Expression of autotrophic genes under CO2 environment and genome mining of desert bacterium Cupriavidus sp. HPC(L)

Abstract

Increasing levels of atmospheric CO2 and plastic pollution are major environmental threats that need serious attention. The invisible microbial world has the key to solve this issue by sinking CO2 to PHB, biofuels and other bio-based products. Cupriavidus is one of them, that synthesis PHB from CO2. The study demonstrate autotrophic growth of Cupriavidus sp. HPC(L), gene expression of rubisco (cbbLR), carbonic anhydrase (ca) and phosphoenolpyruvate (ppc) carboxylase and genome mining. Under autotrophic condition, there was 104 folds increase in CFU/ml after three months. The genome was sequenced to track CO2 fixation routes available through molecular and bioinformatics tools. The relative gene expression of cbbLR, ca and ppc increased by 2.5 to 3.0 fold under CO2. The bacterium uses Calvin cycle for CO2 fixation. Genome shows presence of carboxylases, polyhydroxybutyrate synthesis gene cluster and sox pathway gene, that makes it apt for sinking CO2 to PHB for sustainable environment.