Using Nile Red and BODIPY 493/503 dye-staining and fluorescence microscopy, twenty cyanobacterial strains, including ten commercially available strains and ten environmental isolates from estuaries, freshwater ponds, and lagoons, were screened for the accumulation of ecologically important and potentially biotechnologically significant carbon storage granules such as polyhydroxyalkanoates (PHA). Dye-staining granules were observed in six strains. Three Synechocystis, spp. strains WHSYN, LSNM, and CGF-1, and a Phormidium-like sp. CGFILA were isolated from environmental sources and found to produce granules of polyhydroxyalkanoate (PHA) according to PHA synthase gene (phaC) PCR screening and ¹H NMR analyses. The environmental isolate, Nodularia sp. Las Olas and commercially available Phormidium cf. iriguum CCALA 759 displayed granules but screened negative for PHA according to phaC PCR and ¹H NMR analyses. Partial polyhydroxyalkanoate synthase subunit C (phaC) and 16S rRNA gene sequences obtained from the PHA-accumulating strains and analyzed alongside publicly available phaC, phaE, 16S rRNA, and 23S rRNA data help in understanding the distribution and evolutionary history of PHA biosynthesis within the phylum Cyanobacteria. The data show that the presence of phaC is highly conserved within the genus Synechocystis, and present in at least one isolate of Phormidium. Maximum likelihood analyses and cophylogenetic modeling of PHA synthase gene sequences provide evidence of a recent horizontal gene transfer event between distant genera of cyanobacteria related to Pleurocapsa sp. PCC 7327 and Phormidium-like sp. CGFILA. These findings will help guide additional screening for PHA producers, and may explain why some Phormidium species produce PHAs, while others do not.

中文翻译：

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聚羟基脂肪酸酯颗粒的筛选和表征，以及蓝藻中聚羟基脂肪酸酯合酶基因PhaC的系统发育分析

使用 Nile Red 和 BODIPY 493/503 染料染色和荧光显微镜，筛选了 20 株蓝藻菌株，包括 10 种市售菌株和 10 种来自河口、淡水池塘和泻湖的环境分离株，以发现具有生态重要性和潜在生物技术意义的碳的积累储存颗粒，例如聚羟基链烷酸酯 (PHA)。在六个菌株中观察到染料染色颗粒。三集胞藻属 菌株WHSYN、LSNM和CGF-1，以及Phormidium样 sp。CGFILA是从环境来源中分离出来的，发现根据 PHA 合酶基因产生聚羟基链烷酸酯 (PHA) 颗粒。phaC ) PCR 筛选和¹ H NMR 分析。环境隔离物，Nodularia sp。Las Olas 和市售的Phormidium cf. iriguum CCCALA 759 显示颗粒，但根据phaC PCR 和¹ H NMR 分析筛选出 PHA 阴性。从 PHA 积累菌株中获得的部分聚羟基链烷酸合酶亚基 C ( phaC)和 16S rRNA 基因序列与公开可用的phaC、phaE一起分析、16S rRNA 和 23S rRNA 数据有助于了解 PHA 生物合成在蓝藻门内的分布和进化历史。数据表明，phaC的存在在集胞藻属中是高度保守的，并且存在于至少一种Phormidium分离物中。PHA 合酶基因序列的最大似然分析和共系发育模型为最近在与Pleurocapsa sp 相关的远距离蓝细菌属之间发生的水平基因转移事件提供了证据。PCC 7327 和Phormidium样 sp。CGFILA。这些发现将有助于指导对 PHA 生产者的额外筛选，并可能解释为什么有些Phormidium物种产生 PHA，而其他物种则不会。