• Journal of the Korean Society of Tobacco Science
• /
• v.26 no.2 s.52
• /
• pp.79-84
• /
• 2004

During the screening of antiviral substances having inhibitory effects on tobacco mosaic virus (TMV) infection to tobacco plants, we found a bacterial isolate KTGBP10, which was identified as a Stenotrophomonas sp., strongly inhibited the infection of TMV. When the culture filtrate from KTGBP10 was applied on the upper surface of leaves of Xanthi-nc tobacco plants at the same time or 24 hours before TMV inoculation, almost complete inhibition of TMV infection was achieved. And $40\%$ inhibition was shown with application of the culture filtrate to the under surface of leaves. In field trials, transmission of TMV from diseased seedlings to the healthy ones during transplanting work was reduced by $87.1\~92.6\%$ when the culture filtrate or cell suspension was sprayed onto the tobacco seedlings, cv. NC82, 24 hours before transplanting. No toxic effect was observed on the tobacco plants. When the broth filtrate of KTGBP10 was supplied by soaking through the cut-leaves before and/or after virus inoculation, the TMV infection was also inhibited by $50.4\~65.3\%$.

• Korean Journal of Veterinary Service
• /
• v.37 no.3
• /
• pp.203-212
• /
• 2014

Frog culture industry is not yet familiar but has much potential. Generally, in farm, the population density is higher than that of in nature and frog farm is not the exception. But when population density is high, it can easily leads to stressful condition, poor sanitation. When a disease occur, it is a primary factor that makes the population more susceptible and the results more grave. Because of severe Rhabditoidea- helminth infection and subsequent bacterial septicemia, 50~70% of the total population had been died in a farm in Jeong-sun in Gangwon-do and Chungju in Chungcheongbuk-do from late June, 2012 to September, 2012. Diseased frogs showed ruptured lung, bloody ascites, liver discoloration, myocardium weakness, congested kidney, microcytic anemia and so on. Enterobacteriacea, Citrobacter.sp, Cupriavidus metallidurans, Acinetobacter.sp were isolated as major bacterium that had caused septicemia in frogs. Among isolated bacterium, Cupriavidus metallidurans, Ewingella americana, Shewanella aquimarina and Pseudoalteromonas sp. have not reported as potential pathogens in frogs before. It is a good example that severe helminth infection in frogs can lead to secondary infection of bacteria.

• KSBB Journal
• /
• v.25 no.6
• /
• pp.513-519
• /
• 2010

Marine bacterium producing pigment was isolated from the solar saltern of Mijo-myeon, Namhae, Korea. Based on phenotypic characteristics and 16S rRNA sequence analysis, the strain was identified as Kocuria sp., which produced a yellow pigment. The pigment showed UV absorption maximum at 469nm. The bacterial strain grew well on Marine broth 2216 culture medium. Productivity of the pigment reached the maximum value after 44 hours at $30^{\circ}C$, 2% NaCl and pH 6.0. The pigment was produced best when supplied by 1% lactose as a carbon source and 1% beef extract as a nitrogen source. The result of the color stability study showed that pigment extracted from the strain by ethanol was stable at $-20-25^{\circ}C$ and also showed higher stability over 70% for 14 days in light conditions at $25^{\circ}C$. The pigment extract was also stable for all metal ions tested, except for $FeCl_2$.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.26 no.1
• /
• pp.107-124
• /
• 2000

A bacterial strain No. HB-5, which was capable of producing a pretense in the culture conditions, was isolated from the soil . The pretense was purified from cultural filtrate of Bacillus sp. HB-5 by membrane ultrafiltration and DEAE- cellulose chromatography, gel filtration on Sephadex G-100. The molecular weight was estimated to be 60k4a. The optimal pH and temperature for the activity of the purified pretense pH were 11 and 5$0^{\circ}C$ , respectively. The enzyme was stable within a pH range 8-12 and up to 6$0^{\circ}C$ . The enzyme activity was highly inhibited by PMSF at 1mM. The proteolytic actions of pretense and papain on human epidermis keratins which are major protein impurities on the skin, were compared. The bacterial pretense degraded more effectively than papain. Product containing 2% protease exhibited 21% increase on the skin coloration index. These results suggest that cosmetic product containing pretense produced by Bacillus sp. HB-5 could remove the adherent keratin layer and then make a softer skin.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.1
• /
• pp.14-21
• /
• 2005

By using PCR with nirS gene primers, three nirSharboring denitrifying bacteria (strain N6, strain N23, and strain R13) were newly isolated from activated sludge of a weak municipal wastewater treatment plant. Small-subunit rRNA gene-based analysis indicated that strain N6, strain N23, and strain R13 were closely related to Arthrobacter sp.,Staphylococcus sp., and Bacillus sp., respectively. In an attempt to identify their roles in biological nitrate and nitrite removal from sewage, we investigated their specific denitrification rates (SDNRs) for $NO_-^3$ - and $NO_-^2$ - in various cultures. All purecultures of each isolated nirS-harboring bacterial strain could remove $NO_-^3$ - and $NO_-^2$ - simultaneously in high efficiency, and the carbon requirements for $NO_-^3$ - removal of strain N6 and strain R13 were effectively low at 3.1 and 4.1 g COD/g $NO_3N$, respectively. In the case of mix-cultures of the strains (N6+N23, N6+R13, N23+R13, and N6+N23+R13), their SDNRs for $NO_-^3$ - were also effective, and their carbon requirements for $NO_-^3$ - removal were also effective at 3.0- 3.8 g COD/g NO3N. However, all tested mix-cultures accumulated $NO_-^2$ - in their culture media. On the other hand, the continuous culture of activated sludge mixed with strain N6 showed no significant increase of $NO_-^3$ - removal in comparison with strain N6's pure culture. These results suggest that nitrate and nitrite removal in biological wastewater treatment might be dependent on complicated bacterial interactions, including several effective denitrifying bacteria isolated in this study, rather than the specific bacterial types present and the number of bacterial types in activated sludge.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.11
• /
• pp.1617-1626
• /
• 2013

The Bacterial community structure and its complexity of the enrichment culture during the isolation and screening of imidacloprid-degrading strain were studied using denaturating gradient gel electrophoresis analysis. The dominant bacteria in the original tea rhizosphere soil were uncultured bacteria, Rhizobium sp., Sinorhizobium, Ochrobactrum sp., Alcaligenes, Bacillus sp., Bacterium, Klebsiella sp., and Ensifer adhaerens. The bacterial community structure was altered extensively and its complexity reduced during the enrichment process, and four culturable bacteria, Ochrobactrum sp., Rhizobium sp., Geobacillus stearothermophilus, and Alcaligenes faecalis, remained in the final enrichment. Only one indigenous strain, BCL-1, with imidacloprid-degrading potential, was isolated from the sixth enrichment culture. This isolate was a gram-negative rod-shaped bacterium and identified as the genus Ochrobactrum based on its morphological, physiological, and biochemical properties and its 16S rRNA gene sequence. The degradation test showed that approximately 67.67% of the imidacloprid (50 mg/l) was degraded within 48 h by strain BCL-1. The optimum conditions for degradation were a pH of 8 and $30^{\circ}C$. The simulation of imidacloprid bioremediation by strain BCL-1 in soil demonstrated that the best performance in situ (tea soil) resulted in the degradation of 92.44% of the imidacloprid (100 mg/g) within 20 days, which was better than those observed in the ex situ simulations that were 64.66% (cabbage soil), 41.15% (potato soil), and 54.15% (tomato soil).

• Korean Journal of Microbiology
• /
• v.37 no.1
• /
• pp.15-20
• /
• 2001

In this study, we have isolated bacterial cell wall lytic enzyme in the culture supernatant of Aspergillus sp. HCLF-4. This hydrolase showed cell wall lytic activity against Anabaena cylindrica. The extracellular enzyme was produced by Aspergillus sp. HCLF-4 when it was grown in a PDB media containing 0.05% heat killed Micrococcus luteus cells. The molecular weight of lytic enzyme was about 14.3 kDa. The optimal pH and temperature for the activity of this enzyme were 3.0~4.0 and $30^{\circ}C$, respectively. This hydrolase activity was reduced by $Na^{+}$, $Li^{+}$, $Ca^{2+}$, $Cu^{2+}$, $Fe^{3+}$, EDTA, and PMSF, whereas it was increased by $Mg^{2+}$, $Mn^{2+}$>. The enzyme has N-acetylmuramyl-L-amidase or endopeptidase activity.

• Journal of fish pathology
• /
• v.13 no.1
• /
• pp.45-51
• /
• 2000

Bacterial diseases with mixed infection have recently occurred at land-based flounder farms in Korea. Thus, single antibacterial is not effective for therapy of mixed bacterial diseases of fish because of their different causative bacteria. The purpose of the present study was to obtain basic data for positive usefulness of a combination of antibacterials used for synergism to mixed bacterial diseases of fish. Snergistic interaction in combination of antibacterials was determined by in vitro antimicrobial activity against selected fish-pathogenic bacteria, Vibrio anguillarum, Edwardsiella tarda, Streptococcus sp., Staphylococcus epidermidis, on the basis of Checkerboard assay using fractional inhibitory concentration (FIC) indices. Synergistic interactions were observed in combinations of (oxytetracycline HCL+lincomycin), (tetracycline HCL+florfenicol), (oxytetracycline HCL+florfenicol) against V. anguillarum, (sodium nifurstyrenate+florfenicol), (tetracycline HCL+florfenicol), (sodium nifurstyrenate+oxolinic acid), (oxytetracycline HCL+florfenicol) against E. tarda, (ciprofloxacine+oleandomycin), (oxytetracycline HCL+oleandomycin), (tetracycline HCL+oleandomycin), (oxytetracycline HCL+lincomycin), (oxytetracycline HCL+spiramycin), (oxytetracycline HCL+erythromycin), (doxycycline HCL+oleandomycin), (tetracycline HCL+spiramycin) against Streptococcus sp., and (ciprofloxacine+erythromycin), (florfenicol+erythromycin), (doxycycline HCL+oleandomycin), (ciprofloxacine+oleandomycin) against S. epidermidis.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.4
• /
• pp.527-537
• /
• 2019

Three types of meongge (Halocynthia roretzi) jeotgal (MJ) were prepared with 3 different types of salts (12%, w/v): purified salt (PS), solar salt aged for 3 years (SS), and bamboo salt that had been recrystalized 3 times (BS). One set of MJ was fermented with starters, Bacillus subtilis JS2 and Tetragenococcus halophilus BS1-37 (each 6 log CFU/g), and another set without starters for 42 days at $10^{\circ}C$. The LAB count of the SSMJ (non-starter) was highest at day 28 (2.30 log CFU/g). The pH of the PSMJ and SSMJ was 5.72-5.77 at day 0, and 5.40-5.50 at day 42. BSMJ showed higher pH and lower titratable acidities than other samples. Amino-type nitrogen (ANN) increased continuously, and SSMJ showed higher values than other samples from day 14. Bacterial species of non-starter MJ were examined by culture independent method. Clone libraries of 16S rRNA genes were constructed in Escherichia coli from total DNA from non-starter MJ samples at day 0, 14, and 28. Thirty clones per each sample were randomly selected and DNA sequences were analyzed. Variovorax sp., uncultured bacterium, and Acidovorax sp. were the most dominant group at day 0, 14, and 28, respectively. Lactobacillus sakei and Streptococcus sp. were the next dominant group in SSMJ at day 28. A Streptococcus sp. was detected from PSMJ at day 28. Sensory evaluation for MJ samples at day 28 showed that SSMJ got higher overall acceptability scores. These results showed that solar salt can cause desirable changes in the microbial community of fermented foods, thereby positively affecting their overall quality.

• 한국생물공학회:학술대회논문집
• /
• 2002.04a
• /
• pp.359-360
• /
• 2002

A bacterial strain able to degrade terephthalic acid (TPA) was isolated and identified to belong to the Corynebacterium sp. It was named Corynebacterium sp. YT-14. When stirred loop bioreactor was used in a batch type system for removing terephthalic acid from weight loss treatment wastewater and complex dyeing process wastwater, the removal efficiency of terephthalic acid was 85.4% after 7 days of treatment of the weight loss treatment wastewater, while no residual terephthalic acid was detected after 3 days of treatment of the complex dyeing process wastewater