Production of single cell protein from soy molasses using Candida tropicalis

An effective bioprocess to produce single cell protein (SCP) from soy molasses using Candida tropicalis CGMCC 2.587 was developed. In a triangular flask, the optimal medium was 7 g/100 mL soy molasses concentration, 0.2 g/L yeast extract and 0.03 g/L CaCl2, while the optimal environmental conditions were initial pH 5.5 and 30°C. Under these optimal conditions, maximum cell dry weight and total protein attained 10.83 and 6.11 g/L in a 10-L bioreactor. SCP contained 56.42%, and 5.28% crude protein and nucleic acid, respectively. SCP was rich in essential amino acids. Overall, 80.3, 98.2, 56.1 and 46.9% of total sugars, sucrose, raffinose and stachyose, respectively, were utilized in soy molasses. These results suggested that C. tropicalis CGMCC 2.587 might be applied effectively to produce SCP using soy molasses as a low-cost substrate.