• 한국식물병리학회지
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• 제13권3호
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• pp.172-178
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• 1997

십자화과 작물에 발생하는 검은썩음병(Black rot or Black vein of crucifer)의 병원성 세균인 Xanthomonas campestris pv. crucifer)의 병원성 세균인 Xanthomonas campestris pv. campestris를 분리, 동정하고 병원성을 검정하였다. 이 X. c. pv. campestris 는 3가지 종의 Chinese cabbage에 병원성을 나타내었고, 병원성과 관련된 특성을 결정하기 위하여 Tn5 mutagenesis를 실시 cellulase negative mutant를 선발하여 병원성 검정하였다. 선발된 cellulase negative mutant를 배추에 분무 접종하여 광학 현미경과 전자현미경으로 관찰한 결과 cellulase negative mutant는 wild type와 함께 기공표면과 기공하부조직에서 정착하였지만 그 밀도는 낮았다. 반면 접종 24시간 이후 wild type은 기공표면과 기공하부조직이 lysis되기 시작하여 48시간 이후에는 병원성의 진전으로 보다 많이 lysis되었다. 6일 후, wild type은 cellulase활성에 의해 식물체 조직에서 높은 증식력을 보이며 조직을 lysis 시키고 또한 조직 깊숙이 침입, 정착하는 것을 관찰하였다. 이 결과로 X. c. pv.c campestris의 cellulase는 병원성에 관여하는 중요한 요인으로 생각된다.

• 한국미생물·생명공학회지
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• 제23권3호
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• pp.275-281
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• 1995

From the plasmid pYA300 carring a CMCase of Rhizobium fredii USDA193 plasmid was subcloned into pBluescript II KS(+)/pBluescript II SK(+) vectors and designated pYA500 and pYA600, respectively. Escherchia coli cells transformed with pYA500 porduced the CMCase more than with pYA600. The orientation of the cloned fragment in pBluescript vector had the effect on gene expression in E. coli background. When the 1.7 kb CMCase gene fragment of R. fredii USDA193 was hybridized to EcoRI-digested total DNA from R. meliloti and R. fredii USDA 191 the unique bands hybridized respectively, indicating that some genetic diversity exists in the EcoRI restriction enzyme site for CMCase gene in Rhizobium strains. The optimum pH of enzyme activity was 7 and the optimum temperature of that was nearly 37$\circ$C. The cellulase-minus derivatives of pYA500 were constructed by Tn5 insertional mutation. Among 6000 transconjugants, two mutant plasmids (designated pYA500::Tn5a and pYA500::Tn5b) were detected from the cellulase- negative transconjugants. The product of CMCase gene was analyzed by one dimensional SDS- PAGE of the cell extracts. About 45 kDa protein was considered to be a product of CMCase gene.

• Asian-Australasian Journal of Animal Sciences
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• 제20권5호
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• pp.802-810
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• 2007

Fibrobacter succinogenes, a Gram-negative, anaerobic ruminal bacterium is a major fibre digesting species in the rumen. It intensively degrades plant cell walls by an erosion type of mechanism, burrowing its way through the complex matrix of cellulose and hemicellulose with the release of digestible and undigested cell wall fragments. The enzymes involved in this process include a combination of glucanases, xylanases, arabinofuranosidase(s) and esterases. The genome of the bacterium has been sequenced and this has revealed in excess of 100 putative glycosyl hydrolase, pectate lyase and carbohydrate esterase genes, which is greater than the numbers reported present in other major cellulolytic organisms for which genomes have been sequenced. Modelling of the amino acid sequences of two glycanases, CedA and EGB, by reference to crystallized homologs has enabled prediction of the major features of their tertiary structures. Two dimensional gel electrophoresis in conjunction with mass spectroscopy has permitted the documentation of proteins over expressed in F. succinogenes grown on cellulose, and analysis of the cell surfaces of mutant strains unable to bind to cellulose has enabled the identification of candidate proteins with roles in adhesion to the plant cell wall substrate, the precursor to cellulose biodegradation.