Identification of a strain of Auricularia and Taguchi optimization of petroleum-polluted soil mycoremediation

Abstract

Petroleum contamination has become a serious global concern due to adverse effects on terrestrial ecosystems. Bioremediation has been known as one of the most effective and economical solutions to reduce and eliminate pollutions caused by petroleum compounds. In this study, mycoremediation of contaminated soil was evaluated using a strain of Auricularia to simultaneously produce high-value biomass. Pre-culture media was prepared by growing the fungus on different lignocellulosic materials derived from agricultural wastes. Sequence analysis of the Internal Transcribed Spacer (ITS) regions confirmed that the strain belonged to Auricularia auricularia-judae with high homology. A four-factor Taguchi design was then adopted to determine the optimal points of temperature (25 and 35 °C), type of media (mixtures of rice bran, tea waste, wheat straw, corn sticks, and sawdust), inoculum size (2 and 6 g), and nitrogen source (urea, ammonium nitrate, and nitrogen-free). The findings indicated that after 45 d, the mixture of rice bran, sawdust, and tea waste with 6 g inoculum in the absence of nitrogen at 35 °C ended up in striking efficiency of 71%. To the best of our knowledge, the study is a highly efficient bioremediation of petroleum-polluted soils using an edible strain of fungus. High degradation performance of Auricularia highlights the crucial role of lignocellulosic waste materials for biodegradation process.

Keywords:

• Auricularia
• bioremediation
• lignocellulosic wastes
• petroleum-polluted soils
• Taguchi design

Disclosure statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.