Research Highlights

Zymomonas mobilis has properties that make it a good candidate for industrial biofuel production: high catabolic rate, low biomass generation, resistance to inhibitors in lignocellulosic hydrolysates; an a growing set of genetic engineering tools. Recent efforts have targeted Z. mobilis for isobutanol production, but isobutanol toxicity limits growth and productivity. The physiological effects of isobutanol on Z. mobilis are poorly understood.  

This study demonstrates the viability of low-productivity former cropland for long-term bioenergy production and suggests there is no single crop best suited for all such soils. Yield trends suggest polyculture may outperform monocultures over the long term.

Many bacteria use self-assembling, protein-based organelles to form a semipermeable barrier that keeps out toxic or volatile intermediates while allowing substrates and products to pass through. Such microcompartments could be used to encapsulate non-native enzymes and incorporate challenging metabolic pathways into industrially relevant bacteria such as Zymomonas mobilis.    

Water stress during switchgrass growth caused by the soil type may affect the yeast fermentability, which may not be evident through initial evaluation of upstream biomass metrics such as biomass yield, composition, and digestibility.

Researchers used existing land cover data sets to train a computer algorithm to classify land use patterns in satellite imagery. These classifiers were then used to map cropland annually from 1986 to 2018 at a 30-meter resolution. Researchers then identified the location and time of abandonment using a moving temporal window for each pixel and estimated the accuracy against visually interpreted sample locations and publicly available datasets.  

Belowground carbon content was higher in the switchgrass grown in prairie soil. Switchgrass grown in prairie soils situated on slopes also had higher biomass carbon in both the above- and belowground plant growth as compared to switchgrass grown in the prairie soil of depressions. Prairie systems consistently outcompete monoculture systems in plant diversity, carbon content, and microbial carbon content. 

Findings suggest that decomposition dynamics of plant residues is a combined effect of vegetative history, in part through its impact on microbial communities, the chemical and physical characteristics of plant residue, and soil pore structure, which together create temporally dynamic micro-environmental conditions that influence decomposition.

The study assessed soil carbon gains across a variety of marginal soils at experimental sites in Michigan and Wisconsin. Cropping systems were randomly assigned to plots within each of the six unfertilized and untilled sites. Researchers used X-ray computed microtomography to analyze pore structures in harvested soil cores and loose soil surrounding the cores.

Great Lakes Bioenergy Research Center scientists have patented technology that can be used to make plants with modified lignin amenable to degradation and production of commodity chemicals used in pharmaceutical drugs and cosmetics, potentially enhancing the value to biorefineries.

The newly patented process uses water as the solvent, no chromatography, inexpensive reagents, no protecting groups, and scalable technology. Modifications  of  this  process  have  the  potential  to  produce  an array of chemical building blocks for the manufacturing materials and chemical products like plastics, surfactants, pigments, and pharmaceuticals.