Isolation and identification of microflora of farm ponds and gastrointestinal tract of western white shrimp (Litopenaeus vannamei) beside their evaluation as probiotic

Nowadays, Shrimp culture has been prevailed in most of tropical countries; however, a variety of diseases have currently affected the business worldwide. Infectious bacterial agents are the most significant hygienic problems observed in the cultured shrimps . This study was aimed to isolate and identify microflora of farm ponds and western white shrimp gastrointestinal tract (Litopenaeus vannamei) in the Bushehr Province farm ponds and their survey as probiotic. The shrimp and pond water samples were collected from 10 farm ponds (located at Bushehr Province). After transferring the samples to laboratory, the shrimp samples were autopsied to access to their intestinal microflora. The isolated bacteria were identified based on biochemical tests, morphology and Biolog software. Antibacterial activities of the isolates against 6 common pathogenic bacteria in shrimps were then investigated using well diffusion and disk diffusion methods. Overall, 12 bacterial genera were isolated from the farm ponds and shrimp gastrointestinal tract. The majority of bacterial species most abundantly isolated were Bacillus, Vibrio and Pseudomonas. Among the isolated bacteria, Bacillus, Micrococcus and Corynebacterium showed the most antibacterial activity against evaluated pathogenic bacteria. Almost all the isolated bacteria from shrimp gastrointestinal tract were found in farm ponds as well. The bacterium Bacillus sp., for instance, is able to inhibit the growth of pathogens through secreting antimicrobial products.