Solaiman Daniel K Y, Catara Vittoria, Greco Sebastiana
Agricultural Research Service, US Department of Agriculture, Eastern Regional Research Center, 600 E Mermaid Lane, Wyndmoor, PA 19038, USA.
J Ind Microbiol Biotechnol. 2005 Feb;32(2):75-82. doi: 10.1007/s10295-005-0205-6. Epub 2005 Feb 22.
A collection of Pseudomonas corrugata and P. mediterranea strains, two closely related species, was evaluated for the presence and variability of pha loci. Using PCR methods that specifically amplify segments of medium-chain-length poly(hydroxyalkanoate) (mcl-PHA) synthase genes, we demonstrated the presence of phaC1 and phaC2 in all P. mediterranea strains tested and in six out of 56 strains of P. corrugata screened. The remaining 50 strains of P. corrugata yielded only the phaC2 subgene fragment on detection by a combined PCR-restriction endonuclease analysis method or a semi-nested PCR-amplification approach. A Southern hybridization study on a representative strain from this group, however, indicated the presence of the phaC1 gene. Nucleic acid sequences of the subgene phaC fragments of the representative strains from the three groups showed an overall similarity ranging from 95% to 100%. The major repeat-unit monomers of the mcl-PHAs isolated from these selected strains are beta-hydroxyoctanoate (33-47 mol%) and beta-hydroxydecanoate (26-36 mol%). These results differentiate for the first time the strains of P. corrugata into two pha-distinguishable groups. This study also documents for the first time the production of mcl-PHA in P. mediterranea.
对皱波假单胞菌和地中海假单胞菌这两个密切相关的物种的菌株集合进行了聚羟基脂肪酸酯（pha）基因座的存在和变异性评估。使用特异性扩增中链长度聚羟基脂肪酸酯（mcl-PHA）合酶基因片段的PCR方法，我们证明了在所有测试的地中海假单胞菌菌株以及56株皱波假单胞菌中的6株中存在phaC1和phaC2。通过联合PCR-限制性内切酶分析方法或半巢式PCR扩增方法检测，其余50株皱波假单胞菌仅产生phaC2亚基因片段。然而，对该组中一个代表性菌株的Southern杂交研究表明存在phaC1基因。这三组代表性菌株的phaC亚基因片段的核酸序列总体相似性在95%至100%之间。从这些选定菌株中分离出的mcl-PHAs的主要重复单元单体是β-羟基辛酸（33-47摩尔%）和β-羟基癸酸（26-36摩尔%）。这些结果首次将皱波假单胞菌菌株分为两个pha可区分的组。本研究还首次记录了地中海假单胞菌中mcl-PHA的产生。
