3.3 Difference in Bacterial community composition
The analysis of co-occurring bacterial communities revealed the presence
of 36 phyla, 88 orders, 242 classes, 413 families, 858 genera, and 1,422
species across all samples. As shown in Figure 5-a the top 10 bacterial
phyla in terms of relative abundance were Proteobacteria, Bacteroidetes,
Verrucomicrobia, Firmicutes, Actinobacteria, Campylobacterota,
Dadabacteria, Vibrio vermicularis, Bdellovibrionota, and
Desulfobacterota. The remaining 16 bacterial phyla were classified under
the “other” category.
After the first MHWs, the composition of co-occurring bacterial
communities was similar between the CA and HA groups. After the 5-day
recovery, the relative abundance of Ascomycetes and Micrococcus warty
decreased significantly, while the Mycobacterium anisopliae increased
significantly in the HB group. After the second MHWs, the relative
abundance of Ascomycetes and Warty Microbacteria phylum showed a
significant decrease, while the Anabaena phylum exhibited a significant
increase in the HC group.
At the same time, we analyzed the distribution of symbiotic microbial
communities at the genus level, which is depicted in Figure 5-b. The top
15 bacterial genera in terms of relative abundance were u.
Flavobacteriaceae, Marivita , u. Legionellaceae, Ruegeria ,Achromobacter , Methylotenera , Limnobacter ,Mycoplasma , Halomonas , Donghicola ,Rubritalea , u. Helicobacteraceae, u. Bacteria, Coxiella ,
and u. Rhizobiaceae.
Considering the relative abundance of coral symbiotic bacteria, after
the first MHWs, the HA group exhibited an increase of u. Legionellaceae,Ruegeria , and Achromobacter , while a decrease of u.
Flavobacteriaceae, Marivita , Methylotenera ,Limnobacter , Donghicola , and Coxiella . Following
the 5-day recovery, the HB group showed an increase in the relative
abundance of u. Flavobacteriaceae, u. Legionellaceae, andAchromobacter , along with a decrease of Marivita ,Ruegeria , Methylotenera , and Rubritalea . After the
second MHWs, the HC group displayed an increase in the relative
abundance of u. Flavobacteriaceae, u. Legionellaceae ,Achromobacter , and Halomonas , while Marivita ,Ruegeria , Methylotenera , and Rubritalea showed
decreased. Finally, after the secondary 5-day recovery, the HD group
exhibited an increase in the relative abundance of Rubritalea ,
whereas the relative abundance of u. Flavobacteriaceae, Marivita ,
and Ruegeria .
Fig. 5. Coral symbiotic bacterial community structure, a:
histogram of community analysis at the phylum level, b: histogram of
community analysis at the genus level. Unclassified species are
indicated by u. (unclassified) plus the family name.