Abstract

Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by various yeasts. Mmf1, a putative transporter of MELs, is conserved in the MEL biosynthesis gene clusters of diverse MEL producers, including the genera Ustilago, Pseudozyma, Moesziomyces, and Sporisorium. To clarify the function of Mmf1, we generated the gene-deleted strain of P. tsukubaensis ΔPtMMF1 and evaluated its MEL production. Using thin-layer chromatography analyses, we detected most MELs produced by ΔPtMMF1 in the culture supernatant. The spot size of diacylated MEL-B (the only product of the parental strain) was significantly smaller for strain ΔPtMMF1 than for the parental strain, and a mono-acylated MEL-D spot was detected. In addition, an unknown glycolipid was detected in the sample extracted from strain ΔPtMMF1. Liquid chromatography–mass spectrometry and nuclear magnetic resonance analyses revealed that the unknown glycolipid was a novel MEL homologue, mono-acylated MEL-B.

Key points

• P. tsukubaensis is able to secrete MELs without PtMMF1p.

• Strain ΔPtMMF1 mainly produced mono-acylated MELs.

中文翻译：

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推定的转运蛋白基因PtMMF1缺失的菌株在筑波假单胞菌中产生单酰化的甘露糖基赤藓糖醇脂质

摘要

甘露糖基赤藓糖醇脂质（MELs）是由各种酵母产生的糖脂生物表面活性剂。Mmf1，MELS的推定转运体，在不同的MEL生产商，包括下列属的生物合成MEL基因簇是保守的黑粉菌，Pseudozyma，Moesziomyces，和玉米丝。为了澄清Mmf1的功能，我们产生的基因缺失株P. tsukubaensis Δ PtMMF1并评价其MEL生产。使用薄层色谱法分析，我们检测到的由Δ产生最MELS PtMMF1在培养上清液中。对于菌株ΔPtMMF1，二酰化MEL-B（亲本菌株的唯一产物）的斑点大小明显较小。与亲本菌株相比，检测到单酰化的MEL-D斑点。另外，在从菌株ΔPtMMF1提取的样品中检测到未知的糖脂。液相色谱-质谱和核磁共振分析表明，未知的糖脂是一种新型的MEL同源物，单酰化MEL-B。

关键点

•筑波假单胞菌能够分泌不含PtMMF1p的MEL。

•菌株ΔPtMMF1主要生产单酰化的MEL。