Radiochemical investigation of the respiration of spores of Bacillus cereus

✍ Scribed by Desser, H. ;Broda, E.

• Book ID: 104763469
• Publisher: Springer-Verlag
• Year: 1969
• Weight: 481 KB
• Volume: 65
• Category: Article
• ISSN: 0003-9276
• DOI: 10.1007/bf00412066

✦ Synopsis

The endogenous respiration of laC-labelled spores of B. cereus was measured through the 14CO2 produced, and the rate expressed as Q (~zl COJh • rag). New upper limits for respiration in various conditions have been set.

Dry spores had no measurable activity; Q < 10 -~ at room temperature and < 10 -a at 35 ~ C. For wet spores of different harvests, at 30 ~ C, Q lay between 0.0013 to 0.067. Near 40oC, respiration showed a maximum. Thermal history has a great influence on Q. CO S production by heat-killed spores is attributed largely to infection.

Water or 10 -3 z~ sodium phosphate buffer (ptI = 6.5) gave equal spore respiration, in strong NaC1 it was less. Azide enhanced respiration dramatically. A temporary increase was also found with non-radioactive glucose. Exogenous respiration of spores in glucose exceeded endogenous respiration.

Endogenous and exogenous respiration of vegetative forms were much larger than those of spores and were time-dependent. The ratio of minimum (endogenous, dry spores) and maximum (exogenous, wet vegetative cells) respiration was at least 3 • 10 5.