Article Abstract:
Transposon-generated mutants (M-4, M-5 and M-7) of Bacteroides ovatus unable to utilize guar gum were analyzed. Restriction analysis showed M-4 and M-5 contained the transposon at the same site, while M-5 and the M-7 loci did not overlap. The wild type clone of the M-5 region failed to form transconjugants in complementation experiments, while the M-7 clone failed to complement M-7 mutants. Two promoter regions were identified in the M-7 locus. This locus appears to have a regulatory function, since multiple copies of an M-7 fragment containing one promoter affected proteins not encoded on the segment.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
A 3.8-kbp segment of the Bacteroides ovatus chromosome which contains the genes for xylanase (xylI) and xylosidase-arabinosidase (xsa) was analyzed. Site-directed insertion mutagenesis showed that xylI and xsa belong to a single operon, with xylI in the upstream orientation. In addition, preliminary indications suggest the presence of another arabinosidase gene upstream of xylI. Physiological analyses of the insertion mutants showed that the product of xsa is the rate-limiting enzyme in xylan utilization.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
The regulatory phenomena in the amylase production by Streptococcus bovis and the molecular characteristics of this activity are discussed. Nutritional and time-course expriments were used in the examination of the amylolytic activity and the cloning and expression of the gene in Eschirichia coli and Bacillus subtilis. The utility of the amylase gene for the identification of S. bovis strains as agenetic probe was demonstrated.
User Contributions:
Comment about this article or add new information about this topic: