Effect of submerged culture conditions on exopolysaccharides production by Armillaria luteo-virens Sacc QH and kinetic modeling

Abstract

This work aimed to develop the submerged cultivation conditions for improved exopolysaccharides (EPS) production by Armillaria luteo-virens Sacc. The effects of culture temperature, aeration rate, inoculum level, initial pH, and additives on EPS formation and mycelial growth are investigated. The aeration rate, initial pH, and inoculum level significantly affected EPS production under the submerged cultivation. The developed conditions were as follows: cultivation temperature 23 °C, initial pH 5.0, aeration rate 0.5 vvm, 0.5% Tween 80, inoculum level 5% (v/v), and shaking speed 120 r/min. Under the developed conditions, the highest EPS production was 13.01 g/L at 5 days culture time. EPS production was examined in a 5 L bioreactor, and an unstructured kinetic model for EPS formation was well developed. The verified investigations in the large-scale cultivation system showed that the developed models are able to predict the submerged cultivation process of EPS formation. Current results revealed that the submerged cultivation conditions can be utilized to control EPS production, and the unstructured models developed are suitable for explaining EPS production by A. luteo-virens Sacc QH in a large-scale cultivation bioreactor.