A multi-omics approach to lignocellulolytic enzyme discovery reveals a new ligninase activity from Parascedosporium putredinis NO1.

Lignocellulose, the structural component of plant cells, is a major agricultural byproduct and the most abundant terrestrial source of biopolymers on Earth. The complex and insoluble nature of lignocellulose limits its conversion into value-added commodities, and currently, efficient transformation requires expensive pretreatments and high loadings of enzymes. Here, we report on a fungus from the Parascedosporium genus, isolated from a wheat-straw composting community, that secretes a large and diverse array of carbohydrate-active enzymes (CAZymes) when grown on lignocellulosic substrates. We describe an oxidase activity that cleaves the major ß-ether units in lignin, thereby releasing the flavonoid tricin from monocot lignin and enhancing the digestion of lignocellulose by polysaccharidase mixtures. We show that the enzyme, which holds potential for the biorefining industry, is widely distributed among lignocellulose-degrading fungi from the Sordariomycetes phylum.

Assessing the Viability of Recovery of Hydroxycinnamic Acids from Lignocellulosic Biorefinery Alkaline Pretreatment Waste Streams.

Invited for this month's cover is the research team from the D.O.E. Great Lake Bioenergy Research Center (GLBRC) at the University of Wisconsin-Madison. The cover image shows how a diverse team with expertise in many different fields works together in an integrated fashion to address complex problems. Only when the whole system, from field to the liquid fuels and co-products, is assessed, can we identify the key parameters needed to design an economically viable biorefinery-based economy. Cover art by Chelsea Mamott. The Full Paper itself is available at 10.1002/cssc.201903345.

Assessing the Viability of Recovery of Hydroxycinnamic Acids from Lignocellulosic Biorefinery Alkaline Pretreatment Waste Streams.

The hydroxycinnamic acids p-coumaric acid (pCA) and ferulic acid (FA) add diversity to the portfolio of products produced by using grass-fed lignocellulosic biorefineries. The level of lignin-bound pCA in Zea mays was modified by the alteration of p-coumaroyl-CoA monolignol transferase expression. The biomass was processed in a lab-scale alkaline-pretreatment biorefinery process and the data were used for a baseline technoeconomic analysis to determine where to direct future research efforts to couple plant design to biomass utilization processes. It is concluded that future plant engineering efforts should focus on strategies that ramp up accumulation of one type of hydroxycinnamate (pCA or FA) predominantly and suppress that of the other. Technoeconomic analysis indicates that target extraction titers of one hydroxycinnamic acid need to be >50 g kg-1 biomass, at least five times higher than observed titers for the impure pCA/FA product mixture from wild-type maize. The technical challenge for process engineers is to develop a viable process that requires more than 80 % reduction of the isolation costs.