Fungi-based treatment of real brewery waste streams and its effects on water quality

Nutrient-rich liquid waste streams generated during the beer brewing were treated by submerged fungal growth. Among five filamentous fungal strains tested, Pleurotus ostreatus and Trichoderma harzianum were selected for treatment of run-off from spent grain and hot trub, respectively. In both waste streams, nitrogen was well removed by fungal treatment, with a maximum reduction of 91.5 ± 0.5% of total nitrogen in run-off from spent grain treated with P. ostreatus and 77.0 ± 3.1% in hot trub treated with T. harzianum . Removal of phosphorus was considerably lower, with maximum removal of total phosphorus of 30.8 ± 11.1% for the P. ostreatus treatment and 16.6 ± 7.8% for the T. harzianum treatment. Considering the high concentration of phosphorus in the waste sources (320–600 mg L −1 ), additional techniques for its removal are needed. In the P. ostreatus treatment, a total amount of 13.2 ± 2.2 g L −1 dwt of biomass with a protein concentration of 11.6 ± 2.1% was produced.