• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.76-83
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• 1999

Studies were conducted during 2 months from May of 1997 to evaluate the effects of pig manure compost(PMC) on soil microbial flora. To do so, a field experiment of Chinese cabbage(Brassica campestris L.) was conducted in a randomized block design on a sandy loam soil and microbial floral characteristics in soils were analyzed. Treatments to control included the application of PMC at (A) $8Mg\;ha^{-1}$CM-8), (B) $29Mg\;ha^{-1}$(CM-2,9), and (C) $57Mg\;ha^{-1}$(CM-57), and of chemical fertilizer(D) at $320N-80P_2O_5-200K_2O\;kg\;ha^{-1}$(NPK). In each treatment, the rhizosphere and non-rhizosphere soils were tested for the analysis of microbial populations. The populations of bacteria, actinomycetes, and fungi increased in soils with the applications of PMC and chemical fertilizer, but that of Bacillus sp. decreased. However, the population of fluorescent Pseudomonas sp. was reduced in NPK plots only. With increasing application rates of PMC, the number of colony forming units(cfu) of bacteria (Pseudomonas sp. and actinomycetes) and fungi increased. in all PMC-treated plots, the population density peaked at early growth stage for bacteria(including Bacillus sp.), at late growth for fluorscent Pseudomonas sp., and at harvest for fungi and actinomycetes. The rhizosphere effect was greatest for fluorscent Pseudomonas sp. As the application rates of PMC increased, Total N, organic matter, available phosphate, and exchangeable -K, -Ca, and -Mg increased compared to control, but soil pH was lowered. In NPK plots, EC was 3.4-fold and exchangeable K was 5-fold higher than control.

• Korean Journal of Veterinary Research
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• v.46 no.3
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• pp.255-261
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• 2006

Experimental animals have been used to biological and medical purposes and the animals must be, for these purposes, healthy and clean to microbial infection. However, the animals can be easily exposed to pathogenic microorganism via several routes. Of the routes, environmental conditions are the most important factors to keep the animals healthy and clean, especially air condition. Monitoring of air-condition has been required to keep the animal healthy and clean. However, any guideline is not available for experimental conditions with pigs. Therefore, the sampling times and points were compared in different conditions to establish an optimal protocol for monitoring of air borne bacteria. Tryptic soy agar(TSA), blood agar containing 5% defibrinated sheep blood and Sabraud dextrose agar(SDA) were used as media to capture total bacteria, pathogenic bacteria and fungi, respectively. Two methods, compulsive capture using an air-sampler and capturing fall-down bacteria were used to capture the microorganisms in the air. The points and time of capturing were different at each experiment. Air borne microorganisms were captured at three and five points in the open and closed equipments, respectively. Air was collected using an air-sampler for 1 min and 5 min and the agar plates as open status were left from 30 min to 2hr. At first, we monitored an experimental laboratory which dealt with several pathogenic bacteria and then, a protocol obtained from the investigation was applied to open or close experimental conditions with pigs. Number of bacteria was high from 10:00 to 15:00, especially on 13:30-15:30 but sharply decreased after 17:00. The tendency of the number of bacteria was similar between two methods even though the absolute number was higher with air sampler. Critical difference in the number of cells was observed at 5 min with air sampler and 2 hr with fall-down capturing method. However, 1 min with air sampler and 1 hr with fall-down capturing were the best condition to identify bacterial species collected from the air. Number of bacteria were different depending on the sampling points in closed condition but not in opened condition. Based on our results, a guide-line was suggested for screening air-borne microorganism in the experimental conditions with pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.5
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• pp.690-700
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• 2012

The experiment was conducted by in vitro fermentation and bacterial community analysis to investigate the reduction of odorous compounds in response to the use of feed additives (FA) during carbohydrate overload in growing pigs. Soluble starch at 1% (control) and various FA at 0.1% Ginseng meal (FA1); Persimmon leaf (FA2); Gingko nut (FA3) and Oregano lippia (FA4) were added to fecal slurry and incubated anaerobically for 12 and 24 h. In vitro parameters and microbial diversity of the dominant bacteria following fermentation were analyzed using Denaturing Gradient Gel Electrophoresis (DGGE), band cloning and sequencing of the V3 region. Results showed that total gas production increased with the advancement of incubation (p<0.05). pH values of FAs and control groups were decreased except the FA4 group which increased somewhat from 12 to 24 h (p<0.05). Ammonia nitrogen ($NH_3$-N) and $H_2S$ gas concentrations were comparatively lower in both stages in FA4 treatment than in the other groups (p<0.05). Hence, $NH_3$-N concentrations in liquid phases were increased (p<0.05) from 12 to 24 h, but the trend was lowest in FA4 than in the other groups at both stages. The total VFA production was comparatively lower and butyrate levels were moderate in FA4 group than in the the other groups during both stages (p<0.05). Indirect odor-reducing compounds such as $NO_2$, $NO_3$ and $SO_4$ concentrations were higher in the FA4 and FA3 than in the other groups at 24 h (p<0.05). After fermentation, ten dominant bands appeared, six of which appeared in all samples and four in only the FA4 treated group. The total number of DGGE bands and diversity was higher in the FA4-group compared to other groups. Additionally, similarity indices were lowest (71%) in the FA4, which represented a different bacterial community compared with the other groups. These findings indicate that $NH_3$-N, $H_2S$ and VFA production was minimal, and pH was also better in the FA4 group than in the other groups. Furthermore, the conversion of odor-reducing indirect compounds or their intermediates was higher in the FA4 group in compared to the other groups. FA4 group generated less odorous products and more indirect products by in vitro fermentation at 24 h, and their microbial pattern appeared to differ from that of the other groups. These findings suggest that this particular FA could change the microbial population, which may have a beneficial effect on odor reduction. It is recommended that the oregano lippia may be supplied to growing pigs as FA along with excess carbohydrate sources to reduce the production of odorous compounds.

• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.172-178
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• 2006

The dynamics of bacterial populations belonging to $\alpha\;\beta\;\gamma-subclass$ proteobacteria, Cytophaga-Flavobacterium (CF) group and sulfate reducing bacteria (SRB) in water column of the middle reaches of Nakdong River depending on sediment harvesting were analyzed by fluorescent in situ hybridization (FISH) at sediment harvesting site (near the Seongju bridge) and non-sediment harvesting site (near the Gumi bridge). In addition, some physico-chemical parameters such as temperature, pH, $chi-\alpha$ and electrical conductivity were measured. Regarding the number of total cell counts, cells stained by DAPI, there were no substantial quantitative differences between both sites, but those fluctuation at sediment Harvesting site was greater. And also the ratios of CFgroup and SRB to total cell counts tend to increase at sediment harvesting site with higher $chl-\alpha$, maybe due to the resuspension of sediment into water column. But the total proportion of all determined bacterial populations to total cell counts were greater at non-sediment harvesting site, compared with those at sediment harvesting site. Since the detectibility of bacteria by FISH depends on their metabolic activity, those lower proportion at the sediment harvesting site implies that sediment harvesting may lead to malfunction of those bacteria respect to nutrient recycling and subsequently negative effects on microbial food web.

• Culinary science and hospitality research
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• v.12 no.4 s.31
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• pp.225-235
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• 2006

This study was carried out to investigate the optimum conditions for the preparation of natto(unripe Chungkukjang) using Sowonkong(small soybeans) and Bacillus subtilis KCCM 11315. The changes in the contents of amino-type nitrogen, ammonia-type nitrogen, total acidity and total sugar, and those in the pH, browning materials and microbial growth were determined during fermentation and aging of natto(unripe Chungkukjang). The amounts of amino-type nitrogen and ammonia-type nitrogen were increased gradually during the fermentation at $40^{\circ}C$ for 72 hours, but those of total acidity and total sugar were decreased. The pH was gradually alkalized, and more water soluble browning materials were produced during fermentation. The number of viable cells was the highest at the 36 hours of fermentation. The content of ammonia-type nitrogen was significantly decreased during aging at $4^{\circ}C$ for 48 hours. In view of the results as above, it seems possible to conclude that the natto(unripe Chungkukjang) fermented by Bacillus subtilis KCCM 11315 at $40^{\circ}C$ for 36 hours and then aged at $4^{\circ}C$ for 48 hours was suitable for manufacturing natto(unripe Chungkukjang).

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1247-1253
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• 1999

Yakju(rice wine) was sterilized with high-voltage pulses of short time on a batch pulsed electric field(PEF) system. The initial microbial counts of Yakju were 7.52 X $10^4\;CFU/mL$ for total aerobes, 2.20 X $10^4\;CFU/mL$ for lactic acid bacteria and 7.08 X $10^4\;CFU/mL$ for yeasts. The pH, acidity and electric conductivity of Yakju were 3.36, 0.462% and 1.24 mS/cm, respectively. Yakju was treated with 2-250 of pulses exponential-wave formed electric pulses under the field strength of 12.5-25 kV/cm. The critical strengths of the electrical field for the sterilization of Yakju were 7.5 kV/cm for total aerobes, 8.5 kV/cm for lactic acid bacteria and 6.5 kV/cm for yeasts. Logarithmic survival rates decreased linearly at low pulse number, but curvilinearly at high pulse number. The PEF sterilization kinetics of Yakju could be analysed by In s = In A-k In (n) and the sterilization rate constant increased with electric field strength and the size of target microorganisms. No changed in pH, acidity, and the growth of microorganisms were found in the PEF treated Yakju during the storage for 6 weeks at both $4^{\circ}C$ And $30^{\circ}C$.

• Journal of Environmental Health Sciences
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• v.43 no.2
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• pp.143-156
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• 2017

The purpose of this study was to investigate water quality through a field survey at six floor fountain sites. The floor fountain facilities were designed and operated in such a way that tap water was stored in a water tank and recycled repeatedly. The water tank was cleaned once or twice per week in the summer. The number of facility users was low during the day due to sweltering heat, but up to 40 people, mainly children, were using them around 8 pm. Since the operation time was as short as 30 minutes, it is considered necessary to extend it for at least one hour for the number of users. As a result of the water quality test of the reservoir tank prior to operation after cleaning, it was measured to be within drinking water quality standards at the six facilities. As a result of the water quality test after use, ammonia nitrogen was measured to be 1.45 mg/L at Site IV. This exceeded the drinking water quality standard of 0.5 mg/L. In the case of turbidity, two cases exceed at 7.38 and 4.52 NTU when applying 4 NTU as the water quality standard for waterscape facilities. Twenty-eight cases exceed the standard of drinking water quality. The result of microbiological tests, at five sites excepting Site I, where disinfectant was injected, was that the maximum total colony count was 180,000 CFU/mL, total coliforms was 2,100,000 CFU/100 mL, fecal coliforms was 4,600 CFU/100 mL, Escherichia coli was 170 MPN/100 mL and Enterococcus was 100 CFU/100 mL. This exceeded the water quality standards of drinking water. Children are very likely to inhale because the water spews from below and falls from above, so it is necessary to apply water quality standards for ammonia nitrogen, turbidity and microbes. Current floor fountain facilities are highly susceptible to disease caused by microbial contamination because of water cycling and reuse, so it is necessary to change the water every day, clean the water tank, and perform chlorination. Therefore, it is necessary to inject calcium hypochlorite according to the free chlorine water quality standard of swimming pools with a different water tank capacity. In addition, facilities should be improved to prevent the reuse of water by installing the water tank at a separate location.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1761-1768
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• 2006

In this study, the comparative effects of transgenic corn (Mon 810 and Event 176) and isogenic corn (DK729) were investigated for their influence on in vitro rumen fermentation. This study consisted of three treatments with 0.25 g rice straw, 0.25 g of corn (Mon810/Event176/DK 729) mixed with 30 ml rumen fluid-basal medium in a serum bottle. They were prepared in oxygen free conditions and incubated at $39^{\circ}C$ in a shaking incubator. The influence of transgenic corn on the number of bacterial population, F. succinogenes (cellulolytic) and S. bovis (amylolytic), was quantified using RT-PCR. Fermentative parameters were measured at 0, 2, 4, 8, 12 and 24 h and substrate digestibility was measured at 12 and 24 h. No significant differences were observed in digestibility of dry matter, NDF, ADF at 12 and 24 h for both transgenic and isogenic form of corns (p>0.05) as well as in fermentative parameters. Fluid pH remained unaffected by hybrid trait and decreased with VFA accumulation as incubation time progressed. No influence of corn trait itself was seen on concentration of total VFA, acetic, propionic, butyric and valeric acids. There were no significant differences (p<0.05) in total gas production, composition of gas (methane and hydrogen) at all times of sampling, as well as in NH3-N production. Bacterial quantification using RT-PCR showed that the population number was not affected by transgenic corn. From this study it is concluded that transgenic corn (Mon810 and Event 176) had no adverse effects on rumen fermentation and digestibility compared to isogenic corn. However, regular monitoring of these transgenic feeds is needed by present day researchers to enable consumers with the option to select their preferred food source for animal or human consumption.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.78-83
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• 2001

To use the by-products of whelk processing, whelk internal organ with the addition of bromelain were used to make jeotgal, Korean traditional salted and fermented seafood sauce. The products were prepared at different salt concentrations of 10, 15 and 20% with various bromelain contents 0, 0.01, 0.1 and 0.5%. The samples were stored at $10^{\circ}C$ and the chemical and microbiological analyses were evaluated for four weeks. The initial pH (near 6.1) in all conditions decreased in the beginning stage of aging, then gradually increased until three weeks and finally decreased to $5.6{\sim}6.0$. The sample with lower salt concentration showed less pH change For two weeks. The samples treated with higher bromelain in 10% and 15% salt concentration showed higher pH values after 4 weeks compared to the nontreated control. Amino nitrogen in the samples increased at lower salt concentration and at higher bromelain content. The amino nitrogen showed maximum value, 780 mg%, at 10% salt and 0.5% bromelain treatment. Total nitrogen contents increased with aging periods, especially increased rapidly in high concentrations of bromelain treated samples at early stages of aging. The higher salt concentrations in the product decreased the total microbial number and lactic acid bacterial number.

• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.220-226
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• 2007

For the analysis of hazard factors and the development of GAP (Good Agricultural Practices) Ginseng, 10 ginseng cultural farms wished certified GAP were selected at Geumsan-gun area, a representative site of ginseng cultivation in Korea. In order to verify the safety of GAP ginseng, possible contamination of pesticide and heavy metal residues, and microbial hazard were analyzed. Soil and water around ginseng cultivation field, and ginseng were investigated. Eighty-one pesticides including carbendazim were used as typical pesticide against plant pathogens and insect pests of ginseng plant and general crops. There was no excess the maximum residue limit (MRL) in residue figure of the soil. Including the residue figure of the arsenic (0.81 ml/kg) and 7 other heavy metals was also suitable to cultivate the ginseng plant. The irrigation water and dilution water for pesticide application were also safety level for GAP. Fresh ginsengs from the farms were sampled and investigated pesticide residues and contaminations of bacteria. Among 23 pesticides tested, we didn't detect any kinds of pesticide residues, but tolclofos-methyl was frequently found in the other ginseng field. On the investigation of microorganism hazards, 2 gram negative bacteria and 1 gram positive bacterium were found in the fresh ginseng. Number of total bacteria was $1.5{\times}10^3$ cfu/ml, which was less than the other agriculture products. At these results, 10 selected ginseng farms were good cultural places for GAP ginseng production and the ginseng cultured from Geumsan-gun area were a good safe far human.