Biotransformation of rice and sunflower side-streams by monosporic strains of Pleurotus sapidus in a biorefinery approach

POSTEMSKY P; BIDEGAIN, M.A.; FERNANDEZ LAHORE M.; OMARINI A

Hamburgo

Congreso; 9th International Congress on Biocatalysis (Biocat2018); 2018

Hamburg University of Technology (TUHH)

Biotransformation of rice and sunflower side-streams by monosporic strains of Pleurotus sapidus in a biorefinery approachPostemsky P. 1, Bidegain M. 1, Fernandez-Lahore M. 2, Omarini A.Introduction: Application of white-rot fungi solid-state fermentation (SSF) of lignocellulosic biomass areenzyme-related bioprocess conceived as a sustainable way to deal with huge amounts of residues(Omarini et al., 2015). Its advantages are a low environmental impact, a simple increase of scale and areasonable use of water (Postemsky et al., 2017).Objectives: This study applies an innovative source of mycelia to increase the value of rice and sunflowerdiscarded biomass. It consisted in the in vitro selection of monosporic strains (Mk) of Pleurotus sapidusable to degrade efficiently xenobiotic compounds. Afterward, selected Mks were studied for theirperformance to grow and produce laccase and peroxidase enzymes under laboratory and in pilot-scaleexperiments.Materials & methods: P. sapidus Dk3174 was used as a source of spores (Omarini et al., 2014). Isolationand selection of Mks were done by exposing spores to grow in RBBR enriched media. Qualitativeoxidoreductase assay on plates was used to reveal enzyme traits and detect the best phenolic oxidizingstrains. In vitro selection of 15 Mks growing on rice and sunflower side-streams evaluated: Myceliumgrowth traits and enzyme profile activity. Scale up the SSF compared enzyme traits in either MK6 vsDk3174 and in Pasteurization vs Sterilizationdecontamination treatments.Results: Viable Mks were obtained from fructifications of Dk 3174. Degradation of RBBR was used toidentify those Mks with greater ligninolytic potential. Further selection was done according to the in vitrogrowth and enzymatic performance in media with 39% of rice or sunflower side-streams. Pilot-scalestudies revealed that sterilized/pasteurized substrates employing the MK6 strain produced differentenzymes titers and were comparable with the Dk strain.Conclusion: Mks showed high variability of RBBR degradation, growth rate, biomass and enzymeproduction. Mk 6 was select to perform the SSF scale-up for enzyme production. Laccase was the mainresponsible for the biomass degradation. SSF with Mks provided an interesting tool to produce high-valuemetabolites (enzymes) using a low-cost raw material under the concept of Biorefinery. It should beexpected that the evolution of these technologies will collaborate in regional-based bioeconomies at thetime that prosecutes a valorization of cereal and grains side-streams