Causes of Can Swelling and Blackening of Canned Baby Clams. 3. Bacteriology and Chemistry of Sea‐Bottom Mud Involved in Can Spoilage

摘要

SUMMARY—Bacterial spores grown in medium containing calcium chloride were found to be very thermoresistant. If raw baby clams were collected from muds with a high calcium content, the canned product usually spoiled. Sea‐bottom muds high in calcium may, therefore, have an effect upon the thermoresistance of the spores. There was no relationship between iron and magnesium content of muds and the spoilage of the canned product. The amount of hydrogen sulfide was in proportion to the organic matter and humus content of the muds. Unless chemical or bacteriological factors are involved, the hydrogen sulfide content of the mud itself would not be sufficient to cause spoilage of the canned clams. Qualitative and quantitative tests for sulfate and sulfite ions showed an inverse relationship with the amount of hydrogen sulfide. This might be a result of reduction of sulfate in the muds.Thermophilic spore formers are widely distributed in all locations of the Ariake Sea. If baby clams are collected from this area and improperly cleaned, they may contain enough bacteria to cause spoilage in the canned product. The spore‐forming bacteria isolated from muds were classified and consisted of 83Clostridiumand 17Bacillusg