Ecology and Taxonomy of Psychrotolerant Bacteria in Artificial Cold Environments
Isao Yumoto and Koji Yamazaki
from: Cold-Adapted Microorganisms (Edited by: Isao Yumoto). Caister Academic Press, U.K. (2013)
A variety of artificial cold environmental conditions exist around human activities. These environments involve several factors that define the kinds of bacteria existing in niches. These environmental factors change with time owing to changes in the environment caused by existing microorganisms and their metabolisms. Namely, the inevitable selection of bacteria occurs in each artificial cold environment and the successive changes in microbiota occur according to changes in environmental factors. Some of the microorganisms in these microbial communities are useful for the degradation of organic matter in cold environments and for food preservation. On the other hand, several microorganisms adapted to artificial cold environments cause food spoilage. The frequently isolated psychrotolerant bacterial genera in artificial cold environments are Pseudomonas, Psychrobacter, Staphylococcus and Photobacterium. Lactic acid bacteria are also frequently detected under anaerobic conditions. To date, it has been reported that these genera are widely distributed in natural as well as artificial cold environments. It is intriguing why these bacterial genera are widely distributed in cold environments and why certain species belonging to these genera are able to survive in artificial cold environments. The frequent detection of members of above-mentioned genera in artificial cold environments suggests that the important factors that define the existence of these genera in cold artificial environments are i) chances of invasion of such cold environments from ambient environments, ii) chances of invasion through their own basic components, iii) ability to rapidly propagate at low temperature and iv) presence or absence of oxygen. It is also considered that these genera are genetically widely diverse, and cold artificial environment adaptation mechanisms of certain species belonging to these genera make their distribution wider not only in natural cold environments but also in artificial cold environments read more ...