Enhancement of validamycin A production by addition of ethanol in fermentation of Streptomyces hygroscopicus 5008

► Validamycin A productivity reached 18 g/L and increased by 60% with ethanol addition. ► An effective and valuable strategy for antibiotics fermentation was reported. ► Effect mechanism based on signal, gene transcription and enzyme activity was explored. ► A signal transduction cascade from ethanol to validamycin A production was proposed.