• Microbiology and Biotechnology Letters
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• v.51 no.1
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• pp.83-92
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• 2023

In this study, bioconversion of rutin to quercetin was confirmed by the fermentation of Korean indigenous probiotics and tartary buckwheat. Based on whole genome sequencing of 17 probiotics species, α-rhamnosidase, related to bioconversion of isoquercetin (quercetin 3-β-D glucoside) from rutin, is identified in the genome of CBT BG7, LC5, LR5, LP3, LA1, and LGA1. β-Glucosidase, related to bioconversion of isoquercetin to quercetin, is identified in the genome of all 17 species. Among the 17 probiotics species, 6 probiotics including CBT BG7, LR5, LP3, LA1, LGA1 and ST3 performed the bioconversion of rutin to quercetin up to 21.5 ± 0.3% at 7 days after fermentation. The fermentation of each probiotics together with enzyme complex Cellulase KN^® was conducted to reduce the time of bioconversion. As a result, CBT LA1 which showed the highest yield of bioconversion of 21.5 ± 0.3% when the enzyme complex was not added showed high bioconversion yield of 84.6 ± 0.5% with adding the enzyme complex at 1 day after fermentation. In particular, CBT ST3 (96.2 ± 0.4%), SL6 (90.1 ± 1.4%) and LP3 (90.0 ± 0.4%) showed high yield of bioconversion more than 90%. In addition, such probiotics including high levels in quercetin indicated the inhibitory effects of NO production in LPS-induced RAW264.7 cells. In this study, we confirmed that the fermentation of Korean indigenous probiotics and enzyme complex together with roasted tartary buckwheat increased the content of quercetin and reduced the time of bioconversion of rutin to quercetin which is a bioactive compound related to anti-inflammatory, antioxidants, anti-obesity, and anti-diabetes.

• Korean Journal of Microbiology
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• v.42 no.4
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• pp.306-312
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• 2006

Disposal of food garbage in most large cities is very troublesome task. To date, microbiological treatment has been received an attention as a garbage decomposition process. In this study, the inoculation effect of some cellulase, amylase and protease-producing bacteria and photosynthetic bacteria on food garbage treatment was examined. They were added into a treatment reactor specially designed in this study together with food garbage and incubated in various conditions for 15 days and the removals of food garbage and foul smell produced during the treatment were analyzed. Average decomposition percentages of the inoculated food garbage in treatment reactor were 11 and 18.8% under intermittent aeration (once in a day) and continuous aeration conditions (2 L/min), respectively, and these were higher than removal percentages in the corresponding uninoculated reactors,3.4 and 13.8%. Optimal pH and temperature for food garbage decomposition by inoculated bacteria were pH 7.0 and $30^{\circ}C$. Maximal decomposition percentage in the inoculated food garbage was 35% under the optimal condition (pH 7, $30^{\circ}C$, and continuous aeration). The malodor compounds generated from food garbage treatment such as complex foul smell and sulfur compounds were effectively reduced about 84% and 25.5%, respectively, with a biofilter composed of purple nonsulfur bacteria trapped in sponge. This decomposing capability of food garbage by these bacteria can be utilized for the rapid and efficient treatment of food garbage.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.460-465
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• 1990

Regeneration of protoplast was effective by preincubating spore suspension containing 30$\mu g$/ml of 2-DG for 4 hours, and CBE medium containing casamino acid, bovine serum albumin, ergosterol and myoinositol was found to be more efficient than any other regeneration medium tested in this experiment. The regeneration frequency was about 30%. Optimal conditions for conidial protoplast fusion were obtained by treatment of protoplasts with 10 mM $CaCl_2$ and 30% polyethylene glycol 4000 (pH 7.5) as fusogenic agent at $37^{\circ}C$ for 10 minutes. The fusion frequency was $8.2\times 10^{-4}$. The higher productivity of enzyme of fusant FWN-56 was achived: 2.3-fold for CMCase, 1.5-fold for avicelase, 1.8-fold for $\beta$-glucosidase and 2.5-fold for xylanase compared to that obtained in two parental strains. The genetic stability of fusant after maintenance on minimal medium for more than 4 weeks was high because segregant rate was below 1%. The conidial DNA content of fusant was 1.4-1.6 times higher than that of the parental strains, The nucleus size of fusants were also higher than that of each parental strains.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.585-591
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• 2014

To evaluate the potential utility of pretreatment of raw biomass with a complex microbial system, we investigated the degradation of rice straw by BMC-9, a lignocellulose decomposition strain obtained from a biogas slurry compost environment. The degradation characteristics and corresponding changes in the bacterial community were assessed. The results showed that rapid degradation occurred from day 0 to day 9, with a peak total biomass bacterium concentration of $3.3{\times}10^8$ copies/ml on day 1. The pH of the fermentation broth declined initially and then increased, and the mass of rice straw decreased steadily. The highest concentrations of volatile fatty acid contents (0.291 mg/l lactic acid, 0.31 mg/l formic acid, 1.93 mg/l acetic acid, and 0.73 mg/l propionic acid) as well as the highest xylanse activity (1.79 U/ml) and carboxymethyl cellulase activity (0.37 U/ml) occurred on day 9. The greatest diversity among the microbial community also occurred on day 9, with the presence of bacteria belonging to Clostridium sp., Bacillus sp., and Geobacillus sp. Together, our results indicate that BMC-9 has a strong ability to rapidly degrade the lignocelluloses of rice straw under relatively inexpensive conditions, and the optimum fermentation time is 9 days.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2011.04a
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• pp.81-91
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• 2011

Current fuel ethanol research and development deals with process engineering trends for improving biotechnological production of ethanol. Recently, a large amount of studies regarding the utilization of lignocellulosic biomass as a good feedstock for producing fuel ethanol is being carried out worldwide. The plant biomass is mainly composed of cellulose, hemicellulose and lignin. The main challenge in the conversion of biomass into ethanol is the complex, rigid and harsh structures which require efficient process and cost effective to break down. The isolation of microorganisms is one of the means for obtaining enzymes with properties suitable for industrial applications. For these reasons, crude cultures containing cellulosic biomass degrading microorganisms were isolated from rice field soil, cow farm soil and rotten rice straw from cow farm. Carboxymethyl cellulose (CMC), xylan and Avicel (microcrystalline cellulose) degradation zone of clearance on agar platefrom rice field soil resulted approximately at 25 mm, 24 mm and 22 mm respectively. As for cow farm soil, CMC, xylan and Avicel degradation clearancezone on agar plate resulted around at 24mm, 23mm and 21 mm respectively. Rotten rice straw from cow farm also resulted for CMC, xylan and Avicel degradation zone almost at 24 mm, 23 mm and 22 mm respectively. The objective of this study is to isolatebiomass degrading microbial strains having good efficiency in cellulose hydrolysis and observed the effects of different substrates (CMC, xylan and Avicel) on the production of cellulase enzymes (endo-glucanase, exo-glucanase, cellobiase, xylanase and avicelase) for producing low cost biofuel from cellulosic materials.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.5
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• pp.382-390
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• 2006

Various microorganisms were isolated from the surface waters and sediments of eutrophic lakes and reservoirs in Korea to enable an investigation of bacteria having algal lytic activities against Anabaena flos-aquae when water blooming occurs and to study enzyme profiles of algal lytic bacteria. Two bacterial strains, AFK-07 and AFK-13, were cultured, characterized and identified as Acinetobacter johnsonii and Sinorhizobium sp., respectively. The A. johnsonii AFK-07 exhibited a high level of degradatory activities against A. flos-aquae, and produced alginase, caseinase, lipase, fucodian hydrolase, and laminarinase. Moreover, many kinds of glycosidase, such as ${\beta}-galactosidase,\;{\beta}-glucosidase,\;{\beta}-glucosaminidase,\;and\; {\beta}-xylosidase$, which hydrolyzed ${\beta}-O-glycosidic$ bonds, were found in cell-free extracts of A. johnsonii AFK-07. Other glycosidases such as ${\alpha}-galactosidase,\;{\alpha}-N-Ac-galactosidase,\;{\alpha}-mannosidase,\; and\;{\alpha}-L-fucosidase$, which cleave ${\alpha}-O-glycosidic$ bonds, were not identified in AFK-07. In the Sinorhizobium sp. AFK-13, the enzymes alginase, amylase, proteinase (caseinase and gelatinase), carboxymethyl-cellulase (CMCase), laminarinase, and lipase were notable. No glycosidase was produced in the AFK-13 strain. Therefore, the enzyme system of A. johnsonii AFK-07 had a more complex mechanism in place to degrade the cyanobacteria cell walls than did the enzyme system of Sinorhizobium sp. AFK-13. The polysaccharides or the peptidoglycans of A. flos-aquae may be hydrolyzed and metabolized to a range of easily utilized monosaccharides or other low molecular weight organic substances by strain AFK-07 of. A. johnsonii, while the products of polysaccharide degradation or peptidoglycans were more likely to be utilized by Sinorhizobium sp. AFK-13. These bacterial interactions may offer an alternative effective approach to controlling the water choking effects of summer blooms affecting our lakes and reservoirs.

• The Korean Journal of Mycology
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• v.14 no.3
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• pp.189-194
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• 1986

The aim of this study was to investigate physiological chracteristics of Lentinus edodes in Korea. We tried to detect properties of the several wood-degradative enzymes and investigate patterns of the enzyme production. A specific carbon source was used in the enzyme induction media for each enzymes, and the crude extract was used for the enzyme solution. With these enzyme solution, we investigated optimum temperature and pH conditions of their reactions. Moreover we investigated transition patterns of the enzyme production of the several wood-degrad­ative enzmes from Complex and Saw dust media for the purpose of studying the mechanisms of the wood component degradation by this fungus. It was assumed that the order of the wood com­ponent degradation was cellulose, xylan, and then pectic substances, and that the synergistic effects of these substances also influenced the degradation of wood components.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.702-710
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• 2016

The bioactivity of soy grits cheonggukjang was enhanced by fermentation using three ${\beta}$-glucosidase-producing Bacillus subtilis strains (HJ 18-9, HJ 25-8, and HJ 18-9+HJ 25-8) for 48 h at $37^{\circ}C$. The results indicate that protease, cellulase, and a-amylase activities significantly increased (P<0.05) with increasing fermentation time. In addition, the amino-type nitrogen content of B. subtilis-fermented soy grits cheonggukjang increased to 91.0~168.0 mg% after 48 h of fermentation. Among the isoflavones in soy grits cheonggukjang, contents of ${\beta}$-glucosides or acetyl-glucosides were reduced while aglycone content increased upon fermentation. In particular, soy grits cheonggukjang fermented with B. subtilis HJ18-9 and HJ25-8 showed the largest increases in aglycone content compared to complex treatment. These results provide useful information for development starter (single and complex) as well as for production of high quality fermented soybean food.

• Journal of Life Science
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• v.34 no.7
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• pp.485-492
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• 2024

Sea cucumbers contain more than 50% protein in their solid content, and they also possess various bioactive substances such as saponins and mucopolysaccharides. This study analyzed the activities of various enzymes derived from Bacillus and lactic acid bacteria and determined to degrade the components of sea cucumbers. Among the analyzed strains, B. subtilis K26 showed the highest activities in protease and xylanase and relatively high activity in cellulase. Accordingly, samples of sea cucumber and water were mixed in equal proportions, sterilized, and then fermented by inoculating them with B. subtilis K26. Following this, a higher amino acid content was observed between 1.5 and 7.5 hr, a lower residual solid content in this time, and a lesser fermentation odor. The saponin content in fermented sea cucumber powder extracted with butanol was measured to be 1.12 mg/g. The chondroitin sulfate content was evaluated to be 5.11 mg/g in raw sea cucumber. The total polyphenol content, flavonoid content, and antioxidant activities were 6.95 mg gallic acid equivalent/g, 3.69 mg quercetin equivalent/g, and 3.69 mg quercetin equivalent/g in raw sea cucumber, respectively. Moreover, the DNA damage protective effect of fermented sea cucumber extract was found to be concentration-dependent, with a very strong effect at very low concentrations. Overall, we suggest that sea cucumber fermented with B. subtilis K26 has a high potential as a food for inhibiting oxidation, enhancing immunity, and improving muscle function in the human body thanks to its high free amino acid content.

• Applied Biological Chemistry
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• v.22 no.2
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• pp.65-90
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• 1979

This study was conducted to establish the brewing method which would be useful for the production of Kochuzang. Kojis, which were made from various materials and microorganisms under a covered condition, were investigated and compared. Yeasts (Saccharomyces rouxii and Torulopsis versatilis) were added to Kochuzang, and the enzyme activity, microflora, chemical composition, nitrogen content, alcohol content and free sugars of Kochuzang were investigated and analysed. The results obtained are as follows: 1. Koji making (1) Glutinous rice-soybean group was superior to glutinous rice group in the saccharogenic and liquefying amylase activities of three day-Koji. (2) Protease activity (acid, neutral and alkaline) of glutinous rice-soybean Koji, which was inoculated with Aspergillus oryzae A, was increased till the 5th day, while other groups showed maximum activity after the 3rd day. (3) The maximum cellulose activity of Aspergillus oryzae B-Koji and A-Koji was observed after the 2nd day and the 3rd day, respectively. High cellulose activity of Aspergillus oryzae B-Koji and A-Koji was respectively shown in glutinous rice group and glutinous rice-soybean group at maximum. (4) Compared with glutinous rice Koji, glutinous rice-soybean Koji gave larger number of yeast and aerobic bacteria. 2. Kochuzang Fermentation (1) Each Kochuzang group shoved different liquefying and saccharogenic amylase activities. The highest activities were generally shown in 10 to 40 days after mashing and remarkably reduced in the last stage of aging. (2) Protease activities of each group were strong in order of acid, neutral and alkaline protease. Especially acid protease showed highest activity at the 40th to 50th day Kochuzang. (3) Each group showed maximum cellulase activity in the 40th and 50th day-Kochuzang and then decreased. (4) Osmophilic yeast of yeast-added Kochuzang after one-month aging was distinctively outnumbered compared with non-yeast-added Kochuzang, but two groups were similar after two months. (5) Yeast-added group and non-added group gave almost the same number of halophilic lactic acid bacteria in Kochuzang, but the non-added group gave slightly larger number of aerobic bacteria than the yeast-added group. (6) Amino nitrogen contents in all test group were increased rapidly till the 60th day of Kochuzang aged. After that the contents were increased slowly. (7) Ethyl alcohol contents of 20day-fermented Kochuzang were high in order of Saccharomyces rouxii-added group, Torulopsis versatilis-added group, Saccharomyces rouxii and Torulopsis versatilis mixed group and non-yeast-added group. But all test group showed about 2% in ethyl alcohol content after 40days of aging. (8) Alcohol content in the 7 month-aged Kochuzang of all test groups was high in order of ethyl alcohol, n-butyl alcohol, n-propyl alcohol and iso-propyl alcohol. Torulopsis versatilis-added group had the highest value of ethyl alcohol, n-propyl alcohol and n-butyl alcohol. (9) Reducing sugar in Kochuzang was increased after 20 days of aging compared with the 10days-ferment. The reducing sugar content in Saccharomyces rouxii-added group was distinctively small compared with that of other groups, decreasing after 30days of aging. (10) Rhamnose, fructose, glucose and maltose were isolated from the 10 day fermented Kochuzang. Raffinose was also found after 300 days-aged group, and fructose content was high in the 300days-aged Kochuzang. However, glucose content was smaller than that of 10days-fermented Kochuzang. (11) For the organoleptic tests of Kochuzang, taste, flavour and color of yeast-added group were superior to the non yeast-added group. Especially the complex yeast group among the yeast added groups were the best of all. Yeast-added group after 300 days of aging took higher paint in flavour test than that of non-added group. Therefore, brewing method like complex yeast added group seems to be advantageous for short time brewing Kochuzang.