title: Accumulation of cellobiose lipids under nitrogen-limiting conditions by two ustilaginomycetous yeasts, Pseudozyma aphidis and Pseudozyma hubeiensis.
abstract: Some basidiomycetous yeast strains extracellularly produce cellobiose lipids (CLs), glycolipid biosurfactants which have strong fungicidal activity. The representative CL producer Ustilago maydis produces CLs together with the other glycolipids, mannosylerythritol lipids (MELs); the preference of the two glycolipids is affected considerably by the nitrogen source. To develop new CL producers, 12 MEL producers were cultured under the nitrogen-limited conditions. Pseudozyma aphidis and Pseudozyma. hubeiensis were characterized as new CL producers. CL production was induced on three strains, P. aphidis, Pseudozyma graminicola, and P. hubeiensis under these conditions. The putative homologous genes of U. maydis cyp1, which encodes a P450 monooxygenase, essential for CL biosynthesis, were partially amplified from their genomic DNA. The nucleotide sequences of the gene fragments from P. hubeiensis and P. aphidis shared identities with U. maydis cyp1 of 99% and 78%, respectively. Furthermore, all of the deduced translation products are tightly clustered in the phylogenic tree of the monooxygenase. These results suggest that the genes involved with CL biosynthesis must be widely distributed in the basidiomycetous fungi as well as the MEL biosynthesis genes, and thus, the genus Pseudozyma has great potential as a biosurfactant producer.
authors.affiliation: Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan.
authors.forename: Tomotake
authors.initials: T
authors.lastname: Morita
authors.forename: Tokuma
authors.initials: T
authors.lastname: Fukuoka
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Imura
authors.forename: Dai
authors.initials: D
authors.lastname: Kitamoto
mesh_terms: D001483:Base Sequence; D002475:Cellobiose / Q000737:chemistry / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D006017:Glycolipids / Q000737:chemistry / Q000378:metabolism*; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D006899:Mixed Function Oxygenases / Q000235:genetics; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000172:deficiency* / Q000378:metabolism; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D014587:Ustilaginales / Q000235:genetics / Q000378:metabolism*
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D005656:Fungal Proteins; D006017:Glycolipids; D008055:Lipids; C439671:mannosylerythritol lipid; D002475:Cellobiose; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D009584:Nitrogen