Vampirovibrio chlorellavorus is recognized as a pathogen of commercially‐relevant Chlorella species. Algal infection and total loss of productivity (biomass) often occurs when susceptible algal hosts are cultivated in outdoor open pond systems. The pathogenic life cycle of this bacterium has been inferred from laboratory and field observations, and corroborated in part by the genomic analyses for two Arizona isolates recovered from an open algal reactor. V. chlorellavorus predation has been reported to occur in geographically‐ and environmentally‐diverse conditions. Genomic analyses of these and additional field isolates is expected to reveal new information about the extent of ecological diversity and genes involved in host‐pathogen interactions. The draft genome sequences for two isolates of the predatory V. chlorellavorus (Cyanobacteria; Ca. Melainabacteria) from an outdoor cultivation system located in the Arizona Sonoran Desert were assembled and annotated. The genomes were sequenced and analyzed to identify genes (proteins) with predicted involvement in predation, infection, and cell death of Chlorella host species prioritized for biofuel production at sites identified as highly suitable for algal production in the southwestern USA. Genomic analyses identified several predicted genes encoding secreted proteins that are potentially involved in pathogenicity, and at least three apparently complete sets of virulence (Vir) genes, characteristic of the VirB‐VirD type system encoding the canonical VirB1‐11 and VirD4 proteins, respectively. Additional protein functions were predicted suggesting their involvement in quorum sensing and motility. The genomes of two previously uncharacterized V. chlorellavorus isolates reveal nucleotide and protein level divergence between each other, and a previously sequenced V. chlorellavorus genome. This new knowledge will enhance the fundamental understanding of trans‐kingdom interactions between a unique cosmopolitan cyanobacterial pathogen and its green microalgal host, of broad interest as a source of harvestable biomass for biofuels or bioproducts.

中文翻译：

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Vampirovibrio chlorellavorus 基因组序列草图、注释和致病性决定因素的初步表征

Vampirovibrio chlorellavorus 被认为是商业相关小球藻物种的病原体。在室外开放池塘系统中培养易感藻类宿主时，经常会发生藻类感染和生产力（生物量）的完全丧失。这种细菌的致病生命周期是从实验室和现场观察中推断出来的，并且部分通过对从开放藻类反应器中回收的两个亚利桑那分离株的基因组分析得到证实。据报道，小球藻捕食发生在地理和环境多样化的条件下。对这些和其他野外分离物的基因组分析有望揭示有关生态多样性程度和宿主 - 病原体相互作用中涉及的基因的新信息。两个掠食性绿藻（蓝藻；Ca. Melainabacteria) 来自位于亚利桑那州索诺兰沙漠的室外栽培系统，并进行了组装和注释。对基因组进行测序和分析，以确定在美国西南部被确定为非常适合藻类生产的地点优先用于生物燃料生产的小球藻宿主物种的捕食、感染和细胞死亡中预测参与的基因（蛋白质）。基因组分析确定了几种预测基因，这些基因编码可能与致病性有关的分泌蛋白，以及至少三组明显完整的毒力 (Vir) 基因，它们分别是编码经典 VirB1-11 和 VirD4 蛋白的 VirB-VirD 类型系统的特征。预测了额外的蛋白质功能，表明它们参与群体感应和运动。两个先前未表征的小球藻菌株的基因组揭示了彼此之间的核苷酸和蛋白质水平差异，以及先前测序的小球藻基因组。这一新知识将增强对独特的世界性蓝藻病原体与其绿色微藻宿主之间跨界相互作用的基本理解，作为生物燃料或生物产品的可收获生物质来源具有广泛的兴趣。