Saccharification Performances of Miscanthus at the Pilot and Miniaturized Assay Scales: Genotype and Year Variabilities According to the Biomass Composition

Abstract

HIGHLIGHTS Biomass production and cell wall composition are differentially impacted by harvesting year and genotypes, influencing then cellulose conversion in miniaturized assay.Using a high-throughput miniaturized and semi-automated method for performing the pretreatment and saccharification steps at laboratory scale allows for the assessment of these factors on the biomass potential for producing bioethanol before moving to the industrial scale.The large genetic diversity of the perennial grass miscanthus makes it suitable for producing cellulosic ethanol in biorefineries. The saccharification potential and year variability of five genotypes belonging to Miscanthus × giganteus and Miscanthus sinensis were explored using a miniaturized and semi-automated method, allowing the application of a hot water treatment followed by an enzymatic hydrolysis. The studied genotypes highlighted distinct cellulose conversion yields due to their distinct cell wall compositions. An inter-year comparison revealed significant variations in the biomass productivity and cell wall compositions. Compared to the recalcitrant genotypes, more digestible genotypes contained higher amounts of hemicellulosic carbohydrates and lower amounts of cellulose and lignin. In contrast to hemicellulosic carbohydrates, the relationships analysis between the biomass traits and cellulose conversion clearly showed the same negative effect of cellulose and lignin on cellulose digestion. The miniaturized and semi-automated method we developed was usable at the laboratory scale and was reliable for mimicking the saccharification at the pilot scale using a steam explosion pretreatment and enzymatic hydrolysis. Therefore, this miniaturized method will allow the reliable screening of many genotypes for saccharification potential. These findings provide valuable information and tools for breeders to create genotypes combining high yield, suitable biomass composition, and high saccharification yields.

Miscanthus Sinensis is as Efficient as Miscanthus × Giganteus for Nitrogen Recycling in spite of Smaller Nitrogen Fluxes

“…Msin could potentially be cultivated on marginal lands with higher yields and under more stressful conditions than M×g [20]. Msin genotypes also present contrasted biomass compositions which can be better adapted to different end-uses [10,[24][25].…”

A Comparative Study of Maize and Miscanthus Regarding Cell-Wall Composition and Stem Anatomy for Conversion into Bioethanol and Polymer Composites

“…Méchin et al [28] reported that the stem digestibility of maize was negatively correlated with their Klason lignin content while the presence of ferulate was shown to impede the degradation of plant tissue [29]. In miscanthus, Belmokhtar et al [14] found that the more digestible genotypes contained higher amounts of hemicellulosic carbohydrates and lower amounts of cellulose and lignin. Van der Weijde et al [30] reported that the most important traits that contributed favorably to the saccharification efficiency of miscanthus were a high content of ferulic acid, a high ratio of p-coumaric acid to lignin and a low lignin content.…”

“…In contrast to composites, the role of CW composition and structure in saccharification efficiency is well documented for maize stover [2,12]. In miscanthus, genotype saccharification performances have been analyzed regarding the composition [13,14] and the fine structure of its CW polymers [5,15]. Saccharification efficiency is negatively correlated with lignin while the structural features of arabinoxylan and xyloglucan are found to contribute positively to hydrolysis [15].…”

Variability of stem solidness among miscanthus genotypes and its role on mechanical properties of polypropylene composites

“…The LANO laboratory (Saint‐Lô, France) carried out the biochemical analyses to determine cellulose, hemicellulosic carbohydrates, and lignin contents, according to a protocol adapted from that of Van Soest and Wine (1967). More details are given by Belmokhtar et al (2017). Spectra were obtained while scanning the miscanthus samples with an Antaris II NIRS analyser (ThermoScientific) providing spectra from 4000 to 10,000 cm −1 with 1557 points (4 cm −1 spacing).…”

“…These different components of the miscanthus biomass constitute an abundant source of carbon, which leads miscanthus to be currently cultivated mainly for the production of bioenergy in Europe. Combustion was initially identified as an important potential use for miscanthus (Lewandowski et al, 1995) while the production of ethanol (Belmokthar et al, 2017; van der Weijde et al, 2013) and anaerobic digestion were identified as interesting options later on (Kiesel et al, 2017; Thomas et al, 2019). Composites reinforced with miscanthus stems are being increasingly studied due to attractive mechanical properties associated with their light‐weight compared to glass fibers (Girones et al 2016).…”