• KSBB Journal
• /
• v.13 no.3
• /
• pp.325-330
• /
• 1998

The methylotrophic yeast, Pichia pastoris, is known to be a potential host to offer many advantages for production of recombinant proteins. Fermentation parameters were optimized to enhance the heterologous ${\beta}$-galactosidase productivity with P. pastoris. Optimum concentration of methanol, used as inducer, was observed to be 8 g/L and the extent of repression of AOX1 promoter by glycerol was lower than by glucose. The degradation of the gene product ${\beta}$-galactosidase by protease was inhibited as the pH increased from 5 to 8 and the yeast extract(1%) as nitrogen source increased expression level 4 times higher compared to yeast nitrogen base(1%) as nitrogen source increased expression level 4 times higher compared to yeast nitrogen base(1%). Induction method, in which methanol is just added to fermentation medium without centrifugation, was found to be as much effective as the one with centrifugation.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.87.2-87
• /
• 2003

Long-term repeated culturing of biocontrol agents on a certain medium often results in reduced biocontrol efficacy and altered physiology. Effect of culturing media on biocontrol ability and physiological state of Burkholderia gladioli strain B543 was investigated. Over 20 times repeated cultivation of B. giadioli strain B543 on Kings B medium or nutrient agar medium showed improved biological control of cucumber damping-off caused by Pythium ultimum, while one time cultivation on KB or NA did not. The repeated cultivation also induced the physiological changes of the biocontrol agent such as antifungal activity and the production of protease and siderophore. Our result indicates that adaptation to proper culturing medium can alter biocontrol ability and must consider in optimizing the use of biocontrol agents.

• Tuberculosis and Respiratory Diseases
• /
• v.79 no.4
• /
• pp.207-213
• /
• 2016

Chronic obstructive pulmonary disease (COPD) encompasses several clinical syndromes, most notably emphysema and chronic bronchitis. Most of the current treatments fail to attenuate severity and progression of the disease, thereby requiring better mechanistic understandings of pathogenesis to develop disease-modifying therapeutics. A number of theories on COPD pathogenesis have been promulgated wherein an increase in protease burden from chronic inflammation, exaggerated production of reactive oxygen species and the resulting oxidant injury, or superfluous cell death responses caused by enhanced cellular injury/damage were proposed as the culprit. These hypotheses are not mutually exclusive and together likely represent the multifaceted biological processes involved in COPD pathogenesis. Recent studies demonstrate that mitochondria are involved in innate immune signaling that plays important roles in cigarette smoke-induced inflammasome activation, pulmonary inflammation and tissue remodeling responses. These responses are reviewed herein and synthesized into a view of COPD pathogenesis whereby mitochondria play a central role.

• BMB Reports
• /
• v.32 no.3
• /
• pp.247-253
• /
• 1999

Chicken egg ovalbumin is a non-inhibitory member of the serpin (serine protease inhibitors) family whose members share a common tertiary fold. In the present study, we succeeded in high-level production of a disulfide-free form of refolded recombinant ovalbumin. Conformational characterization of the recombinant ovalbumim revealed that it is well-folded, following two-state unfolding transition with the midpoint of transition at 4.7 M at $25^{\circ}C$. This value is very close to that of the reduced form of authentic ovalbumin. The recombinant ovalbumin can serve as a model molecule of non-inhibitory serpins in comparative studies with inhibitory members of the serpin family.

• 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.

• Asian-Australasian Journal of Animal Sciences
• /
• v.10 no.4
• /
• pp.398-401
• /
• 1997

A caecal fermentation study was conducted in 30 Angora rabbits equally placed under five whole diets (75 concentrate : 25 roughage) supplemented with processed Neem (Azadirachta indica) kernel meal (NKM ; 2% urea or 1.5% NaOH, W/W), replacing isonitrogenously either at 50 or 100% level of deoiled peanut (Arachis hypogea) meal, for 18 wk period. The total volatile fatty acids level was depressed (p < 0.05) in all the experimental groups (0.02 to 0.04 mEq/g) and ammonia-nitrogen was lowest (p < 0.05; $24.9{\mu}mol/g$) in rabbits fed NaOH treated NKM supplemented diet. Enzyme activity (unit/g) of carboxy methyl-cellulase, ${\alpha}$-amylase, protease and urease exhibited much variation and did not differ significantly. Hence, the results could not confirm a possible adverse effect of feeding NKM on caecal fermentation.

• Microbiology and Biotechnology Letters
• /
• v.23 no.5
• /
• pp.544-549
• /
• 1995

The alkaline elastase is an extracellular serine protease of the alkalophilic Bacillus strain Ya-B. To increase the gene copy number and the production level of the alkaline elastase Ya-B, we designed, on the B. subtilis chromosome, a gene amplification of the 10.6 kb repeating unit containing amyE, aleE (alkaline elastase Ya-B gene) and tmrB. The aleE was inserted between amyE and tmrB, and B. subtilis APT119 strain was transformed with this amyE-aleE-tmrB-junction region fragment. As a result, we succeeded in obtaining tunicamycin-resistant (Tm$^{r}$) transformants (Tf-1, Tf-2) in which the designed gene amplification of 10.6 kb occurred in chromosome. The transformants showed high productivity of $\alpha $-amylase and alkaline elastase Ya-B. The copy number of the repeating unit (amyE-aleE-tmrB) was estimated to be 25, but plasmid vector (pUC19) was not integrated. The amplified aleE of chromosome was more stable than that of plasmid in absence of antibiotics.

• Microbiology and Biotechnology Letters
• /
• v.21 no.2
• /
• pp.125-131
• /
• 1993

The s-type pyocin, one kind of bacteriocins, is a bactericidal substabce of protein nature produced by certain Pseudomonas aeruginosa and is active against some other strains of the same or closely related species. Among many Pseudomonas aeruginosa strains collected from the patients at the Hospitals in Seoul and Taegu cities, some Pseudomonas aeruginosa pyocinogeny were determined by pyocin typing. As a result, Pseudomonas aeruginosa 90-2-2205 was selected as the S-type pyocin producing microorganism due to its highest antimicrobial and protease sensitivity.

• The Microorganisms and Industry
• /
• v.26 no.1
• /
• pp.8-17
• /
• 2000

Thirtythree strains of the Aspergillus spp. isolated from foodstuffs were observed through some physiological characteristics for detection of identification key of Aspergillus spp. 1) Each strain of Aspergillus spp. had their specific characteristics and could be used for identification of species. 2) Excellent amylase-producing fungi were observed among the isolated strains of Aspergillus spp. 3) Amylase activities increased for one week incubation period. 4) In the tests of common characters of aflatoxin-producing fungi among the 33 strains of Aspergillus spp., for example, conidial size, presence of sclerotia, kojic acid, and pigment production, coloration of phenol, reduction of methylene blue, etc.

• The Korean Journal of Food And Nutrition
• /
• v.7 no.1
• /
• pp.8-15
• /
• 1994

To utilize hemicellulosic biomass efficiently, the microorganism producing xylanase was isolated from fermented sawdust. It was a Gram positive, aerobic and rod shape bacterium. It had endospore and secreted strong hydrolases, such as amylase and protease. Through morphological, cultural and physiological tests, it was identified as Bacillus sp. GS. To increase the productivity of xylanase from Bacillus sp. GS, the enzyme production medium was optimized. The composition of the medium and incubation conditions were like follows xylan 1.25%, yeast extract 0.1%, NaN030.2%, K2HP04 0.1%, MgSO4 0.02%, mineral salt 0.005%, pH 6.5, incubation temperature 37$^{\circ}C$.