| The immense ocean is the cradle of life. Marine microbes show the diversity at the species, heredity & variation inside the species and ecological functions, which is called marine microbial diversity.Bacteria of Vibrionaoeae exist widely in the semi-salty water, bayou, seawater and sediment. Vibrionaceae consists of Vibrio, Aeromonas, Plesiomonas and Photobacterium. And there are more than 37 species belong to Vibrio. Nowadays, most interests of the scientists are focused on the pathogenic species.Some species of Vibrionaceae are the important human pathogens. People can be infected by drinking unclean water, eating the raw marine products or semi-cooked food contaminated with the pathogenic bacteria. For example, Vibrio cholearae can cause serious diarrhea of human, Vibrio parahaemolyticus cause food poisoning, and Vibrio vulnificus can infect people by the wound.More than half of Vibrio also cause diseases of marine animals such as fishes, shrimps, seashells. And vibriosis is one of the most important bacterial diseases of aquatic animals caused by some Vibrio strains, which happened widely in all over the world and has caused great loss in marine aquaculture. However, Some strains of Vibrio alginolyticus can be used as probiotics in cultural shrimp pool.The bacterial diversities in aquaculture area, industrial polluted area, and unpolluted area near the seashore around Qingdao were investigated from Oct., 1999 to Oct., 2000. The main basic physical and chemical parameters, the bacterial flora in different environment were studied throughout one year. The results showed that the bacteria number changed with the seasons in seawater, but not too much in sediment and other environments. The average bacterial numbers were 1.4*104 cfu /mL in marine aquaculture seawater, 5.4*104 cfu /mL in industrial polluted seawater, and less than 102 cfu/mL in unpolluted seawater. At Laoshantou the bacteria numbers in seawater was less than 101 cfu /mL.540 bacterial strains were isolated from different marine environments, of which 78 isolates were Gram-positive bacteria, and 462 isolates were Gram-negative bacteria. The 462 isolates of Gram-negative bacteria were identified to genus by the methods of basic physiological and biochemical reactions. The results showed mat the isolates mainly belonged to nine genus: Aeromonas, Vibrio, Photobacterium, Pseudomonas, Lucibacterium, Moraxella, Flavobacterium, Chromobacterium and Cytophage.Vibrionaceae was the dominating community in each studied environments, and 83.1% of the isolated strains belonged to Vibrionaceae on the surface of fish body. Aeromonas was the dominating genus in seawater, sediment and on the seaweed's surface. Vibrio was the dominating genus on the surface of the fish body.The 428 Gram-negative strains were further identified by BIOLOG-GN system. 322 isolates of all gram-negative strains reacted normally, and 139 isolates were identified to species, 34 isolates were identified to genus. There were 74 strains belonged to Vibrionaceae among the 322 isolates, 59 of which were identified to species, including many pathogens of marine animals and human such as V. alginolyticus, V. parahaeolyticus and V. harveyi. V. alginolyticus, V. parahaeolyticus, V. harveyi, V. carachariae were identified from the aquatic area. V. alginolyticus, V. carachahae, V. metschnikovii were identified from the industrial polluted area. Only two V. harveyi strains were identified from unpolluted area.A pair of oligo-nucleotide primers was designed based on the metal-protease gene of Vibrio anguillarum. The specific sequence of metal-protease gene was amplified and detected in 12 strains of Vibrio anguillarum but not in other 34 Vibrio strains. It showed that the primers were special to detection of Vibrio anguillarum and the minimum DNA concentration for PCR detection of Vibrio anguillarum was 0.1ng by using the PCR method, 6 bacteria isolated from diseased marine fishes were proved to be Vibrio anguillarum. The Vibrios in the other cultured marine animals and seawater from...
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