The Potential of the Non-Lignolytic Filamentous Fungus Penicillium sp. CHY-2, Isolated from Antarctic Soil for the Biodegradation

Abstract

The present investigation examined the potential of the filamentous fungus Penicillium sp. CHY-2, which was isolated from Antarctic soil, to biodegrade eight different aliphatic and aromatic hydrocarbons, including octane, decane, dodecane, ethylbenzene, butylbenzene, naphthalene, acenaphthene, and benzo[a]pyrene. The degree of polycyclic aromatic hydrocarbon contamination of environmental matrices has increased over the last several years due to an increase in industrial activities. Interest has surrounded the occurrence and distribution of polycyclic aromatic hydrocarbons for many decades because they pose a serious threat to the health of humans and ecosystems. Among all the compounds, CHY-2 showed the highest level of degradation for decane (49.0%), followed by butylbenzene (42.0%) and dodecane (33.0%), and lower levels of degradation for naphthalene (15.0%), acenaphthene (10.0%), octane (8.0%), ethylbenzene (4.0%), and benzo[a]pyrene (2.0%) at 20 \(^{\circ}\)C. The addition of carbon sources such as glucose (5 g L^-1) and Tween-80 (5 g L^-1) enhanced decane degradation by about 1.8-fold and 1.61-fold respectively at 20 \(^{\circ}\)C. The metabolites produced during the degradation of decane were identified by gas chromatography-mass spectrometry (GC-MS). Furthermore, the enzyme manganese peroxidase (MnP) from CHY-2 was purified. MnP was found to consist of monomers with a molecular mass of 36 kDa. The purified MnP had an optimum pH of 5.0 and temperature of 30 \(^{\circ}\)C. The K_m and V max values of MnP towards Mn²⁺ were 1.31 mM and 185.19 mM min^-1 respectively. These results indicated that the strain CHY-2 could be used for the degradation of hydrocarbons and could have promising applications in the treatment of hydrocarbon contaminated sites.