Evidence for 1,8-dihydroxynaphthalene melanin in three halophilic black yeasts grown under saline and non-saline conditions.
The ascomycetous black yeasts Hortaea werneckii, Phaeotheca triangularis, and Trimmatostroma salinum are halophilic fungi that inhabit hypersaline water of solar salterns. They are characterized by slow, meristematic growth and very thick, darkly pigmented cell walls. The dark pigment, generally thought to be melanin, is consistently present in their cell walls when they grow under saline and non-saline conditions. We used the inhibitor tricyclazole to test the fungi in this study for the presence of 1,8-dihydroxynaphthalene (DHN)-melanin biosynthesis, since fungal melanins reportedly are derived either from DHN, tyrosine via 3,4-dihydroxyphenylalanine, gamma-glutaminyl-3,4-dihydroxybenzene, or catechol. Tricyclazole-treated cultures of the fungi were reddish-brown in color and contained typical intermediates of the DHN-melanin pathway, as demonstrated by high-performance liquid chromatography. This investigation showed that the three fungi synthesized DHN-melanin under saline and non-saline growth conditions.
Kogej
Tina
T
University of Ljubljana, Biotech. Faculty, Department of Biology, Vecna pot 111, SI-1000 Ljubljana, Slovenia. tina.kogej@uni-lj.si
Wheeler
Michael H
MH
Lanisnik Rizner
Tea
T
Gunde-Cimerman
Nina
N
D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003470:Culture Media / Q000494:pharmacology; D008543:Melanins / Q000378:metabolism*; D009284:Naphthols / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology*; D013844:Thiazoles / Q000494:pharmacology; D015003:Yeasts / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*
C423455:1,8-dihydroxynaphthalene melanin; D003470:Culture Media; D008543:Melanins; D009284:Naphthols; D013844:Thiazoles; D012965:Sodium Chloride; C041191:tricyclazole