• KSBB Journal
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• v.29 no.3
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• pp.131-138
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• 2014

In this study, we isolated two novel chitinase producing bacterial strains from yellow loess samples collected from Jullanamdo province. The chitinase producing bacteria were isolated based on the zone size of clearance in the chitin agar plates. Both of them were gram positive, rod ($2{\sim}3{\times}0.3{\sim}0.4{\mu}m$), spore-forming, and motility positive. They were facultative anaerobic, catalase positive and hydrolyzed starch, gelatin, and casein. From the 16s rRNA gene sequence analysis, the isolates were labeled as Bacillus licheniformis KYLS-CU01 and B. licheniformis KYLS-CU02. The isolates showed higher extracellular chitinase activities than B. licheniformis ATCC 14580 as a control. The optimum temperature and pH for chitinase production were $40^{\circ}C$ and pH 7.0, respectively. Response Surface Methodology (RSM) was used to optimize the culture medium for efficient production of the chitinase. Under this optimal condition, 1.5 times higher chitinase activity of B. licheniformis KYLS-CU02 was obtained. Extracellular chitinases of the two isolates were purified through ammonium sulfate precipitation and anion-exchange DEAE-cellulose column chromatography. The specific activities of purified chitinase from B. licheniformis KYLS-CU01 and B. licheniformis KYLS-CU02 were 7.65 and 5.21 U/mg protein, respectively. The molecular weights of the two purified chitinases were 59 kDa. Further, the purified chitinase of B. licheniformis KYLS-CU01 showed high antifungal activity against Fusarium sp.. In conclusion, these two bacterial isolates can be used as a biopesticide to control pathogenic fungi.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.7
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• pp.964-969
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• 2006

The efficacy of garlic extract and $PGF_2{\alpha}$ in the treatment of endometritis in cows was evaluated. A total of 26 parous cows affected with endometritis were randomly allocated into three groups. Group I (n = 10) animals were infused (IU) with 10 ml garlic extract mixed with 90 ml normal saline, three times at 12 h interval starting from the day of estrum, whereas the animals of Group II (n = 10) were treated with a single injection of $PGF_2{\alpha}$ (25 mg Lutalyse) on the $10^{th}$ to $12^{th}$ day after estrus, and group III (n = 6) remained as control. Cervico-vaginal mucus (CVM) was collected from each animal at pre- and post-treatment estrus and subjected to white side test, pH determination and total bacterial load. The clinical recovery of cows was assessed by negative white side test reaction, pH value and total bacterial count of CVM at subsequent estrus. The recovered animals were inseminated with frozen-thawed semen twice at 12 h intervals and pregnancy was confirmed at 45-60 days following insemination. A significant decline (p<0.05) in pH of CVM was observed in both the treatment groups at subsequent estrus. After treatment there was a significant (p<0.05) reduction in bacterial load, whereas, it was increased in control group. A total number of 65 isolates were identified in CVM samples comprising mostly of facultative anaerobic bacteria. Plasma $T_4$ and $T_3$ concentrations were increased in all the treated animals, whereas, a decline was observed in cortisol levels following treatment. The overall conception rate was 50% in treated groups as compared to nil pregnancy in the control.

• Applied Biological Chemistry
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• v.28 no.2
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• pp.98-105
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• 1985

In the sheep and cattle's rumen, facultative anaerobic cellulolytic bacteria were isolated by using Hungate's roll tube technique. In the 21 isolated species, one was screened by its strong cellulolytic activity and identified as Cellulomonas fimi C-14 by investigate morphological, cultural, physiological characteristics and electron microgram. Optimum conditions of the cell growth and enzyme production were pH 6.5 an $30^{\circ}C$, Thiamine and biotin support a good growth of C. fimi C-14. In the enzyme activities, Crystalline cellulose hydrolyzing activity, CMCase activity and ${\beta}-glucosidase$ activity were 20.6, 226.6 and 0.56$(unit{\times}10^3/ml)$ at pH 6.0, $40^{\circ}C$. By addition of fungal cellulase, enzyme activity was increased. Simultaneous Saccharification Fermentation is better than two step fermentation in ethanol yield with Saccharomyces cerevisiae DY2.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.175-180
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• 2003

Microbial Fe(III) reduction is an important factor for biogeochemical cycle in anaerobic environments, especially sediment of freshwater such as lakes, ponds and rivers. In addition, the Fe(III) reduction serves as a model for potential mechanisms for the oxidation of organic compounds and the reduction of toxic heavy metals, such as chrome or uranium. Shewanella putrefaciens DK-1 was a gram-negative, facultative anaerobic Fe(III) reducer and used ferric ion as a terminal electron acceptor for the oxidation of organic compounds to $CO_{2}$ or other oxidized metabolites. The ability of reducing activity and utilization of various electron acceptors and donors for S. putrefaciens DK-1 were investigated. S. putrefaciens DK-1 was capable of using a wide variety of electron acceptor, including $NO_{3}^{-}$, Fe(III), AQDS, and Mn(IV). However, its ability to utilize electron donors was limited. Lactate and formate were used as electron donors but acetate and toluene were not used. Fe(III) reduction of S. putrefaciens DK-l was inhibited by the presence of either $NO_{3}^{-}$ or $NO_{2}^{-}$. Further S. putrefaciens DK-1 used humic acid as an electron acceptor and humic acid was re-oxidized by nitrate. Environmental samples showing the Fe(III)-reducing activity were used to investigate effects of the limiting factors such as carbon, nitrogen and phosphorus on the Fe(III) reducing bacteria. The highest Fe (III) reducing activity was measured, when lactate as a carbon source and S. putrefaciens DK-1 as an Fe(III) reducer added in untreated sediment samples of Cheon-ho and Dae-ho reservoirs.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.171-176
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• 2000

A wastewater treatment pond system was developed for treatment and recycling of dairy cattle excreta of $5\;m^1$ per day. The wastes were diluted by the water used for clearing stalls. The system was composed of three ponds in series. A submerged gas collector for the recovery of methane was installed at the bottom of secondary pond with water depth of 2.4m. This paper deals mainly with performance of methane fermentation of secondary pond which is faclutative one. The average $BOD_5$, SS, TN, and TP concentrations of influent into secondary pond were 49.1, 53.4, 48.6, and 5.3 mg/l, and those of effluent from it were 27.9, 45.7, 30.8, 3.2 mg/l respectively. Methane fermentation of 2.4-meter-deep secondary pond bottom was well established at $16^{\circ}C$ and gas garnered from the collector at that temperature was 80% methane. Literature on methane fermentation of wastewater treatment ponds shows that methane bacteria grow well around $24^{\circ}C$, the rate of daily accumulation and decomposition of sludge is approximately equal at $19^{\circ}C$, and activities of methanogenic bacteria are ceased below $14^{\circ}C$. The good methane fermentation of the pond bottom around $16^{\circ}C$, about $3^{\circ}C$ lower than $19^{\circ}C$, results from temperature stability, anaerobic condition, and neutral pH of the bottom sludge layer. It is recommended that the depth of pond water could be 2.4m. Gas from the collector during active methane fermentation was almost 83% methane, less than 17% nitrogen. Carbon dioxide was less than 1% of the gas, which indicates that carbon dioxide produced in bottom sludges was dissolved in the overlaying water column. Thus a purified methane can be collected and used as energy source. Sludge accumulation on the pond bottom for a nine month period was 1.3cm and annual sludge depth can be estimated to be 1.7cm. Design of additional pond depth of 0.3m can lead to 15 - 20 year sludge removal.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.2
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• pp.237-243
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• 2020

Listeria sp. is one of the pathogenic bacteria causes the infection listeriosis, through mainly raw food such as fishery food, dairy food and vegetables. Listeria sp. is a Gram-positive, non-spore-forming, motile, and facultative anaerobic bacterium. Because of the tolerance of Listeria sp. to low temperature and high salt concentration, it is very difficult to prevent them contaminated in the food, which do not require heating, especially, such as raw fishery products. So prevention and removal of bacterial contamination at the food manufacturing stage is the best method. In this study, therefore, several natural products including Psidium guajava and Geranium thunbergii were screened to investigate the antibacterial activity against Listeria sp., with expectation of fewer side effects and fewer resistance problems. Significant effects of two extracts were confirmed by well diffusion assay, MIC assay, and growth inhibition assay. P. guajava and G. thunbergii showed MIC values at 64-256 ㎍/mL meaning strong antibacterial activities against 6 kind of Listeria sp. tested. And the growth of Listeria sp. in the liquid media was actually inhibited by the addition of these two extracts.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.461-469
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• 2003

Effects of fruit of Lycium chinense (Chinese matrimony vine) on enzyme activities, and microbial and physicochemical properties of kochjuang were investigated during 12 weeks of fermentation. Enzyme activities were higher during middle of fermentation, and protease activities increased as the ratio of L. chinense increased. Facultative anaerobic bacteria counts decreased in L. chinense-added kochujang, whereas viable cell count of yeasts was higher in 1% L. chinense-added kochujang. Consistency of kochujang decreased by addition of L. chinense. Hunter L- and a-values of L. chinense added kochujang were high, causing slight change in total color difference (E) as the ratio of L chinense increased. Moisture contents of kochujang increased during fermentation, whereas water activities decreased. As the ratio of L. chinense increased, water activities increased. Titrable acidities and oxidation-reduction potential increased by addition of L. chinense. Total sugar contents of kochujang decreased rapidly during fermentation, whereas reducing sugar contents increased up to $2{\sim}4$ weeks of fermentation. As the ratio of L. chinense increased, reducing sugar contents decreased. Ethanol contents of kochujang increased during fermentation, with higher values in 3% L. chinense-added kochujang. Amino and ammonia nitrogen contents of kochujang increased L. chinense content increased. After 12 weeks of fermentation, sensory results showed 3% L. chinense-added kochujang showed highest taste and overall acceptability, and color acceptability increased as L. chinense content increased.