High Throughput Screening Technologies in Biomass Characterization

Abstract

Biomass analysis is a slow and tedious process and not solely due to the long generation time for most plant species. Screening large numbers of plant variants for various geno-, pheno-, and chemo-types, whether naturally occurring or engineered in the lab, has multiple challenges. Plant cell walls are complex, heterogeneous networks that are difficult to deconstruct and analyze. Macroheterogeneity from tissue types, age, and environmental factors makes representative sampling a challenge and natural variability generates a significant range in data. Using high throughput (HTP) methodologies allows for large sample sets and replicates to be examined, narrowing in on more precise data for various analyses. This review provides a comprehensive survey of high throughput screening as applied to biomass characterization, from compositional analysis of cell walls by NIR, NMR, mass spectrometry, and wet chemistry to functional screening of changes in recalcitrance via HTP thermochemical pretreatment coupled to enzyme hydrolysis and microscale fermentation. The advancements and development of most high-throughput methods have been achieved through utilization of state-of-the art equipment and robotics, rapid detection methods, as well as reduction in sample size and preparation procedures. The computational analysis of the large amount of data generated using high throughput analytical techniques has recently become more sophisticated, faster and economically viable, enabling a more comprehensive understanding of biomass genomics, structure, composition, and properties. Therefore, methodology for analyzing large datasets generated by the various analytical techniques is also covered.

Lignocellulosic Biomass: Understanding Recalcitrance and Predicting Hydrolysis

“…Several studies have developed high throughput methodologies to characterize the composition and the structure of large sets of LB samples using wet chemistry and spectroscopy (Studer et al, 2010;Krasznai et al, 2018). These methods have the advantages of being fast and automatic with a very low sample mass and minimal sample preparation (Decker et al, 2018). For instance, Selig et al developed a high throughput method to determine glucan and xylan content in poplar, pine, wheat stover and pine using a glucose oxidase and a xylose dehydrogenase-based assays instead of HPLC analysis which reduced remarkably the duration of the analysis from 48 to 5-6 h (Selig et al, 2011).…”

Accurate Determination of Genotypic Variance of Cell Wall Characteristics of a Populus trichocarpa Pedigree Using High-Throughput Pyrolysis-Molecular Beam Mass Spectrometry

“…Py-MBMS was performed according to previously described methods (9,18,23,60). Briefly, 4 mg of debarked, dried and ground material (1 mm mesh) was pyrolyzed in a Frontier PY2020 at 500°C for 30 seconds.…”

“…Accurate and affordable measurement of a trait is crucial for breeding in general and for heritability estimation in particular. Although precise methods to estimate lignin content and composition using wet chemistry are available, they are time-consuming and not practical for large sample sets (18).…”

Comparison of Methodologies Used to Determine Monolignol Ratios in Lignocellulosic Biomass

“…produced spectra consisting of ions derived from S, G, H, and other lignin monomers bound by various types of linkages. Lignin contents were determined based on methods described previously [35,37,38] in order to estimate Klason lignin content (wt %) using mean-normalized spectra to remove mass-dependent variation; S/G ratios were determined using unique (minimal-overlapping) ions of known origin that produced S/G ratios consistent with other methods in the literature [37,67]. Therefore, traditional S/G ratios as determined by py-MBMS are covered in the context of being exible where other ions may be considered as being derived from S, G, and H monomers based on the results from NMR and thioacidolysis.…”

“…Methods that measure the S/G ratio by analyzing pyrolysis products give highly reproducible results; however, the measured S/G ratios do not always compare well with other degradative techniques [29][30][31][32][33][34]. Pyrolysis or thermal degradative methods coupled with chromatographic and/or mass spectrometry techniques can be performed on whole or minimally processed biomass and can be used in high-throughput platforms to analyze lignin content and composition in biomass [3,[35][36][37][38][39]. However, thermal degradation may overestimate the S content as products generated from labile ether linkages are detected whereas condensed linkages (either inherent or produced) may not be incorporated in the analyses, not unlike chemical degradation methods [40,41].…”