INFLUENCE OF PREHEATING, pH, AND HOLDING TEMPERATURE UPON VIABILITY OF BACTERIAL SPORES STORED FOR LONG PERIODS IN BUFFER SUBSTRATES

Publisher Website
Google Scholar
Abstract
The influence of initial heat shock, substrate pH and storage temperature was studied in relation to spore viability in Bacillus macerans, B. brevis, B. subtilis, B. stear other-mophilus, Clostridium botulinum and P. A. 3679. Spore (plate) counts were made of each sample before and after prestorage heating and after varying storage periods in buffer substrates. In most instances prestorage heat shock caused increase loss of viability during storage. Spores of C. botulinum and P. A. 3679, in contrast to those of aerobic species, maintained their viability almost without change over a period of 3 years. Viability of the aerobes was maintained much longer at pH 8.0 than in the acid substrates. The rate of decline in the spore populations was characteristically a function both of pH and temperature.