Five lots of fish were examined microbiologically for aerobic plate count at 10 and 30 C. coliform and enterococcus counts, presence of coagulase-positive Staphylococcus aureus and genera of bacteria appearing on the aerobic plates. After initial analyses. fish were stored in ice, held there for a week and then aerobic plate counts and isolation of colonies for identification as to genus were done again. Aerobic plate counts ranged from 104 to 107 per gram of skin at the beginning of storage in ice and increased to 106 to 109 per gram at the end of 7 days of storage. Coliforms and enterococci were found in fresh fish but no S. aureus was detected. Gram-negative bacteria accounted for about half of the bacteria on fresh fish, predominated as spoilage advanced and eventually formed the major part of the flora. Pseudomonas, Moraxella and Alcaligenes were the principal genera of gram-negative bacteria at the end of storage.
1Central American Research Institute for Industry.
2University of Wisconsin.