Journal of Agricultural Science and Food Research

Journal of Agricultural Science and Food Research
Open Access

ISSN: 2593-9173


Production of Protein Feed from Sweet Sorghum Stalk by the Two-Step Solid State Fermentation

Chen Hongzhang, Wang Yumei and Dai Shuhua

 Ensiling of agricultural straw produces feed with low protein content. To get high protein feed with high production and low cost, a two-step solid state fermentation was designed and several factors were optimized to maximize the yield. Candida tropicalis was first inoculated sweet sorghum stalk under aerobic condition for cell growth and protein content (PC) in the substrate after the first-step reached 26.3%. In the second-step, Lactobacillus rhamnosus was inoculated the sterilized substrate harvested from the first step, and cultured under anaerobic condition. After L. rhamnosus fermented at 40ºC for 80 h, the protein content in the product reached 35.7%. The pilot-plant scale fermentation was carried out according to the optimized conditions. By the two-step fermentation, 200 tons of feed was produced from two tons of dry sweet sorghum stalk and the protein content in the product was 13.77%, higher than silage in sale. The two-step process, which was easy to operate, provided high protein feed from agricultural waste in a cost effective way and the optimization of fermentation conditions in the two-step fermentation provided theoretical guideline for plant-scale production.