Enhanced production of lipstatin from Streptomyces toxytricini by optimizing fermentation conditions and medium

Abstract

This paper is concerned with optimization of fermentation conditions for lipstatin production with Streptomyces toxytricini zjut011 by the single factor and orthogonal tests. Five single factors of important effects on lipstatin production were explored. _L-Leucine was identified to be the most suitable precursor for lipstatin biosynthesis and for the first time the divalent cations Mg²⁺, Co²⁺ and Zn²⁺ were found to have significant effect on enhancing lipstatin fermentation titer. The effects of the additives on the lipstatin production were in the order of _L-leucine ＞ Mg²⁺ ＞ Co²⁺ ＞ Zn²⁺ ＞ octanoic acid. The optimized conditions for lipstatin production were determined as 45.72 mmol/L of _L-leucine (added on the 4 th day), 31.1985 mmol/L of octanoic acid (added on the 6th day), 12 mmol/L of Mg²⁺, 1 mmol/L of Co²⁺ and 0.25 mmol/L of Zn²⁺. Under these conditions, a maximum lipstatin of 4.208 g/ml was achieved in verification experiments in 500 ml shake flasks.