RT Journal Article SR Electronic(1) A1 Okamoto, Susumu A1 Sakurada, Masaru A1 Kubo, Yasuyuki A1 Tsuji, Gento A1 Fujii, Isao A1 Ebizuka, Yutaka A1 Ono, Makoto A1 Nagasawa, Hiromichi A1 Sakuda, ShoheiYR 2001 T1 Inhibitory effect of aflastatin A on melanin biosynthesis by Colletotrichum lagenarium JF Microbiology, VO 147 IS 9 SP 2623 OP 2628 DO https://doi.org/10.1099/00221287-147-9-2623 PB Microbiology Society, SN 1465-2080, AB The effect of aflastatin A (AsA), a novel inhibitor of aflatoxin production, on melanin biosynthesis of Colletotrichum lagenarium was examined. Addition of a low concentration of AsA (0·5 μg ml−1) to the culture medium almost completely inhibited the melanin production of this organism. AsA also inhibited the production of scytalone, an early intermediate of melanin biosynthesis. Melanin production was restored by addition of exogenous scytalone in the presence of AsA, suggesting that the late steps after the synthesis of scytalone were not significantly affected by AsA. This was confirmed by the results from RT-PCR analysis of the expression of genes encoding melanin biosynthetic enzymes (SCD1, THR1) and a regulatory gene (CMR1). By contrast, expression of PKS1 was severely impaired by AsA, although catalytic activity of a polyketide synthase (PKS1) was not inhibited by AsA. These results indicate that AsA inhibits an early step in melanin production, which suppresses the expression of PKS1. , UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-147-9-2623