• Microbiology and Biotechnology Letters
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• v.49 no.1
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• pp.45-56
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• 2021

Improved amylases were developed from protoplast fusants of two amylase-producing Aspergillus species. Twenty regenerated fusants were screened for amylase production using Remazol Brilliant Blue agar. Crude enzyme extracts produced by solid state fermentation of rice bran were assayed for activity. Three variable factors (temperature, pH and enzyme type) were optimized to increase the amylase activity of the parents and selected fusants using rice bran medium and solid state fermentation. Analysis of this optimization was completed using the Central Composite Design (CCD) of the Response Surface Methodology (RSM). Amylase activity assays conducted at room temperature and 80℃ demonstrated that Aspergillus designates, T5 (920.21 U/ml, 966.67 U/ml), T13 (430 U/ml, 1011.11 U/ml) and T14 (500.63 U/ml, 1012.00 U/ml) all exhibited improved function making them the preferred fusants. Amylases produced from these fusants were observed to be active over the entire pH range evaluated in this study. Fusants T5 and T14 demonstrated optimal activity under acidic and alkaline conditions, respectively. Fusants T13 and T14 produced the most amylase at 72 h while parents TA, TC and fusant T5 produced the most amylase after 96 h of incubation. Response surface methodology examinations revealed that the enzyme from fusant T5 was the optimal enzyme demonstrating the highest activity (1055.17 U/ml) at pH 4 and a temperature of 40℃. This enzyme lost activity with further increases in temperature. Starch hydrolysis using fusant T5 gave the highest yield of glucose (1.6158 g/100 ml). The significant activities of the selected fusants at 28 ± 2℃ and 80℃ and the higher sugar yields from cassava starch hydrolysis over their parental strains indicate that it is possible to improve amylase activity using the protoplast fusion technique.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.4
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• pp.267-273
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• 2004

The optimization of culture conditions for the bacterium Pseudomonas aeruginosa BYK-2 KCTC 18012P, was performed to increase its rhamnolipid production. The optimum level for carbon, nitrogen sources, temperature and pH, for rhamnolipid production in a flask, were identified as 25 g/L fish oil, 0.01% (w/v) urea, 25 and pH 7.0, respectively. Optimum conditions for batch culture, using a 7-L jar fermentor, were 200 rpm of agitation speed and a 2.0 L/min aeration rate. Under the optimum conditions, on fish oil for 216 h, the final cell and rhamnolipid concentrations were 5.3 g/L and 17.0 g/L respectively. Fed-batch fermentation, with different feeding conditions, was carried out in order to increase, cell growth and rhamnolipid production by the Pseudomonas aeruginosa, BYK-2 KCTC 18012P. When 2.5 g of fish oil and 100 mL basal salts medium, containing 0.01 % (w/v) urea, were fed intermittently during the fermentation, the final cell and rhamnolipid concentrations at 264 h, were 6.1 and 22.7 g/L respectively. The fed-batch culture resulted in a 1.2-fold increase in the dry cell mass and a 1.3-fold increase in rhamnolipid production, compared to the production of the batch culture. The rhamnolipid production-substrate conversion factor (0.75 g/g) was higher than that of the batch culture (0.68 g/g).

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.479-485
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• 2012

In order to develop methods that would enlarge the feed resources in Tibet, mixtures of hulless-barley straw and tall fescue were ensiled with four levels (0, 10%, 20%, and 30% of fresh weight) of wet hulless-barley distillers' grains (WHDG). The silos were opened after 7, 14 or 30 d of ensiling, and the fermentation characteristics and nutritive quality of the silages were analyzed. WHDG addition significantly improved fermentation quality, as indicated by the faster decline of pH, rapid accumulation of lactic acid (LA) (p<0.05), and lower butyric acid content and ammonia-N/total N (p<0.05) as compared with the control. These results indicated that WHDG additions not only effectively inhibited the activity of aerobic bacteria, but also resulted in faster and greatly enhanced LA production and pH value decline, which restricted activity of undesirable bacteria, resulting in more residual water soluble carbohydrates (WSC) in the silages. The protein content of WHDG-containing silages were significantly higher (p<0.05) higher than that of the control. In conclusion, the addition of WHDG increased the fermentation and nutritive quality of straw-grass silage, and this effect was more marked when the inclusion rate of WHDG was greater than 20%.

• Journal of Conservation Science
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• v.25 no.1
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• pp.39-47
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• 2009

This paper reports a study on physical properties of the traditional adhesives for developing natural adhesives. This is to certify that the superiority of tradition through systematic surveys and experiments as well. We used three kinds of starches differing fermentation time(7 years, 4 years 8 months, and 2 years 8 months) which are fermented from wheat flour starches. The amylose contents, total sugar contents, crystallinity, particle size and shape, viscosity, pH, and adhesive strength were examined. The effect of fermentation time on physical properties of fermented wheat flour were studied. It was found that fermentation time effect various physical properties such as total sugar contents, amylose contents, crystallinity, viscosity, and so on.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.531-535
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• 2017

In this study, Leuconostoc mesenteroides CJNU0041 was isolated from Korean traditional food kimchi and antimicrobial activity of fermented broccoli with the isolate was tested against pathogenic Clostridium difficile. L. mesenteroides CJNU0041 showed higher glucosidase activity than other isolates. As the results of physiological properties such as pH and viable cell count during broccoli fermentation with L. mesenteroides CJNU0041, we confirmed that 48 hours was optimal fermentation time. As the results of metabolite analysis by HPLC, metabolites were changed during the fermentation. Especially, the growth of C. difficile was inhibited by the fermented broccoli. Therefore, L. mesenteroides CJNU0041 might be a candidate for improving the functionality of natural materials by lactic acid fermentation.

• Microbiology and Biotechnology Letters
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• v.51 no.3
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• pp.250-256
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• 2023

Cannabis sativa (CS) has been in the spotlight not only for its medical uses but also as a raw material for cosmetics. As fermented cosmetics are known to have various health benefits, they have been extensively researched. Here, we investigated the characteristics of CS stems fermented using various gut microbes. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay and melanin content analysis revealed that melan-a cells containing CS stems fermented with Weissella paramesenteroides (CSWP) showed considerably reduced melanin content. Additionally, CSWP downregulated the expression of several melanogenesis factors, tyrosinase-related protein-1, and tyrosinase-related protein-2. This study suggests that the anti-melanogenic effect of CSWP could provide a new basis for the development of skin-lightening agents.

• Journal of Life Science
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• v.18 no.8
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• pp.1049-1052
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• 2008

Microbial production of cellulolytic enzymes by Aspergillus niger in solid state fermentation (SSF) and submerged state fermentation (SF) in laboratory scale was compared. Czapek Dox liquid broth amended with cellulose (0.5%) was used for cultivation in SF, whereas rice bran was used as a solid support, moistened with cellulose, amended Czapek Dox broth for growth in SSF. The production of Carboxymethyl cellulase, Filter paperase and ${\beta}$-Glucosidase was monitored at regular intervals. The peak production of the enzymes occurred within 3 days of incubation in SSF as against $\geq$ 7 days in SF. SSF gave higher yields of enzymes in comparison to SF. Maximum titres of 0.40, 0.62 and 0.013 U/ml in respect of FPase, CMCase and ${\beta}$-glucosidase in SSF were recovered as against 0.13, 0.06 and 0.0013 U/ml in SF respectively, at their respective peak time intervals. Hence, SSF appeared to be a better choice for production of cellulolytic enzymes by Aspergillus niger.

• The Korean Journal of Food And Nutrition
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• v.23 no.3
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• pp.324-331
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• 2010

This study was designed to test the effects of enzyme treatments on the extraction of total phenolic compounds and on color characteristics in wines from domestic MBA(Muscat Bailey A) grapes. The total phenolic compound content of the MBA grape wine was $1,352.8{\pm}37.8\;mg/{\ell}$ at 10 days of fermentation. Furthermore, MBA wines treated with 2%(v/v) of Pectinex and Viscozyme had 14.5%(p<0.05) and 3.8% increase, respectively, in total phenolic compound content by 10 days of fermentation. Pectinex treatment was more effective for phenolic levels than Viscozyme treatment. The L, a and b values of the MBA grape wine were 7.4, 9.2 and -1.2, respectively, by 10 days of fermentation. The values in case of Pectinex enzyme treatment were 7.0, 10.6 and -0.8, respectively, and these values were significantly different according to Pectinex treatment(p<0.05). But the values in case of Viscozyme enzyme treatment were 7.2, 9.8 and -1.1, respectively, and these values were not different according to Viscozyme treatment. The hue and color intensity values of the MBA grape wine were 0.492 and 0.785, respectively, by 10 days of fermentation. The values in case of Pectinex enzyme treatment were 0.460 and 0.881, respectively. And as a result of the Pectinex treatment, the hue value of wine was decreased and color intensity was increased slightly(p<0.05). But the values in case of Viscozyme enzyme treatment were 0.482 and 0.805, respectively, and these values were not different according to the Viscozyme treatment.

• Food Science and Preservation
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• v.20 no.5
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• pp.699-704
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• 2013

Buckwheat Soksungjang (BS) is a bealmijang manufactured with buckwheat and soybeans. We manufactured BS using Bacillus subtilis HJ18-4 (HJ18-4), which has high enzyme activities and antibacterial effects. HJ18-4 was inoculated in a different process during the BS manufacturing, which was the meju-making time (Treat 1), and the salt water time was added (Treat 2). The physiochemical and microbial characteristics of the BS were analyzed. As a result, the total aerobic counts (7~8 log CFU/mL) in the BS increased after 15 days of fermentation. Especially, Treat 1 showed higher total aerobic counts and amino-type nitrogen (65.38~202.52 mg%) than Treat 2. During the BS fermentation, the reduction of the sugar contents and the enzyme (protease and amylase) activities decreased. In the relative quantitative expression level of PlcR, Treat 1 did not show toxin gene expressions at the end of the fermentation on Day 23. Treat 1 showed suitable B. cereus physiochemical quality characteristics and inhibition effects. When the modified-form type of fermented soybean paste was manufactured with a single starter, it could not reproduce the natural fermentation quality. These results suggest that the addition of a starter (HJ18-4) in the Meju manufacturing process could enhance the quality characteristics of the manufactured BS via natural fermentation and by suppressing B. cereus.

• Food Science and Preservation
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• v.24 no.2
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• pp.237-245
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• 2017

Lactic acid fermentation of Flammulina velutipes (FV) powder was optimized to produce higher content of ${\gamma}-aminobutyric$ acid (GABA). FV powder (10%) was fermented with 0.5% yeast extract, 1% glucose, 5% mono sodium-L-glutamate (MSG) by Lactobacillus plantarum EJ2014 for 5 days at $30^{\circ}C$. The pH decreased from 6.1 to 4.4 for first 2 days after then increased to 6.2 for following 5 days. While the acidity increased from 0.5% to 1.3% for 2 days, after then decreased to 0.4% for 5 days. Viable cell count showed higher value of $2.2{\times}10^9CFU/mL$ after fermentation for 5 days. In particular, 3.54% MSG as a substrate was completely utilized during lactic acid fermentation, indicating higher 2.31% GABA content. The fermented FV powder showed higher antioxidant properties than that of un-fermented FV power. $IC_{50}$ values of DPPH radical scavenging and ABTS radical scavenging activities were 1.11 mg/mL and 2.58 mg/mL, respectively. Conclusively, natural fermented seasoning from the lactic acid fermentation of 30g of FV powder and 1 g of roasted wheat bran could provide the functional ingredients with 17% GABA, probiotics and dietary fiber, which is used for health food and functional seasoning.