Master of Science (MS)
Number of Pages
Arthrobacters exhibit a dimorphic growth cycle where exponential phase cells appear as irregular bacilli and stationary phase cells as cocci. Arthrobacter globiformis was found to form myceloids when subjected to osmotic stress. Addition of known osmoprotective compounds did not relieve this effect. Since myceloid formation may result from altered penicillin-binding proteins (PBPs), PBP profiles of stressed and unstressed A. globiformis were studied. Eight PBPs were identified, ranging in molecular mass from 91,000 to 30,000 daltons. Myceloids appeared to lack PBP 2a (84 kD) and PBP 2b (82 kD) in all growth conditions. The myceloids were 12-20 times more sensitive to beta-lactam antibiotics than the normal bacteria and 320 times more resistant to streptomycin. Myceloids were more sensitive to heat than the coccal forms and more resistant to long term starvation in a buffer lacking a nitrogen source. These results indicate that myceloid formation in A. globiformis may result from the altered synthesis of specific PBPs.
Arthrobacter; Cell; Formation; Globiformis; Myceloid; Osmotic; Stress
Microbiology; Molecular biology
University of Nevada, Las Vegas
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Perera, Ganegodage Shyama, "Myceloid cell formation in Arthrobacter globiformis during osmotic stress" (1993). UNLV Retrospective Theses & Dissertations. 331.