Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, MD 21202, USA.
Mar Drugs. 2024 Jul 27;22(8):342. doi: 10.3390/md22080342.
Dinoflagellates are one of the largest groups of marine microalgae and exhibit diverse trophic strategies. Some dinoflagellates can produce secondary metabolites that are known to be toxic, which can lead to ecologically harmful blooms. is one species of dinoflagellate that produces toxic compounds and is used as a model for dinoflagellate studies. The impact of the microbiome on growth and metabolite synthesis is not yet fully understood, nor is the impact of bacterial data on sequencing and assembly. An antibiotic cocktail was previously shown to eliminate 16S amplification from the dinoflagellate culture. Even with drastically reduced bacterial numbers during antibiotic treatment, bacterial sequences were still present. In this experiment, we used novel Nanopore long-read sequencing techniques on cultures to assemble 15 full bacterial genomes ranging from 2.9 to 6.0 Mb and found that the use of antibiotics decreased the percentage of reads mapping back to bacteria. We also identified shifts in the microbiome composition and identified a potentially deleterious bacterial species arising in the absence of the antibiotic treatment. Multiple antibiotic resistance genes were identified, as well as evidence that the bacterial population does not contribute to toxic secondary metabolite synthesis.
甲藻是海洋微藻中最大的类群之一，表现出多种营养策略。一些甲藻可以产生次生代谢物，已知这些代谢物具有毒性，可能导致生态有害的水华。 是一种产生有毒化合物的甲藻，被用作甲藻研究的模型。微生物组对 的生长和代谢物合成的影响尚未完全了解，细菌数据对测序和组装的影响也不清楚。以前的研究表明，抗生素混合物可以消除甲藻培养物中的 16S 扩增。即使在抗生素治疗期间细菌数量急剧减少，仍存在细菌序列。在本实验中，我们使用新型纳米孔长读测序技术对 进行了测序，组装了 15 个完整的细菌基因组，大小从 2.9 到 6.0 Mb，发现抗生素的使用降低了回指细菌的reads 的百分比。我们还观察到微生物组组成的变化，并确定了在没有抗生素处理的情况下出现的一种潜在有害细菌物种。鉴定出了多种抗生素耐药基因，并证明细菌种群不会促进有毒次生代谢物的合成。
