3.5 | Intestinal microbiota depletion promotes the
potential key players in the regenerating intestine ofApostichopus japonicus
At 97% sequence identity, the CV samples contained 1,877 OTUs, the
samples from the XGF group contained 1,620 OTUs, and the GF samples
contained 1,228 OTUs (Table S2). We analyzed both genus and species
numbers in the samples from the 3 groups to further identify the
differences in the bacterial communities of A. japonicusintestines during regeneration stages. The CV, XGF and GF groups
contained 597, 578 and 446 genera, respectively. The number of OTUs and
bacterial species from GF samples were significantly lower than those
from CV samples. No developmental defects or regrowth rate
differentiation were observed in the XGF samples compared to those in
the CV samples; therefore, we compared and analyzed the CV and GF groups
in this study.
Analysis of bacterial communities revealed distinct taxonomic
compositions between the CV and GF samples at the order and genus
levels. In CV samples, the Oceanospirillales order prevailed (average of
41.51% of all the reads) and was represented mostly by the
Halomonadaceae (41.04%) family, mainly related to Halomonas(41.03%) genus. Alteromonadales (14.87%) was the next most abundant
order, represented mainly by the Pseudoalteromonadaceae (7.74%) and
Colwelliaceae (5.24%) families and the Pseudoalteromonas(7.11%) and Colwellia (5.15%) genera. The next most abundant
order was Burkholderiales (8.08%), which was represented mainly by the
Burkholderiaceae (7.41%) family and the Ralstonia (7.29%) genus
(Table
1, Table S3-4).
In GF samples, the most abundant order was Flavobacteriales (52.68%),
which was represented mostly by the Flavobacteriaceae (50.15%) family,
with Flavobacterium , Polaribacter ,Flavobacteriaceae_uncultured and Crocinitomix comprising
41.78%, 2.85%, 1.5% and 1.08% of the total, respectively.
Burkholderiales (average 9.25%) was the next most abundant order,
represented mainly by the Burkholderiaceae (8.18%) family, mainly
related to the Ralstonia (7.92%) genus. Rhodobacterales was also
present (6.59%), mainly related to the Rhodobacteraceae (6.59%) family
(Table 1, Table S3-4).
The average abundances of Flavobacteriaceae (4.42%) and Rhodobacterales
(3.91%) (the potential key players) in CV samples were significantly
lower than those in GF samples.