Inhibitory mechanism of different treated manure biogas slurry on some fungi

In order to understand the inhibitory mechanism of manure biogas slurry (MBS) on some microorganism, five kinds of fungi were tested on PDA medium containing MBS in this experiment. They were Rhizoctonia solani(RS), Fusarium solani (FS), Fusarium nivale (FN), Fusarium oxysporum (FO) and Sclerotinia sclerotiorum (SS). MBS was diluted with distilled water to different concentrations for 2 groups. One group was sterilized for 20min under 121°C, while the other group was not sterilized. Centrifugal supernatant (CS) was trained as the same as the MBS. Diameters of colony were measured, and inhibitory rate was calculated. The results showed that inhibitory effect of non-sterilized MBS or CS on the fungi was stronger. Inhibitory effects on Rhizoctonia solani, Fusarium solani and Fusarium oxysporum was the strongest, but inhibitory effect on Sclerotinia sclerotiorum was the weakest. Inhibition effect of sterilized MBS and CS on fungi was not significant. Therefore, the microbial community of MBS played an important role in the inhibiting process. Main inhibition factor in MBS may be the metabolites of microbes in the fermentation process or other active substances.