Effects of bleach powder on the midgut digestive enzymes of silkworms.

[Objectives] To investigate the effect of bleach powder on silkworm intestinal bacteria and digestive enzymes, [Methods] Silkworms were either fed mulberry leaves that had been disinfected with bleach powder or untreated mulberry leaves, and their intestinal bacteria were isolated and identified by 16S rDNA sequencing. [Results] The overall amount of bacteria, and of enzyme-producing bacteria, in the midgut was generally inhibited by bleach powder, regardless of the effective chlorine concentration although there was a positive correlation between the strength of this inhibitory effect and chlorine concentration, Compared to the Control, the abundance of amylase-producing bacteria, as well as the average production of protease, were significantly lower in larvae that had been fed leaves treated with bleach powder, With the exception of the the lowest effective chlorine concentration, 0.3%, exposure to all other concentrations of bleach powder reduced the diversity of mid-gut bacteria to a single genus; Staphylococcus sp., In contrast, the control group and the 0.3% treatment group had relatively diverse enzyme-producing bacteria, including Staphylococcus sp., Lelliottia sp., and Buttiauxella sp. [Conclusion] Both intestinal bacterial community diversity and bacterial digestive enzymes werre significantly inhibited by bleach powder, particularly bacterial protease production and the abundance of amylase-producing bacteria. [ABSTRACT FROM AUTHOR]