Toxic Effects of Butanol in the Plane of the Cell Membrane.

Solvent toxicity limits -butanol fermentation titer, increasing the cost and energy consumption for subsequent separation processes and making biobased production more expensive and energy-intensive than petrochemical approaches. Amphiphilic solvents such as -butanol partition into the cell membrane of fermenting microorganisms, thinning the transverse structure, and eventually causing a loss of membrane potential and cell death. In this work, we demonstrate the deleterious effects of -butanol partitioning upon the lateral dimension of the membrane structure, called membrane domains or lipid rafts.

Effect of alkali treatment and fungal degradation on the nanostructure and cellulose arrangement in Scots pine cell walls - A neutron and X-ray scattering study.

Research on new conservation treatments for historical wood requires considerable amounts of appropriate wood material, which is hard to acquire. Thus, we produced biologically and chemically degraded model wood that could be used as a representative material in future research on consolidating agents. Using chemical composition determinations, we found that fungal decay targeted mainly polysaccharides, while alkaline treatment mostly reduced hemicelluloses and lignin content.

SANS investigation of fungal loosenins reveal substrate dependent impacts of protein 1 action on inter-fibril distance and packing order of cellulosic substrates.

Background: Microbial expansin-related proteins include fungal loosenins, which have been previously shown to disrupt cellulose networks and enhance the enzymatic conversion of cellulosic substrates. Despite showing beneficial impacts to cellulose processing, detailed characterization of cellulosic materials after loosenin treatment is lacking. In this study, small-angle neutron scattering (SANS) was used to investigate the effects of three recombinantly produced loosenins that originate from Phanerochaete carnosa, PcaLOOL7, PcaLOOL9, and PcaLOOL12, on the organization of holocellulose preparations from Eucalyptus and Spruce wood samples.

SANS reveals lipid-dependent oligomerization of an intramembrane aspartyl protease from H. volcanii.

Reactions that occur within the lipid membrane involve, at minimum, ternary complexes among the enzyme, substrate, and lipid. For many systems, the impact of the lipid in regulating activity or oligomerization state is poorly understood. Here, we used small-angle neutron scattering (SANS) to structurally characterize an intramembrane aspartyl protease (IAP), a class of membrane-bound enzymes that use membrane-embedded aspartate residues to hydrolyze transmembrane segments of biologically relevant substrates.

Ectopic Production of 3,4-Dihydroxybenzoate Affects Cellulose Structure and Organization.

Lignocellulosic biomass is a highly sustainable and largely carbon dioxide neutral feedstock for the production of biofuels and advanced biomaterials. Although thermochemical pretreatment is typically used to increase the efficiency of cell wall deconstruction, genetic engineering of the major plant cell wall polymers, especially lignin, has shown promise as an alternative approach to reduce biomass recalcitrance. Poplar trees with reduced lignin content and altered composition were previously developed by overexpressing bacterial 3-dehydroshikimate dehydratase (QsuB) enzyme to divert carbon flux from the shikimate pathway.