Kogej Tina, Wheeler Michael H, Lanisnik Rizner Tea, Gunde-Cimerman Nina
University of Ljubljana, Biotech. Faculty, Department of Biology, Vecna pot 111, SI-1000 Ljubljana, Slovenia.
FEMS Microbiol Lett. 2004 Mar 19;232(2):203-9. doi: 10.1016/S0378-1097(04)00073-4.
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.
子囊菌纲的黑酵母沃氏霍塔酵母、三角暗绒孢酵母和盐生三裂酵母是嗜盐真菌，栖息于太阳能盐田的高盐水中。它们的特点是生长缓慢、呈分生组织状，且细胞壁非常厚、色素沉着很深。这种深色色素一般被认为是黑色素，当它们在含盐和非含盐条件下生长时，细胞壁中始终存在。在本研究中，我们使用抑制剂三环唑来检测这些真菌是否存在1,8 - 二羟基萘（DHN）-黑色素生物合成途径，因为据报道真菌黑色素要么来源于DHN，要么通过3,4 - 二羟基苯丙氨酸、γ - 谷氨酰胺基 - 3,4 - 二羟基苯或儿茶酚来源于酪氨酸。经三环唑处理的真菌培养物呈红棕色，并且含有DHN - 黑色素途径的典型中间体，高效液相色谱分析证明了这一点。这项研究表明，这三种真菌在含盐和非含盐生长条件下均能合成DHN - 黑色素。
