Transcriptomic analysis of Rhodococcus opacus R7 grown on polyethylene by RNA-seq. Transcriptome of Rhodococcus opacus R7 on polyethylene

Jessica Zampolli 1, Alessandro Orro 2, Andrea Manconi 2, Diletta Ami 1, Antonino Natalello 1, Patrizia Di Gennaro 1* 1 Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy 2 Institute of Biomedical Technologies, National Research Council, CNR, via Fratelli Cervi 19, 20133 Segrate, Milan, Italy Plastic waste management has become a global issue, especially for polyethylene that is the most abundant synthetic plastic worldwide, and one of the most resistant to biodegradation. Indeed, only few Rhodococcus bacteria, a suitable and prominent genus for the biodegradation of recalcitrant contaminants, have been reported for the ability to degrade diverse types of polyethylene. Here, RNA-seq approach unveiled for the first time Rhodococcus opacus R7 complex genetic system based on a network of oxidoreductases for polyethylene biodegradation in a short time. The proposed polyethylene degradative pathway includes external laccase-like multi-copper oxidase (LMCO) encoding genes activated as first step of oxidation. Following the entrance of the smaller aliphatic fragments by specific membrane transporters, an alkane monooxygenase (alkB) and a P450 hydroxylase (cyp450) oxidize short polyethylene fragments leading to the β-oxidation pathway. Diverse environmental and biotechnological applications contributing to plastic elimination can be achievable thanks to these marker sequences.