• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.663-667
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• 1992

The production of vinegar containing 16.0-18.0% of acetic acid was examined in two stage fermentation consisting of semi-continuous and fed-batch type. The optimum conditions were obtained when the fermentation was carried out at agitation of 600 rpm, aeration of 0.1 vvm and temperature of $30^{\circ}C$. The initial and residual ethanol concentration in 1st stage were $50.0g/{\ell}$ and $5.0g/{\ell}$, respectively, and the ethanol concentration in 2nd stage was maintained from 5.0 to $10.0g/{\ell}$. The maximum productivity was 3.3 gll-hr and the acidity was 17.6% after the two days of acetic acid fermentation.

• Journal of Microbiology and Biotechnology
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• v.21 no.4
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• pp.430-437
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• 2011

The effects of the agitation and aeration rates on the production of serratiopeptidase (SRP) in a 5-L fermentor (working volume 2-l) were systematically investigated using Serratia marcescens NRRL B-23112. The dissolved oxygen concentration, pH, biomass, SRP yield, and maltose utilization were all continuously measured during the course of the fermentation runs. The efficiencies of the aeration and agitation were evaluated based on the volumetric mass transfer coefficient ($K_La$). The maximum SRP production of 11,580 EU/ml with a specific SRP productivity of 78.8 EU/g/h was obtained with an agitation of 400 rpm and aeration of 0.075 vvm, which was 58% higher than the shake-flask level. The $K_La$ for the fermentation system supporting the maximum production (400 rpm, 0.075 vvm) was 11.3 $h^{-1}$. Under these fermentor optimized conditions, kinetic modeling was performed to understand the detailed course of the fermentation process. The resulting logistic and Luedeking-Piret models provided an effective description of the SRP fermentation, where the correlation coefficients for cell growth, SRP formation, and substrate consumption were 0.99, 0.94, and 0.84, respectively, revealing a good agreement between the model-predicted and experimental results. The kinetic analysis of the batch fermentation process for the production of SRP demonstrated the SRP production to be mixed growth associated.

• Journal of Microbiology and Biotechnology
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• v.28 no.3
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• pp.401-408
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• 2018

The waste seaweed from Gwangalli beach, Busan, Korea was utilized as biomass for ethanol production. Sagassum fulvellum (brown seaweed, Mojaban in Korean name) comprised 72% of the biomass. The optimal hyper thermal acid hydrolysis conditions were obtained as 8% slurry contents, 138 mM sulfuric acid, and $160^{\circ}C$ of treatment temperature for 10 min with a low content of inhibitory compounds. To obtain more monosaccharides, enzymatic saccharification was carried out with Viscozyme L for 48 h. After pretreatment, 34 g/l of monosaccharides were obtained. Pichia stipitis and Pichia angophorae were selected as optimal co-fermentation yeasts to convert all of the monosaccharides in the hydrolysate to ethanol. Co-fermentation was carried out with various inoculum ratios of P. stipitis and P. angophorae. The maximum ethanol concentration of 16.0 g/l was produced using P. stipitis and P. angophorae in a 3:1 inoculum ratio, with an ethanol yield of 0.47 in 72 h. Ethanol fermentation using yeast co-culture may offer an efficient disposal method for waste seaweed while enhancing the utilization of monosaccharides and production of ethanol.

• Journal of the Korean Society of Food Culture
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• v.35 no.5
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• pp.450-458
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• 2020

This study examined the optimal temperature and time conditions to maintain high quality Dongchimi during the fermentation and storage period. Dongchimi was fermented at low (5℃), medium (10 and 15℃), and high (20℃) temperatures until the acidity reached 0.2, 0.3, and 0.4%. respectively. From the consumer's preference test enrolling five consumers, Dongchimi fermented at 15℃ until an acidity of 0.3% (for approximately six days) was evaluated to be the optimal status because of its high score of overall acceptance, taste, and odor of consumers. To determine the optimal storage temperature of fermentation, Dongchimi was stored at three different temperatures (-1, 2, 5℃) for four weeks after fermenting at 15℃ for six days. During the storage period, most of the physicochemical properties (pH, acidity, reducing sugar content, and organic acid) and microbiological properties changed significantly in the 2 and 5℃ groups, resulting in a significant change in descriptive sensory analysis of Dongchimi. These results indicate that fermentation at 15℃ and storage at -1℃ for Dongchimi enables it to maintain the best quality for a long time.

• Journal of Microbiology and Biotechnology
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• v.24 no.9
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• pp.1245-1253
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• 2014

One-step sulfuric acid saccharification of the red alga Pterocladiella capillacea was optimized, and various detoxification methods (neutralization, overliming, and electrodialysis) of the acid hydrolysate were evaluated for fermentation with the thermotolerant yeast Kluyveromyces marxianus. A proximate composition analysis indicated that P. capillacea was rich in carbohydrates. A significant galactose recovery of $81.1{\pm}5%$ was also achieved under the conditions of a 12% (w/v) biomass load, 5% (v/v) sulfuric acid, $121^{\circ}C$, and hydrolysis for 30 min. Among the various detoxification methods, electrodialysis was identified as the most suitable for fermentable sugar recovery and organic acid removal (100% reduction of formic and levulinic acids), even though it failed to reduce the amount of the inhibitor 5-HMF. As a result, K. marxianus fermentation with the electrodialyzed acid hydrolysate of P. capillacea resulted in the best ethanol levels and fermentation efficiency.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1473-1481
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• 2018

A cellulase hyperproducing mutant strain, JNDY-13, was obtained using the ARTP mutation system and with Trichoderma reesei RUT-C30 as the parent strain. Whole-genome sequencing of JNDY-13 confirmed that 105 of the 653 SNPs were point mutations, 336 mutations were deletions and 165 were insertions. Moreover, 99 mutations were insertions and duplications. Among all the mutations, the one that occurred in the galactokinase gene might be related to the production of cellulases in T. reesei JNDY-13. Moreover, the up-regulation of cellulase and hemicellulase genes in JNDY-13 might contribute to higher cellulases production. Under optimal conditions, the highest cellulase activity by batch fermentation reached 4.35 U/ml, and the highest activity of fed-batch fermentation achieved was 5.40 U/ml.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.473-481
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• 2006

This study was carried out to investigate the properties of cucumber kimchi prepared with different minor ingredients(potato, puchu). Acidity, pH, color value, hardness, and lactic acid bacteria were measured under the condition of $10^{\circ}C$ for 25 days. Five conditions of making cucumber kimchi included: cucumber kimchi with puchu 300g(treatment 1, control), cucumber kimchi with potato 90g, puchu 210 g(treatment 2, 5-1), cucumber kimchi with potato 150g, puchu 150 g(treatment 3, S-2), cucumber kimchi with potato 210g, puchu 90 g(treatment 4, S-3), cucumber kimchi with potato 270g, puchu 30g(treatment 5, S-4). Hardness of cucumber kimchi appeared higher values as the potatoe's volume increased(S-1, S-2, S-3, S-4), during all fermentation days. The results showed very significant values in pH(p<0.001), acidity(p<0.001), 'L' of lightness(p<0.05), hardness(p<0.001), lactic acid bacteria(p<0.001) according to fermentation. And the results showed very significant values in 'a' of redness(p<0.01), hardness(p<0.001) according to cucumber kimchi samples. These results showed that fermentation patterns of cucumber kimchi were influenced by the different minor ingredients used.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.593-603
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• 1999

Poly(3-hydroxybutyrate) (PHB) production by fermentation was examined under both restricted- and ample-oxygen supply conditions in a single fed-batch fermentation. Recombinant Escherichia coli transformed with the PHB production plasmid pSYLl07 was grown to reach high cell density (227 g/l dry cell weight) with a high PHB content (78％ of dry cell weight), using a glucose-based minimal medium. A simple flux model containing 12 fluxes was developed and applied to the fermentation data. A superior closure (95％) of the carbon mass balance was achieved. When the data were put into use, the results demonstrated a surprisingly large excretion of formate and lactate. Even though periods of severe oxygen limitation coincided with rapid acetate and lactate excretion, PHB productivity and carbon utilization efficiency were not significantly impaired. These results are very positive in reducing oxygen demand in an industrial PHA fermentation without sacrificing its PHA productivity, thereby reducing overall production costs.

• Textile Coloration and Finishing
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• v.27 no.3
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• pp.202-209
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• 2015

Many of the natural dyes used for natural dyeing are difficult to maintain colorfastness due to their complex structure and specific properties. Therefore, there is a need for developing of color sustainable ability for use as an advanced coloring agent for fabrics, which would eco benign or not. In this study, the natural dye extracted from the waste of grape fruits was used to dye cotton fabric. Thus, the present study aims at extraction of color from grape seeds, skin, and stem through fermentation and then employing the same in dyeing and mordanting of cotton. Dyeing experiments were done under different conditions of fermentation and protein type mordants which were treated before and after dyeing. Experimental fabrics were used with cotton after scouring. Color value of dyed fabrics and color fastness of cotton dyed fabrics to washing and light were measured. The fastness of dyed experimental fabrics was increased by mordanting of protein fermentation and the color of dyed cotton was light red purple. The color of dyed fabric found with the optimum mordant treatment when treated with pre milk-mordant at $40^{\circ}C$ for 30min and 3% grape seed extract. On the whole, reddish tone very slightly increased with the milk pre-mordant. The color fastness of dyed cotton fabrics to light and washing was increased after fermentation.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.256-261
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• 2006

Soybeans were fermented with Monascus sp. to select strain with highest mevinolin production through solidstate fermentation. Monascus pilosus IFO 480 showed highest yield of 2.2 mg mevinolin per g dry weight without citrinin, toxic fungal secondary metabolite, as byproduct. Nutrient broth used for soybean fermentation with Monascus sp. was composed of 3.4 rice powder, 1.1 peptone, 2.6 glycine, 12.9 glucose, initial pH 6.0 (%, w/v). Mevinolin was present in fermentation substrate largely as hydroxy carboxylate form (open lactone, 91.8-96.8%), which is used as hypocholesterolemic agent. Production of mevinolin continued up to 50 days fermentation time at $30^{\circ}C$.