Combined fungal and bacterial pretreatment of wheat and pearl millet straw for biogas production – A study from batch to continuous stirred tank reactors. (February 2021) - Yadav, Monika
Graphical abstract: Highlights: Fungal pretreatment of wheat and pearl millet straw with C. globosporum fungus. Addition of chitinolytic bacterium to improve biogas yield from pretreated straw. Highest biogas (610 mL g −1 VS) for combined pretreated wheat straw in batch reactors. 16% higher biogas yield for pretreated straw with fungus and bacterium in CSTRs. Abstract: In present study, chitinolytic bacteria were employed to bioaugment the biogas production from fungal pretreated agricultural residues. The fungal pretreatment of wheat and pearl millet straw was done by Chaetomium globosporum . Pretreated straw were digested anaerobically at batch scale with and without the presence of chitinolytic bacteria. Contrary to untreated samples, the addition of chitionolytic bacteria with pretreated wheat and pearl millet straw provided 41 and 57% higher biogas yield. The study was further upscaled to continuous stirred tank reactors. At continuous scale too, wheat straw pretreated with Chaetomium globosporum combined with chitinolytic bacteria resulted in 16% higher biogas yield in contrast to untreated straw. Higher abundance of methanogens was detected in reactors running with pretreated wheat straw during microbial community analysis. The identified bacteria belonged mostly to Firmicutes, Bacteroidetes, Proteobacteria phyla.