Bacterial Diversity Associated with the Coccolithophorid AlgaeEmiliania huxleyiandCoccolithus pelagicusf.braarudii

Abstract

Coccolithophores are unicellular calcifying marine phytoplankton that can form large and conspicuous blooms in the oceans and make significant contributions to oceanic carbon cycling and atmospheric CO2 regulation. Despite their importance, the bacterial diversity associated with these algae has not been explored for ecological or biotechnological reasons. Bacterial membership of Emiliania huxleyi and Coccolithus pelagicus f. braarudii cultures was assessed using cultivation and cultivation-independent methods. The communities were species rich compared to other phytoplankton cultures. Community analysis identified specific taxa which cooccur in all cultures (Marinobacter and Marivita). Hydrocarbon-degrading bacteria were found in all cultures. The presence of Acidobacteria, Acidimicrobidae, Schlegelella, and Thermomonas was unprecedented but were potentially explained by calcification associated with coccolith production. One strain of Acidobacteria was cultivated and is closely related to a marine Acidobacteria isolated from a sponge. From this assessment of the bacterial diversity of coccolithophores, a number of biotechnological opportunities are evident, from bioprospecting for novel taxa such as Acidobacteria to helping understand the relationship between obligate hydrocarbonoclastic bacteria occurrence with phytoplankton and to revealing bacterial taxa that have a specific association with algae and may be suitable candidates as a means to improve the efficiency of mass algal cultivation.

Bacterial influence on alkenones in live microalgae

“…), and P. inhibens was previously found in the bacterial assemblage associated with E. huxleyi (Green et al. ).…”

Coccolithoviruses: A Review of Cross-Kingdom Genomic Thievery and Metabolic Thuggery

“…In their study, bacteria belonging to the Roseobacter genus and SAR86 and SAR11 clades account, together, for >50% of the bacterial rDNA in surface waters, whereas a cyanobacterium and members of the Alphaprotobacteria are associated with chlorophyll a-rich waters in the euphotic zone (0–50 m in depth), the typical niche at which coccolithophores are found [76]. A link between coccolithophores and bacteria is also found in cultures of E. huxleyi and Coccolithus pelagicus , which are enriched in hydrocarbon-degrading bacteria belonging to Marinobacter and Marivita [77]. These bacteria can colonize exopolymeric substances exuded by microalgae, but the ecological role of this phenomenon is unknown [78].…”

“…These hits were against members of the genus Clostridium , Sphingobacterium and Niveispirillum respectively (Table 6, and Tables S8–S10). Bacteria from these genera are consistently found in all coccolithophore cultures studied by Green et al [77]. The hits against the Sphingobacteriales are particularly intriguing as members of this order are characterized by the presence of cellular lipid components that are comprised of high concentrations of sphingophospholipids [79].…”

Microbial dynamics during harmful dinoflagellate Ostreopsis cf. ovata growth: Bacterial succession and viral abundance pattern

“…ovata exponential growth phase. Roseovarius ‐affiliated phylotypes have been recovered from different cultured marine algal species (Biebl et al., ; Onda et al., ), also concurrently with Oceanicaulis (Abby et al., ; Kuo & Lin, ) and Fabibacter relatives (Green, Echavarri‐Bravo, Brennan, & Hart, ), and in association with toxic dinoflagellate blooms (Vanucci, Guidi, et al., ; Yang et al., ). Metagenomic and biochemical analyses highlighted the large metabolic portfolio of Roseovarius (Bruns et al., ; Riedel et al., ), including synthesis of dual nature compounds (i.e., algal growth promoting and algicidal ones; Ziesche et al., ).…”