• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.710-712
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• 2003

A new species of Gram-negative halophilic cartenoid producing bacterium was isolated from the Haeundae Coast, Korea. This strain is non-motile, aerobic, orange-pigmented, rod-shaped, and produced carotenoids, mainly astaxanthin. All the type strains of the genus Paracoccus were compared with this strain using 16S rDNA sequence analysis, fatty acid patterns, and physiological reaction profiles. From the results obtained, this strain is classified as a new species, Paracoccus sp..

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권1호
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• pp.17-22
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• 2004

A bacterial strain WJ-98 found to produce active extracellular keratinase was isolated from the soil of a poultry factory. It was identified as Paracoccus sp. based on its 16S rRNA sequence analysis, morphological and physiological characteristics. The optimal culture conditions for the production of keratinase by Paracoccus sp. WJ-98 were investigated. The optimal medium composition for keratinase production was determined to be 1.0% keratin, 0.05% urea and NaCl, 0.03% K$_2$HPO$_4$, 0.04% KH$_2$PO$_4$, and 0.01% MgCl$_2$$.$6H$_2$O. Optimal initial pH and temperature for the production of keratinase were 7.5 and 37$^{\circ}C$, respectively. The maximum keratinase production of 90 U/mL was reached after 84 h of cultivation under the optimal culturing conditions. The keratinase from Paracoccus sp. WJ-98 was partially purified from a culture broth by using ammonium sulfate precipitation, ion-exchange chromatography on DEAE-cellulose, followed by gel filtration chromatography on Sephadex G-75. Optimum pH and temperature for the enzyme reaction were pH 6.8 and 50$^{\circ}C$, respectively and the enzymes were stable in the pH range from 6.0 to 8.0 and below 50$^{\circ}C$. The enzyme activity was significantly inhibited by EDTA, Zn$\^$2+/ and Hg$\^$2+/. Inquiry into the characteristics of keratinase production from these bacteria may yield useful agricultural feed processing applications.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.59.1-59.1
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• 2007

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• KSBB Journal
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• 제24권3호
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• pp.321-326
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• 2009

Paracoccus sp.의 astaxanthin 생산성 증가를 위해 반응표면 분석법을 사용하여 최적의 배지조성을 설계하였다. Paracoccus의 성장 배지인 Marine Broth와 modified Blaszczyk 배지를 사용하여 astaxanthin 생산성을 측정한 결과 각각 0.39 mg/L, 0.40 mg/L의 astaxanthin 농도를 보였다. Modified Blaszczyk 배지의 조성을 각각 변수로 두어 가장 많은 영향을 주는 성분을 알아본 결과 $MgSO_4$와 yeast extract로 확인되었다. 중심합성계획법에 따라 $MgSO_4$ ($0.397{\sim}4.621$ g/L), yeast extract ($2.879{\sim}7.121$ g/L)를 달리하였을 때, astaxanthin 생상성에 대한 회귀식의 $R^2$은 0.894로 나타났고, 이에 따른 최대 생산량에 0.925 mg/L로 예상되었으며 이때의 $MgSO_4$와 yeast extract의 농도는 각각 2.83과 7.02 g/L로 나타났다. 이에 대한 확인실험 결과 2.83 $MgSO_4$ g/L, 7.02 yeast extract g/L에서 1.021 mg/L의 astaxanthin이 생산되었으며, 배지의 최적화에 따라 250% 이상의 생산성 증가가 확인되어졌다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.713-713
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• 2003

• Journal of Microbiology and Biotechnology
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• 제20권8호
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• pp.1230-1239
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• 2010

Five bacterial species, capable of degrading the recalcitrant organic compounds (ROCs) diethyleneglycol monomethylether (DGMME), 1-amino-2-propanol (APOL), 1-methyl-2-pyrrolidinone (NMP), diethyleneglycol monoethylether (DGMEE), tetraethyleneglycol (TEG), and tetrahydrothiophene 1,1-dioxide (sulfolane), were isolated from an enrichment culture. Cupriavidus sp. catabolized $93.5{\pm}1.7$ mg/l of TEG, $99.3{\pm}1.2$ mg/l of DGMME, $96.1{\pm}1.6$ mg/l of APOL, and $99.5{\pm}0.5$ mg/l of NMP in 3 days. Acineobacter sp. catabolized 100 mg/l of DGMME, $99.9{\pm}0.1$ mg/l of NMP, and 100 mg/l of DGMEE in 3 days. Pseudomonas sp.3 catabolized $95.7{\pm}1.2$ mg/l of APOL and $99.8{\pm}0.3$ mg/l of NMP. Paracoccus sp. catabolized $98.3{\pm}0.6$ mg/l of DGMME and $98.3{\pm}1.0$ mg/l of DGMEE in 3 days. A maximum $43{\pm}2.0$ mg/l of sulfolane was catabolized by Paracoccus sp. in 3 days. When a mixed culture composed of the five bacterial species was applied to real wastewater containing DGMME, APOL, NMP, DGMEE, or TEG, 92~99% of each individual ROC was catabolized within 3 days. However, at least 9 days were required for the complete mineralization of sulfolane. Bacterial community diversity, analyzed on the basis of the TGGE pattern of 16S rDNA extracted from viable cells, was found to be significantly reduced in a conventional bioreactor after 6 days of incubation. However, biodiversity was maintained after 12 days of incubation in an electrochemical bioreactor. In conclusion, the electrochemical reduction reaction enhanced the diversity of the bacterial community and actively catabolized sulfolane.

• Journal of Microbiology and Biotechnology
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• 제18권12호
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• pp.1958-1965
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• 2008

A denitrifying polyphosphate-accumulating bacterium (YKP-9) was isolated from activated sludge of a 5-stage biological nutrient removal process with step feed system. This organism was a Gram-negative, coccus-shaped, facultative aerobic chemoorganotroph. It had a respiratory type of metabolism with oxygen, nitrate, and nitrite as terminal electron acceptors. The 16S rRNA gene sequence of strain YKP-9 was most similar to the 16S rRNA gene sequence of Paracoccus sp. OL18 (AY312056) (similarity level, 97%). Denitrifying polyphosphate accumulation by strain YKP-9 was examined under anaerobic-anoxic and anaerobic-oxic batch conditions. It was able to use external carbon sources for polyhydroxyalkanoates(PHA) synthesis and to release phosphate under anaerobic condition. It accumulated polyphosphate and grew a little on energy provided by external carbon sources under anoxic condition, but did neither accumulate polyphosphate nor grow in the absence of external carbon sources under anoxic condition. Cells with intracellular PHA cannot accumulate polyphosphate in the absence of external carbon sources under anoxic condition. Under oxic condition, it grew but could not accumulate polyphosphate with external carbon sources. Based on the results from this study, strain YKP-9 is a new-type denitrifying polyphosphate-accumulating bacterium that accumulates polyphosphate only under anoxic condition, with nitrate and nitrite as the electron acceptors in the presence of external carbon sources.

• Journal of Microbiology and Biotechnology
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• 제25권10호
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• pp.1670-1679
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• 2015

Two hollow fiber membrane biofilm reactors (HF-MBfRs) were operated for autotrophic nitrification and hydrogenotrophic denitrification for over 300 days. Oxygen and hydrogen were supplied through the hollow fiber membrane for nitrification and denitrification, respectively. During the period, the nitrogen was removed with the efficiency of 82-97% for ammonium and 87-97% for nitrate and with the nitrogen removal load of 0.09-0.26 kg NH₄⁺-N/m³/d and 0.10-0.21 kg NO₃^--N/m³/d, depending on hydraulic retention time variation by the two HF-MBfRs for autotrophic nitrification and hydrogenotrophic denitrification, respectively. Biofilms were collected from diverse topological positions in the reactors, each at different nitrogen loading rates, and the microbial communities were analyzed with partial 16S rRNA gene sequences in denaturing gradient gel electrophoresis (DGGE). Detected DGGE band sequences in the reactors were correlated with nitrification or denitrification. The profile of the DGGE bands depended on the NH₄⁺ or NO₃^- loading rate, but it was hard to find a major strain affecting the nitrogen removal efficiency. Nitrospira-related phylum was detected in all biofilm samples from the nitrification reactors. Paracoccus sp. and Aquaspirillum sp., which are an autohydrogenotrophic bacterium and an oligotrophic denitrifier, respectively, were observed in the denitrification reactors. The distribution of microbial communities was relatively stable at different nitrogen loading rates, and DGGE analysis based on 16S rRNA (341f /534r) could successfully detect nitrate-oxidizing and hydrogen-oxidizing bacteria but not ammonium-oxidizing bacteria in the HF-MBfRs.

• Journal of Microbiology
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• 제35권3호
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• pp.165-171
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• 1997

A sulfer-oxidizing bacterium was isolated from mine wastewater and characterized. The isolate was gra-negative, rod (0.2 * 1.2-1.5.mu.m), nonmotiloe, catalase positive, and oxidase prositive. The opotimal pH and temperature for growth were 7.0 and 30.deg.C. respectively. The optimum thiosulfate concentration was 70 mM and the maximum growth rate was 0.081 hr. The major ubiquinone contained in the isolate was Q-8. The cellular fatty acid composition was $C_{16 : 0}$, $C_{18 : 1}$, $C_{17cyc}$,and $C_{19cyc}$ as nonpolar fatty acids, and 3-OH C10 : 0 and 3-OH $C_{12 : 0}$ as hydroxylated fatty acids. The isolate was a facultative chemolithoautotroph which can grow autotrophically on sodium thiosulfate and sodium sulfide and which can grow heterotrophically on yeast extract. It can also grow mixotrophically on sodium thiosulfate and yeast extract. Comparison of the 16S rRNA gene sequence of the isolate with that of Thiobacillus species and Paracoccus thiocyanatus revealed that it is closely related to T. caldus which belongs to the .betha.-subclass of the class Proteobacteria. However, the isolated could not grow at extremely low pH (pH 1-3.5). On the basis of the phenotypic, chemotaxonomic and phylogenetic data, the isolate was tentatively named Thiobacillus sp. strain C.ain C.