Producing bioethanol using lignocellulosic biomass as feedstock has become the trend for biofuel production in the future. The lignocellulosic biomass is pretreated and hydrolyzed to generate hydrolysate, which is used as fermentation media for ethanol production. During the pretreatment step, inhibitory compounds are formed which affect the growth and ethanol production of microorganisms.
Studying the inhibitory compounds in the hydrolysates using exometabolomics and biostatistics tools is the focus of this NMC associate project A5. The full-factorial experimental design requires the preparation a variety of hydrolysates with various inhibitory effects. 24 different hydrolysates were produced from 6 biomass types using 4 methods. These 24 hydrolysates were tested in growth experiments on small scale to confirm their diversity in inhibitory effects. Two metabolomics tools were developed for analyzing hydrolysate samples, namely ethylacetate extraction GC-MS and ethylchloroformate GC-MS.
These tools were applied on the time-point samples from two batches of fermentations, which contained 6 and 8 different hydrolysates, respectively. The resulting data-sets will be used to conduct an initial biostatistics study, which will provide valuable information to further improve the experimental design and biostatistics tools to achieve the ultimate goal of this project: understanding substrate dynamics and identifying inhibitory compounds in lignocellulosic biomass hydrolysates.