Inhibitory activity of home-made garbage enzyme against aquatic pathogens and isolation and identification of its fermentation strains

In order to evaluate the inhibitory activity of home-made garbage enzyme against aquatic pathogens and to isolate their fermentation strains, we determined the minimum inhibitory concentrations of the home-made garbage enzyme on the aquatic pathogenic microorganisms Vibrio candida SP-1, V. harveyi SP-1, V. rotiferianus SP-1 and Aeromonas hydrophila 245 as 11.5%, 11%, 6.2% and 11% in volume fraction by turbidimetric method. The minimum bactericidal concentrations were determined as 16%, 16%, 16% and 12% in volume fraction by flat line scribing method. The challenge test proves that the supernatant of home-made garbage enzyme decreased (90.5±6.49) % of the mortality in zebrafish induced by A. hydrophila. The sensitivity tests of pH, temperature and protease prove that the main antibacterial active substances of home-made garbage enzyme were acidic substances that were stable to heating and protease treatment. Furthermore, the primary fermentation strain was separated from the garbage enzyme and identified as Pichia kudriavzevii by ITS sequence analysis. The results provide a theoretical basis for applying home-made garbage enzyme in combating bacterial diseases in aquaculture.