Obtaining filamentous fungi and lipases from sewage treatment plant residue for fat degradation in anaerobic reactors

PeerJ

Melissa L.E. Gutarra¹  Anna Cristina P. Lima²  Magali C. Cammarota² 

[1] Campus Xerem, Federal University of Rio de Janeiro, Duque de Caxias, Rio de Janeiro, Brasil;School of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brasil;

关键词: Sewage treatment;    Residues;    Solid-state fermentation;    Filamentous fungi;    Anaerobic reactor;    Lipase;   

DOI  :  10.7717/peerj.5368

来源: DOAJ

【 摘 要 】

A residue from the primary treatment of a Wastewater Treatment Plant (WWTP) was used to isolate filamentous fungi with lipase production potential. Two of the 27 isolated fungi presented high hydrolysis index and were selected for lipase production by solid-state fermentation (SSF). The fermentations were conducted at 30 °C for 48 h, with moist air circulation, using 20% (w/w) of the residue mixture with a basal medium (agroindustrial residue—babassu cake), obtaining a solid enzymatic preparation (SEP) with lipase activity of 19 U/g with the fungus identified as Aspergillus terreus. Scum, collected in an anaerobic reactor operating in a WWTP, was hydrolyzed with SEP and subjected to anaerobic biodegradability tests at 30 °C. Different dilutions of crude (Control) or hydrolyzed scum in raw sewage were evaluated. The dilution of 5% (v/v) of hydrolyzed scum in raw sewage proved the most adequate, as it resulted in higher methane yield compared to the raw sewage (196 and 133 mL CH4/g CODadded, respectively), without increasing the chemical oxygen demand (COD) of the treated sewage (138 and 134 mg/L). The enzymatic hydrolysis of the scum, followed by dilution in the influent sewage, is technically feasible and increases methane production in anaerobic reactors.

【 授权许可】

Unknown