• 한국생물공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.740-744
• /
• 2003

The antimicrobial substance produced by Lactobacillus bulgaricus was inactivated by pretense, which confirmed it as a bacteriocin and referred to 'bulgaricin HJ'. The bulgaricin HJ showed the inhibitory activity against mastitis pathogens, gram-positive and gram-negative bacteria. The optimal conditions for the production of bulgaricin HJ were at the temperature of $30^{\circ}C$ and 10 h after cultivation of L. bulgaricus. Staph. and Strep. agalactiae, common bovine mastitis pathogens, were treated with bulgaricin HJ by the agar well diffusion method and showed antimirobial activities to the bovine mastitis pathogens. The activity of the bulgaricin HJ was maintained at pH 6-7 and $100^{\circ}C$ for 60 min against the mastitis pathogens. The bulgaricin HJ was determined as class IV bacteriocin by various enzyme treatments. Colony forming units analysis with indicator strains by the treatments of bulgaricin HJ indicates that the mode of bacteriocin action was bactericidal rather than bacteriostatic.

• Food Science and Preservation
• /
• v.8 no.2
• /
• pp.199-205
• /
• 2001

Red mold was isolated from meju prepared by traditional mtehod and characterized. The isolated red mold grew well on potato dextrose agar medium, In microscopic observation, it had a septum in mycelium and ellipsoidal spore. Optimal temperature and pH for growth were 30$\^{C}$ and 6.0, respectively. Enzyme activities such as protease, a-amylase and glucoamulase in ted mold were lower than those in Aspergillus oryzae. A competitive growth between red mold and Asp. oryzae was greatly affecten by cultivation temperature. The growth of isolated red mold on meju was predominant at below 30$\^{C}$ as compared with Asp. oryzae.

• Microbiology and Biotechnology Letters
• /
• v.25 no.6
• /
• pp.606-611
• /
• 1997

Entomogenous fungi which attack living insects are powerful means for microbiological insecticide. The purpose of this study is to establish the culture conditions and media for mass production of Beauveria sp. C208 which has a broad host range as a potential microbiological pesticide. The temperature and pH range for optimal cultivation of this strain were 28$circ$C and pH 5.0-7.0. For Beauveria sp. C 208, 2% rice straw and 0.6% tryptone were found as the proper carbon and nitrogen sources, considering cell mass, enzyme activities such as chitinase, protease and lipase, and spore concentration.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.1
• /
• pp.44-49
• /
• 1999

Cellulase production by fed-batch cultivation of Trichoderma reesei Rut C30 with various initial concentrations of Solka Floc in 1 % wheat bran-containing medium was investigated. The cellulase activity and productivity increased with initial Solka Floc concentration up to 5%. When a total Solka Floc concentration of 90 g/l was used for cellulase production, CMC (carboxymethyl cellulose) and FP (filter paper) activities, productivity, and yield were 359.7 U/ml, 30.61 U/ml, 161 FPU $L^{-1}$ $h^{-1}$, and 340 FPU $g^{-1}$, respectively. It was important to maintain a high cell concentration during cellulase production to obtain high cellulase activity and productivity. Cellulase powder was prepared by ammonium sulfate precipitation: FP activity was 396.7 U/g and CMC activity was 6481 U/g.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.5
• /
• pp.673-677
• /
• 2006

A perfusion culture of transgenic Nicotiana tabacum cell suspensions, transformed to express recombinant glucuronidase (GUS), was successfully performed in a 5-1 stirred tank bioreactor. With 0.1 $day^{-1}$ of perfusion rate, the maximum dry cell weight (DCW) reached to 29.5 g/l in 16 days, which was 2.1-fold higher than the obtained in batch culture (14.3 g/l). In terms of the production of GUS, the volumetric activity could be increased up to 12.8 U/ml by using perfusion, compared with 4.9 U/ml in batch culture. The specific GUS activities in both perfusion and batch cultures were maintained at similar levels, 200-400 U/g DCW. Consequently, a perfusion culture could be a good strategy for the enhanced production of recombinant proteins in a plant cell culture system.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.8
• /
• pp.818-821
• /
• 2011

An agar-degrading bacterium was isolated from the guts of spiny turban shells. It was identified as a Pseudoalteromonas species and named Pseudoalteromonas sp. JYBCL 1. The viscosity of the inoculated agar medium decreased by more than 60% after 20 h cultivation. The agarase produced by the isolate had optimal activities at $35^{\circ}C$ and pH 7. The enzyme had extremely strong resistance to ionic stress compared with other known agarases. Its molecular mass was estimated at about 60 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The agarase could saccharify Gelidium amansii directly, with an efficiency about half that compared with agar saccharification.

• Microbiology and Biotechnology Letters
• /
• v.25 no.2
• /
• pp.218-223
• /
• 1997

For the utilization of animal blood produced in slaughter for the cultivation of lactic acid bacteria, the nitrogen sources in a complex(MRS) medium were replaced by blood plasma proteins. Focusing the purpose on the industrial production of a probiotics, the hydrolytic activities of three industrially applicable proteases were compared for the effective digestion of the proteins, and Alcalase(the product of Novo Nordisk) was selected with comparatively high activity. The growth of Streptococcus thermophilus KCCM12020 was best among the four strains of lactic acid bacteria tested. With Alcalase-digested proteins in the medium, the growth rates and the final cell concentrations were higher than those with non-digested proteins. The cell mass produced in the medium containing blood proteins as nitrogen sources, $2.5{\times}10^9$ CFU/ml, was significantly high and about 70% of that in MRS medium, showing a great possibility for the utilization of animal blood proteins as economic nitrogen sources in the production of cell mass of lactic acid bacteria.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.3 no.2
• /
• pp.96-102
• /
• 1998

Primary hepatocytes of small animals such as rat and rabbit were often used for the study of extracorporeal liver support systems. Freshly isolated rat hepatocytes form spheroids within tow days when cultivated as suspension in spinner vessels. These spheroids showed enhanced liver specific functions and more differentiated morphology compared to hepatocytes cultured as monolayers However, shear stress caused by continuous agitation deteriorated spheroids gradually. In this work we immobilized spheroids to prolong liver specific activities. First, hepatocyte spheroids were suspended in collagen solution containing calcium chloride and then dropped into alginate solution. A thin layer of calcium alginate was formed around the droplet and then was removed after the inner collagen was gelled by treatment of sodium citrate buffer. Spheroids embedded in collagen-gel bead maintained liver specific functions such as albumin secretion rate longer than hepatocyte spheroids exposed to shear stress. Therefore, we suggest that this immobilization technique may offer an effective long-term hepatocyte cultivation and facilitase the development of a bioartificial liver support device.

• Journal of Microbiology and Biotechnology
• /
• v.8 no.3
• /
• pp.208-213
• /
• 1998

The effect of the addition of wheat bran to the growth medium on the production of cellulolytic enzymes of Trichoderma reesei Rut C30 was studied in batch culture using shake flasks. The activity of cellulase was enhanced by the addition of wheat bran to the cellulase production medium. $KH_2PO_4$-$K_2HPO_4$ buffer was used for pH control during cellulase production. As a result, high cellulase activities were obtained in shake flask culture; a CMC (carboxymethyl cellulose) activity of 125.78 U/ml was obtained from 2% Avicel- and 3% wheat bran-containing medium and an FP (filter paper) activity of 12.85U/ml was obtained from 1% Avicel- and 5% wheat bran-containing medium after 6 days of cultivation.

• Proceedings of the Korean Society of Organic Agriculture Conference
• /
• 2009.12a
• /
• pp.314-314
• /
• 2009

The effects of mixtures of each of rice hull charcoal and wood charcoal with pyroligneous acid on the cultivation and antioxidant activities of rice were investigated. Results of the total phenolic compounds, DPPH radical electron-donating ability and xanthine oxidase stress activity analyses revealed that the environment-friendly materials increased the total antioxidant capacity in rice. In the case of palatability of rice, total amylose blue value and starch-I2color reaction analyses, data showed that environment-friendly materials generally decreased the amylose content of rice. Also, the environment-friendly materials improved the rice endosperm quality.