Kittichonm U-taynapun, Boonkob Viriyapongsutee, Nukool Intrasungkha and Kijjakarn Supamattaya

pp. 247 - 259

Abstract

The Fluorescent in situ hybridization (FISH) technique and conventional method were used to analyse the bacterial community in the gut of white shrimp cultured in earthen ponds. Samples were collected from three parts, hepatopancreas, anterior intestine and posterior intestine. Gut bacterial community was
enumerated by 15 probes in FISH and 3 bacterial culture technique media. The results showed that bacteria specific probes determined bacterial community and Eubacteria as the dominant group of microbial community in the studied gut portions. β-Proteobacteria group (29.53±5.39%) and γ-Proteobacteria group (26.18±6.88%) were major groups of bacterial flora in the hepatopancreas. In contrast, low G+C gram positive bacteria group (LGC) was the most abundant group detected in anterior intestine (36.40±3.53%) and posterior intestine (30.32±4.63%). Vibrio spp. were detected very less in hepatopancreas (0.25±0.43%) and were present in 3 of 9 samples. In the case of bacterial detection using cultivation method, the number of bacterial groups verified by TSA, TCBS and MRS showed high variation in every part of the studied
digestive tract portions; however, no vibrio or lactic acid bacteria were present in the hepatopancreas of healthy shrimp. This study reveals the proportion of bacterial community in the digestive tract of white shrimp which can be used as important database for studying the change of the bacterial community in an
abnormal condition including the efficiency of probiotics in the gut (in vivo) of white shrimp.

Keywords

• fluorescent in situ hybridization (FISH)
• bacterial communities
• gut
• Penaeus vannamei