cerevisiae was one of the predominant strains of the fermentation process. The number of Saccharomyces cerevisiae was $4.3{\times}10^6$ per milliliter at the completion of the brewing and human consumption. In a few days after the completion of the brewing. Bacillus subtilis and some species of Staphylococcus spp. began to grow and those organisms were responsible for the spoilage. 2. Maximum pH, during the brewing, was 5.8 on the first day of fermentation and rapidly decreased until 6th day of fermentation at pH 4.3. 3. Maximum alcholic content was 14.5 degree on the 4th day of fermentation, 10.3 degree on the 5th day and this degree was continued during the experimentation. 4. Maximum temperature, during Takju brewing was 34.deg.C on the 3rd day of fermentation and rapidly decreased up to 23.deg.C on the 6th day and this temperature was continued until the brewing process was finished. 5. Maximum total acidity was 0.57 percent on the 4th day of fermentation and gradually decreased by brewing process was completed. 6. Survival time of major enteric pathogenic bacteria in Takju was as follows : Shigella dysenteriae and Escherichia coli were isolated in two hours and 14 hours respectively, but Salmonella typhi, Vibrio parahemolyticus were not isolated even in an hour after the inoculation of those organisms in undiluted Takju. In diluted Takju, Salmonella typhi, Vibrio parahemolyticus were not isolated even in an hour after the inoculation of those organisms in undiluted Takju. In diluted Takju, Salmonella typhi, Shigella dysenteriae, and Escherichia coli were survived for 50-60 hours, but Vibrio cholerae and Vibrio parahemolyticus were not isolated even if treated within one hour.

• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.24-28
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• 1989

Effect of various fermentation parameter was investigated on the production of prednisolone by microbial $\Delta$'-dehydrogenation of hydrocortisone. The microbial conversion process was conducted by using pseudo-crystallo-fermentation techniques. The optimum temperature for the bioconversion process was found to be 35$^{\circ}C$. It was noted that the production rate of prednisolone was little affected within the initial pH range of 6.5-7.8, and also by the use of surfactant, Tween 80. Production rate of prednisolone was significantly reduced by the use of the antifoam agent, neolin. In a fermentor operation, however, large amount of antifoam agent should be used to remove foams generated by the high aeration rate, which resulted in n lower production rate of prednisolone than that from the shake flask experiment.

• Journal of Pharmacopuncture
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• v.13 no.2
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• pp.33-49
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• 2010

Objectives: The aim of this experiment is to provide an objective differentiation of cultivated ginseng, mountain ginseng through component analysis, and to know the change of gin senoside components in the process of heating and fermentation Methods: Comparative analyses of ginsenoside $Rb_1$, $Rb_2$, Rc, Rd, Re, Rf, $Rg_1$, $Rg_3$, $Rh_1$, and $Rh_2$, from the cultivated ginseng 4 and 6 years, and mountain cultivated ginseng were conducted using HPLC (High Performance Liquid Chromatography, hereafter HPLC). And the same analyses were conducted in the process of heating and fermentation using mixed Lactobacillus rhamnosus, Lactobacillus plantarum, Bifidobacterium lactis for 7 days. Results: The change of ginsenosides to the process of red ginseng and fermentation, cultivated ginseng and mountain cultivated ginseng were showed another results. Mountain ginseng showed a lot of change compared with cultivated ginsengs. In the 7 days of fermentation, mountain ginseng showed that ginsenoside $Rg_1$, $Rb_1$, $Rb_2$, Rc, and Rd were decreased and increased ginsenoside Re, Rf, $Rg_3$ and $Rh_1$ were increased compared with cultivated ginseng Conclusions: It seemed that ginsenosides of mountain cultivated ginseng was better resolved than cultivated ginseng because the difference of structure or distribution of ginsenosides in the condition of fermentation.

• KSBB Journal
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• v.17 no.6
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• pp.566-570
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• 2002

In lactic acid fermentation, the end product inhibition by lactic acid causes several problems. The most important of which are low lactate formation rate and its recovery from fermentation broth. To overcome these problems, extractive lactic acid fermentation was carried out in a bioreactor, which was connected to a column packed with anion exchange resin (Amberlite IRA-400, 250 g). The system was started as a batch process, and then the separation process was started when the lactic acid concentration reached 10 g/L, 20 g/L or 30 g/L. In each case, total lactic acid concentration was reached to 48.6, 53.6, 52.6 g/L with its productivity of 1.2 g/L $.$ h, 1.6 g/L $.$ h, and 1.3 g/L $.$ h, respectively Especially, in the case of the 20 g/L recycling-initiation process, extractive fermentation reduced tie fermentation time (17 hrs) by 34% in comparison with the conventional batch process. The direct consequence of this time reduction was shown by a 1.8 fold increase in overall lactic acid productivity.

• KSBB Journal
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• v.28 no.5
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• pp.295-302
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• 2013

Indigo is utilized in various industries including textile dyeing, cosmetics, printing and medicinal products and its reduced form, leuco-indigo, is mainly used in these process. Chemical reducing agent (sodium dithionite, sodium sulfide, etc.) is preferred to use for the formation of leucoindigo in industry. In traditional indigo fermentation process, microorganisms can participate in the reduction of indigo and thus it has been known to reduce environmental pollution and noxious byproducts. However, in fermentation method using microorganisms it is difficult to standardize large scale production process due to low yield and reproducibility. In this study, we attempted to develop the indigo reduction process using microbial flora which was isolated from naturally fermented indigo vat or deduced by metagenomic approach. From the results of library analyses of PCR-amplified 16S rRNA genes from the traditional indigo fermentation vat sample (metagenome), it was confirmed that Alkalibacteriums (71%) was distinctly dominant in population. Some strains were identified after confirming that they become pure culture in nutrient media modified slightly. Four strains were separated in this process and each strain showed obvious reducing ability toward indigo in dyeing test. It is expected that the analyzed results will provide important data for standardizing the natural fermentation of indigo and investigating the mechanism of indigo reduction.