Insights into the carbonic anhydrases and autotrophic carbon dioxide fixation pathways of high CO2 tolerant Rhodovulum viride JA756

Publication date: October 2018Source: Microbiological Research, Volume 215Author(s): Lakshmi Venkata Naga Satya Khandavalli, Tushar Lodha, Maaged Abdullah, Lalitha Guruprasad, Sasikala Chintalapati, Venkata Ramana ChintalapatiAbstractBiofixation of CO2 is being extensively investigated to solve the global warming problem. Purple non-sulfur bacteria are fast growers that consume CO2 and produce beneficial biomass. Better the growth at higher CO2 levels, more efficient are the strains for biofixation. Nine among fifty strains that were analyzed at elevated CO2 levels responded with better growth. Considering its enhanced growth at high CO2 and metabolic versatility, Rhodovulum viride strain JA756 was chosen to make further studies. Strain JA756 tolerates up to 50% (v/v) CO2 with its optimum between 20–40% (v/v), yielding a biomass of 3.4 g. L−1. The pattern of specific enzyme activity of carbonic anhydrase corresponded well with that of its growth. To gain insights into the genomic composition and genes related to carbonic anhydrases and CO2 fixation, draft genome sequencing of JA756 was carried out which revealed the presence of two non-homologous genes encoding for β and γ carbonic anhydrases, both of which are assumed to be implicated in maintaining intracellular inorganic carbon concentration at equilibrium. Most of the genes involved in the Calvin pathway, reductive tricarboxylic acid pathway, 3-hydroxypropionate bicycle and C4 pathways were found in the draft geno...
Source: Microbiological Research - Category: Infectious Diseases Source Type: research