Fig. 2

Phylogenetic tree of bacteria cultured from the three marine sediment samples and correlation analysis of cultured bacteria and total communities during enrichment culturing. The phylogenetic tree was constructed from almost full-length 16S rRNA gene sequences (amplified using 27F/1492R). Red tree branches indicate that the species was isolated after enrichment culture, while black tree branches indicate that the species was isolated by directly culture on MA (enrichment culture of 0 days). Novel candidate species (red circle, 16S rRNA gene similarity< 98%), genera (blue circle, similarity< 95%), families (green circle, similarity< 90%), and orders (black circle, similarity< 86%) are indicated by colored dots on the branch. Major phylum names are indicated and marked in different colors. An orange background for species indicates the phylum Bacteroidetes, a yellow background indicates the phylum Proteobacteria, a green background indicates the phylum Actinobacteria, and a blue background indicates the phylum Firmicutes. The bar chart indicates that the mean reads number of 282 cultured species during different periods of enrichment (blue bar indicates 0 days of enrichment, green bar indicates 5 days after enrichment, yellow bar indicates 12 days after enrichment, orange bar indicates 21 days after enrichment, and red bar indicates 30 days after enrichment). The heatmap indicates the mean read abundance of 282 cultured species during different periods of enrichment (color ranging from gray to black represents a read number from 0 to 166 in rarefied sequences). Black star indicates the isolated species were enriched (enrichment ratio > 1) after enrichment culture. In addition, detailed information of each species is shown in Additional file 3: Tables S3, Additional file 4: Table S4, and Additional file 5: Table S5.