MICB 201 Lecture Notes - Lecture 14: Exponential Function, Enterotoxin, Bacillus Cereus
Document Summary
Gamma radiation: there are no natural sources of gamma radiation in the environments where microorganisms live, used in food sterilization, food is placed near a gamma-ray source (e. g. co60) Important part of killing effect: creation of hydroxyl radical from water and damage (fragment) of bacterial dna and proteins. Co60 h2o in food hydroxyl radicals damage (fragment) dna and proteins. Elephant dung (feces) surgical instruments subjected to gamma-irradiation the cooling water surrounding the cores of nuclear reactors: not pathogenic to humans. Each cell contains many chromosome copies: important in radiation resistance. Because gamma-radiation (cid:862)hits(cid:863) (cid:894)frag(cid:373)e(cid:374)ts(cid:895) dna at random, this has the potential to generate overlapping fragments which can be joined together by homologous recombination. Resting cells: vegetative cell: active cellular form capable of reproduction, resting cell: dormant cellular form (not dead), but not capable of reproduction, most prokaryotes do not form resting cells and not all resting cells are the same. Endospores formed by some members of the firmicutes.
