Potential for single cell protein production by yeast isolated from fermented foods

In this study, 36 yeast strains were isolated from fermented foods collected in different areas of Northern Vietnam. The screening process yielded 15/36 strains capable of good growth with Cell Dry Weight (CDW) ranging from 10-14 g/L, and 10/36 strains having the potential for single cell protein production with Total Protein Content (TPC) exceeding 57% (g/100 g cell dry weight) after 24 h of cultivation in YPD liquid medium. The yeast strain YPI-Y2 (with CDW reaching 14.03 g/L; TPC reaching 62.3%) was identified as closely related to the species Pichia kudriavzevii (99.77%) based on ITS rDNA sequence analysis and comparison. The nutritional and cultivation characteristics of the P. kudriavzevii YPI-Y2 strain, oriented towards cell biomass production and protein accumulation, were determined. The optimal cultivation temperature and initial medium pH condition for the growth and protein accumulation of the YPI-Y2 yeast strain were 30℃ and 6.5, respectively, while the suitable carbon source was identified as D-fructose. Simultaneously, this yeast strain maintained good growth and protein accumulation capability on inorganic nitrogen sources (except urea, with 35.62% of TPC). Under su