Baker Lydia J, Alegado Rosanna A, Kemp Paul F
Oceanography Department, University of Hawai'i Mānoa, Honolulu, HI, USA.
Environ Microbiol Rep. 2016 Oct;8(5):917-927. doi: 10.1111/1758-2229.12456. Epub 2016 Sep 9.
Diatoms are photosynthetic unicellular eukaryotes found ubiquitously in aquatic systems. Frequent physical associations with other microorganisms such as bacteria may influence diatom fitness. The predictability of bacterial-diatom interactions is hypothesized to depend on availability of nutrients as well as the physiological state of the host. Biotic and abiotic factors such as nutrient levels, host growth stage and host viral infection were manipulated to determine their effect on the ecological succession of bacterial communities associated with a single cell line of Chaetoceros sp. KBDT20; this was assessed using the relative abundance of bacterial phylotypes based on 16S rDNA sequences. A single bacterial family, Alteromonadaceae, dominated the attached-bacterial community (84.0%), with the most prevalent phylotypes belonging to the Alteromonas and Marinobacter genera. The taxa comprising the other 16% of the attached bacterial assemblage include Alphaproteobacteria, Betaproteobacteria, Bacilli, Deltaproteobacteria, other Gammaproteobacteria and Flavobacteria. Nutrient concentration and host growth stage had a statistically significant effect on the phylogenetic composition of the attached bacteria. It was inferred that interactions between attached bacteria, as well as the inherent stochasticity mediating contact may also contribute to diatom-bacterial associations.
硅藻是光合单细胞真核生物，广泛存在于水生系统中。它们经常与细菌等其他微生物发生物理关联，这可能会影响硅藻的适应性。据推测，细菌与硅藻相互作用的可预测性取决于营养物质的可用性以及宿主的生理状态。通过控制营养水平、宿主生长阶段和宿主病毒感染等生物和非生物因素，来确定它们对与角毛藻属单细胞系KBDT20相关的细菌群落生态演替的影响；这是基于16S rDNA序列，通过细菌系统发育型的相对丰度来评估的。一个单一的细菌科——交替单胞菌科，在附着细菌群落中占主导地位（84.0%），最普遍的系统发育型属于交替单胞菌属和海杆菌属。构成附着细菌组合中另外16%的分类群包括α-变形菌纲、β-变形菌纲、芽孢杆菌纲、δ-变形菌纲、其他γ-变形菌纲和黄杆菌纲。营养浓度和宿主生长阶段对附着细菌的系统发育组成具有统计学上的显著影响。据推断，附着细菌之间的相互作用以及介导接触的内在随机性也可能有助于硅藻与细菌的关联。
