Production of single-cell protein from apple pomace by high-density solid-state fermentation

The crude protein content was significantly increased by mutagenic strains-Aspergillus niger ZM-8,Saccharomyces cerevisiae,Candida tropicalis and Geotrichum candidum using apple pomace as raw material.The optimal formulation of complex microbial community was obtained by orthogonal experiments as follows:S.cerevisiae 0.5g,Candida tropicalis 1.0g,Geotrichum candidum 1.5g and A.niger ZM-8 1.5g.The optimal medium was as follows:sugar 4g,ammonium sulfate 7g,urea 2g and salt 2g.Under these conditions,the crude protein content of the product was 28.8%,which was increased by 335%compared to that before optimization.