Rapeseed and sunflower meal: a review on biotechnology status and challenges.

Rapeseed and sunflower are two of the world's major oilseeds. Rapeseed and sunflower meal (RSM and SFM), the by-products of oil extraction, are produced in large quantities. They are mainly composed of proteins, lignocellulosic fibres and minerals. They were initially used as a protein complement in animal feed rations and sometimes as fertilizer or as combustible source. More recently, new alternatives to these traditional uses have been developed that draw on the structure and physicochemical properties of RSM and SFM, which are plentiful sources of nitrogen and carbon nutrients. This feature, together with their cheapness and ready availability, supports the cultivation of various microorganisms in both submerged cultures and solid-state fermentation. Recent studies have thus emphasized the potential utilisation of RSM and SFM in fermentative processes, including saccharification and production of enzymes, antibiotics, antioxidants and other bio-products, opening new challenging perspectives in white biotechnology applications.

Peculiarities of Pycnoporus species for applications in biotechnology.

The genus Pycnoporus forms a cosmopolitan group of four species belonging to the polyporoid white-rot fungi, the most representative group of homobasidiomycetes causing wood decay. Pycnoporus fungi are listed as food- and cosmetic-grade microorganisms and emerged in the early 1990s as a genus whose biochemistry, biodegradation and biotechnological properties have since been progressively detailed. First highlighted for their original metabolic pathways involved in the functionalization of plant cell wall aromatic compounds to yield high-value molecules, e.g. aromas and antioxidants, the Pycnoporus species were later explored for their potential to produce various enzymes of industrial interest, such as hydrolases and oxidases. However, the most noteworthy feature of the genus Pycnoporus is its ability to overproduce high redox potential laccase-a multi-copper extracellular phenoloxidase-as the predominant ligninolytic enzyme. A major potential use of the Pycnoporus fungi is thus to harness their laccases for various applications such as the bioconversion of agricultural by-products and raw plant materials into valuable products, the biopulping and biobleaching of paper pulp and the biodegradation of organopollutants, xenobiotics and industrial contaminants. All the studies performed in the last decade show the genus Pycnoporus to be a strong contender for white biotechnology. In this review, we describe the properties of Pycnoporus fungi in relation to their biotechnological applications and potential.