Changes of intestinal microflora in Hepialus gonggaensis larvae after feeding with Carnobacterium sp.Hg4-03 as a probiotic strain

Abstract:

Abstract: [Objective] We investigated the influence of Carnobacterium sp. Hg4-03 on intestinal microflora of the 4th instar Hepialus gonggaensis larvae, an economically important insect. [Methods] The effect was observed by molecular techniques based on the sequence of 16S rDNA V3 region gene and PCR/DGGE (Denaturing gradient gel electrophoresis). The health larvae were divided randomly into treatment group1, treatment group2 and control group, and fed on their natural food added with different amount of Carnobacterium sp. Hg4-03 ( group 1 and group 2) or ddH2O ( control). After 14 days and 28 days, 6 larvae from each group were randomly selected to be dissected and contents of guts were collected for bacterial diversity analysis. [Results] The result showed that bacterial diversity index of treatment groups with Hg4-03 was higher than control group, and the species of bacteria increased. Comparing the bands of DGGE profiles between three groups, the intensity of band stand for Carnobacterium sp. Hg4-03 have enhanced. Another band with swelled intensity found in profiles come from treatment group2 after 28 d fed, the sequence analysis showed it belongs to Bacillus subtilis. [Conclusion] Feeding with Carnobacterium sp. Hg4-03 could balance the bacteria in larvae gut and increase bacteria diversity, that means the bacteria made a positive effect on the bacterial diversity of H. gonggaensis larval gut. Hg4-03 may be used as probiotic bacteria for rearing H. gonggaensis larvae in controlling conditions or the larvae’s hemi-wild rearing.