Mineralization and responses of bacterial spores to heat and oxidative agents

Abstract

Mineralization of bacterial spores with Ca2+ and a variety of other mineral cations enhances resistance to heat damage. Part of the enhancement is associated with increased dehydration of the mineralized protoplast or spore core, while part is independent of dehydration and effective for resistance even to dry heat. Spore mineralization was found also to enhance resistance to oxidative damage caused by agents such as tertiary butyl hydroperoxide or H2O2. In contrast, mineral cations in the environment increased oxidative damage, presumably by catalyzing radical formation. Metal ion chelators such as o-phenanthroline protected spores against such damage.

Sensitivities to Hydrogen Peroxide Vapor of Intact and Decoated Spores of Bacillus subtilis As Influenced by Divalent Cations Supplemented in Sporulation Medium.

“…The Fe" content was relatively low even in Fe-supplemented spores themselves and, instead, Ca" was a major constituent. These findings concur with previous results of other researchers (Kihm et al, 1990 ;Marquis and Shin, 1994) . As compared with that in the spores of strain 168, the Mn" content in Mn-supplemented spores of strain ATCC9372 was relatively low.…”

Behavioural pattern of vegetative cells and spores of Bacillus cereus as affected by time-temperature combinations used in processing of Indian traditional foods

“…The wide variations observed in the thermal inactivation pattern of spores of B. cereus could be attributed to one or more of the following (1) characteristics of strains of B. cereus with environmentally induced resistance due to dipicolinic acid content, degree of hydration and mineral content (Marquis and Shin 1994;Palop et al 1996;Mazas et al 1999b;Melly et al 2002;Baweja et al 2008), (2) temperatures which have induced spore formation as well as other conditions prevailing during sporulation (Condon et al 1992;Baweja et al 2008) and (3) heterogeneity in the cluster of spores with respect to germination and/or survival (Byrne et al 2006).…”

Resistance ofBacillusEndospores to Extreme Terrestrial and Extraterrestrial Environments

“…Using these procedures, spores with extremely low divalent cation levels can be generated (H ϩ , Na ϩ , or K ϩ spores), as can spores with high levels of any of a variety of divalent cations (Ca 2ϩ , Mg 2ϩ , and Mn 2ϩ ). Upon analyses of spore wet-heat resistance, Ca 2ϩ spores are the most resistant, with resistance similar to that of native spores, while H ϩ spores are the least resistant; in general, divalent cation-loaded spores are more resistant than monovalent cation-loaded spores (12,52,98,99). While studies are not as extensive, increased spore core mineralization is also associated with increased resistance to oxidizing agents (98) and, at least in spores of Bacillus stearothermophilus, with increased resistance to dry heat (1).…”