Seasonal distribution and character of heterotrophic marine bacteria in the intertidal zone of the Yellow Sea near Kunsan, Korea

Annual distribution of heterotrophic marine bacteria and seasonal characteristics were investigated in the intertidal water and sediments of the Yellow Sea near Kunsan, Korea. The heterotrophic marine bacteria ranged from 7.5 x 102 to 1.1 x 105 CFU ml-1 in water and 1.62 x 104 to 4.78 x 106 CFU g-1 dry sediment. As for the morphological distribution measured by epifluorescence microscopy, rod-shaped bacteria were more than 74 % of all cells during the investigation period. Average biovolume of sampled bacteria ranged from 3.19 ± 0.59 x 10-2 to 6.19 ± O.76 x 10-2 µm3 for coccoid bacteria, and from 4.57 ± 0.17 x 10-2 to 12.94 ± 0.21 x 10-2 µm3 for rod-shaped ones. Isolated bacteria showed utilization of various carbon sources such as glucose, maltose, lactose, xylose and arabinose, and tolerance to a range of salinities. In total 82 strains were isolated from seawater and 114 strains from sediments. Dominant genera were Pseudomonas, Vibrio, Flavobacterium and Acinetobacter in seawater, and Pseudomonas, Acinetobacter, Vibrio and Mycobacterium in sediments