Microflora of Drainage from Ice in Fishing Vessel Fishholds

Abstract

The microbial load in ice-melt drainage collected from fishholds of fishing vessels stowing lizard fish, black croakers, cuttle fish, or nemipterids was very high, ranging from 2.1 � 10 7 to 2.2 � 10 9 /ml for bacteria and 6.3 � 10 3 to 7.2 � 10 4 /ml for yeasts and molds. Analysis of 100 colonies each randomly isolated from drainage samples of cuttle fish and lizard fish showed that the occurrence of bacterial genera as a percentage of the total was Moraxella-Acinetobacter , 61 to 62%; Pseudomonas , 19 to 21%; Alcaligens , 5 to 10%; Flavobacterium , 1 to 4%; Micrococcus , 1 to 4%; Bacillus, Vibrio 0 to 2%; Corynebacterium , 1 to 2%; and others, 1 to 2%. The organisms demonstrated versatile hydrolytic activities to a wide range of biological substrates including casein, gelatin, starch, DNA, and RNA. The possible connection between these bacteria and the deterioration of fish quality are discussed.