• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2001.06a
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• pp.165-168
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• 2001

Regulation of pyrimidine nucleotide synthesis has been studied extensively in enteric bacteria and Bacillus species. Varieties of control modes have been proposed for regulation of pyrimidine nucleotide biosynthetic (pyr) genes. In Bacillus caldolyticus and B. subtilis, it has been proved that pyrimidine de novo biosynthetic operon is controlled by a regulatory protein PyrR-mediated attenuation. Another Gram-positive bacteria including Enterococcus faecalis, Lactobacillus plantarum, and wctococcus lactis have been found to constitute a pyr gene cluster containing the pyrR gene. In addition, it has been proposed that the structure of the 5' leader region of the Gram-negative extreme thermophile Thermus strain Z05 pyr operon provides a novel mechanism of PyrR-dependent coupled transcription-translation attenuation. Bacterial genome sequencing projects have identified the PyrR homologues in Haemophilus influenzae, Synechocystis sp., Mycobacterium tuberculosis, Streptococcus pneumoniae, S. pyogenes, and Clostridium acetobutylicum, which are currently investigating for their physiological functions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.35-40
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• 2000

The effect of levanheptaose produced by levanase from Streptomyces sp. 366L on principle intestinal microflora was investigated. The reaction product, levanheptaose, was used as a carbon source for various intestinal microflora. As a results, Bifidobacterium adolescentis, Lactobacillus acidophilus, and Eubacterium limosum grew effectively in the in vitro experiment, whereas Clostridium perfringens, E. coli, and Staphylococcus aureus did not. Therefore levanheptaose seems to promote selectively the growth of B. adolescentis and L. acidophilus. In the in vivo experiment, the effect of levanheptaose on the growth of intestinal microflora, $\beta$-fructosidase activity, pH, and butyrate concentration were examined in rats. Apparently, the number of fecal Bifidobacteria, the amount of butyrate, and $\beta$-fructosidase activity were increased, whereas total aerobes and pH were reduced in rats fed by levanheptaose diets, compared with those of control diets. We concluded that those effects may be beneficial in improving gastrointestinal health.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.4
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• pp.495-502
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• 2014

The effect of Bacillus subtilis natto on hindgut fermentation and microbiota of early lactation Holstein dairy cows was investigated in this study. Thirty-six Holstein dairy cows in early lactation were randomly allocated to three groups: no B. subtilis natto as the control group, B. subtilis natto with $0.5{\times}10^{11}cfu$ as DMF1 group and B. subtilis natto with $1.0{\times}10^{11}cfu$ as DMF2 group. After 14 days of adaptation period, the formal experiment was started and lasted for 63 days. Fecal samples were collected directly from the rectum of each animal on the morning at the end of eighth week and placed into sterile plastic bags. The pH, $NH_3$-N and VFA concentration were determined and fecal bacteria DNA was extracted and analyzed by DGGE. The results showed that the addition of B. subtilus natto at either treatment level resulted in a decrease in fecal $NH_3$-N concentration but had no effect on fecal pH and VFA. The DGGE profile revealed that B. subtilis natto affected the population of fecal bacteria. The diversity index of Shannon-Wiener in DFM1 decreased significantly compared to the control. Fecal Alistipes sp., Clostridium sp., Roseospira sp., beta proteobacterium were decreased and Bifidobacterium was increased after supplementing with B. subtilis natto. This study demonstrated that B. subtilis natto had a tendency to change fecal microbiota balance.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.585-591
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• 2014

To evaluate the potential utility of pretreatment of raw biomass with a complex microbial system, we investigated the degradation of rice straw by BMC-9, a lignocellulose decomposition strain obtained from a biogas slurry compost environment. The degradation characteristics and corresponding changes in the bacterial community were assessed. The results showed that rapid degradation occurred from day 0 to day 9, with a peak total biomass bacterium concentration of $3.3{\times}10^8$ copies/ml on day 1. The pH of the fermentation broth declined initially and then increased, and the mass of rice straw decreased steadily. The highest concentrations of volatile fatty acid contents (0.291 mg/l lactic acid, 0.31 mg/l formic acid, 1.93 mg/l acetic acid, and 0.73 mg/l propionic acid) as well as the highest xylanse activity (1.79 U/ml) and carboxymethyl cellulase activity (0.37 U/ml) occurred on day 9. The greatest diversity among the microbial community also occurred on day 9, with the presence of bacteria belonging to Clostridium sp., Bacillus sp., and Geobacillus sp. Together, our results indicate that BMC-9 has a strong ability to rapidly degrade the lignocelluloses of rice straw under relatively inexpensive conditions, and the optimum fermentation time is 9 days.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.10
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• pp.1677-1684
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• 2018

Objective: To find biological functions such as antibacterial and antioxidant activities in several tropical plants and to investigate the possibility of antibiotic substitute agents to prevent and treat diseases caused by pathogenic bacteria. Methods: Plants such as Poncirus trifoliata fruit (Makrut), Zingiber officinale Rosc (Khing), Areca catechu L. (Mak), Solanum melongena L. I (Makkhuayao), and Solanum melongena L. II (Makhurapro) were extracted by methanol, n-hexane, chloroform, ethyl acetate, butanol and water. The free radical scavenging activities were measured using 2-diphenyl-2-picryl hydrazyl photometric assay. Antibacterial activities with a minimum inhibitory concentration (MIC) were observed by agar diffusion assay against pathogenic strains of Escherichia coli, Burkholderia sp., Haemopilus somnus, Haemopilus parasuis, Clostridium perfringens, and Pantoea agglomerans. Results: Poncirus trifoliata fruit methanol extract showed antibacterial activities against gram-negative and gram-positive pathogens. Additionally, this showed the strongest antibacterial activity against Burkholderia sp. and Haemopilus somnus with MIC $131{\mu}g/mL$, respectively. Areca catechu L. water extract showed antibacterial activities against Burkholderia sp., Haemopilus somnus, and Haemopilus parasuis. The MIC value for Haemopilus parasuis was $105{\mu}g/mL$ in this. Antioxidant activity of Zingiber officinale Rosc n-hexane extract showed 2.23 mg/mL effective concentration 50% ($EC_{50}$) value was the highest activity among tropical plants extracts. Total polyphenol content in Zingiber officinale Rosc methanol extract was $48.4{\mu}g/mL$ and flavonoid content was $22.1{\mu}g/mL$ showed the highest values among tested plants extracts. Conclusion: Taken together, these results suggest that tropical plants used in this study may have a potential benefit as an alternative antibiotics agent through their antibacterial and antioxidant activities.

• Food Science of Animal Resources
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• v.32 no.1
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• pp.31-39
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• 2012

The purpose of this study was to isolate bacteriocin-producing bacteria with antagonistic activities against pathogens from the intestines of pigs for probiotic use. Lactobacillus sp. AP 116 possessing antimicrobial property was selected from a total of 500 isolates. The AP 116 strain showed a relatively broad spectrum of inhibitory activity against Listeria monocytogenes, Clostridium perfringens, Pediococcus dextrinicus, and Enterococcus strains using the spot-on-lawn method. Bacteriocin activity remained unchanged after 15 min of heat treatment at $121^{\circ}C$ and exposure to organic solvents; however, it diminished after treatment with proteolytic enzymes. Maximum production of bacteriocin occurred at $34^{\circ}C$ when a pH of 6.0 was maintained throughout the culture during fermentation. According to a tricine SDS-PAGE analysis, the molecular weight of the bacteriocin was approximately 5 kDa. The isolate tolerated bile salts and low pH, and also induced nitric oxide (NO) in mouse peritoneal macrophages. Bacteriocin and bacteriocin-producing bacteria, such as Lactobacillus sp. AP 116, could be potential candidates for use as probiotics as an alternative to antibiotics in the pig industry.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.1
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• pp.1-9
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• 2013

Long term hydrogen production was investigated in an anaerobic sequencing batch reactor (ASBR) using mixed microflora. Glucose (about 8,250 mg/L) was used as a substrate for the ASBR operation under the condition of pH 5.5 and $37^{\circ}C$ with mixing at 150 rpm. The experiment was carried out over a period of 160 days. Hydrogen yield was 0.8mol $H_2/mol$ glucose with F/M ratio 2 at initial operation period. The hydrogen yield reached to maximum 2.6 mol $H_2/mol$ glucose at 80th day operation. However decreased hydrogen yield was observed after 80 days operation and eventually no hydrogen yield. Although well-known hydrogen producer Clostridium sp. was detected in the reactor by PCR-DGGE analysis, changed reactor operation was the major reason of the decreased hydrogen production, such as low F/M ratio of 0.5 and high propionic acid concentration 2,130 mg/L. Consequently the long period operation resulted in MLSS accumulation and then low F/M ration stimulating propionic acid formation which consumes hydrogen produced in the reactor.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.973-977
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• 2013

These studies were attempted to investigate the change of microbial community of anode of microbial fuel cell using swine wastewater in the enrichment step with the lapse of time. Microbial fuel cells enriched by a 1 : 1 mixture of anaerobic digestive juices of the sewage treatment plant and livestock wastewater. Enrichment culture step was divided into three stages to indentify the microorganisms. It was separated by each lag phase, exponential phase, and stationary phase. These steps were determined by the change of the current value. The current after enrichment was generated about $0.84{\pm}0.06mA$. We were cut out the different 17 bands in the DGGE fingerprint gel to do sequencing. The bands which the concentration was increasing or newly appearing with the lapse of time were included for this study. In the lag and exponential phase, Clostridium, Rhodocyclaceae, Bacteriodetes, and Uncultured bacterium etc. were detected. There were in the stationary phase Geobacter sp., Rhodocyclaceae, Candidatus, Nitrospira, Flavobactriaceae and uncultured bacterium etc. Geobactor among microorganisms detected in this study is known as the Electrochemically active microorganisms. It may include electrochemically active microorganisms to be considered as electrical activity microorganisms.

• Journal of Microbiology and Biotechnology
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• v.22 no.10
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• pp.1330-1335
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• 2012

Foot and mouth disease (FMD) is one of the acute infectious diseases in hoofed and even-toed mammals, including pigs, and it occurs via acute infection by Aphthovirus. When FMD is suspected, animals around the location of origin are typically slaughtered and buried. Other methods such as rendering, composting, and incineration have not been verified in practice in Korea. After the FMD incident, the regular monitoring of the microbial community is required, as microorganisms greatly modify the characteristics of the ecosystem in which they live. This is the result of their metabolic activities causing chemical changes to take place in the surrounding environment. In this study, we investigated changes in the microbial community during a 24 week period with DNA extracts from leachate, formed by the decomposition of buried pigs at a laboratory test site, using denaturing gradient gel electrophoresis (DGGE) with a genomic DNA. Our results revealed that Bacteroides coprosuis, which is common in pig excreta, and Sporanaerobacter acetigenes, which is a sulfur-reduced microbe, were continuously observed. During the early stages (0~2 weeks) of tissue decomposition, Clostridium cochlearium, Fusobacterium ulcerans, and Fusobacterium sp., which are involved in skin decomposition, were also observed. In addition, various microbes such as Turicibacter sanguinis, Clostridium haemolyticum, Bacteroides propionicifaciens, and Comamonas sp. were seen during the later stages (16~24 weeks). In particular, the number of existing microbial species gradually increased during the early stages, including the exponential phase, decreased during the middle stages, and then increased again during the later stages. Therefore, these results indicate that the decomposition of pigs continues for a long period of time and leachate is created continuously during this process. It is known that leachate can easily flow into the neighboring environment, so a long-term management plan is needed in burial locations for FMD-infected animals.

• Korean Journal of Poultry Science
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• v.41 no.3
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• pp.165-171
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• 2014

The objective of this experiment was to investigate the effect of dietary supplementation of copper-soy proteinate (Cu-SP) and herbal mixture (HBM) on growth performance, intestinal microflora, and immune response in broiler. A total 1,000 1-d old ROSS 308 (initial $BW=41{\pm}0.38g$) were randomly allotted to 1 of 5 dietary treatments with 4 replicates during d 35 of the feeding trial. Dietary included: (1) Control : control diet, (2) Antibiotics : control diet + Avilamycin 6 ppm, (3) Cu-SP : control diet + 100 ppm Cu-soy proteinate, (4) HBM : control diet + 0.15% herbal mixture, (5) Cu-SP+HBM : control diet + 100 ppm Cu-soy proteinate + 0.2% herbal mixture. Two-phase feeding program with a starter diet from d 0 to 21, and a finisher diet from d 22 to 35 was used in the experiment. Within each phase, a diet was formulated to meet or exceed NRC requirements of broilers for macro- and micronutrients. The diet and water were available ad libitum. Result indicated that during d 22 to 35 and over all periods of the experiment, feed intake and feed conversion ratio were greater (P<0.05) for other treatment than control. Significant differences were found in lymphocyte (LY), and stress indicator (HE:LY ratio). Lymphocyte was greater (P<0.05) for Cu-SP + HBM treatment than control. However, stress indicator (HE:LY ratio) were greater (P<0.05) for control than Cu-SP + HBM treatment. The plasma IgG was higher (P<0.05) in the antibiotics, HBM, and Cu-SP+HBM treatments groups compared with control. The population of Clostridium perfringens in the antibiotics, Cu-SP, HBM, Cu-SP + HBM treatment groups were lower (P<0.05) than those control. These result suggested that dietary copper-soy proteinate or herbal mixture may be used as an alternative to antibiotics to improve growth performance, and intestinal health of birds.