Abstract:
We had the beneficial bacteria for wastewater treatment, the next step
was heterotrophic nitrogen removal in Pangasius fish’ (TRA) ponds in the
Mekong Delta. A total of 2318 heterotrophic nitrogen removal (HNR)
bacteria isolated from piggery wastes (after biogas container) were
classified in four kinds of heterotrophic ammonia-oxidizing bacteria
(569 isolates), nitrite-oxidizing bacteria (580 isolates),
nitrate-oxidizing bacteria (600 isolates) and heterotrophic nitrifying
and denitrifying bacteria (569 isolates). The virtually complete 16S
rRNA gene was PCR amplified and sequenced. The sequences from the
selected HNR bacteria showed high degrees of similarity to those of the
GenBank references strains (between 97% and 99.8%). Phylogenetic trees
based on the 16S rDNA sequences displayed high consistency, with nodes
supported by high bootstrap (500) values. These presumptive HNR isolates
were divided four groups that included members of genera
<em>Arthrobacter, Corynebacterium,
Rhodococcus</em> (high G+C content gram-positive
bacteria), <em>Staphylococcus, Bacillus</em>
(low G+C content gram-positive bacteria) and
<em>Klebsiella</em&