• Asian-Australasian Journal of Animal Sciences
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• 제20권2호
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• pp.200-207
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• 2007

In vitro rumen incubation studies were conducted to determine effects of initial pH on bacterial attachment and fiber digestion. Ruminal fluid pH was adjusted to 5.7, 6.2 and 6.7, and three major fibrolytic bacteria attached to rice straw in the mixed culture were quantified with real-time PCR. The numbers of attached and unattached Fibrobacter succinogenes, Ruminococcus flavefaciens and Ruminocococcus albus were lower (p<0.05) at initial pH of 5.7 without significant difference between those at higher initial pH. Lowering incubation media pH to 5.7 also increased bacterial numbers detached from substrate regardless of bacterial species. Dry matter digestibility, gas accumulation and total VFA production were pH-dependent. Unlike bacterial attachment, maintaining an initial pH of 6.7 increased digestion over initial pH of 6.2. After 48 h in vitro rumen fermentation, average increases in DM digestion, gas accumulation, and total VFA production at initial pH of 6.2 and 6.7 were 2.8 and 4.4, 2.0 and 3.0, and 1.2 and 1.6 times those at initial pH of 5.7, respectively. The lag time to reach above 2% DM digestibility at low initial pH was taken more times (8 h) than at high and middle initial pH (4 h). Current data clearly indicate that ruminal pH is one of the important determinants of fiber digestion, which is modulated via the effect on bacterial attachment to fiber substrates.

• 미생물학회지
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• 제43권1호
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• pp.14-18
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• 2007

바이칼호에 서식하는 있는2속(genus Baikalospongia와 Lubomirskia)(5.13)의 해면 내에 서식하고 있는 세균군집 구조를 조사하기 위하여 fluorescent in situ hybridization (FISH) 방법을 적용하였다. Baikalospongia와 Lubomirskia 속에 속하는 해면에 서식하는 총세균수는 각각 $7.2{\times}10^{7}-4.2{\times}10^{8}\;cells/ml$과 $1.2{\times}10^{8}-1.6{\times}10^{8}\;cells/ml$였다. 인근 호숫물의 총세균수는 $2.3{\times}7.7{\times}10^{5}\;cells/ml$ 범위로 해면에 서식하는 총세균수가 약 $10^{3}-10^{4}$배 더 높았다. 총세균수에 대한 세균군집 구조의 비율은 ${\alpha}-,\;{\beta}-,\;{\gamma}-Proteobacteria\;group$과 Cytophaga-Flavobacterium group외 다른 세균군이 genus Baikalospongia는 42.0-60.3%, Lubomirskia에서는 40.7-51.9%로, 호수물에서는 22.6-46.3%와 같이 나타났다. 이는 일반 담수에서 특정 군집이 우점하는 경향과는 다른 것으로써, 바이칼의 호숫물과 해면에 있는 세균들은 독특한 군집구조를 이루고 있음을 확인하였다.

• Journal of Microbiology
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• 제45권2호
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• pp.171-174
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• 2007

The growth stimulation of wild plants by several bacterial species showing plant growth-promoting capabilities was examined in a barren lakeside area at Lake Paro, Korea. Microbial numbers and activities in the field soil were monitored for 73 days after inoculation of the bacteria. The acridine orange direct counts for the total soil bacterial populations ranged between $2.0-2.3{\times}10^{9}\;cells/g$ soil and $1.4-1.8{\times}10^{9}\;cells/g$ soil in the inoculated and uninoculated soils, respectively. The numbers of Pseudomonas spp., which is known as a typical plant growth-promoting rhizobacteria, and the total microbial activity were higher in the inoculated soil compared to those in the uninoculated soil. The average shoot and root lengths of the wild plants grown in the inoculated soil were 17.3 cm and 12.4 cm, respectively, and longer than those of 11.4 cm and 8.5 cm in the uninoculated soil. The total dry weight of the harvested wild plants was also higher in the inoculated soil (42.0 g) compared to the uninoculated soil (35.1 g). The plant growth-promoting capabilities of the inoculated bacteria may be used for the rapid revegetation of barren or disturbed land, and as biofertilizer in agriculture.

• Journal of Microbiology and Biotechnology
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• 제23권1호
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• pp.40-46
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• 2013

A variety of nuruk were collected from various provinces in Korea, and their microflora profiles were analyzed at the species level. A total of 42 nuruk samples were collected and when the viable cell numbers in these nuruk were enumerated, the average cell numbers of bacteria, fungi, yeast, and lactic acid bacteria from all nuruk were 7.21, 7.91, 3.49, and 4.88 log CFU/10 g, respectively. There were no significant differences in viable cell numbers of bacteria or fungi according to regions collected. Bacillus amyloliquefaciens and B. subtilis were the predominant bacterial strains in most samples. A significant portion, 13 out of 42 nuruk, contained foodborne pathogens such as B. cereus or Cronobacter sakazakii. There were various species of lactic acid bacteria such as Enterococcus faecium and Pediococcus pentosaceus in nuruk. It was unexpectedly found that only 13 among the 42 nuruk samples contained Aspergillus oryzae, the representative saccharifying fungi in makgeolli, whereas a fungi Lichtheimia corymbifera was widely distributed in nuruk. It was also found that Pichia jadinii was the predominant yeast strain in most nuruk, but the representative alcohol fermentation strain, Saccharomyces cerevisiae, was isolated from only 18 out of the 42 nuruk. These results suggested that a variety of species of fungi and yeast were distributed in nuruk and involved in the fermentation of makgeolli. In this study, a total of 64 bacterial species, 39 fugal species, and 15 yeast species were identified from nuruk. Among these strains, 37 bacterial species, 20 fungal species, and 8 yeast species were distributed less than 0.1%.

• 생태와환경
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• 제41권1호
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• pp.19-25
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• 2008

팔당호에 설치된 인공식물섬 식생기반재 내에서 세균의 생태학적 기능을 파악하기 위하여 식생기반재 내의 공극수와 호숫물에서 총인(TP), 용존인(DIP), 총질소(TN), 질산성질소$(NO_3)$총세균수, 활성세균수와 체외효소활성도를 측정하였다. 인공식물섬 식생기반재의 공극수에서 TN과 $NO_3$농도는 각각 $4.4\sim7.5mg\;L^{-1}$, $1.2\sim3.8mg\;L^{-1}$ 범위로 호숫물보다 약 2배 높게 나타났으며, TP와 DIP값도 식생기반재 공극수에서 각각 $1.4\sim4.1mg\;L^{-1}$, $0.003\sim0.137mg\;L^{-1}$ 범위로 TP 값은 호숫물보다 약 $4\sim25$배, DIP값은 5.3배 높은 값이었다. 총세균수와 활성세균수는 호숫물보다 10배 이상 값을 보였다. 또한 phosphatase 및 $\beta$-glucosidase 활성도도 인공식물섬 공극수에서 호숫물보다 10배 이상의 높은 결과를 보여 식생기반재 내부에서 세균에 의한 영양염류의 농축과 왕성한 유기물질분해가 일어나고, 이 과정에서 수초의 성장, 동물플랑크톤의 증식 등 새로운 수생태계가 조성된 것으로 사료된다.

• 미생물학회지
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• 제34권3호
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• pp.169-174
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• 1998

소양호에서 세균군집의 계절적, 수심별 변화를 파악하고자 총세균수와 EUB338, ALG1b, BET42a, GAM42a와 CF probe 등 fluorescent rRNA target oligonuvleotide probe와 반응하는 세균 개체수를 측정하였다. 총세균수는 $0.5{\sim}2.01{\times}10^6cells{\cdot}ml^{-1}$이였으며, 2 m와 5 m 수층에서 높게 나타났다. 총세균수에 대한 Eubacteria의 비율은 22~100%이였고, Proteobacteria ${\alpha}$-group은 Eubacteria의 2.6~66.7%, ${\beta}$-group은 4.5~53.5%, ${\gamma}$-group은 4.6~76.7%, 그리고 Cytophage-Flavobacterium group은 2.1~35.9%이였다. 또한 세균군집은 계절별, 수심별로 다양한 변화를 보여, 겨울철은 ${\beta}$-group이, 봄철과 초여름은 ${\gamma}$-group이, 여름철은 ${\alpha}$-group이 우점하였고, Cytophage-Flavobacterium group이 특정적으로 우점하는 시기는 없었다. 이러한 세균 군집 구조의 분포로 계절별, 수심별로 호수에 대한 독특한 특징을 알 수 있었다.

• 한국환경농학회지
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• 제1권1호
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• pp.48-52
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• 1982

수중미생물(水中微生物)의 계수방법(計數方法)은 크게 둘로 나누인다. 첫째 방법(方法)은 replicon개염(槪念)에 기초(基礎)를 둔 것으로 살아있는균(菌)과 죽은 균(菌)을 구별할 수 있으나 사용(使用)되는 배지(培地)가 생리적(生理的)으로 다른 다양(多樣)한 세균(細菌)들로 구성된 수중세균(水中細菌)의 생육(生育)에 적합하지 않아서 전(全) 세균수(細菌數)를 계수(計數)할 수 없다. 둘째 방법(方法)은 직접 검경하여 계수(計數)하는 방법(方法)으로 살아있는 균(菌)과 죽은균(菌), 세균(細菌)과 particle의 구별(區別)이 곤란하다. 그러나 최근 세균염색수(細菌染色術)의 발달(發達)로 수중세균(水中細菌)을 육안(肉眼)으로 쉽게 구별(區別)하여 계수(計數)할 수 있는 방법(方法)이 가능(可能)하게 되었다. 이 방법(方法)은 형광현징경(螢光顯徵鏡)을 사용(使用)하여 acridine orange로 염색(染色)된 수중(水中)의 전세균수(全細菌數)를 측정(測定)하는 방법(方法)이다. 따라서 본(本) 연구(硏究)는 상수도원(上水道源)의 세균오염도(細菌汚染度)를 측정(測定)하는데 새로운 방법(方法)으로서 epifluorcscence microscopy를 제시(提示)하는데 있으며 이의 사용성가능여부(使用性可能與否)를 진단(診斷)하기 위해 chlorine과 chloramine을 시료수(試料水)에 처리(處理)하여 경시적으로 세균수(細菌數)를 조사(調査)하여 평판법(平板法)과 비교(比較)하였다. 시료수(試料水)(sample water)의 전세균수(全細菌數)는 형광검경법(螢光檢鏡法)에 의(依)해 정확(正確)히 측정(測定)되었으며 분리능력(分離能力)(resolution)에 있어서 탁월(卓越)하였고 또한 경제적(經濟的)이고도 간편하였다. 그리고 소독살균제(消毒殺菌劑)로는 chloramine이 감소(監素)보다 수중세균(水中細菌)에 미치는 영향(影響)은 훨씬 컸다.

• 한국환경농학회지
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• 제25권3호
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• pp.262-267
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• 2006

Increased application of glyphosate (Gly) in glyphosate-resistant (GR) soybean cropping systems may affect rhizospheric microorganisms including IAA-producing rhizobacteria (IPR) and their effect on the growth of soybean. This field experiment was conducted to assess IPR populations in the rhizosphere of GR soybean ('Roundup-Ready' DeKalb DKB38-52) treated with glyphosate and foliar amendment treatments such as $PT21^{(R)}$ (urea solution with N 21 %) and $Grozyme^{(R)}$ (Biostimulant: mixtures of micro nutrients and enzymes). Effects of herbicide, sampling date, and their interaction on total bacterial numbers were significant (P < 0.001, 0.001, 0.013, respectively). Total bacteria (TB) numbers were increased with glyphosate treatment at 20 d after application and highest TB populations were associated with $Grozyme^{(R)}$ application, possibly due to the additional substrate from this product. The IPR of the soybean rhizosphere was significantly affected by herbicide, sampling date, and the herbicide*foliar amendment interaction. The ratios of numbers of IPR to TB ranged from 0.79 to 0.99 across the sampling dates irrespective of treatments. IPR numbers were slightly hindered by glyphosate application regardless of foliar amendment.

• 한국동물위생학회지
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• 제23권4호
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• pp.361-366
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• 2000

The growth of bacteria on the surface of the meat was monitored to investigate the relationships between microbiological quality and some environmental factors such as the chilling temperature, alcohol spraying, and transport in slaughter process of pigs. The temperature changes of the surface and inner part of pork carcass were monitored with GreenTrack$\textregistered$ system during the process of chilling and transport Of the 100pigs tested, the prevalence of level on number of standard plate count (SPC) less than $10^4$ CFU/$\textrm{cm}^2$ and Escherichia coli less than $10^2$ CFU/$\textrm{cm}^2$ in pig were 82% and 80%, respectively. Suface bacterial numbers are decreased in the course of chilling process of the carcass. Alcohol spray process before packing meat also could decrease the surface bacterial count. In conclusion, this study could be overemphasized the importance of relationship between microbiological quality and refrigerating temperature in the process of refrigeration and cutting.

• 미생물학회지
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• 제22권3호
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• pp.157-165
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• 1984

Seasonal and spatial variations in propagule numbers of Trichoderma species were investigated every other month for one year in deciduous and coniferous forest soils and evaluated the relationships of Trichoderma spp. populations to soil environmental factors. The total population of Trichoderma spp. increased until summer and then declined until winter. The yearly mean frequency of Trichoderma spp. exceeded 1.4% of total fungal propagules in two sites. Decreases of absolute an relative propagule numbers of Trichoderma spp. with increasing soil depth were found and variation in Trichoderma spp. propagules caused by differences in soil depth ($0{\sim}50cm$) was greater than that caused by differences in sampling time. The most common species occurring in two sites was T. viride, followed by T. polysporum, T. koningii, and T. hamatum. Individual species of Trichoderma showed diferent abundance trend in accordance with sampling time. T. viride was dorminant from spring to autumn, while T. polysporum dominated over the other speicies in winter. Variations in propagule number of Trichoderma sppp. were principally mediated by the actions of biotic environmental factors rather than by the direct effects of abiotic factors. In multiple-regression analyses, 48% of the total vaiation in Trichoderma spp. propagules in deciduous site could be accounted for by total fungal propagules and soil CMCase actvity. In coniferous site, 65% of total variation could be accounted for by total fungal and bacterial propagules, moisture content and organic carbon content.