Metabolic interactions between microbiomes and algal hosts within the phycosphere of marine macroalgae are drawing increasing attention due to their roles in food webs,global nutrient cycles,industries,and their poten...Metabolic interactions between microbiomes and algal hosts within the phycosphere of marine macroalgae are drawing increasing attention due to their roles in food webs,global nutrient cycles,industries,and their potential as food resources.However,these relations remain poorly understood.In this study,43 marine macroalgae,including red,brown,and green algae,were collected from the coastal areas of Korea.We identified the bacterial communities within the loosely and tightly attached environments(LAEs and TAEs,respectively)of the phycosphere,along with those in the surrounding seawater,using 16S rRNA gene sequencing.β-Diversity analysis revealed significant differences between the bacterial communi-ties among the three,with minimal variation related to sampling location or algal color.Indicator value analysis identified Pseudoalteromonas(in the LAE and TAE),Psychromonas(in the LAE),Marinomonas(in the LAE),and Litorimonas(in the TAE)as the dominant taxa in the phycosphere,in contrast to seawater.Network analysis suggested positive correla-tions among taxa within the same environments and negative correlations between those in the LAE and TAE,highlighting their distinct ecological conditions.Analysis using the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States and Kyoto Encyclopedia of Genes and Genomes pathways revealed functional variations between the phycosphere-and seawater-residing microbes.The microbial taxa-function relationships were assessed through Spearman’s rank-order correlation.Additionally,bacterial species belonging to the core taxa were isolated and their genomes sequenced.Their metabolic traits were analyzed via bioinformatics,recognizing key metabolic features essential for symbiotic inter-actions with algal hosts and survival within the phycosphere.The findings of this study advance our understanding of the marine algal phycosphere microbiome by detailing the metabolic characteristics of potential keystone species.展开更多
Cultivable bacteria coexisting in the cultures of two microalgal species, Chattonella marina(Raphidophyceae)and Skeletonema costatum(diatom, Bacillariophyceae), which have been maintained in the laboratory for several...Cultivable bacteria coexisting in the cultures of two microalgal species, Chattonella marina(Raphidophyceae)and Skeletonema costatum(diatom, Bacillariophyceae), which have been maintained in the laboratory for several years, were examined in this study. Forty-eight and thirty-four cultivable bacterial strains were isolated from different growth stages of C. marina and S. costatum cultures, respectively. A total of twelve unique bacterial phylotypes were isolated. These bacterial phylotypes belonged to Alphaproteobacteria, Gammaproteobacteria,Bacteroidetes, and Actinobacteria. Alphaproteobacteria predominated in phycospheres of both microalgae, and Rhodobacteraceae was the most common family. Bacterial phylotypes were more diversified in cultures of S.costatum than in those of C. marina. Bacterial concentrations increased remarkably after the late stationary phase of C. marina, which might account for the decline in algal cells. One phylotype of S. costatum-associated bacteria had inhibitory effects on Chaetoceros curvisetus(Bacillariophyceae). However, most bacterial phylotypes from cultures of C. marina showed significant inhibition of the growth of C. curvisetus. The results suggested that bacteria associated with C. marina might have some ecological roles in its competition with diatoms.展开更多
基金supported by grants from the Marine Biotics project(20210469)funded by the Ministry of Ocean and Fisheries,Republic of Korea.
文摘Metabolic interactions between microbiomes and algal hosts within the phycosphere of marine macroalgae are drawing increasing attention due to their roles in food webs,global nutrient cycles,industries,and their potential as food resources.However,these relations remain poorly understood.In this study,43 marine macroalgae,including red,brown,and green algae,were collected from the coastal areas of Korea.We identified the bacterial communities within the loosely and tightly attached environments(LAEs and TAEs,respectively)of the phycosphere,along with those in the surrounding seawater,using 16S rRNA gene sequencing.β-Diversity analysis revealed significant differences between the bacterial communi-ties among the three,with minimal variation related to sampling location or algal color.Indicator value analysis identified Pseudoalteromonas(in the LAE and TAE),Psychromonas(in the LAE),Marinomonas(in the LAE),and Litorimonas(in the TAE)as the dominant taxa in the phycosphere,in contrast to seawater.Network analysis suggested positive correla-tions among taxa within the same environments and negative correlations between those in the LAE and TAE,highlighting their distinct ecological conditions.Analysis using the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States and Kyoto Encyclopedia of Genes and Genomes pathways revealed functional variations between the phycosphere-and seawater-residing microbes.The microbial taxa-function relationships were assessed through Spearman’s rank-order correlation.Additionally,bacterial species belonging to the core taxa were isolated and their genomes sequenced.Their metabolic traits were analyzed via bioinformatics,recognizing key metabolic features essential for symbiotic inter-actions with algal hosts and survival within the phycosphere.The findings of this study advance our understanding of the marine algal phycosphere microbiome by detailing the metabolic characteristics of potential keystone species.
基金The National Natural Science Foundation of China under contract Nos 41476132 and 41276154
文摘Cultivable bacteria coexisting in the cultures of two microalgal species, Chattonella marina(Raphidophyceae)and Skeletonema costatum(diatom, Bacillariophyceae), which have been maintained in the laboratory for several years, were examined in this study. Forty-eight and thirty-four cultivable bacterial strains were isolated from different growth stages of C. marina and S. costatum cultures, respectively. A total of twelve unique bacterial phylotypes were isolated. These bacterial phylotypes belonged to Alphaproteobacteria, Gammaproteobacteria,Bacteroidetes, and Actinobacteria. Alphaproteobacteria predominated in phycospheres of both microalgae, and Rhodobacteraceae was the most common family. Bacterial phylotypes were more diversified in cultures of S.costatum than in those of C. marina. Bacterial concentrations increased remarkably after the late stationary phase of C. marina, which might account for the decline in algal cells. One phylotype of S. costatum-associated bacteria had inhibitory effects on Chaetoceros curvisetus(Bacillariophyceae). However, most bacterial phylotypes from cultures of C. marina showed significant inhibition of the growth of C. curvisetus. The results suggested that bacteria associated with C. marina might have some ecological roles in its competition with diatoms.
