Effects of amino acid and trace element supplementation on pneumocandin production by Glarea lozoyensis: impact on titer, analogue levels, and the identification of new analogues of pneumocandin B-0

Addition of the amino acids threonine, serine, proline, and arginine to fer mentations of the fungus Glarea lozoyensis influenced both the pneumocandin titer and the spectrum of analogues produced. Addition of threonine or ser ine altered the levels of the "serine analogues" of pneumocandins B-0 and B -5 and allowed for their isolation and identification. Proline supplementat ion resulted in a dose-dependent increase in the levels of pneumocandins Bo and E-0, whereas pneumocandins C-0 and D-0 decreased as a function of prol ine level. Moreover, proline supplementation resulted in an overall increas e in the synthesis of both trans-3- and trans-4- hydroxyproline while maint aining a low trans-4- hydroxyproline to frans-3-hydroxyproline ratio compar ed to the unsupplemented culture. Pneumocandin production and the synthesis of hydroxyprolines was also affected by addition of the proline-related am ino acid arginine but not by the addition of glutamine or ornithine, Zinc, cobalt, copper, and nickel, trace elements that are known to inhibit alpha -ketoglutarate- dependent dioxygenases, affected the pneumocandin B-0 titer and altered the levels of pneumocandins B-1, B-2, B-5, B-6, and E-0, analo gues that possess altered proline, ornithine, and tyrosine hydroxylation pa tterns.