Abstract
Group-wise diversity of sediment methylotrophs of Chilika lake (Lat. 19°28′–19°54′N; Long. 85°06′–85°35′E) Odisha, India at various identified sites was studied. Both the culturable and unculturable (metagenome) methylotrophs were investigated in the lake sediments employing both
mxaF
and 16S rRNA genes as markers. ARDRA profiling, 16S rRNA gene sequencing, PAGE profiling of
Hae
III,
Eco
RI restricted
mxaF
gene and the
mxaF
gene sequences using culture-dependent approach revealed the relatedness of α-proteobacteria and
Methylobacterium
,
Hyphomicrobium
and
Ancyclobacter
sp. The total viable counts of the culturable aerobic methylotrophs were relatively higher in sediments near the sea mouth (S3; Panaspada), also demonstrated relatively high salinity (0.1 M NaCl) tolerance. Metagenomic DNA from the sediments, amplified using GC clamp
mxaF
primers and resolved through DGGE, revealed the diversity within the unculturable methylotrophic bacterium
Methylobacterium organophilum
,
Ancyclobacter aquaticus
,
Burkholderiales
and
Hyphomicrobium
sp. Culture-independent analyses revealed that up to 90 % of the methylotrophs were unculturable. The study enhances the general understandings of the metagenomic methylotrophs from such a special ecological niche.