Photo-driven heterogeneous microbial consortium reducing CO2 to hydrocarbons fuel

Carbon dioxide as feedstock for hydrocarbon synthesis attracts numerous efforts via the biological or chemical approaches. With the purpose of constructing a robust and highly-efficient platform for CO 2 bioconversion to fuel, we investigated a photo-driven bioprocess of directing CO 2 reduction to C 1 –C 6 alkanes/alkenes discovered from the enriched microbial consortia. GC-MS analysis revealed that the maximum yield of total gaseous hydrocarbons was 169.66 μM with the average CO 2 reduction rate of 100.87 μM/day decreasing from 11573.39 μM to 5905.73 μM during 50 days culturing. The pathway of CO 2 bioconversion was proposed according to the 16S rRNA and metagenomic sequencing that rTCA and Wood-Ljungdahl were mainly contributed to CO 2 fixation, and nitrogenase was responsible for the hydrocarbon syntheses. Following these results, a versatile consortium-based platform was developed via the neural network method with the selected Pseudomonas sp., Serratia sp., Candidatus sp., Clostridium sp., Enterococcus sp., Salmonella sp., Rhodospirillum sp., Thalassospira sp., Thioclava sp., Stenotrophomonas sp. and Desulfovibrio sp., which showed the improved CO 2 reduction rate of 107.54 μM/day and the higher selectivity of C 1 –C 4 alkanes than the original consortia. This study demonstrated that this artificially constructed consortium could be a promising platform for converting CO 2 to the diverse gaseous alkanes and alkenes . • Photo-driven and direct CO 2 reduction to hydrocarbons by marine microorganism. • Short chain alkanes (C 1 –C 6 ) and alkenes (C 2 –C 3 ) were biosynthesized. • CO 2 reduction rate was 100.87 uM/day. • CBB cycle, reductive TCA cycle and Wood-Ljungdahl pathway were responsible for carbon fixation. • Nitrogenase played important roles on hydrocarbon synthesis.