• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.991-994
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• 2000

Single cell of an indigenous phototrophic bacterium, Rhodovulum sulfidophilum, was incorporated in commercial fish feed for Oreochromis niloticus. The bacterial cell was analyzed for nutritional value and tested for toxicity and acceptability as an aquaculture feed supplement. The results showed higher survival rate and significantly higher growth rate (p<0.001) in O. niloticus fed with the bacteria incorporated fish feed. It is suggested that R sulfidophilum can be utilized as an aquaculture feed supplement.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.10
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• pp.1399-1406
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• 2000

A continuous culture study was conducted to determine the impact of ruminal degradable soy protein (S-RDP) level and dilution rate (D) on growth of ruminal non-structural carbohydrate-fermenting microbes. Corn starch, urea and isolated soy protein (ISP) were used to formulate three diets with S-RDP levels of 0, 35 and 70% of total dietary CP. Two Ds were 0.03 and $0.06h^{-1}$ of the fermenter volume in a single-effluent continuous culture system. As S-RDP levels increased, digestibilities of dietary dry matter (DM), organic matter (OM) and crude protein (CP) linearly (p=0.001) decreased, whereas digestion of dietary starch linearly (p=0.001) increased. Increasing D from 0.03 to $0.06h^{-1}$ resulted in decreased digestibilities of dietary DM and OM, but had no effect on digestibilities of dietary starch (p=0.77) and CP (p=0.103). Fermenter pH, the concentration of volatile fatty acids (VFA) and daily VFA production were unaffected (p=0.159-0.517) by S-RDP levels. Molar percentages of acetate, propionate and butyrate were greatly affected by S-RDP levels (p=0.016-0.091), but unaffected by D (p=0.331-0.442). With increasing S-RDP levels and D, daily bacterial counts, daily microbial N production (DMNP) and microbial efficiency (MOEFF; grams of microbial N produced per kilogram of OM truly digested) were enhanced (p=0.001). The increased microbial efficiency with increasing S-RDP levels is probably the result of peptides or amino acids that served as a stimulus for optimal protein synthesis. The quantity of ruminal degradable protein from soy proteins required for optimum protein synthesis of non-structural carbohydrate-fermenting microbes appears to be equivalent to 9.5% of dietary fermented OM.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.960-965
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• 2001

The effects of different feeding ratios of concentrate (C) and roughage (R) on balance of long chain fatty acids and microbial fatty acids in the rumen of sheep were investigated. The diets were divided into 8:2 (concentrate feeding), 4:6 (middle mixture) and 0:10 (roughage feeding) ratios (C:R). Duodenal digesta was collected through 24 hours after feeding. Biohydrogenation rate, total duodenal flow of fatty acids and microbial fatty acids were measured. Total duodenal flow of fatty acids was significantly (p<0.05) increased with increasing concentrate. Total duodenal flow of fatty acid was greater than intake of fatty acid in all diets. In comparison with intake of each fatty acid, duodenal flow of stearic acid ($C_{18:0}$) remarkably increased in all diets. Biohydrogenation rate for total C18 unsaturated fatty acids in the rumen tended to increase (p<0.10) when sheep were fed the middle mixture. In particular, biohydrogenation rate of linoleic acid ($C_{18:2}$) and linolenic acid ($C_{18:3}$) with the middle mixture were highest (p<0.05) compared with other diets. Duodenal flow of protozoal fatty acids was significantly (p<0.05) increased with the increased supply of concentrate. That of bacterial fatty acids was significantly (p<0.05) increased with both concentrate diets compared with the roughage feeding diet. $C_{18:0}$ occupied the greater part of both protozoal and bacterial fatty acids in all treatments. Results indicated that biohydrogenation of free unsaturated fatty acids was actively carried out when the middle mixture diet was supplied, and that microbial uptake and synthesis of fatty acids were accelerated by adding the supply of concentrate.

• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.265-270
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• 1995

Transposon mutation of Xanthomonas campestris pv. vesicatoria (Xcv) was induced by using transposon omegon ($\Omega$)-Km (Tn $\Omega$Km), which was confirmed by resistance to kanamycin (KMr), and nonpathogenic mutants were selected through the inoculation test on pepper plants. The mutagenesis frequency was about 6$\times$10-8, and 53 out of 2,000 Kmr bacterial colonies tested were nonpathogenic to the pepper cultivar Cheung-Hong. Optimum conditions for the Tn $\Omega$Km mutagenesis of Xcv were Luria Bertani (LB) broth medium for culture of Xcv, yeast extract-dextrose-CaCO3 (YDC) agar medium for selection of Tn $\Omega$Km-mediated mutants, and over 1 to 2 in the ratio of the donor (Escherichia coli S17-1 with the plasmid pJFF350 $\Omega$Km) and the recipient (Xcv) in the culture for the mutagenesis. One of the 4 nonpathogenic mutants (WNP1, WNP3, WNP4 and WNP5), which had been reconfirmed through the inoculation on pepper cv. Dabokgun, showed no differences in the production of exoenzymes such as protease and polygalacturonase and extracellular polysaccharides in vitro and the bacterial growth rate from those of the wild type of Xcv.

• Herbal Formula Science
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• v.16 no.1
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• pp.79-94
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• 2008

Although inflammatory mediators such as nitric oxide(NO) and pro-inflammatory cytokines are involved in host defense mechanism, these overproduction contributes to the pathogenesis of several diseases such as otitis media, hearing loss, periodontitis, bacterial sepsis, rheumatoid arthritis, chronic inflammation and autoimmune diseases. We investigate the anti-inflammatory effects of water extract from Ji-Pae-San(JPSWE) fomulated with Angelica dahurica plus Fritillaria Verticillata, Angelica dahurica(ADWE), and Fritillaria Verticillata(FUVE) in vitro and in vivo. Each extract inhibited the production of inflammatory mediators(NO, $IL-1{\beta}$, IL-6, $TNF-{\alpha}$, and prostaglandin $E_2$) and the expression of inducible NO synthase(iNOS) and cyclooxygenase-2(COX-2) in lipopolysaccharide(LPS)-stimulated RAW 264.7 macrophages in a dose-dependent manner. These inhibitory effects were synergistically increased by their combination. JPSWE also inhibited $TNF-{\alpha}$, $IL-1{\beta}$, IL-6. and $PGE_2$ production as well as COX activity in LPS-stimulated mice. Moreover, JPSWE significantly suppressed death by LPS-septic shock in mice(survival rate: 100%). These results suggest that Ji-Pae-San may be useful for therapeutic drugs against inflammatory immune diseases, probably by suppressing the production of inflammatory mediators.

• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.475-482
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• 2021

Prodigiosins, which are natural tripyrrole red pigments and synthetic derivatives, reportedly have multiple biological effects mainly on various types of cancer cells. However, the effects of bacterial prodigiosin on non-cancerous HaCaT human skin keratinocytes have not been reported. Therefore, the present study aimed to investigate the functional activities of prodigiosin derived from cultures of the bacterium Hahella chejuensis in HaCaT cells. Cell viability, the cell proliferation rate, and reactive oxygen species (ROS) production in vitro were assayed following treatment of HaCaT cells with prodigiosin. Prodigiosin did not cause cytotoxicity and notably increased proliferation of HaCaT cells. Furthermore, prodigiosin reduced ultraviolet (UV) irradiation-induced ROS production and the inflammatory response in HaCaT cells. More importantly, prodigiosin reduced matrix metalloproteinase-9 expression and increased collagen synthesis in UV-irradiated HaCaT cells, demonstrating that it elicits anti-aging effects. In conclusion, our results reveal that H. chejuensis-derived prodigiosin is a potential natural product to develop functional cosmetic ingredients.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.639-643
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• 2002

Water quality, bacterial phase and fish growth rate were analyzed in the process of artificial seed production of flounder (Paralichtys oliraceus) larvae to investigate the water quality in rearing tank using Ultra Filtration System (UES). Sand Filtration System (SFS) and Ultra Filtration System (Ins) were set up in the experimental group. For the analysis of water quality, pH, salinity, DO, SS, COD, $NH_{4}^{+},\;NO_{2}^{-},\;NO^-,\;DIN$ (dissolved inorganic nitrogen) and DU (dissolved inorganic phosphate) were measured. There was no data difference between SFS group and UES group in most analysis items, but the UEs group showed low salinity and low 55 values, such that salinity was $33.5\%_{\circ}$ in SES group and $30.2\%_{\circ}$ in WS group and 55 was 15.5 mL/L in SES group and 7.0 mL/L for UPS group. For changes in bacterial phase and TBC (Total Bacterial Counts), in SES group, 6$\times$10^{5}CFU/mL in seawater decreased to the ratio of about 116, and TBC, Genus Vibrio and bacteria in the Genus Acinetobacter and Genus Micrococcus sharply increased after nine days, while stable bacterial phase was maintained low in UES group during the experiment except for Genus Ajteromonas. In the growth of the larvae, fish length was 17.0 mm (SGR 14.0) in the SES group and 18.8 mm (SGR 14.3) in the UFS group. It is concluded that when water is supplied for artificial seed production with WS, stabilization of water quality condition and inhibition of bacterial multiplication are possible. When production environment becomes stable, stable growth of fish becomes possible by reduction of environmental stress.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.58-64
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• 1997

$H_2$ production by Chromatium sp., a large purple sulfur bacterium blooming in lake Kaiike, under various environmental conditions was examined. Chromatium sp. produced $H_2$ only in the presence of light and $H_2$. Maximum $H_2$ production ($0.01\;{\mu}mol/hr/(mg\;dry\;cell\;weight)$) was obtained in the solution of 20 mg $H_2S-S/l$ under low light intensity (1000 lux) at $30^{\circ}C$. $H_2$ production was severely inhibited by the presence of $N_2\;or\;NH_4^+$. The rate observed for Chromatium sp. was relatively low compared to that of other phototrophic bacteria. Chromatium sp. is probably a most potent Ha producing species in lake Kaiike, since the bacterium readily produced $H_2$ photoautotrophically even at low light intensities by the application of suboptimal $H_2$ concentrations. Based on the photoautotrophic characteristics of bacterial $H_2$ production, it is suggested that Chromatium sp. can be an economic and practical species for biological $H_2$ production system, particularly in temperate region.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.342-349
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• 2017

Polylactic acid (PLA) has been highlighted as an alternative renewable polymer for the replacement of petroleum-based plastic materials, and is considered to be biodegradable. On the other hand, the biodegradation of PLA by terminal degraders, such as microorganisms, requires a lengthy period in the natural environment, and its mechanism is not completely understood. PLA biodegradation studies have been conducted using mainly undefined mixed cultures, but only a few bacterial strains have been isolated and examined. For further characterization of PLA biodegradation, in this study, the PLA-degrading bacteria from digester sludge were isolated and identified using a polymer film-based screening method. The enrichment of sludge on PLA granules was conducted with the serial transference of a subculture into fresh media for 40 days, and the attached biofilm was inoculated on a PLA film on an agar plate. 3D optical microscopy showed that the isolates physically degraded the PLA film due to bacterial degradation. 16S rRNA gene sequencing identified the microbial colonies to be Pseudomonas sp. MYK1 and Bacillus sp. MYK2. The two isolates exhibited significantly higher specific gas production rates from PLA biodegradation compared with that of the initial sludge inoculum.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1311-1320
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• 2005

The purpose of this research is to survey characteristics of microbial community and the removal efficiency of organic materials for biological activated carbon in water treatment plant. Coal based activated carbon retained more attached bacterial biomass on the surface of the activated carbon than the other activated carbon with operating time and materials. The heterotrophic plate count(HPC), eubacteria(EUB) and 4,6-diamidino-2-phenylindole(DAPI) counts were ranged from $0.95{\times}10^7$ to $52.4{\times}10^7$ CFU/g, from $3.8{\times}10^8$ to $134.2{\times}10^8$ cells/g and from $7.0{\times}10^8$ to $250.2{\times}10^8$ cells/g, respectively. The biomass of EUB and DAPI appeared to be much more $10^2$ than HPC, which were increasing in bed volume of 20,000 at the stage of steady-state. The change of microbial community by analyzing fluorescent in situ hybridization(FISH) method with rRNA-targeted oligonucleotide probes, the dominant group was $\alpha$-proteobacteria($\alpha$ group) and high G+C content bacteria(HGC) the lowest distributing rate before reaching the bed volume of 20,000. After reaching the bed volume of 20,000, $\alpha$ group and other groups of bacteria became decreased, on the other hand, the proportion of both $\beta$-proteobacteria($\beta$ group) and $\gamma$-proteobacteri($\gamma$ group) were increasing. Coconut and wood based activated carbons had similar trend with coal based activated carbon, but the rate of $\alpha$ group on coal based activated carbon had gradually increased. Bacterial production with the operating period appeared highest in coal based activated carbon at the range of $1.2{\sim}3.4\;mg-C/m^3{\cdot}h$ while the coconut and wood based activated carbon were ranged from 1.1 to 2.6 $mg-C/m^3{\cdot}h$ and from 0.7 to 3.5 $mg-C/m^3{\cdot}h$ respectively. The removal efficiency of assimilable organic carbon(AOC) showed to be highly correlated with bacterial production. The correlation coefficient between removal efficiency of AOC and bacterial production were 0.679 at wood based activated carbon, 0.291 at coconut based activated carbon and 0.762 at coal based activated carbon, respectively.