Involvement of glucose catabolism in avermectin production by Streptomyces avermitilis

The addition of glucose in the early stage of fermentation suppressed not only avermectin production but also the activity of 6-phosphogluconate dehydrogenase in the pentose phosphate pathway. On the other hand, when glucose was added at the late stage of fermentation, suppression of avermectin formation and 6-phosphogluconate dehydrogenase activity was not observed but avermectin formation was increased and about a twofold-higher content of avermectins than that of the control fermentation was accumulated.