Isolation of psychrophilic species of Bacillus

Larkin, J. M. (Washington State University, Pullman), and J. L. Stokes. Isolation of psychrophilic species of Bacillus. J. Bacteriol. 91:1667-1671. 1966.-Ninety psychrophilic isolates of Bacillus were obtained from soil, mud, and water by selective enrichment at 0 C. They grew well at 0 C, optimally at 20 to 25 C, and failed to grow at 30 or 35 C. Their minimal and maximal growth temperatures were lower than those for mesophilic species of Bacillus by 10 C or more. Growth of psychrophilic isolates also occurred at -2 and -4.5 C, and both spore formation and spore germination occurred at 0 C.