Microalgae as a biofuel source are of great interest. Bacterial phycosphere inhabitants of algal cultures are hypothesized to contribute to productivity. In this study, the bacterial composition of the Chlorella sorokiniana phycosphere was determined over several production cycles in different growing seasons by 16S rRNA gene sequencing and identification. The diversity of the phycosphere increased with time during each individual reactor run, based on Faith’s phylogenetic diversity metric versus days post‐inoculation (R = 0.66, P < 0.001). During summer months, Vampirovibrio chlorellavorus, an obligate predatory bacterium, was prevalent. Bacterial sequences assigned to the Rhizobiales, Betaproteobacteriales and Chitinophagales were positively associated with algal biomass productivity. Applications of the general biocide, benzalkonium chloride, to a subset of experiments intended to abate V. chlorellavorus appeared to temporarily suppress phycosphere bacterial growth, however, there was no relationship between those bacterial taxa suppressed by benzalkonium chloride and their association with algal productivity, based on multinomial model correlations. Algal health was approximated using a model‐based metric, or the ‘Health Index’ that indicated a robust, positive relationship between C. sorokiniana fitness and presence of members belonging to the Burholderiaceae and Allorhizobium–Neorhizobium–Pararhizobium–Rhizobium clade. Bacterial community composition was linked to the efficiency of microalgal biomass production and algal health.

中文翻译：

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基于多个纵向分析，室外小球藻小球藻反应器中藻类生产力与藻圈组成之间的关联。

微藻作为生物燃料来源备受关注。藻类培养的细菌藻圈居民被认为有助于生产力。在这项研究中，通过16S rRNA基因测序和鉴定，在不同生长季节的几个生产周期中确定了Sorokiniana藻小球藻的细菌组成。根据Faith的系统发生多样性指标，接种后的几天，每个反应堆运行期间，藻圈的多样性随时间增加（R  = 0.66，P  <0.001）。在夏季的几个月，绿藻Vampirovibrio，专性掠食性细菌，是普遍的。分配给根瘤菌，β-变形细菌和几丁质的细菌序列与藻类生物量生产力呈正相关。普通杀生物剂苯扎氯铵在旨在减轻小球藻的实验中的应用似乎暂时抑制了藻圈细菌的生长，但是，苯扎氯铵所抑制的细菌类群与藻类生产力的关系并不存在。关于多项式模型的相关性。使用基于模型的指标或“健康指数”来估算藻类的健康状况，该指标表明梭菌之间存在牢固的正相关关系。隶属于Burholderiaceae和Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium进化枝的成员的健康状况和存在。细菌群落组成与微藻生物质生产效率和藻类健康有关。