Production of ferulic acid, 2,3 Butanediole and microbial plant biostimulants from lignocellulosic biomass by a two-step cascading process

The DEBUT project aims to develop a small biorefinery process, which include two main steps: biomass pre-treatment with natural deep eutectic solvents (NaDES) and feruloyl-esterase (FAE) and one pot production of a versatile chemical, 2,3 butanediol (2,3-BD), from NaDES-FAE pre-treated lignocellulose biomass, by simultaneous saccharification and fermentation (SSF), done by a plant biostimulant microbial consortia. Several NaDESs were synthesized by combinations natural compounds such as organic salts (choline chloride, betaine), alcohols (glycerol, ethylene-glycol, 2,3 butanediol, etc.), or organic acids (lactic acid, citric acid, malic acid, ascorbic acid etc), in different molar ratios. Ferulic acid and its derivatives solubility was tested into several NaDESs as a function of solvent concentration and temperature. NaDES made from choline chloride(ChCl) and urea, ethylene-glycol (EG), glycerol (Gly) and 2,3 butanediol (2,3 BD) were selected. These NaDES were tailored with water to optimize feruloyl-esterase activity, ferulic acid and lignin extraction. The pre-treatment with aqueous NaDES comprising ChCl:Gly and ChCl:2,3 BD were the most efficient on fractionation of wheat straw into three major streams: cellulose-rich pulp, lignin, and ferulic acid-rich liquor. For saccharification and fermentation of the cellulose-rich pulp a microbial consortium was selected. This consortium includes two strains of Trichoderma, T. asperellum T36b NCAIM F 001434 and T. harzianum Td50b NCAIM F001412 and a strain of Paenibacillus graminis FL400, NCAIM B 001365. The sequential process for saccharification and fermentation includes the following steps: addition to the suspension of cellulose-rich pulp material of a pelletized fungal inocula, containing the selected Trichoderma plant biostimulant consortium, and incubation for 96-120 hours under shaking at a temperature of 35°C; separation of supernatant and use of supernatant for fermentation with strains of Paenibacillus to produce (2R,3R) 2,3 butandiol; separation (2R,3R) 2,3 butandiol from the culture medium by extractive distillation with oleic acid and drying of the remaining suspension in the distillation flask, containing endo-spores forming gram positive bacteria, by spraying, at an inlet temperature of 140-150°C and at an outlet temperature of 80-85 °C. The main biochemicals resulting from biorefinery process, ferulic acid and 2,3-BD, are value added products. Ferulic acids address mainly dietary supplement and cosmetic industries. 2,3-BD is a versatile chemical, with a fast-growing market. Proposed biorefinery process produce also agricultural inputs - microbial plant biostimulants. Even though represent around 30% of the estimated income of the proposed process, plant biostimulant are necessary to enhance overall profitability and to improve eco-efficiency. The effects of microbial biostimulants (Trichoderma consortium, P.graminis) have been tested on tomato plants grown under controlled conditions. The biostimulant effect of the Trichoderma consortium was tested also on the accumulation of bioactive compounds in the Passiflora caerulea leaves. Bioproduct based P. graminis was also tested as an enhancers of beans plant nodulation by rhizobia. Selected NaDES eco-toxicity against aquatic organisms was evaluated.


Dr. Florin Oancea

National Institute for Research & Development in Chemistry and Petrochemistry - ICECHIM, Romania


Project partners:

National Institute for Research & Development in Chemistry and Petrochemistry - ICECHIM, Romania

Norgenotech AS, Norway

Norwegian Institute for Water Research, Norway