• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.522-529
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• 1998

This experiment was conducted to study the effects of lactic acid bacteria (LAB) inoculation either alone or in combination with cell wall degrading enzymes on the fermentation characteristics and chemical compositions of Rhodesgrass silage. Over to 1 kg of fresh Rhodesgrass sample a treatment of inoculant LAB with or without addition of an enzyme of Acremoniumcellulase (A) or Meicelase (M) or a mixture of both enzymes (AM) was applied. The treatments were control untreated, LAB-treated (application rate $1.0{\times}10^5cfu/g$ fresh sample), LAB+A 0.005%, LAB+A 0.01%, LAB+A 0.02%, LAB+M 0.005%, LAB+M 0.01%, LAB+M 0.02 %, LAB+AM 0.005%, LAB+AM 0.01%, and LAB+AM 0.02%. The sample was ensiled into 2-L vinyl bottle silo, with 9 silages of each treatment were made. Three silages of each treatment were incubated at 20, 30 and $40^{\circ}C$ for 2-months of storage period. All silages were well preserved with their fermentation quality has low pH values (3.91-4.26) and high lactic acid concentrations (4.11-9.89 %DM). No differences were found in fermentation quality and chemical composition of the control untreated silage as compared to the LAB-treated silage. Combined treatment of LAB+cellulases improved the fermentation quality of silages measured in terms of lower (p < 0.01) pH values and higher (p < 0.05) lactic concentrations than those of LAB-treated silages. Increasing amount of cellulase addition resulted in decrease (p < 0.05) of pH value and increase (p < 0.05) of lactic acid concentration. LAB + cellulase treatments (all cellulase types) reduced (p < 0.01) NDF, ADF and in vitro dry matter digestibility of silages compared with the control untreated silages. The fermentation quality and the rate of cell wall reduction were higher (p < 0.01) in the silages treated with LAB + cellulase A than in the silages treated with either LAB+cellulase M or LAB + cellulase AM. Incubation temperature of $40^{\circ}C$ was likely to be more appropriate environment for stimulating the fermentation of Rhodesgrass silages than those of 20 and $30^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.1 no.3
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• pp.151-156
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• 1991

In order to construct a yeast strain having high ethanol tolerance together with good lactose fermentation ability, the protoplast fusion using Saccharomyces cerevisiae STV 89 and Kluyveromyces fragilis CBS 397 was carried out. Auxotrophic mutants of K. fragilis were obtained as a selection marker by treatment of ethylmethane sulfonate. The best mutant for protoplast fusion was selected based on the capabilities of ${\beta}-galactosidase$ production and lactose fermentation. The protoplast fusion using polyethylene glycol and calcium chloride solution led to the fusion frequence of $3{\times}10^{-6}$ and a number of fusants were obtained. Among these fusants, a fusant F-3-19 showed the best results in terms of ethanol tolerance, ${\beta}-galactosidase$ activity and lactose fermentation. The performance of lactose fermentation and ethanol tolerance by this fusant were better than those of K. fragilis. Study on the ethanol tolerance having relation to fatty acid composition and intracellular ethanol concentration revealed that the fusant F-3-19 had a higher unsaturated fatty acids content and accumulated less amount of intracellular ethanol compared with a parent of K. fragilis.

• Journal of Microbiology and Biotechnology
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• v.25 no.10
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• pp.1653-1659
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• 2015

Epothilone, which is produced by the myxobacterium Sorangium cellulosum, contributes significant value in medicinal development. However, under submerged culture conditions, S. cellulosum will accumulate to form bacterial clumps, which hinder nutrient and metabolite transportation. Therefore, the production of epothilone by liquid fermentation is limited. In this study, diatomite-based porous ceramics were made from diatomite, paraffin, and poremaking agent (saw dust). Appropriate methods to modify the porous ceramics were also identified. After optimizing the preparation and modification conditions, we determined the optimal prescription to prepare high-performance porous ceramics. The structure of porous ceramics can provide a solid surface area where S. cellulosum can grow and metabolize to prevent the formation of bacterial clumps. S. cellulosum cells that do not form clumps will change their erratic metabolic behavior under submerged culture conditions. As a result, the unstable production of epothilone by this strain can be changed in the fermentation process, and the purpose of increasing epothilone production can be achieved. After 8 days of fermentation under optimized conditions, the epothilone yield reached 90.2 mg/l, which was increased four times compared with the fermentation without porous ceramics.

• Korean Journal of Veterinary Research
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• v.31 no.4
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• pp.509-513
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• 1991

Preliminary survey on the prevalence of swine internal parasites was carried out at 91 pens of 4 piggeries being operated by the sawdust fermentation floor system in Kyunggi province. To investigate the effects of viability of eggs., larva and cysts, temperatures at the underlayer of the sawdust floor and rooms of pens were taken three times a day for 8 days. In a pig farm which has been operated by the sawdust fermentation floor system for G years, eggs and larva of Ascaris suum, Trichuris suis, Oesophagostomum sp., Hyostrongylus sp. and Strongyloides ransomi were detected from 42(70.0%) among 60 pens. Cysts and oocysts of coccidia, Balantidium coli, Entamoeba sp. were also detected from 50(83.3%) among 60 pens. In three pig farms which have been operated by the sawdust fermentation floor system for one year, eggs and larva of nematoda were not detected at all, and the contamination rates of protozoan cysts and oocysts was relatively low situation. The change of the temperature in the pig room was variable according to outside condition, whereas that in underfloor was consistently stable between $28^{\circ}C$ to $30^{\circ}C$ which was strictly suitable for the development of eggs, larva and cysts.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.110-116
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• 2010

Lactic acid (LA) fermentation by Lactobacillus salivarius ATCC 11741 immobilized on loofa sponge (LS) was evaluated. To increase the surface area of LS for cell immobilization, $H_2O_2$ and chitosan were introduced as surface modifying reagents. Four chitosans of different molecular weights were separately coated on LS. All experiments were conducted in shaking flask mode at 100 rpm rotating speed and $37^{\circ}C$ with 5% $CaCO_3$ as a pH regulating agent. The effects of initial glucose concentration were investigated in the range of 20-100 g/l on LA fermentation by free cells. The results indicate that the maximum concentration of LA was produced with 50 g/l glucose concentration. The immobilized cell system produced 1.5 times higher concentration than free cells for 24 h of fermentation. Moreover, immobilized cells can shorten the fermentation time by 2-fold compared with free cells at the same level of LA concentration. At 1% (w/v) chitosan in 2% (v/v) acetic acid, the Yp/s and productivities of various molecular weights of chitosans were insignificantly different. Repeated batch fermentations showed 5 effective recycles with Yp/s and productivity in the range of 0.55-0.85 and 0.90-1.20 g/l.h, respectively. It is evident that immobilization of L. salivarius onto LS permits reuse of the system under these fermentation conditions. Scanning electron micrographs indicated that there were more intact cells on the chitosan-treated LS than on the untreated LS, thus confirming the effectiveness of the LS-chitosan combination when being utilized as a promising immobilization carrier for LA fermentation.

• Journal of the Korean Home Economics Association
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• v.26 no.1
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• pp.51-59
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• 1988

In the present study, an attempt was made to observe the effect of calcium-sources and preservatives on Kimchi fermentation. After pre-fermentation at room temperature for 16 hours, each Kimchi was stored at 4$^{\circ}C$. Changes of vitamin contents(vitamin C, thiamin, riboflavin and $\beta$-carotene) during the fermentation of Kimchi were determined. It was also attempt to relate the fermentation of Kimchi with the changes in chemical and organoleptic characteristics, such as pH, total acidity and reducing sugar. The findings were summarized as follows; 1. During Kimchi fermentation, the pH decreased steady and total acidity increased slowly in the follow order: K-Sorbate+acetic acid, k-Sorbate, Ca-Lactate and Control. the lower of pH and the higher of total acidity, the less of reducing sugar was remained. 2. changes of total vitamin C and reduced ascorbic acid contents during the Kimchi fermentation did not differ significantly from each other. At the begining of fermentation, Kimchi samples contained 20~25mg/100g of total vitamin C and 5~14 mg/100g of reduced ascorbic acid. In the final stage, however, 15~19 mg/100g of total vitamin C and 1~3 mg/100g of reduced ascorbic acid were remained. 3. The contents of thiam in and riboflavin were 30 to 42 meg/100g and 50 to 67 meg/100g at the initial stage, respectively. They increased with the degree of maturity (approximately 2 times of the content of the initial stage) and then gradually decreased. The content of $\beta$-carotene was found to be decreased with the degree of maturity. 4. The results of sensory evaluation indicated that Kimchi added with Ca-Carbonate, Ca-Carbonate+acetic acid and Ca-lactate were better than Control.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.704-709
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• 2006

The mucilage production and tyrosine content in soy milk cake (SMC) fermented by Bacillus firmus NA-1, Bacillus subtilis GT-D, and B. subtilis KU-A was improved by fortification with 10% defatted soybean flour. The fibrinolytic activity and consistency of the SMC were drastically increased by solid-state fermentation for 1 day. However, the consistency of the fermented SMC gradually decreased during fermentation for 3 days. Furthermore, the tyrosine content of the freeze-dried powder of SMC fermented by three Bacillus sp. was 9 times higher than that of unfermented SMC. The soybean proteins, including the 7S and 11S subunits, were partially digested during alkaline fermentation, producing lower molecular-weight peptides. The fibrinolytic enzyme produced in SMC fermented by B. firmus NA-l and B. subtilis KU-A exhibited higher thermal stability than that of B. subtilis GT-D fermentation. The powder obtained from B. subtilis GT-D fermentation had an ${\alpha}$-amylase activity and lower consistency compared to those of B. firmus NA-1 and B. subtilis KU-A. In addition, this powder contained 6.3% moisture content, 27% crude protein content and 9 units of fibrinolytic activity and proteolytic activity.

• Preventive Nutrition and Food Science
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• v.6 no.4
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• pp.206-210
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• 2001

Starch is an abundant resource in plant biomass, and it should be hydrolyzed enzymatically into fermentable sugars for ethanol fermentation. A genetic recombinant yeast, Saccharomyces cerevisiae GA-7458, was constructed by integrating the structural gene of both $\alpha$-amylase from Bacillus stearothermophilus and the gene (STA1) encoding glucoamylase from S. diastaticus into the chromosome of S. cerevisiae SH7458. The recombinant yeast showed active enzymatic activities of $\alpha$-amylase and glucoamylase. The productivity of ethanol fermentation from the pH-controlled batch culture (pH 5.5) was 2.6 times greater than that of the pH-uncontrolled batch culture. Moreover, in a fed-batch culture, more ethanol was produced (13.2 g/L), and the production yield was 0.38 with 2% of corn starch. Importantly, the integrated plasmids were fully maintained during ethanol fermentation.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.41-45
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• 1996

This study was conducted to develop the fermentation kinetic model for the prediction of acidity and pH changes in Kimchi as a function of fermentation temperatures. The fitness of the model was evaluated using traditional two-step method and an alternative non-linear regression method. The changes in acidity and pH during fermentation followed the pattern of the first order reaction of a two-step method. As the fermentation temperature increased from 4$^{\circ}C$ to 28, the reaction rates of acidity and pH were increased 8.4 and 7.6 times, respectively. The activation energies of acidity and pH were 16.125 and 16.003kcal/mole. The average activation energies of acidity and pH using a non-linear method were 16.006 by the first order and 15.813 kcal/mole by the zero order, respectively. The non-linear procedure had better fitting 개 experimental data of the acidity and pH than two-step method. The shelf-lives based on the time to reach the 1.0% of acidity were 33.1day at 4$^{\circ}C$ and 2.8 day 28$^{\circ}C$.

• Korean Journal of Medicinal Crop Science
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• v.20 no.2
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• pp.117-123
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• 2012

This study compared the contents of low molecular ginsenoside according to fermentation process in low grade fresh ginseng. Low grade fresh ginseng was directly inoculated with a 24 h seed culture of $Bifidobacterium$ Longum B6., $Lactobacillus$ $casei$., and incubated at $36^{\circ}C$ for 72 h. $Bifidobacterium$ Longum B6 was specifically was found to show the best growth on $3,255{\times}10^6\;CFU/m{\ell}$ after 48 h of fermentation. The content of ginsenoside Rb1, Re and Rd were decreased with the fermentation but ginsenoside Rh2 and Rg2 increased after fermentation process. In the case of low molecular ginsenoside conversion yields were 56.07% of Rh2, 12.03% of Rg3 and 77.11% of Rg2, respectively. In addition, compound-K was irregular conversion yield as long as 72 h of fermentation. This results indicate that fermentation process could increase the low molecular ginsenoside in low grade fresh ginseng.