• 미생물학회지
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• 제7권1호
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• pp.29-40
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• 1969

Two kinds of organic materials, powders of Salicornia and Oryza sativa L. wre added as a source of organic matter to the suspensions of saline soils(soil : water = 1:3) to be 4 per cent of dried saline soil grams. And then, the samples were incubated at $28^{\circ}C$ to improve the decomposition of organic materials by soil microflora. Resutls of this experiment are summarized as followings : 1) The pH of soil suspension showed its highest value on the second or third week after the treatments, which were similar to those of the soil microflora. Results of this experiment are summarized as follwings : 1) The pH of soil suspension showed its highest value on the second ot third week after the treatments, which were similar to those of the soil microflora populations. 2) Salinity increased up to the second week and the highest value of it appeared in the samples which were treated with the powder of Salicornia. In general, the salinity of all samples decreased on the third week after the treatment. The fact was assumed the possibilities of desalination from saline soil by the microbial actions. 3) Soil microflora such as bacteria, actinomycetes and fungi, were determined its populations soil microflora is to act as decomposer in soil. Both of the bacteria and actinomycytes population showed in the third weak after the tratment. In general, 30-years old of saline soil contained microbial population much more than those of 5-year old of saline soil. Salicornia powder favored the increase of both the bacteria and fungal population, and Oryza sativa L. seemed to have been a great role in increase of actinomycetes. Especially, fungal population of the untreated soil suspension contained higher microbial populations more than those of the soils treated with both of the organic materials. 4) Sugar contents of soil suspesions decreased remarkably on the first week after the treatments. 5) The amount of nitrate had similar tendency to those of population changes of soil microflora. Total acidity decreased continuously and the amount of potassium showed its highest value on the third week treatment. However, the amount of phosphorus was determined to be insignificant.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권4호
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• pp.50-59
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• 2016

Spatial and temporal changes in nitrification activities and distribution of microbial population of ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) in paddy soils were investigated. Soil samples were collected in March and October 2015 from rice paddy with and without the presence of confined animal feeding operations. Incubation experiments and quantitative polymerase chain reaction showed that AOA's contribution to nitrification kinetics was much higher in locations where organic nitrogen in animal waste is expected to significantly contribute to overall nitrogen budget, and temporal variations in nitrification kinetics were much smaller for AOA than AOB. These differences were interpreted to indicate that different microbial responses of two microbial populations to the types and concentrations of nitrogen substrates were the main determining factors of nitrification processes in the paddy soils. The copy numbers of ammonium monooxygenase gene showed that AOA colonized the paddy soils in higher numbers than AOB with stable distribution while AOB showed variation especially in March. Although small in numbers, AOB population turned out to exert more influence on nitrification potential than AOA, which was attributed to higher fluctuation in AOB cell numbers and nitrification reaction rate per cells.

• Asian-Australasian Journal of Animal Sciences
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• 제26권7호
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• pp.952-960
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• 2013

The objective of this study was to investigate the effect of carbohydrate source and cottonseed meal level in the concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in swamp buffaloes. Four, 4-yr old rumen fistulated swamp buffaloes were randomly assigned to receive four dietary treatments according to a $2{\times}2$ factorial arrangement in a $4{\times}4$ Latin square design. Factor A was carbohydrate source; cassava chip (CC) and CC+rice bran at a ratio 3:1 (CR3:1), and factor B was level of cottonseed meal (CM); 109 g CP/kg (LCM) and 328 g CP/kg (HCM) in isonitrogenous diets (490 g CP/kg). Buffaloes received urea-treated rice straw ad libitum and supplemented with 5 g concentrate/kg BW. It was found that carbohydrate source did not affect feed intake, nutrient intake, digested nutrients, nutrient digestibility, ammonia nitrogen concentration, fungi and bacterial populations, or microbial protein synthesis (p>0.05). Ruminal pH at 6 h after feeding and the population of protozoa at 4 h after feeding were higher when buffalo were fed with CC than in the CR3:1 treatment (p<0.05). Buffalo fed with HCM had a lower roughage intake, nutrient intake, population of total viable and cellulolytic bacteria and microbial nitrogen supply than the LCM fed group (p<0.05). However, nutrient digestibility, ruminal pH, ammonia concentration, population of protozoa and fungi, and efficiency of microbial protein synthesis were not affected by cottonseed meal levels (p>0.05). Based on this experiment, concentrate with a low level of cottonseed meal could be fed with cassava chips as an energy source in swamp buffalo receiving rice straw.

• 한국산림과학회지
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• 제83권3호
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• pp.372-379
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• 1994

본 연구는 서로 다른 두가지 토양에서 천연갱신되어 자라고 있는 trembling aspen(Populus tremuloides Michx.) 임분의 수확이 토양미생물상 및 토양호흡률에 미치는 영향을 조사하며 토양호흡률이 토양미생물상 변이의 지표로 활용될 수 있는지에 대한 연구 결과이다. 다섯 가지의 수확처리(지상부 전체 임목수확, 겨울철 수확통로, 수확 잔재목 제거, 수확 잔재목 및 낙엽류 제거, 춘계 답압)를 1990년과 1991년 사이의 겨울 및 봄 사이에 시행하였고, 1991년 및 1992년의 2년간에 걸쳐 수확후 산림토양의 동태를 조사하였다. 각 임분의 토양형에 관계없이 토양호흡률은 수확후 약간 감소하거나 변동이 없었으나 미생물수는 수확후 2년동안 점차 증가하였다. 미생물수는 식질토양에서 보다 사질토양에서 보다 급속하고 지속적인 증가양상을 나타내었는데, 이것은 수확 결과 미생물 활성에 영향하는 토양의 이화학적 특성이 식질토양보다는 사질토양에서 큰 변화가 있었음을 시사한다. 그러나, 두가지 종류의 처리(세 수준의 유기물 제거 및 두 수준의 답압 처리)는, 두 지역 모두, 수확후 2년간의 미생물상이나 토양호흡률에 유의차를 나타내지 않았다. 본 연구의 대상임분이었던 trembling aspen은 수확후에도 뿌리의 활력이 떨어지지 않고 맹아발생을 위한 대사를 진행하여, 뿌리의 호흡과 미생물의 호흡을 포함하는 전체 토양 호흡에서 뿌리의 호흡이 차지하는 비율이 높은 결과를 낳아, 전체 토양호흡을 미생물의 활력도 변이의 지표로 활용하기 어려웠다.

• 한국식품위생안전성학회지
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• 제28권2호
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• pp.174-180
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• 2013

본 연구에서는 토마토의 생산 및 유통단계에서의 위해 미생물 오염도 정도를 파악하고 유통과정 중 외부 손상으로 인해 과즙 유출시 미생물의 증식능력을 측정하기 위해 E. coli O157:H7와 L. monocytogenes의 성장을 토마토 추출물 함량(0.1, 1.0, 10%) 및 다양한 배양온도(5, 15, 25, $35^{\circ}C$)에서 측정하였다. 수확단계에서는 APC 작업 종사자의 장갑에서 총 호기성 세균이 7.77 log로 가장 높게 나타났고, 배양 양액에서 대장균군과 B. cereus가 각각 0.33 log 검출되었다. 수확 후 처리과정으로 APC 과정을 거친 토마토에서 총 호기성 세균이 유의적으로 높게 나타났다. 그 외에 S. aureus, Salmonella spp. 는 검출되지 않았다. 재배방법에 따른 일반, 유기농, 무기농 토마토에서의 미생물 분포도의 유의적인 차이는 나타나지 않았다. 포장 방법 중 봉지 포장제품이 박스 포장제품에 비해 대장균군이 유의적으로 높게 나타났으며 세척에 의한 미생물 저감화 효과는 나타나지 않았다. 토마토 추출물 함량이 높을수록 E. coli O157:H7와 L. monocytogenes의 성장이 높게 나타났으며, 토마토 추출물 10%인 경우 $5^{\circ}C$ 조건에서 가장 낮았고, 15, 25, $35^{\circ}C$에서 72시간 배양시 각각 7.33~8.51, 7.73~8.60 log CFU/g으로 증식하였다.

• 한국토양비료학회지
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• 제44권5호
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• pp.696-701
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• 2011

전북지역 과수원 토양 110개소를 대상으로 토양특성이 미생물분포에 미치는 영향을 조사하였다. 토양 중 미사함량이 많아질수록 호기성세균, 곰팡이, 미생물 biomass C 함량은 증가하였고, 탈수소효소 활성은 토성에 따라 차이가 없었다. 지형에 따른 미생물분포, 미생물의 biomass C 함량, 탈수소효소 활성은 차이가 없었고, 과수종류에 따라 coliform group은 배와 포도 재배지에서 각각 $133.0{\times}10^3\;CFU\;g^{-1}$, $107.4{\times}10^3\;CFU\;g^{-1}$으로 가장 높은 수준을 보였다. 과수재배기간이 길어질수록 미생물 밀도는 감소하는 것으로 나타났다. 토양 pH, 유기물, 치환성 Mg 함량은 모든 미생물분포와 정의 상관관계를 보였고, Bacillus sp.는 조사한 모든 화학성분과 정의 관계를 보였다. 토양미생물의 biomass C 함량과 탈수소효소 활성은 유기물과 치환성 Ca 함량에 대해 고도의 유의성 (p<0.01)을 보였다.

• 한국축산시설환경학회지
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• 제11권2호
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• pp.125-134
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• 2005

본 연구는 남은 음식물에 수분흡수제 또는 영양 보충제로 유기성 부산물인 제과부산물, 밀기울, 맥강, 육계분 등을 혼합한 후 rotary drum 방식의 반건식 살균처리 및 호기적 숙성 과정 별 혼합사료 내의 미생물 분포 및 사료단백질 pepsin 소화율과 in vitro 영양소 소화율을 측정하여 실제 동물 급여 시의 효능을 사전 예측하고자 실시하였다. 살균 처리 공정($80^{\circ}C$에서 30분간)은 전반적으로 균수를 감소시키는 경향과 곰팡이를 사멸시키는 효과가 있었으며(P<0.05), 연이은 숙성 과정은 살균과정에서 감소된 lactic acid bacteria를 증식시키는 효과가 있었다(P<0.05). 열처리 살균 공정은 혼합사료 단백질의 pepsin 소화율을 감소시켰다(P<0.05). 사료원료 건물 및 유기물의 in vitro 소화율은 제과부산물>밀기울>남은 음식물=맥강 순으로 높았다. 상기한 연구 결과는 반건식 남은 음식물 혼합사료의 동물 급여시 중요한 기초 자료로 활용될 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권12호
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• pp.1864-1872
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• 2019

Objective: This study was conducted to evaluate the effects of Ecklonia stolonifera (E. stolonifera) extract addition on in vitro ruminal fermentation characteristics, methanogenesis and microbial populations. Methods: One cannulated Holstein cow ($450{\pm}30kg$) consuming timothy hay and a commercial concentrate (60:40, w/w) twice daily (09:00 and 17:00) at 2% of body weight with free access to water and mineral block were used as rumen fluid donors. In vitro fermentation experiment, with timothy hay as substrate, was conducted for up to 72 h, with E. stolonifera extract added to achieve final concentration 1%, 3%, and 5% on timothy hay basis. Results: Administration of E. stolonifera extract to a ruminant fluid-artificial saliva mixture in vitro increased the total gas production. Unexpectedly, E. stolonifera extracts appeared to increase both methane emissions and hydrogen production, which is contrasts with previous observations with brown algae extracts used under in vitro fermentation conditions. Interestingly, real-time polymerase chain reaction indicated that as compared with the untreated control the ciliate-associated methanogen and Fibrobacter succinogenes populations decreased, whereas the Ruminococcus flavefaciens population increased as a result of E. stolonifera extract supplementation. Conclusion: E. stolonifera showed no detrimental effect on rumen fermentation characteristics and microbial population. Through these results E. stolonifera has potential as a viable feed supplement to ruminants.

• Environmental Engineering Research
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• 제12권2호
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• pp.37-45
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• 2007

Phytoremediation has been used effectively for the biodegradation of oil-based contaminants, including diesel, by the stimulation of soil microbes near plant roots (rhizosphere). However, the technique has rarely been assessed for itsinfluence on soil microbial properties such as population, community structure, and diversity. In this study, the removal efficiency and characteristics of rhizobacteria for phytoremediation of diesel-contaminated soils were assessed using barnyard grass (Echinochloa crusgalli). The concentration of spiked diesel for treatments was around $6000\;mg\;kg^{-1}$. Diesel removal efficiencies reached 100% in rhizosphere soils, 76% in planted bulk soils, and 62% in unplanted bulk soils after 3weeks stabilization and 2 months growth(control, no microbial activity: 32%). The highest populations of culturable soil bacteria ($5.89{\times}10^8$ per g soil) and culturable hydrocarbon-degraders($5.65{\times}10^6$ per g soil) were found in diesel-contaminated rhizosphere soil, also yielding the highest microbial dehydrogenase. This suggests that the populations of soil bacteria, including hydrocarbon-degraders, were significantly increased by a synergistic rhizosphere + diesel effect. The diesel treatment alone resulted in negative population growth. In addition, we investigated the bacterial community structures of each soil sample based on DGGE (Denaturing Gel Gradient Electrophoresis) band patterns. Bacterial community structure was most influenced by the presence of diesel contamination (76.92% dissimilarity to the control) and by a diesel + rhizosphere treatment (65.62% dissimilarity), and least influenced by the rhizosphere treatment alone (48.15% dissimilarity). Based on the number of distinct DGGE bands, the bacterial diversity decreased with diesel treatment, but kept constant in the rhizosphere treatment. The rhizosphere thus positively influenced bacterial population density in diesel-contaminated soil, resulting in high removal efficiency of diesel.

• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.815-825
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• 2019

Objective: To effectively use corn stover resources as animal feed, the changes in microbial population and chemical composition of corn stover during field exposure, and their silage fermentation and in vitro digestibility were studied. Methods: Corn cultivars (Jintian, Jinnuo, and Xianyu) stovers from 4 random sections of the field were harvested at the preliminary dough stage of maturity on September 2, 2015. The corn stover exposed in the field for 0, 7, 15, 30, 60, 90, and 180 d, and their silages at 60 d of ensiling were used for the analysis of microbial population, chemical composition, fermentation quality, and in vitro digestibility. Data were analyzed with a completely randomized $3{\times}6$ [corn stover cultivar $(C){\times}exposure$ d (D)] factorial treatment design. Analysis of variance was performed using SAS ver. 9.0 software (SAS Institute Inc., Cary, NC, USA). Results: Aerobic bacteria were dominant population in fresh corn stover. After ensiling, the lactic acid bacteria (LAB) became the dominant bacteria, while other microbes decreased or dropped below the detection level. The crude protein (CP) and water-soluble carbohydrate (WSC) for fresh stover were 6.74% to 9.51% and 11.75% to 13.21% on a dry matter basis, respectively. After exposure, the CP and WSC contents decreased greatly. Fresh stover had a relatively low dry matter while high WSC content and LAB counts, producing silage of good quality, but the dry stover did not. Silage fermentation inhibited nutrient loss and improved the fermentation quality and in vitro digestibility. Conclusion: The results confirm that fresh corn stover has good ensiling characteristics and that it can produce silage of good quality.