Improving Fermentation of Steamed Stalk to Feed Using Candida utilis and Pachysolen tannophilus

Abstract

In order to improve the protein content of straw feed and reduce the amount of nutrients added, in this paper, the cell wall structure of corn stalk was destroyed by thermophilic digestion and the polysaccharide was degraded into monosaccharide by complex enzyme, and then transformed into bacterial protein by double strain Candida utilis 1807 and Pachysolen tannophilus 1771 fermentation. Single factor experiments and orthogonal test were made to obtain the best process for the feed of double-bacteria synchronous fermentation of stalks. The optimum amount of each nutrient and the inoculation amounts of double bacteria (accounts for the percentage of the original dry straw quality): ammonium sulfate 6.79%, urea 2.72%, yeast powder 1.63%, magnesium sulfate 0.27%, Candida utilis 54.31% and Pachysolen tannophilus 54.31%; The operational parameters of fermentation process were: fermentation temperature 29°C, rotate speed 100 r/min and fermentation time 55 hours. The yield of stalk feed and crude protein was 82.04%, 23.33%, respectively. The crude protein content of stalk feed was 28.44%, which was 4.33 times of original dry stalk. The results showed that the multi-strain distribution and degradation of protein production provide important significance for corn straw bio-utilization.

Evaluation of Crystalline Cellulose of Corn Straw through Different Pretreatments Via X-Ray Diffraction, Scanning Electron Microscopy and Infrared Spectroscopy

“…Numerous pretreatments methods of corn stalk have been reported ， but few people pay attention to the crystallinity of crystalline cellulose (Behera et al, 2014;Rastogi et al, 2017;Hassan et al,2018;Huang et al,2018;Kojima et al,2019;Ponnusamy et al,2019;Xu et al,2019) The study compared of four pretreatments methods that is oven drying, steaming, complex enzymolysis and fermentation by Candida utilis and Pachysolen tannophilus, evaluating the crystallinity of crystalline cellulose after treated with the aid of X-ray diffraction, scanning electron microscopy and infrared spectroscopy. At the same time, the corn stalks's utilization rate of reducing sugar and the output of protein feed have been increased (Chen and Zhang, 2008;Luo et al, 2009;Chen et al, 2009;Yang et al, 2015;Wu et al, 2016;Chen et al, 2018). Thus, comparing the structure of fibrous crystal and crystallinity can provide certain theory reference for improving the high utilization rate of corn stalk.…”