title: Effects of zinc, iron, cobalt, and manganese on Fusarium moniliforme NRRL 13616 growth and fusarin C biosynthesis in submerged cultures.
abstract: The influence of zinc, iron, cobalt, and manganese on submerged cultures of Fusarium moniliforme NRRL 13616 was assessed by measuring dry weight accumulation, fusarin C biosynthesis, and ammonia assimilation. Shake flask cultures were grown in a nitrogen-limited defined medium supplemented with various combinations of metal ions according to partial-factorial experimental designs. Zinc (26 to 3,200 ppb [26 to 3,200 ng/ml]) inhibited fusarin C biosynthesis, increased dry weight accumulation, and increased ammonia assimilation. Carbohydrate was found to be the principal component of the increased dry weight in zinc-supplemented cultures. Zinc-deficient cultures synthesized more lipid and lipidlike compounds, such as fusarin C, than did zinc-supplemented cultures. Microscopic examination showed that zinc-deficient hyphae contained numerous lipid globules which were not present in zinc-supplemented cultures. Addition of zinc (3,200 ppb) to 2- and 4-day-old cultures inhibited further fusarin C biosynthesis but did not stimulate additional dry weight accumulation. Iron (10.0 ppm) and cobalt (9.0 ppm) did not affect fusarin C biosynthesis or dry weight accumulation. Manganese (5.1 ppm) did not affect dry weight accumulation but did increase fusarin C biosynthesis in the absence of zinc. Maximum fusarin C levels, 32.3 micrograms/mg (dry weight), were produced when cultures were supplied manganese, whereas minimum fusarin C levels, 0.07 micrograms/mg (dry weight), were produced when zinc, iron, cobalt, and manganese were supplied. These results suggest a multifunctional role for zinc in affecting F. moniliforme metabolism.
authors.affiliation: Northern Regional Research Center, U.S. Department of Agriculture, Peoria, Illinois 61604.
authors.forename: M A
authors.initials: MA
authors.lastname: Jackson
authors.forename: P J
authors.initials: PJ
authors.lastname: Slininger
authors.forename: R J
authors.initials: RJ
authors.lastname: Bothast
mesh_terms: D000641:Ammonia / Q000378:metabolism; D003035:Cobalt / Q000494:pharmacology*; D003470:Culture Media; D005670:Fusarium / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D007501:Iron / Q000494:pharmacology*; D008345:Manganese / Q000494:pharmacology*; D009153:Mutagens / Q000378:metabolism; D011090:Polyenes / Q000378:metabolism; D015032:Zinc / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D009153:Mutagens; D011090:Polyenes; D003035:Cobalt; D008345:Manganese; D000641:Ammonia; C041403:fusarin C; D007501:Iron; D015032:Zinc