Various bioactive polyketides have been found in Aloe barbadensis. However, the polyketide synthases (PKSs), which participate in biosynthesis of polyketides in A. barbadensis remain unknown. In this study, two type III PKSs (AbPKS1 and AbPKS2) were identified from A. barbadensis. AbPKS1 and AbPKS2 were able to utilize malonyl-CoA to yield heptaketides (TW93a and aloesone) and octaketides (SEK4 and SEK4b), respectively. AbPKS1 also exhibited catalytic promiscuity in recognizing CoA thioesters of aromatics to produce unusual polyketides. What Is more, a whole cell biocatalysis system with the capability of producing 26.4 mg/L of SEK4/SEK4b and 2.1 mg/L of aloesone was successfully established.

中文翻译：

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两种来自芦荟的III型聚酮化合物合酶生物合成聚酮化合物。

在巴巴芦荟中发现了各种生物活性聚酮化合物。但是，参与巴巴德氏菌中聚酮化合物生物合成的聚酮化合物合酶（PKSs）仍然未知。在这项研究中，从巴巴德氏菌中鉴定出两种III型PKS（AbPKS1和AbPKS2）。AbPKS1和AbPKS2能够利用丙二酰辅酶A分别产生七肽（TW93a和芦荟酮）和八肽（SEK4和SEK4b）。AbPKS1在识别芳族化合物的CoA硫酯以产生不寻常的聚酮化合物方面也表现出催化混杂性。此外，成功建立了能够产生26.4 mg / L SEK4 / SEK4b和2.1 mg / L芦荟酮的全细胞生物催化系统。