• Journal of Microbiology and Biotechnology
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• 제14권2호
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• pp.337-343
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• 2004

A bacterial strain concurrently producing extracellular chitosanase and chitinase was isolated from soil and identified as a member of the $\beta$-subgroup of Proteobacteria through its 16S rRNA analysis and some biochemical analyses. The newly discovered strain, named as KNU3, had 99% homology of its 16S rRNA sequence with chitinolytic $\beta$-Proteobacterium CTE108. Strain KNU3 produced 34 kDa of chitosanase in addition to two chitinases of 68 kDa and 30 kDa, respectively. The purified chitosanase protein (ChoK) showed activity toward soluble, colloidal, and glycol chitosan, but did not exhibit any activity toward colloidal chitin. The optimum pH and temperature of ChoK were 6.0 and $70^{\circ}C$, respectively. The chitosanase was stable in the pH 4.0 to 8.0 range at $70^{\circ}C$, while enzyme activity was relatively stable at below $45^{\circ}C$. MALDI-TOF MS and N-terminal amino acid sequence analyses indicated that ChoK protein is related to chitosanases from Matsuebacter sp. and Sphingobacterium multivorum. HPLC analysis of chitosan lysates revealed that glucosamine tetramers and hexamers were the major products of hydrolysis.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.563-569
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• 2004

The DNA sequence of the chitosanase gene (choK) from $\beta$-Proteobacterium KNU3 showed an 1,158-bp open reading frame that encodes a protein of 386 amino acids with a novel 74 signal peptide. The degenerated primers based on the partial deduced amino acid sequences from MALDI- TOF MS analyses yielded the 820 bp of the PCR product. Based on this information, double inverse PCR cloning experiments, which use the two specific sets of PCR primers rather than single set primers, identified the unknown 1.2 kb of the choK gene. Subsequently, a 1.8 kb of full choK gene was cloned from another PCR cloning experiment and it was then subcloned into pGEM T-easy and pUC18 vectors. The recombinant E. coli clone harboring recombinant pUC18 vector produced a clear halo around the colony in the glycol chitosan plates. The recombinant ChoK protein was secreted into medium in a mature form while the intracellular ChoK was produced without signal peptide cleavage. The activity staining of PAGE showed that the recombinant ChoK protein was identical to the chitosanase of wild-type. The comparison of deduced amino acid sequences of choK revealed that there is 92% identity with that of Sphingobacterium multivorum chitosanase. Judging from the conserved module in other bacterial chitosanases, chitosanase of KNU3 strain (ChoK) belongs to the family 80 of glycoside hydrolases.

• Rapid Communication in Photoscience
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• 제2권2호
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• pp.60-63
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• 2013

Rhodopsins belong to a family of membrane-embedded photoactive retinylidene proteins. One opsin gene was isolated from ${\beta}$-proteobacterium (IMCC9480) which had been collected at the North Pole. It is very similar to Xanthorhodopin (XR) of HTCC2181. In this study, we carried out basic characterization of the rhodopsin. It has ${\lambda}max$ of 536, 554, and 546 nm at pH 4.0, 7.0, and 10.0, respectively. Since the pKa of its proton acceptor is around 6.27, we measured its proton pumping activity and photocycling rate at pH 8.0. It has a typical proton acceptor (D99) and donor (E110) which mediate proton translocation from intracellular to extracellular region when deduced from the sequence alignments. On the basis of in vitro proton pumping activity, it was proposed to have fast photocycling rate with M and O intermediates, indicating that it is a typical ion-pumping rhodopsin. Since the XR has not yet been expressed in any other heterologous expression system, we tried to get much more information about the XR through the XR-homologue rhodopsin.

• 대한임상검사과학회지
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• 제48권3호
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• pp.230-236
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• 2016

경제성장으로 생활수준이 향상됨에 따라 국민건강을 직접적으로 위협하는 수질오염에 대해 세계적으로 관심을 갖게 되었으며, 최근 맛 냄새 유발물질 발생의 문제가 대두되기 시작했다. 본 연구에서는 G정수장 내의 모형플랜트에서 사용된 원수 및 각 공정에 대한 공정수를 물 시료로 채취하여 정밀여과막 공정 및 입상활성탄 공정에서 박테리아의 거동에 대해 확인하였고, 또한 입상활성탄의 지속적 사용을 위한 역세척 가동 시 박테리아의 탈리 여부와 종 동정을 실시하였다. 분석 결과, 정밀막여과 공정을 거치는 경우 수계 내 존재하는 박테리아가 제거가 되는 것을 확인하였으며, 역세척 가동시 ${\beta}$-proteobacterium species, Porphyrobacter donghaensis, Polaromonas rhizophaerae, Hydrogenophaga species, Pseudonocardia species 등 총 5종의 우점종 박테리아가 나타나는 것을 확인할 수 있었으며, 정밀여과막 공정 이후 UV 공정을 추가 처리한 공정 처리수를 활성탄 공정에 유입한 2종의 박테리아는 나타나지 않는 것을 확인함에 따라 생물활성탄 공정에 의한 오염물질 제거에서 박테리아 군집의 UV에 대한 민감도가 고려되어야 함을 알 수 있었다. 이를 바탕으로 수처리 공정의 설계에 유용한 지표를 제공하고자 하였다.

• 유기물자원화
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• 제12권4호
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• pp.139-147
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• 2004

본 연구에서는 입단화 촉진을 통한 훼손토양의 복원을 위하여 산불토양으로부터 EPS 생성균주 2종을 순수분리 하였다. EPS 생성세균인 FM-02 균주는 Gram 음성 간균으로 16s-rDNA 염기서열분석 결과, Beta Proteobacterium sp. 에 속하는 종으로 동정 되었고, AL-02 세균은 양성 간균으로 16s-rDNA 염기분석 결과 Zoogloea sp. 와 81%의 유사도를 나타내었다. 분리균주가 생산하는 EPS의 양은 건중량 측정시 FM-02 균주는 1L당 약 1.8g 의 생산율을 보였으며, AL-02의 경우 약 8.3g의 수율을 보였다. 분리균주의 토양입단에 미치는 영향을 알아보기 위해 응집활성을 측정하였으며, FM-02 세균은 active carbon에 대한 응집활성 (FA)이 2.31로 나타났고, AL-02 세균은 kaolin clay에 대한 응집활성 (FA)이 6.21로 나타났다. 이상의 결과로부터, FM-02균주는 active carbon에 대한 높은 응집활성을 고려할 때 화학응집제를 대신한 생분해성 응집활성제로의 응응 가능성을 확인하였으며, AL-02균주는 kaolin clay에 대한 고활성의 응집능과 고생산성의 EPS수율을 갖는 균주로써 훼손된 토양에서 토양입자들의 응집을 통한 입단을 촉진하여 강우에 의한 토사유출 피해를 줄이는데 도움이 될 것으로 기대된다.

• 한국물환경학회지
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• 제20권2호
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• pp.170-175
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• 2004

The purpose of this study was to monitor bacteria present in raw water and to investigate the effect of ozone, UV and combined ozone/UV processes for inactivating bacteria. Both polymerase chain reaction (PCR)-fragment length polymorphic analysis (PRA) and PCR-sequence analysis (PSA) were applied for the simultaneous analysis of numerous bacteria species present in each tested water, such as drinking water (DRW), drinking water source (DRWS) and sewage effluent water (SEW). According to the result, the number of detected bacteria species was zero in DRW, 58 in DRWS and 13 in SEW. After treatment of the each process, the ozone/UV process was the most successful for inactivating almost all bacteria. However, it was found that Flavobacterium sp., Pseudomonas sp. and Beta proteobacterium sp. had strong resistant to all tested processes, requiring further detailed study.

• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.311-315
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• 2012

A novel ${\beta}$-proteobacterium, designated BXN5-$27^T$, was isolated from soil of a ginseng field of Baekdu Mountain in China, and was characterized using a polyphasic approach. The strain was Gram-staining-negative, aerobic, motile, non-spore-forming, and rod shaped. Strain BXN5-$27^T$ exhibited ${\beta}$-glucosidase activity that was responsible for its ability to transform ginsenoside $Rb_1$ (one of the dominant active components of ginseng) to compound Rd. Phylogenetic analysis based on 16S rRNA gene sequences showed that this strain belonged to the family Comamonadaceae; it was most closely related to Ramlibacter henchirensis $TMB834^T$ and Ramlibacter tataouinensis$TTB310^T$ (96.4% and 96.3% similarity, respectively). The G+C content of the genomic DNA was 68.1%. The major menaquinone was Q-8. The major fatty acids were $C_{16:0}$, summed feature 4 (comprising $C_{16:1}$ ${\omega}7c$ and/or iso-$C_{15:0}$ 2OH), and $C_{17:0}$ cyclo. Genomic and chemotaxonomic data supported the affiliation of strain BXN5-$27^T$ to the genus Ramlibacter. However, physiological and biochemical tests differentiated it phenotypically from the other established species of Ramlibacter. Therefore, the isolate represents a novel species, for which the name Ramlibacter ginsenosidimutans sp. nov. is proposed, with the type strain being BXN5-$27^T$ (=DSM $23480^T$ = LMG $24525^T$ = KCTC $22276^T$).

• Asian-Australasian Journal of Animal Sciences
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• 제27권4호
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• pp.495-502
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• 2014

The effect of Bacillus subtilis natto on hindgut fermentation and microbiota of early lactation Holstein dairy cows was investigated in this study. Thirty-six Holstein dairy cows in early lactation were randomly allocated to three groups: no B. subtilis natto as the control group, B. subtilis natto with $0.5{\times}10^{11}cfu$ as DMF1 group and B. subtilis natto with $1.0{\times}10^{11}cfu$ as DMF2 group. After 14 days of adaptation period, the formal experiment was started and lasted for 63 days. Fecal samples were collected directly from the rectum of each animal on the morning at the end of eighth week and placed into sterile plastic bags. The pH, $NH_3$-N and VFA concentration were determined and fecal bacteria DNA was extracted and analyzed by DGGE. The results showed that the addition of B. subtilus natto at either treatment level resulted in a decrease in fecal $NH_3$-N concentration but had no effect on fecal pH and VFA. The DGGE profile revealed that B. subtilis natto affected the population of fecal bacteria. The diversity index of Shannon-Wiener in DFM1 decreased significantly compared to the control. Fecal Alistipes sp., Clostridium sp., Roseospira sp., beta proteobacterium were decreased and Bifidobacterium was increased after supplementing with B. subtilis natto. This study demonstrated that B. subtilis natto had a tendency to change fecal microbiota balance.