Affiliation:
1. Department of Biological Sciences, University of Calgary, Alberta, Canada.
Abstract
Surface growth of an Acinetobacter sp. cultivated under several nutrient regimens was examined by using continuous-flow slide culture, phase-contrast microscopy, scanning confocal laser microscopy, and computer image analysis. Irrigation of attached coccoid stationary-phase Acinetobacter sp. cells with high-nutrient medium resulted in a transition from coccoid to bacillar morphology. Digital image analysis revealed that this transition was biphasic. During phase I, both the length and the width of cells increased. In contrast, cell width remained constant during phase II, while both cell length and cell area increased at a rate greater than in phase I. Cells were capable of growth and division without morphological transition when irrigated with a low-nutrient medium. Rod-shaped cells reverted to cocci by reduction-division when irrigated with starvation medium. This resulted in conservation of cell area (biomass) with an increase in cell number. In addition, the changes in cell morphology were accompanied by changes in the stability of cell attachment. During phase I, coccoid cells remained firmly attached. Following transition in high-nutrient medium, bacillar cells displayed detachment, transient attachment, and drifting behaviors, resulting in a spreading colonization pattern. In contrast, cells irrigated with a low-nutrient medium remained firmly attached to the surface and eventually formed tightly packed microcolonies. It is hypothesized that the coccoid and bacillar Acinetobacter sp. morphotypes and associated behavior represent specialized physiological adaptations for attachment and colonization in low-nutrient systems (coccoid morphotype) or dispersion under high-nutrient conditions (bacillar morphotype).
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference36 articles.
1. American Public Health Association. 1981. Standard methods for the examination of water and waste water p. 9-31. Coordinating ed. M. A. H. Franson. American Public Health Association Washington D.C.
2. Starvation-survival patterns of sixteen freshly isolated open-ocean bacteria;Amy P. S.;Appl. Environ. Microbiol.,1983
3. The influence of environment on envelope properties affecting survival of bacteria in infections. Annu;Brown M. R. W.;Rev. Microbiol.,1985
4. Confocal laser microscopy and digital image analysis in microbial ecology;Caldwell D. E.;Adv. Microb. Ecol.,1992
5. Imaging of bacterial cells by fluorescence exclusion using scanning confocal laser microscopy;Caldwell D. E.;J. Microbiol. Methods,1992
Cited by
139 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献