Screening of potential lignin-degrading fungi from the tropical forest for lignocellulose biotreatment

Abstract

Lignocellulose can be converted into many products replacing products produced from fossil, such as bioenergy, biochemicals and biomaterial products through several treatment. In the bioethanol production, the lignin content in lignocellulose causes the conversion of cellulose to ethanol is less optimal. This research aimed to screen a number of fungal isolated from tropical forests to obtain the lignin-degrading fungi which are potentially used in lignocellulose biotreatment. Screening was conducted by growing fungal isolates on a minimal salt media containing black liquor as a carbon source. Fungal growth ability was observed based on growth index and lignin degradation by fungal isolates was determined by measuring the absorption spectra of the degradation medium at wavelengths of 280 nm and compared to uninoculated control media. The screening results showed that all of 10 isolates had the different ability to grow on minimal media containing black liquor. One fungal isolates identified as Daldania eschscholtzii SA2 146 showed the highest lignin degradation ability that can degrade lignin up to 15% of the total lignin in the media. The lignin degradation by five fungal isolates was range between 5% - 15%. This study proved that the obtained fungal isolates can degrade lignin and potentially be used in lignocellulose biotreatment. Further investigation will be conducted to evaluate the selectivity of potential fungi to degrade lignin.