Enabling community-based metrology for wood-degrading fungi

Rolando Perez,Nathaniel Gaut,Drew Endy,Katarzyna P Adamala,Samuel Clamons,Finn Stirling,Rohinton Kamakaka,Marina Luccioni,Pamela A Silver

doi:10.1186/s40694-020-00092-2

Abstract

BackgroundLignocellulosic biomass could support a greatly-expanded bioeconomy. Current strategies for using biomass typically rely on single-cell organisms and extensive ancillary equipment to produce precursors for downstream manufacturing processes. Alternative forms of bioproduction based on solid-state fermentation and wood-degrading fungi could enable more direct means of manufacture. However, basic methods for cultivating wood-degrading fungi are often ad hoc and not readily reproducible. Here, we developed standard reference strains, substrates, measurements, and methods sufficient to begin to enable reliable reuse of mycological materials and products in simple laboratory settings.ResultsWe show that a widely-available and globally-regularized consumer product (Pringles™) can support the growth of wood-degrading fungi, and that growth on Pringles™-broth can be correlated with growth on media made from a fully-traceable and compositionally characterized substrate (National Institute of Standards and Technology Reference Material 8492 Eastern Cottonwood Whole Biomass Feedstock). We also establish a Relative Extension Unit (REU) framework that is designed to reduce variation in quantification of radial growth measurements. So enabled, we demonstrate that five laboratories were able to compare measurements of wood-fungus performance via a simple radial extension growth rate assay, and that our REU-based approach reduced variation in reported measurements by up to ~ 75%.ConclusionsReliable reuse of materials, measures, and methods is necessary to enable distributed bioproduction processes that can be adopted at all scales, from local to industrial. Our community-based measurement methods incentivize practitioners to coordinate the reuse of standard materials, methods, strains, and to share information supporting work with wood-degrading fungi.

Highlights

Lignocellulosic biomass could support a greatly-expanded bioeconomy
Current biomanufacturing processes typically focus on microbial conversion of lignocellulosic biomass feedstocks to sugars by way of enzymatic hydrolysis followed by fermentation into higher-value products [7]
In getting started, we worked to source five sequenced strains of industrially-relevant wooddegrading fungi: Pleurotus ostreatus, an important gourmet mushroom that is used in mycelium-materials; S. commune, a widely-recognized model organism for mushroom morphogenesis; T. versicolor, a medicinal mushroom used for remediation and mycelium materials; G. lucidum, a medicinal mushroom and favorite of the nascent mycelium materials industry, and P. chrysosporium, a recognized model organism for processing lignocellulosic biomass

Summary

Introduction

Lignocellulosic biomass could support a greatly-expanded bioeconomy. Current strategies for using biomass typically rely on single-cell organisms and extensive ancillary equipment to produce precursors for downstream manufacturing processes. Alternative forms of bioproduction based on solid-state fermentation and wood-degrading fungi could enable more direct means of manufacture. Current biomanufacturing processes typically focus on microbial conversion of lignocellulosic biomass feedstocks to sugars by way of enzymatic hydrolysis followed by fermentation into higher-value products [7]. Such approaches require resource-intensive biomass preprocessing, liquid bioreactors, and ancillary equipment [2]. The direct use of wood-degrading filamentous fungi could facilitate a more ‘circular’ economy supporting sustainable food production, manufacturing, and energy generation [12]. Direct use of wood-degrading fungi could even enable new opportunities for innovation in the global economy, especially in developing countries [12,13,14]

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Results

Discussion

Conclusion