Abstract:

tDistillers grains can be used as the feed for animals because of the rich nutrients. However, the lignin in distillers grains inhibits their utilization by animals. In this study, the conditions for lignin degradation by Ganoderma sp. X1 under solid-state fermentation were optimized, including moisture, temperature and inoculation volume of strain. The results of orthogonal experiments showed that the optimum conditions for Ganoderma sp. X1 to degrade lignin were 75% moisture content, 10% inoculation volume, and at 28 ℃. After incubating for 15 days, the degradation rate of lignin in distillers′ grains was up to 47.10%, and the crude protein increased from 11.41% to 17.30%. The effect of wheat bran on lignin degradation of distillers grains by Ganoderma sp. X1 was further studied using the single factor strategy. After fermentation for 10 days, the lignin degradation rate reached 46.36% and the crude protein increased to 24.80% when the proportion of distillers grains: wheat bran was 5∶ 5. These results showed that addition of wheat bran could shorten the fermentation time and improve the quality of distillers grains as the feed for animals.

Key words: Ganoderma sp. X1, distillers grains, lignin