Spores

Abstract

Apart from their utility in regulation of pH, bicarbonates may promote the formation of spores by increasing COo concentration, as shown by Powell and Hunter (1955). Proliferating vegetative cells, when centrifuged, washed, and shaken in distilled water, form spores only if the prior growth medium is conducive to sporulation. However, B. subtilis derived from an asporogenous medium sporulates in distilled water when supplied with both yeast extract and salts, but not if one of these supplements is omitted (Murrell, 1955), indicating that the spore-generating mechanism is not seriously impaired by limited cultivation in asporogenous media. The known facts, briefly surveyed, indicate that mineral salts are essential for the formation of bacterial spores. The fact that synthetic media without added salts do not produce spores, and the fact that the inadequacy for spore formation of many complex organic media can be corrected by the addition of suitable minerals support this contention. The level of minerals required for sporulation varies with the organism and with cultural conditions such as kind and concentration of nutrients, oxygen supply, temperature, and pH. The importance of manganese in the sporulating process is conspicuously evident. It is required by a wide variety of mesophilic and thermophilic aerobes, at concentrations above those needed for active vegetative growth, and, with one apparent exception, cannot be replaced by any other mineral element. Manganese has been found to broaden the temperature and pH range over which sporulation occurs (Amaha et al, 1956).

Morphological changes in ascospores of Saccharomyces cerevisiae during aerobic and anaerobic germination.

“…And one might often consider the reaction of yeast ascospores to the acid-fast stain to be due to the acid-fastness, similar to the reaction of acid-fast bacteria using the original method of acid-fast staining (4, 7). However, the stainability in Bacillus spores has been found not to be due to the acid-fastness but to the resistance to permeation of the methylene blue into the spore (15). Thus, in yeast spores the stainability to the acid-fast stain was examined preliminarily before germination experiments with light and electron microscopies.…”

Studies on Germination of Calcium- And Zinc-Enriched Spores of Bacillus Cereus T

“…Under favourable conditions they can break their dormancy and become sensitive to heat, leading ultimately to the formation of typical bacterial cells. This process is known as spore germination (1)(2)(3)(4). Germination can be measured by release of dipicolinic acid (DPA) (5,6), and increase in UV resistance (7,8) or by decrease in optical density.…”