Schizonellin A and B, new glycolipids from Schizonella melanogramma

Deml, G.; Anke, Timm; Oberwinkler, Franz; Giannetti, B. M.; Steglich, Wölfgang

doi:10.1016/0031-9422(80)85018-7

Cited by 40 publications

(22 citation statements)

References 15 publications

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“…Depending on the number of acetyl groups, mannosylerythritol lipids can be differentiated into MEL A (fully acetylated), MEL B and MEL C (monoacetylated at R-6 and R-4, respectively), and the fully deacetylated MEL D (18). Mannosylerythritol-containing lipids have been identified in a variety of fungal species, e.g., Schizonella melanogramma, Candida antarctica, Kurtzmanomyces sp., and Pseudozyma aphidis (5,15,18,27). Besides their high surface activity, mannosylerythritol lipids display interesting biological activities.…”

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confidence: 99%

Identification of a Gene Cluster for Biosynthesis of Mannosylerythritol Lipids in the Basidiomycetous Fungus Ustilago maydis

Hewald

Linne

Scherer

et al. 2006

Appl Environ Microbiol

147

135

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Many microorganisms produce surface-active substances that enhance the availability of water-insoluble substrates. Although many of these biosurfactants have interesting potential applications, very little is known about their biosynthesis. The basidiomycetous fungus Ustilago maydis secretes large amounts of mannosylerythritol lipids (MELs) under conditions of nitrogen starvation. We recently described a putative glycosyltransferase, Emt1, which is essential for MEL biosynthesis and whose expression is strongly induced by nitrogen limitation. We used DNA microarray analysis to identify additional genes involved in MEL biosynthesis. Here we show that emt1 is part of a gene cluster which comprises five open reading frames. Three of the newly identified proteins, Mac1, Mac2, and Mat1, contain short sequence motifs characteristic for acyl-and acetyltransferases. Mutational analysis revealed that Mac1 and Mac2 are essential for MEL production, which suggests that they are involved in the acylation of mannosylerythritol. Deletion of mat1 resulted in the secretion of completely deacetylated MELs, as determined by mass spectrometry. We overexpressed Mat1 in Escherichia coli and demonstrated that this enzyme acts as an acetyl coenzyme A-dependent acetyltransferase. Remarkably, Mat1 displays relaxed regioselectivity and is able to acetylate mannosylerythritol at both the C-4 and C-6 hydroxyl groups. Based on these results, we propose a biosynthesis pathway for the generation of mannosylerythritol lipids in U. maydis.

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confidence: 99%

Identification of a Gene Cluster for Biosynthesis of Mannosylerythritol Lipids in the Basidiomycetous Fungus Ustilago maydis

Hewald

Linne

Scherer

et al. 2006

Appl Environ Microbiol

147

135

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“…Sophorose lipids are secreted by Candida bombicola (21), mannosylerythritol lipids (MEL) were first isolated in the dimorphic fungus Ustilago maydis as extracellular oil with a higher density than water (19) and were later detected also in Candida antarctica, Schizonella melanogramma, and Geotrichum candidum (11,24,27). The primary structure of these glycolipids has been determined (6,13,16,27).…”

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confidence: 99%

Genetic Analysis of Biosurfactant Production inUstilago maydis

Hewald

Josephs

Bölker

2005

Appl Environ Microbiol

140

124

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The dimorphic basidiomycete Ustilago maydis produces large amounts of surface-active compounds under conditions of nitrogen starvation. These biosurfactants consist of derivatives of two classes of amphipathic glycolipids. Ustilagic acids are cellobiose lipids in which the disaccharide is O-glycosidically linked to 15,16-dihydroxyhexadecanoic acid. Ustilipids are mannosylerythritol lipids derived from acylated ␤-D-mannopyranosyl-D-erythritol. Whereas the chemical structure of these biosurfactants has been determined, the genetic basis for their biosynthesis and regulation is largely unknown. Here we report the first identification of two genes, emt1 and cyp1, that are essential for the production of fungal extracellular glycolipids. emt1 is required for mannosylerythritol lipid production and codes for a protein with similarity to prokaryotic glycosyltransferases involved in the biosynthesis of macrolide antibiotics. We suggest that Emt1 catalyzes the synthesis of mannosyl-D-erythritol by transfer of GDP-mannose. Deletion of the gene cyp1 resulted in complete loss of ustilagic acid production. Cyp1 encodes a cytochrome P450 monooxygenase which is highly related to a family of plant fatty acid hydroxylases. Therefore we assume that Cyp1 is directly involved in the biosynthesis of the unusual 15,16-dihydroxyhexadecanoic acid. We could show that mannosylerythritol lipid production is responsible for hemolytic activity on blood agar, whereas ustilagic acid secretion is required for long-range pheromone recognition. The mutants described here allow for the first time a genetic analysis of glycolipid production in fungi.

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“…14) Fluharty and O'Brien 15 ) reported that the same strain contained tetraalkanoyl-ME as an intracellular lipid. Deml et al 16 ) reported that Shizonella melanogramma, a parasite on Carex species, produced intracellular antibiotics against Gram-positive bacteria, and that the antibiotics were monoacetyl-monoalkanoyl-ME and diacetyl-monoalkanoyl-ME. We reported that Candida sp.…”

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confidence: 99%