不同防污性能的纳米涂层对海水生物膜中真核菌群的影响

Effects of nano-filled coatings with different antifouling properties on eukaryotic flora in marine biofilm

碳纳米管(Carbon nanotubes,CNTs)和聚二甲基硅氧烷(Polydimethylsiloxane,PDMS)制备的复合防污涂层具有不同的防污性能,但其表面污损早期生物膜中真核群落结构组成与防污性能之间的关系研究还非常少.分别制备防污性能不同的CNTs-PDMS合涂层,通过海洋挂板采集污损早期生物膜样本,提取生物膜宏基因组,通过18S rRNA V4区高通量测序分析,研究其中真核生物群落的组成、群落多样性、多样本间的差异以及与环境因子之间的关联.结果显示,在所观察的24 d时间窗口内,两类涂层表面真核菌群的结构组成随时间发生很大的类似的变化;但是两类涂层的多样性参数本身差异并不很大,只是防污性能较好的涂层真核生物群落的多样性参数和丰富度参数变化趋势均是先增大后减小再增大;而防污性能较差的涂层真核生物群落多样性参数和丰富度参数变化趋势均是先增加后减小.两类涂层还有一个明显的差别是,软水母目Leptothecata在防污打分较高的涂层中含量很低,甚至检测不到,但是在对照及防污打分较低的涂层中其含量要高几倍到几十倍.可见,所有CNTs-PDMS涂层在观察时间段内表面真核群落结构发生很大改变;具备不同防污打分的CNTs-PDMS涂层表面真核菌群结构比较相似,但是它们的菌群结构动态过程具有明显的趋势差异.(图7表4参26)

Low surface energy composite antifouling coatings prepared from carbon nanotubes(CNTs)and polydimethylsiloxane(PDMS)have differential antifouling properties;however,few studies have been undertaken on the structure and function of the eukaryotic flora on the coating surfaces that have different antifouling capacities.Nano-filled coatings were prepared using both CNTs and PDMS.Early biofilm samples were collected from marine hanging plates that had good and poor antifouling scores.Biofilm metagenome DNA was extracted and analyzed by high-throughput sequencing of the 18S rRNA V4 region to study the composition of the eukaryotic community,especially the alpha and beta diversity indexes,richness indexes,abundance of operational taxonomic units,and correlation between flora composition and CNTs parameters/environmental factors.During this 24-day study,the structural composition of the eukaryotic flora on the coating surfaces changed greatly;however,the diversity and richness index values of the two types of coatings were similar.The changing trend of the diversity and richness indexes was increase-decrease-increase again for coatings with high antifouling scores,and increase-decrease for coatings with low antifouling scores.The content of Leptothecata was several-fold to 10-fold lower in the coatings with better antifouling performance than in those with poor antifouling performance.The compositional structure of eukaryotic flora on the surface of all CNTs-PDMS coatings changed significantly during the field test period.The two types of antifouling coatings with differential antifouling performance had similar eukaryotic flora structures but the changing trends of the flora were different.These preliminary observations should be investigated further in future studies.