Green alga cultivation with nanofibers as physical adsorbents of carbon dioxide: Evaluation of gas biofixation and macromolecule production

The objective of this study was to evaluate the biofixation and production of biocompounds by Chlorella fusca LEB 111 cultivated with different concentrations of carbon dioxide (CO2) adsorbent nanofibers in their free form or retained. Cultures were grown in 15% (vv(-1)) CO2 with 0.1, 0.3 and 0.5 g L-1 nanofibers developed with 10% (w v(-1)) polyacrylonitrile (PAN)/dimethylformamide (DMF), with or without nanoparticles; retained or not. The addition of 0.1 g L-1 nanofibers with nanoparticles in their free form to the cultures promoted the accumulation of approximately 3 times more carbon in the medium (46.6 mg L-1), a 45% higher biofixation rate (89.2 mg L-1 d(-1))and increased carbohydrate production by approximately 2.3% (w w(-1)) of that observed in cultures grown without nanofibers. Therefore, nanofibers showed promising potential as physical adsorbents of CO2 in the cultivation to increase gas fixation and promote the synthesis of macromolecules.