Role of the Spore Coat Layers in Bacillus subtilis Spore Resistance to Hydrogen Peroxide, Artificial UV-C, UV-B, and Solar UV Radiation

Abstract

Spores of Bacillus subtilis possess a thick protein coat that consists of an electron-dense outer coat layer and a lamellalike inner coat layer. The spore coat has been shown to confer resistance to lysozyme and other sporicidal substances. In this study, spore coat-defective mutants of B. subtilis (containing the gerE36 and/or cotE::cat mutation) were used to study the relative contributions of spore coat layers to spore resistance to hydrogen peroxide (H 2 O 2 ) and various artificial and solar UV treatments. Spores of strains carrying mutations in gerE and/or cotE were very sensitive to lysozyme and to 5% H 2 O 2 , as were chemically decoated spores of the wild-type parental strain. Spores of all coat-defective strains were as resistant to 254-nm UV-C radiation as wild-type spores were. Spores possessing the gerE36 mutation were significantly more sensitive to artificial UV-B and solar UV radiation than wild-type spores were. In contrast, spores of strains possessing the cotE::cat mutation were significantly more resistant to all of the UV treatments used than wild-type spores were. Spores of strains carrying both the gerE36 and cotE::cat mutations behaved like gerE36 mutant spores. Our results indicate that the spore coat, particularly the inner coat layer, plays a role in spore resistance to environmentally relevant UV wavelengths.

Phylogenetic diversity and vertical distribution of a halobacterial community in the atmosphere of an Asian dust (KOSA) source region, Dunhuang City

“…Bacillus sp. is known to form endospores, which are resistant to environment stress and therefore enhance their survival in the atmosphere (Riesenman and Nicholson 2000). The desiccation condition in atmosphere would select the spore-forming bacterial survival and reduce the diversity of microbial community.…”

Resistance ofBacillusEndospores to Extreme Terrestrial and Extraterrestrial Environments

“…The spore coats appear to play some role in spore resistance, especially in preventing the access of peptidoglycan-lytic enzymes to the spore cortex, and also likely plays a role in spore resistance to some chemicals, such as hydrogen peroxide (38,102,165,169,191). A B. subtilis mutant completely lacking the spore coat layers has been constructed (38).…”

Control of Apple Blue Mold by the Antagonistic YeastPichia anomalaStrain K: Screening of UV Protectants for Preharvest Application

“…The development of resistance in fungal pathogens to fungicides (4,20,38,45,46) and the growing public concern over hazards associated with pesticide application (30,44,49) have resulted in a significant interest in alternative methods for disease control. One alternative method is biological control, which is attractive for the control of postharvest infections because it leaves no chemical residue on the treated fruit (35,46,47).…”