• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.879-884
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• 2012

In this present study, Aspergillus niger NRRL 567 was cultivated on an inert support material and the effects of various fermentation parameters including temperature, nutrient solution pH, inoculation level, and moisture content were observed and optimized by one-factor-at-a-time (OFAT) and response surface methodology (RSM), sequentially. It was found that the incubation temperature of $30^{\circ}C$ with 75% moisture content, nutrient solution pH of 7.1 and inoculation level of $4.0{\times}10^6$ spores/ml were the most favorable. Again, fermentation parameters were optimized using RSM. The determined optimum condition is $26.5^{\circ}C$, pH 9.9, 75.1%, and $6.0{\times}10^6$ spores/ml. Under this optimized condition, A. niger NRRL 567 produced 118.8 g citric acid/kg dry peat moss at 72 hr. Maximum citric acid production of optimized condition by RSM represented a 1.6-fold increase compared to that obtained from control experiment.

• Journal of the Korean Wood Science and Technology
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• v.40 no.4
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• pp.294-301
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• 2012

In this study, we investigated the features of bioethanol fermentation of corncob biomass after oxalic acid pretreatment as well as enzymatic hydrolysis. The enzymatic hydrolysis was performed with Accellerase 1000 and the highest yield of monomeric sugars ($64.8g/{\ell}$) was obtained at $50^{\circ}C$ and pH 4.5 for 96 hrs hydrolysis period. For the ethanol fermentation the monomeric sugars obtained from pretreated corncob were subjected to the biological treatment using Pichia stipitis CBS 6054. It was turned out that ethanol production from oxalic acid pretreated corncob was the most feasible at 10~14% of biomass loading as well as 15 FPU enzyme amount. Under these fermentation condition, the ethanol yield was approached to 0.47 after 24 hrs fermentation period, which was corresponded to 92.2% of conversion rate.

• Journal of environmental and Sanitary engineering
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• v.15 no.3
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• pp.23-23
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• 2000

In this study, to determine the optimum fermentation process for the feed production of food wastes and estimate the practical value of fermented feed using kudzu creeper and sawdust as bulking agent. This study considered initial C/N ratio control as the fermentation process variables. The results are summarized as follows. Minimum water contents of byproducts in the fermentation feed production showed 3994(kudzu), 37%( sawdust) at the C/N ratio 25 and 45%(kudzu, sawdust) at the C/N ratio 35. Temperature variations in the fermentation feed production at the C/n ratio 25 indicated 68'C(kudzu), 70'C (sawdust).Optimum condition of consists of fermentation process of water content, C/N ratio and permeability (porous structure of the mixture). For optimum fermentation of gravitationally, dewatered garbage, the proper mixing ratios of kudzu(moisture contents : 17.3%) and sawdust(moisture contents : 13.2%) were 41% and 39%, respectively Major biological reaction in the aerobic fermentation feed production occurred during 12~14hrs

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.460-465
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• 2001

To prepare vinegar using concentration apple juice, response surface methodology (RSM) was applied to optimize and monitor the vinegar fermentation properties by two stage fermentation. In the first stage, the optimum conditions for maximum alcohol contents were 18.56。Brix of initial sugar concentration, 61.96 rpm of agitation rate and 67.32 hr of fermentation time. The optimum condition for maximum acidity in the second stage (vinegar fermentation) were 201.53 rpm of agitation rate and 179.42 hr of fermentation time. Malic acid content was the highest and its content little changed during acetic acid fermentation. Lactic acid content increased a little during alcohol fermentation. Acetic acid content apparently increased during acetic acid fermentation.

• KSBB Journal
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• v.5 no.1
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• pp.25-35
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• 1990

In the Xanthan gum fermentation by Xanthomonas campestris there are problems of the large energy consumption by long fermentation time, the mass transfer of oxygen and nutrients by high viscous fermentation broth. In this study, the media optimization and the fed batch fermentation were carried out to decrease fermentation time and increase Xanthan gum yield. The $O_2$ uptake rate (OUR) and $CO_2$ evolution rate(CER) which were obtained from the analysis of fermentation exit gas using a gas chromatograph were investigated. As a result, the fermentation time decreased at optimal assimilable nitrogen concentration but increased at poor or rich assimilable nitrogen concentration, the Xanthan gum biosynthesis was stimulated under the limited condition of assimilable nitrogen source and the optimum fermentation medium was obtained as follow; Glucose=30g / l, Peptone=8.0g / l, $K_2HPO_4=2.0g/l$, $MgS0_47H_2O=10g/l$, Sodium acetate=20g/l, Sodium pyruvate=0.5g/1. As the agitation speed and nitrogen concentration increased, the $O_2$ uptake rate and $CO_2$ evolution rate increased. The OUR and CER were 37.3mmol $O_2/\;l$ hr and 20.2 mmol $CO_2/\;L$ hr at peptone 11g / l and agitation speed 990RPM, respectively. In fed batch fermentation, the final concentration of Xanthan gum was enhanced up to 29g / l.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.302-306
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• 2014

The present study was carried out to optimize fermentation parameters for the production of cellulolytic enzymes through solid substrate fermentation of Trichoderma reesei and Aspergillus niger grown on wheat straw. A sequential optimization based on one-factor-at-a-time method was applied to optimize fermentation parameters including temperature, pH, moisture content and particle size. The results of optimization indicated that $40^{\circ}C$, pH 7, moisture content 75% and particle size between 0.25~0.5 mm were found to be the optimum condition at 96 hr fermentation. Under the optimal condition, co-culture of T. reesei and A. niger produced cellulase activities of 10.3 IU, endoglucanase activity of 100.3 IU, ${\beta}$-glucosidase activity of 22.9 IU and xylanase activity of 2261.7 IU/g dry material were obtained. Cellulolytic enzyme production with optimization showed about 72.6, 48.8, 55.2 and 51.9% increase compared to those obtained from control experiment, respectively.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.391-402
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• 2017

Lactic acid bacteria (LAB) are widely used as starter culture in food fermentation due to their harmless entity and health beneficial properties along with the ability to change texture, aroma, flavor and acidity of food products. In this study, five different LAB (FB003, FB058, FB077, FB081, and FB111) isolated from different Korean traditional fermented foods, assigned to Lactobacillus plantarum, Pediococcus pentosaceus, Weissella viridescens, Lactobacillus sakei, and Leuconostoc mesenteroides, respectively, on the basis of their physiological properties and 16S rRNA sequence analysis, to use as fermentation starter and check their ability to fasten the ripening time as well as the overall optimization in the fermentation condition. To check their suitability as starters, their safety, acid and bile tolerance, NaCl and temperature resistance, susceptibility to common antibiotics, and antimicrobial activities were determined. Squid jeotgal samples were prepared by adding $10^8CFU/g$ of each strain in different samples, which were then kept for fermentation at $4^{\circ}C$ and checked for their antioxidant activities at 0, 7, 15, and 21-day intervals. The samples fermented with FB003 and FB077 displayed the highest antioxidant activity. This study revealed two effective starter cultures (FB003, FB077) for squid jeotgal fermentation, which presented increased functionalities. The results of this study will lead to the development of novel industrial-scale production avenues for jeotgal preparation, and offer new insights into the prevention and control of chronic diseases.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.6
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• pp.608-617
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• 2004

This study is conducted to find out the appropriate preparing method and fermenting condition through analysis of physicochemical, microbiological, sensory evaluation of Myungtae sikhae, Korean fermented fishery food which was prepared in simplified and conventional methods. During the fermentation of sikhae at 4℃, pH was decreased gradually, but acidity was increased and salinity was steady state. In this aspect, no significant difference was revealed between sikhae prepared in simplified and conventional methods. Under fermentation at 20℃ and kept at 4℃, pH was decreased to 4.6～4.9 for 15～20 days fermentation with steady state of salinity. However, acidity was changed in conversely. The content of reducing sugar with rapidly decreasing in the beginning of fermentation was continually decreased. The propagation of microorganism in th sikhae depends on the fermentation temperature rather than the preparing methods. Generally low propagation of microorganism began to increase gradually in the sikhae fermented at 4℃ comparing to that fermented at 20℃. In the sikhae fermented at 20℃ and kept at 4℃, the total count including lactic acid bacteria, was rapidly increased after 5 days' fermentation of sikhae is dominated by Lactobacillus sp. and the unique flavor and organic acid were contributed by this flora with Leuconostoc. sp. By the sensory evaluation, the best flavor was revealed in the sikhae, prepared in simplified method fermented for 30 days at 4℃. Until 20 days, sikhae fermented at 20℃ revealed higher score than fermented at 4℃. General preference for the sikhae fermented at 4℃ for 15 days prepared by simplified method and those fermented at 20℃ for 10 days. The sikhae, fermented at 4℃, showed less difference between preparing methods and preferable acceptability after being 25 days. The best acceptability of sikhae fermented at 20℃ showed after 15～25 days. In the final conclusion, the appropriate preparing method of sikhae is to use frozen Alaska pollack with simplified method and fermented at 20℃ for 5 days and then kept at 4℃.

• Food Engineering Progress
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• v.21 no.4
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• pp.403-408
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• 2017

Acetic acid bacteria strains were isolated from a variety of fermented foods and fallen fruits. Among them, the strain MAK88, whose acetic acid fermentation ability, acid-tolerance, and alcohol-tolerance were high, was selected and identified as Acetobacter orientalis. A seed culture of A. orientalis MAK88 was inoculated into onion juice, and the optimum conditions of acetic acid fermentation was investigated. The optimum initial concentration of ethanol in onion juice was 5% (v/v) and in that condition, acidity was 4.31% at 144 h of fermentation. The optimum initial concentration of acetic acid was 1% and the final acidity was 5.32%. The optimum fermentation temperature was determined to be $28^{\circ}C$. The most appropriate preparation method of onion juice was to heat the onion at $121^{\circ}C$ for 15 min and produce juice with pressure followed by filtering, and then sterilization at $121^{\circ}C$ for 15 min. Prepared onion juice was used for fermentation without dilution.

• KSBB Journal
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• v.28 no.6
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• pp.400-407
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• 2013

The growth characteristics and production of color pigments by Monascus strains were investigated during liquid culture, and production of monacolin K in red mold rice was carried out by solid state fermentation. Four different Monascus ruber strains were cultured in potato dextrose yeast extract broth (PDYB) media at $25^{\circ}C$ for 15 days. The high producing strain for red pigment was not corresponded to the strain for yellow pigment. Production of red pigment was high in the strain causing the fast pH change in culture broth. Production of monacolin K in red mold rice by solid state fermentation was influenced by a combination of wet cell weight and spore density in inoculum by liquid culture. Most strains showed the high production of monacolin K in red mold rice, when submerged fermentation was carried out for 5 days as inoculum for solid state fermentation. These results suggest that submerged fermentation period of inoculum have an effect on the production of monacolin K in red mold rice by solid state fermentation, and monacolin K in red mold rice could be increased by controlling the condition of submerged fermentation for inoculum.