• 미생물학회지
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• 제31권1호
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• pp.93-98
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• 1993

수계생태계에서 유기물질의 순환을 이해하기 위하여 팔당호에서 종속영양 활성도와 세균세포의 효소활성의 계절절 변화를 연구하였다. 팔당호 I 의 glucose 전환시간은 수층, 퇴적토에서 2-1,300 시간, 17-170 시간, protein hydrolysate 는 5-900 시간, 15-240 시간, acetic acid 는 4-350 시간, 15-230 시간으로 계절적인 변화를 나타냈다. Glucose, protein hydrolysate, acetate 각각의 호흡율은 수층에서 23-32%, 38-41%, 22-28%로 나타났고 퇴적토에서는 34%, 61% and 41% 로 나타났다. 이 결과로 3가지 유기물질 종류 모두가 수층보다 퇴적토에서는 높은 율로 호흡됨을 알 수 있었다. 한편 세균의 $\alpha$-glucosidase, $\beta$-glucosidase, N-acetyl-$\beta$-D-glucosaminidase, aminopeptidase 활성력을 살펴본 결과 수층에서는 효소 각각에 대해 32-44%, 31-32%, 18-34% 61-67% 의 범위를 나타내었고 퇴적토에서는 34%, 40%, 23% 65%로 나타났다.

• 미생물학회지
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• 제29권5호
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• pp.329-338
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• 1991

From July 1985 to December 1986, 28 variables of phycal-chemical factors, bacteria and heterotrophic activity were investigated 17 times at 3 stations in the estuary of Naktong River and the influences of environmental factors to bacterial population and heterotrophic activity were analyzed through multiple regression. The results of multiple regression were as follows. At station 1, total bacteria and heterotrophic bacteria(Z-25) could explain 57% of the variation of maximum uptake velocity for glucose and 54% of turnover time for glucose was explained by total coliform bacteria and MBOD, Sixty four percent of the variation of Kt+SN was accounted for salinity, MBOD-N and inorganic phosphate. Turnover rate for acetate was also accounted for the change of MBOD-P by 56%. At station 2 maximum uptake velocity for glucose depends on MBOD-N by 81%; turnover time on bacteria by 50%; Kt+Sn on avilable nutrient by 61%. More than 50% of maximum uptake velocity and turnover time for glucose were influenced by bacteria and that of Kt+Sn by the change of nutrient in the surface water of station 3. In the bottom water of station 3, the change of maximumuptake velocity, turnover time and Kt+Sn for glucose was controlled by total bacteria and available nutrient, bacteria, the change of nutrient salts respectively. On the whole, more than 50% of maximum uptake velocity and turnover time for glucose could be due to the change in the number of bacetria and the value of Kt+Sn was affected by the change of nutrient salts. Turnover rate for acetate was controlled by available phosphate at station 1 and by bacteria at station 2 and 3, which showed a distinct difference between the environmental factors which govern the rate of glucose and acetate uptake in the Naktong esturine ecosystem. And bacterial communities were controlled by available nutrients at station 1, by nutrient salts and salinity at station 2 and in the surface water of station 3 and by salinity in the bottom water of station 3.

• The Korean Journal of Ecology
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• 제17권1호
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• pp.79-90
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• 1994

1991년 11월부터 1992년 8월까지 총 8회에 걸쳐 금강하구에서 고군산군도까지 6개 정점을 대상으로 종속영양 세균의 분포와 평군체적 및 세포와 효소활성을 측정하였다. 해양성 종속영양 세균은 1.0X103~5X105 c.f.u./ml의 범주에서 분포하였으며, 간균이 45~72%를 차지하였다. 또한 구균의 평균체적은 (7.69$pm$0.18)X10-2~(8.18$pm$0.38)X10-2$mu$m3, 간균은 (6.09$pm$0.29)X10-2~(7.72$pm$0.41)X10-2$mu$m3의 범주에서 변화하였다. 세포외 효소활성도를 측정한 결과, glucosidase의 활성은 0~3.49$mu$M/l/hr, chitinase의 활성은 0~1.25$mu$M/l/hr, phosphatase는 0~11.95$mu$M/l/hr, amylase는 0~3.80$mu$M/l/hr의 범주에서 측정되어 세포외 효소활성은 여름철에 높은 값을 보였으며, 측정효소중 phosphatase의 활성이 가장 높았다. 종속영양 세균의 분포와 세포외 효소활성은 수온과 유입되는 유기물의 양과 밀접한 관계가 있었으며, 세균의 체적의 크기는 세포외 효소 활성과는 직접적인 관계가 없었다.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.858-868
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• 2009

The abundance, biomass, size distribution, and taxonomic composition of bacterial and protistan (heterotrophic and autotrophic nanoflagellates and ciliates) communities were investigated in six lakes of Masurian Lake District (north-eastern Poland) differing in trophic state. Samples were taken from the trophogenic water layer during summer stratification periods. Image analysis techniques with fluorescent in situ hybridization (FISH) as well as [$^3H$]-methyl-thymidine incorporation methods were applied to analyze differences in the composition and activity of bacterial communities. The greatest differences in trophic parameters were found between the humic lake and remaining non-humic ones. The same bacterial and heterotrophic nanoflagellate (HNF) cell size classes dominated in all the studied lakes. However, distinct increases in the contributions of large bacterial (>$1.0{\mu}m$) and HNF (>$10{\mu}m$) cells were observed in eutrophic lakes. The bacterial community was dominated by the ${\beta}$-Proteohacteria group, which accounted for 27% of total DAPI counts. Ciliate communities were largely composed of Oligotrichida. Positive correlations between bacteria and protists, as well as between nanoflagellates (both heterotrophic and autotrophic) and ciliates, suggest that concentrations of food sources may be important in determining the abundance of protists in the studied lakes.

• 미생물학회지
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• 제28권3호
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• pp.204-209
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• 1990

1987년 9월부터 1988년 8월까지 소양호 4개 정점에서 총 세균수, 종속영양세균수의 분포와 각 종의 alkaline phosphatase의 분비 비율과 활성도를 측정하였다. 총 세균은 $3.2{\times}10^{5}$ - $3.2{\times}10^{6}$ cells/${\mu}\ell$의 범위였으며, 종속 영양세균의 총 세균수는 0.07-2.63%이였다. 종속영양세균의 종 당양성은 여롬과 양어장 인근, Peridinium이 발생하는 곳에서 낮았다. Pseudomonas. Flavobacterium은 모든 정점에서 우점종으로 나타났다. Alkaline phosphatase를 분비하는 비율과 활성도는 Flavobacterium에서 높게 나타나, 유기인산염 분해에 우점세균 중 가장 큰 기여를 하는 것으로 밝혀졌다.

• 한국환경과학회지
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• 제16권7호
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• pp.855-863
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• 2007

In order to understand the temporal distribution of pico- and nanoplankton and factors controlling its distribution at a station in Okkye Bay of Masan Bay located in the southern part of Korea, this study was conducted on two weeks interval from April 2005 to April 2006, and several abiotic and biotic factors were measured. During the study, picoplankton consisted of picoflagellates, cyanobacteria and heterotrophic bacteria, and nanoplankton consisted of nanoflagellates excluding dinoflagellates. The concentration of chlorophyll-a (chl-a) was a mean of $4.33\;{\mu}g/L$, and the nanoplanktonic ($<20\;{\mu}m$) chl-a size fraction was a mean of 39.5 % and significantly correlated with water temperature. The abundances of cyanobacteria and photosynthetic flagellates (PF) were means of $24.4{\times}10^{3}\;cells/mL\;and\;2.87{\times}10^{3}\;cells/mL$, respectively. The contribution of picoflagellates to the PF abundance varied among the sampling occasions and was a mean of 29 %, but to the PF carbon biomass was 2.6 % only. The PF abundance had significant relationships with water temperature, and silicate and TIN concentrations, suggesting that the PF abundance seemed to be primarily bottom-up regulated. The abundance of heterotrophic bacteria was a mean of $3.18{\times}10^{6}\;cells/mL$ and unlike other ecosystems it did not have relationships with chl-a and heterotrophic flagellates (HF), suggesting that bacterial abundance did not seem to be bottom-up or top-down regulated. HF mostly consisted of cells less than $5{\mu}m$ and its abundance was a mean of $2.71{\times}10^{3}\;cells/mL$. Of the HF abundance, picoflagellates occupied about 31 %, and occupied about 9 % of the HF carbon biomass. HF grazing activity on heterotrophic bacteria was relatively low and removed about 10 % of bacterial abundance, suggesting that HF might not be major consumers of bacteria and there seems to be other consumers in Okkye Bay. These results suggest that Okkye Bay may have a unique microbial ecosystem.

• 생태와환경
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• 제37권4호통권109호
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• pp.406-410
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• 2004

2000년 두 댐 저수지와 유입 하천에서 월별 alkaline phosphatase activity (APA)을 측정하였다. 또한 2001년 여름 동안은 한 댐 저수지에서 APA의 수직변화와 관련된 요인들을 조사하였다. APA는 여름 동안 저수지 표층에서 상대적으로 높게 나타났으나 심층에서는 거의 변화가 없었다. 그러나 바닥층 바로 윗부분에서는 APA의 미미한 증가 관찰되었다. APA변화와 용존무기인 농도 변화와는 상관관계가 없었으며, 이 결과 조사 대상 저수지에서 APA는 인 이용성의 상태를 의미하지는 않는 것으로 추정되었다. 시료의 size-fractionation 분석 결과, 조사 대상 저수지들에서 APA는 $0.4{\mu}m$보다 큰 입자들에 흡착된 반면, 유입 하천에서는 용존형태로 존재하는 것으로 판단되었다. 저수지 유광층에서 엽록소-a의 농도와 APA간에 유의한 양의 상관성이 나타났다. 무광층에서 APA는 세균의 colony count와 양의 상관성을 나타냈으나 총 세균수와는 상관성이 없었다.

• 미생물학회지
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• 제26권3호
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• pp.230-236
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• 1988

최근 평화의 댐 건설에 따른 영향으로 다량의 물을 방류하여 미생물 생태계의 큰 변화가 예상되는 파로호에서 미생물 분포 및 활성도에 관하여 1987년 1월부터 11월까지 격월로 조사, 연구하였다. 총 세균수는 $0.3\times 10^{5}-13.1\times10 ^{5}$cells/ml의 비교적 낮은 값을 나타내었으며 3월에 급격한 증가를 보여 $10.7\times 10^{5}-13.1\times10 ^{5}$ cells/ml 의 최고치를 나타애었다. 종속영양세균은 $1.9\times 10^{3}$ - $3.1\times 10^{4}$CFUs/m의 변화를 갖으며 총 세균수의 변화와 유사한 경향을 나타내었다. Alpha-및 beta-glucosidase를 분비하는 세균의 비율은 지역적인 차이보다는 계절적인 변화가 우세하였으며 Phosphatase를 분비하는 세균의 비율은 22.7-63.0%로 최고치를 나타내었다. 전자전달계 활성도는 480-1696${\mu}gO_{2}$/l/day의 변화를 갖으며 지역적으로 유입수에서, 계절적으로 여름에 높았다. 유기연산염의 분해율은 0.4-9.1%/h로 다른 댐보다 낮았으며, 수온이 상승함에 따라 분해율이 커졌으며 Phosphatase를 분비하는 세균의 비율변화와 관계가 있음을 알 수 있였다. 종속영양세균의 생리적 활성도는 여름의 최고치가 8.2%/h로 계절적으로 DOM 증가 에 따른 활성도의 증가가 관찰되었다. 파로호의 급격한 변화는 세균류의 개체수 변화에 큰 영향을 미쳤으냐, 활성도 및 특정호소 분비세균비율에는 영향을 주지 못 하였다. 활성도 및 특정효소 분비비율은 계절적 소장이 뚜렷하여, 식물성플라크톤의 증식과 일차 생산력과의 밀접한 관계를 보였다.

• 한국미생물·생명공학회지
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• 제21권6호
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• pp.577-581
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• 1993

The amino acid threonine was produced from glycine and ethanol in a reaction mixture using cell free extract of the methylotrophic bacterium isolated from soil and identified as mellthylo-bacterium sp. KJ29. Although the isolate could grow on carbon source other than methanol, only the cell free extract from the cells grown on methanol produced threonine. Methanol dehydrogenase (MDH) activity was present only in the cells grown on methanol when compared to the cells grown on heterotrophic substrates.

• 미생물학회지
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• 제23권3호
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• pp.215-222
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• 1985

Distribution pattern and activity of heterotrophec bacteria were measured in the mudflat of Nakdong river estuary. In March and June, 1985, community sizes of amylolytic, lipolytic and proteolytic bacteria as well as total viable counts were measured. Vertical distribution of bacterial community size increased a few orders of magnitude from Narch to June. Heterotrophic activity was estimated in turnover time with $U-[^{14}C]-glucose$. Turnover time reduced considerably in June compared to that of March. To sxamine correlations for measured bacterial groups, turnover time and environmental factors, correlation coefficient matrix was obtained. These measured characteristics did not consistently correlate well with one another.