Study on Bacterial Protein Produced from Cassava Residue

[Objective] The aim to study the suitable strain and condition for producing the bacterial protein by solid state fermentation technique.[Method] The cassava residue was used as raw material and the single strain of mildew and microzymes and their mixed bacterium were taken as tested strains to produce bacterial protein through solid fermentation and the orthogonal test with 4 factors was conducted.[Result] The protein content obtained by mixed bacterium fermentation was higher than that by single bacteria fermentation.When the inorganic nitrogen source was added into the fermentation medium with mixed bacterium the protein content in fermentation product was significantly increased.The orthogonal test showed that the effect of each factor on producing bacterial protein in order was fermentation temperature inoculation ratio moisture content of medium fermentation time.The best combination for fermentation conditions were: fermentation temperature of 30 ℃,fermentation time of 5 days,60% moisture content of medium,the inoculation ratio of mildew and microzymes being 2∶1,under which,15.68% of protein content could be obtained,being increased noticeably compared with the raw material.[Conclusion] The cassava residue with mixed bacterium through solid state fermentation could increase the protein content significantly,so it had higher application value when it was taken as the feed.