Abstract:

In order to select the ideal carrier for Bacillus megaterium, grass charcoal, cow manure, sheep manure, chicken manure and enoki mushroom residue were used as carriers for B. megaterium to determine their effects on the adsorption capacity, effective viable bacteria number, exopolysaccharides (EPS) content and germination index of the bacterial solution. Charcoal had the highest bacterial liquid adsorption capacity which was 1.64 mL/g, but with the extension of storage time, the effective viable bacterial number and EPS content in the charcoal inoculum decreased sharply, and the germination index was less than 80% within 38 days, indicating the plant toxicity. Although the bacterial absorption capacity of chicken manure and enoki mushroom residue was smaller than that of grass charcoal, the effective viable bacterial number and EPS content in the chicken manure inoculum showed a trend of increasing. For the enoki mushroom residue inoculum, the EPS content increased gradually, and the effective viable bacteria number decreased slowly. The germination index of the two carrier inoculants was greater than 80% after 7 days of storage, indicating no plant toxicity. On the 38^th day, the effective viable bacteria number of the chicken manure and enoki mushroom residue inoculants were 1.29×10⁹ CFU/g and 6.20×10⁸ CFU/g, respectively, the EPS content was 535.29 mg/kg and 559.34 mg/kg, respectively, which were significantly higher than other carrier inoculants. Chicken manure and enoki mushroom residue were the ideal carriers for B. megaterium.

Key words: carrier, adsorption capacity, organic waste, Bacillus megaterium, effective viable bacteria number, germinating index, exopolysaccharides