Isolation of a highly efficient phenol-degrading fungus and the preparation of an effective microbial inoculum for activated sludge and its enhancement for hydrogen production

A phenol-degrading fungal strain Magnusiomyces capitatus QWD1 was isolated from activated sludge that was used to treat papermaking wastewater. Through parameters optimization, the optimal degradation conditions were found to encompass (NH₄)₂SO₄ as nitrogen source (14 mmol/L), inoculum concentration of 15%, pH 7 and a temperature of 35 °C. Four different materials were used as carriers for the preparation of the microbial inoculum and the effect of storage temperatures on inoculum viability was investigated. With the prepared bioaugmentation inoculum addition to activated sludge, it was found to markedly increase the original system's treatment efficiency of phenol-containing wastewater. A high-throughput sequencing-based analyze approach revealed that the phenol-degrading inoculum addition can increase the abundance and diversity of fungi in the treatment system, which supports the development of a stable microbial ecosystem. The H₂ production of photosynthetic bacteria with the bioaugmented QWD1 inoculum was 32.4% higher than the control without inoculum addition when using the phenol-containing wastewater.