Great Lakes Bioenergy research consistently results in new discoveries and new technologies. Here, we highlight high-impact research from all three of our research areas.
Researchers at the Great Lakes Bioenergy Research Center (GLBRC) investigated how a prolific ethanol-producing microbe, Zymomonas mobilis, regulates its synthesis of a broad class of industrially relevant molecules called isoprenoids. The work identifies several enzymes that help the microbe overcome the rate-limiting steps in the methyl erythritol-4-phosphate (MEP) isoprenoid biosynthesis pathway.
Biological funneling of aromatics from chemically depolymerized lignin produces a desirable chemical product
Scientists at the Great Lakes Bioenergy Research Center engineered Novosphingobium aromaticivorans DSM12444 to convert multiple lignin-derived aromatics into a single chemical called 2-pyrone-4,6-dicarboxylic acid (PDC), a potential precursor for making polyester, epoxy adhesives, and other bioplastics.
GLBRC scientists have developed a process model demonstrating that engineering energy sorghum for lipid production would increase the crop’s value as a bioenergy feedstock. Technoeconomic analysis reveals that engineering the plant to produce lipid content allows for refining into biodiesel.
New research from the Great Lakes Bioenergy Research Center (GLBRC) unveils a genetically encoded biosensor that triggers green fluorescence in cells with high NADH levels, enabling rapid identification of the strains best primed for biofuel production.
Turning bioenergy crops into fuels and other products requires breaking down the complex mixture of polysaccharides found in plant material. Glycoside hydrolase family 5 (GH5) is a large and diverse family of enzymes able to digest a wide range of polysaccharides. Researchers at the Great Lakes Bioenergy Research Center (GLBRC) described the functional diversity of members of a GH5 subfamily to explore the structural origins of their broad substrate specificity, a step toward engineering better enzymes for converting biomass into biofuels and other specialty bioproducts.
Characterizing microbial strategies for lignin breakdown is important for understanding plant biomass turnover in nature, and could aid in developing industrial systems for producing commodity chemicals from this abundant renewable resource. In this report, Great Lakes Bioenergy Research Center researchers provide new information on the pathway used by sphingomonad bacteria to cleave the β-aryl ether bond commonly found in lignin. Specifically, they report on a previously uncharacterized heterodimeric β-etherase enzyme, with unique properties, from Novosphingobium aromaticivorans and other sphingomonads.
Nitrous oxide (N2O) is a potent greenhouse gas and major component of the net global warming potential of bioenergy crops. Numerous environmental factors influence soil N2O production, making direct correlation difficult to any one factor under field conditions.
The organic matter left over after biofuel production is a rich potential feedstock for making additional high-value bioproducts. GLBRC researchers previously described a small-scale bioreactor that used a mixed microbial community to produce valuable molecules from the conversion residue remaining after lignocellulosic ethanol production. The team has now analyzed the composition and metabolic characteristics of the microbiome as a step toward understanding how to engineer and control microbial communities to optimize production of medium-chain fatty acids (MCFAs), which can be used to make a variety of industrial chemicals and pharmaceuticals.
With the goal of ultimately engineering bioenergy crops to accumulate large amounts of easily digestible sugars, researchers from the Great Lakes Bioenergy Research Center (GLBRC) have identified a transcription factor that is highly co-expressed with the major mixed-linkage glucan (MLG) synthase gene in the model grass Brachypodium distachyon. Characterization of downstream genes regulated by this transcription factor provides insight into the mechanism of MLG production and restructuring, information vital to overcoming known growth defects associated with MLG synthase overexpression.
Identification of a secondary metabolite gene cluster in budding yeasts with important implications for biofuel production
The iron-binding molecule pulcherrimin was described 65 years ago, but the genes responsible for its production in budding yeasts remained uncharacterized. Genomic comparisons across 90 species of the budding yeast subphylum Saccharomycotina revealed a four-gene cluster associated with pulcherrimin production, and targeted gene disruptions in Kluyveromyces lactis revealed likely functions for each of the genes: two biosynthetic enzymes, a transporter, and a putative transcription factor.