Variation in the chemical composition of wheat straw: the role of tissue ratio and composition

Abstract

BackgroundWheat straw is an attractive substrate for second generation ethanol production because it will complement and augment wheat production rather than competing with food production. However, like other sources of lignocellulosic biomass, even from a single species, it is heterogeneous in nature due to the different tissues and cell types, and this has implications for saccharification efficiency. The aim of this study has been to use Fourier transform infrared (FTIR) spectroscopy and Partial least squares (PLS) modelling to rapidly screen wheat cultivars for the levels of component tissues, the carbohydrate composition and lignin content, and the levels of simple cross-linking phenolics such as ferulic and diferulic acids.ResultsFTIR spectroscopy and PLS modelling was used to analyze the tissue and chemical composition of wheat straw biomass. Predictive models were developed to evaluate the variability in the concentrations of the cell wall sugars, cell wall phenolics and acid-insoluble lignin. Models for the main sugars, phenolics and lignin were validated and then used to evaluate the variation in total biomass composition across 90 cultivars of wheat grown over two seasons.ConclusionsWhilst carbohydrate and lignin components varied across the varieties, this mainly reflected differences in the ratios of the component tissues rather than differences in the composition of those tissues. Further analysis indicated that on a mol% basis, relative levels of sugars within the tissues varied to only a small degree. There were no clear associations between simple phenolics and tissues. The results provide a basis for improving biomass quality for biofuels production through selection of cultivars with appropriate tissue ratios.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-014-0121-y) contains supplementary material, which is available to authorized users.

Food and bioenergy: reviewing the potential of dual‐purpose wheat crops

“…Plant height also influences digestibility through taller plants tending to have lower LP (e.g. Collins et al ., ). Jensen et al .…”

“…Plant material digestibility can be influenced by variation in the proportions of lignin, cellulose and hemicellulose composing the cell wall (Pauly & Keegstra, ). There is considerable variation in the contents of these in wheat (Collins et al ., ). For example, Wu et al .…”

“…Plant material digestibility can be influenced by variation in the proportions of lignin, cellulose and hemicellulose composing the cell wall (Pauly & Keegstra, 2008). There is considerable variation in the contents of these in wheat (Collins et al, 2014). For example, Wu et al (2014), in assessing 115 wheat ascensions, found that the plant dry matter consisted of 27.5-36.4% cellulose, 28.4-35.1% hemicellulose and 19.3-24.5% lignin.…”

Carbohydrate microarrays and their use for the identification of molecular markers for plant cell wall composition

“…Some high-throughput cell wall phenotyping approaches such as Fourier transform infra-red screening (16,17), OLIgo Mass Profiling (18), and carbohydrate microarray-based "CoMPP" profiling (19,20) are now available, but have yet to be deployed with the scale and precision required for association mapping. Hence, these methods have generally been used for intervention-based or comparative studies, which do not require the same degree of quantification or replication.…”

Assessment of the Growth and Fruiting of 19 Oyster Mushroom Strains for Indoor Cultivation on Lignocellulosic Wastes

“…The variation in the chemical composition of substrate mixtures from plant residues depends significantly on the origin of plant species (Tao et al 2012), the ratio of component tissues (Collins et al 2014), and the location and soil properties (Xiong et al 2010), which are the main challenges for selecting mushroom strains for cultivation on lignocellulosic wastes (Cohen et al 2002). Moreover, micro-climatic conditions regulate fungal culture homeostasis, affect the duration of fruit body morphogenesis, and define the transition from incubation (vegetative stage of growth) to fruiting (development of sporocarps) (Moore et al 2008).…”