Characterization of a spontaneous adhesion-defective mutant of Ruminococcus albus strain 20

Citation
P. Mosoni et B. Gaillard-martinie, Characterization of a spontaneous adhesion-defective mutant of Ruminococcus albus strain 20, ARCH MICROB, 176(1-2), 2001, pp. 52-61
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
ARCHIVES OF MICROBIOLOGY
ISSN journal
0302-8933 → ACNP
Volume
176
Issue
1-2
Year of publication
2001
Pages
52 - 61
Database
ISI
SICI code
0302-8933(200107)176:1-2<52:COASAM>2.0.ZU;2-1
Abstract
A spontaneous adhesion-defective mutant (mutant D5) of Ruminococcus albus s train 20 was isolated and compared to the parent to investigate the impact of the mutation on cellulolysis and to identify the adhesion mechanism of R . albus. The comparison of kinetics of cellulose degradation by strain 20 a nd mutant D5 showed that the mutation delayed and reduced bacterial growth on cellulose and cellulose degradation. These results were partly explained by a twofold lower cellulase activity in the mutant than in the parent. Th e glycocalyx of strain 20, observed by transmission electron microscopy, wa s large and homogenous, and linked cells to cellulose. The mutant glycocalv x was aggregated at its periphery and cells attached loosely to cellulose. A glycoprotein of 25 kDa (GP25), present in the membrane fraction and the e xtracellular medium of strain 20, was not detected in the same fractions of mutant D5. Though glycoprotein GP25 did not bind to cellulose, it may be i nvolved in adhesion as an intermediate component. Different cell-surface fe atures of mutant D5 (cellulases, glycoprotein GP25, glycocalyx) were thus a ffected, any or all of which may be involved in its adhesion-defective phen otype. These results suggest that adhesion and cellulolysis are linked and that adhesion is a multifactorial phenomenon that involves at least the ext racellular glycocalyx.