• BMB Reports
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• 제34권2호
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• pp.172-175
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• 2001

Catechol 1,2-dioxygenase $I_1$ ($CDI_1$) is the first enzyme of the $\beta$-ketoadipate pathway in Acinetobacter lowffii K24. $CDI_1$ has two cysteines (155, 202) and its enzyme activity is inhibited by the cysteine inhibitor, $AgNO_3$. Two mutants, $CDI_1$ C155V and $CDI_1$ C202V, were obtained by site-directed mutagenesis. The two mutants were overexpressed and the mutated amino acid residues (Cys$\rightarrow$Val) were characterized by peptide mapping and amino acid sequencing. Interestingly, $CDI_1$ C155V was inhibited by $AgNO_3$, whereas $CDI_1$ C202V was not inhibited. This suggests that $Cys^{202}$ is the sole inhibition site by $AgNO_3$ and is close to the active site of the enzyme. However, the results of the biochemical assay of mutated $CDI_1s$ suggest that the two cysteines are not directly involved in the activity of the catechol 1,2-dioxygenase of $CDI_1$.

• 한국동물위생학회지
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• 제33권4호
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• pp.319-326
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• 2010

Bacteroiospermia is a frequently finding in fresh raw and extended porcine semen and can results in detrimental effects on semen quality and longevity. This study aims to evaluate the type of bacterial contaminants in raw and extended porcine semen and the reducing effect of antibiotic test. To investigate bacterial contaminants, out of 387 sample (raw semen 201, extended semen 186) were collected from 6 artifical insemination centers in Gyeongsangnam-do, were inoculated onto blood agar and MacKonkey agar, respectively. Bacterial colonies were selected after culturing for 48 hours, at $37^{\circ}C$, followed by Gram staining, KOH test, oxidase test, catalase test and eventually identified using VITEK System. Total 15 genus and 24 species of bacteria were isolated from these semen samlpes. In raw semen, the most prevalent contaminants were Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis, Staphylococcus auricularis, Delftia acidovorans, Acinetobacter lowffii, S. aureus and others. And in extended porcine semen, A. lowffii, S. aureus, S. auricularis and other bacteria were identified. Most of them was G(-), which is nonpathogenic bacteria. It seems that bacterial contaminants in fresh raw and extended porcine semen originated from multiple sources at the farms/stud, and were from animal origin and non-animal origins. Whereas, the 7 virus which is known to be detected in porcine semen in 75 cases was not detected. This results showed that removal of bacterial contamination in raw and extended porcine semen is essential and farms were kept for biosecurity and individual hygienes.

• 환경생물
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• 제25권3호
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• pp.273-278
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• 2007

[ $2003{\sim}2007$ ]년 통영 바다목장 해역 5개 정점을 대상으로 표층수와 저층수의 종속영양세균의 개체수를 측정하고, 종속영양세균 군집의 종조성 및 우점종을 분석하였다. 종속영양세균은 겨울이나 봄 및 가을에 비하여 해수의 온도가 높은 여름에 더 많이 검출되었으며, 정점별 변화는 특별한 변화 경향이 없었다. 2003년 10월 및 2004년 9월에는 태풍과 집중호우의 영향으로 표층수와 저층수의 개체수가 큰 차이를 나타내지 않거나 저층수의 개체수가 표층수보다 오히려 더 많은 경우도 있었다. 통영 바다목장 해역의 종속영양세균 개체수는 해를 거듭할수록 감소하는 추세를 나타내었다. 종속영양세균 군집의 종조성은 Pseudomonas fluorescens TY1, Pseudomonas stutzeri TY2, Acinetobacter lwoffii TY3, Sphingomonas paucimobilis TY4, Burkholderia mallei TY5, Pasteurella haemolytica TY6, Pasteurella multocida TY7, Comamonas acidovorans TY8, Actinobacillus ureae TY9 및 Chryseobacterium indologenes TY10으로 조사되었고, P. fluorescens TY1과 A lowffii TY3이 우점종으로 분석되었다.