Enhancement of Enduracidin Accumulation from Sweet Sorghum Juice via Alleviation of Oxidative Damage in Streptomyces Fungicidicus M30

Abstract

<jats:title>Abstract</jats:title> <jats:p><jats:bold>Background: </jats:bold>Sweet sorghum juice is the preferred feedstock for enduracidin production, but the fermentation efficiency still need to be further enhanced. Oxygen-mediated microbial cell damage is an effective way to boost cell growth and metabolite accumulation in aerobic fermentation. However, this strategy on enduracidin production from sweet sorghum juice has not been reported yet. <jats:bold>Results: </jats:bold>In this study, enduracidin production titer was significantly enhanced when 90 mM Vitamin C was added at 4 d of fermentation. The enhanced T-AOC and antioxidant enzyme activities may help to further understand the mechanism of Vitamin C effect on regulation of enduracidin accumulation in <jats:italic>S. fungicidicus</jats:italic> M30. The effects of chemical preservative methyl paraben on cell growth and enduracidin production were also evaluated, and 0.04 g/L of methyl paraben had no significant inhibitory effect on cell growth and enduracidin production, indicating that the concentrated sweet sorghum juice assisted by methyl paraben for a long-term storage can be used as the substrate for enduracidin production effectively. Finally, based on the group with 0.04 g/L of methyl paraben and 90 mM Vitamin C, a final enduracidin concentration of 1.14 g/L was achieved from clarificated sweet sorghum juice by M30 strain. <jats:bold>Conclusions:</jats:bold> This work provided a promising strategy to enhance enduracidin production using sweet sorghum juice via adding the antioxidant to boost antioxidant capacity in <jats:italic>S. fungicidicus</jats:italic>.</jats:p>