Reusable Floating Beads with Immobilized Xylose-Fermenting Yeast Cells for Simultaneous Saccharification and Fermentation of Lime-Pretreated Rice Straw.

Novel bioreactor beads for simultaneous saccharification and fermentation (SSF) of lime-pretreated rice straw (RS) into ethanol were prepared. Genetically modified cells expressing genes encoding xylose reductase, xylitol dehydrogenase, and xylulokinase were immobilized in calcium alginate beads containing inorganic lightweight filler particles to reduce specific gravity. For SSF experiments, the beads were floated in slurry composed of lime-pretreated RS and enzymes and incubated under CO atmosphere to reduce the pH for saccharification and fermentation.

Expression of neutral β-glucosidase from Scytalidium thermophilum in Candida glabrata for ethanol production from alkaline-pretreated rice straw.

We successfully expressed the neutral β-glucosidase (BGL4) from Scytalidium thermophilum in the thermotolerant yeast Candida glabrata. Compared to the strain expressing Aspergillus acidic β-glucosidase (BGL1), the BGL4-expressing strain showed a higher cellobiose fermentation ability at pH 6.0 and 40°C, leading to a higher ethanol production from alkaline-pretreated rice straw.

Biochemical characterization of l-arabitol 2-dehydrogenase from Pantoea ananatis.

Two oxidoreductases, XDH and LAD, were found in the same operon that was involved in sugar metabolism in Pantoea ananatis. LAD, whose endogenous substrate was unknown, was recombinantly prepared and biochemically analyzed. Consequently, LAD was identified as l-arabitol 2-dehydrogenase and its substrate specificity was complementary to that of XDH.

Microbial production of xylitol from L-arabinose by metabolically engineered Escherichia coli.

An Escherichia coli strain, ZUC99(pATX210), which can produce xylitol from L-arabinose at a high yield, has been created by introducing a new bioconversion pathway into the cells. This pathway consists of three enzymes: L-arabinose isomerase (which converts L-arabinose to L-ribulose), D-psicose 3-epimerase (which converts L-ribulose to L-xylulose), and L-xylulose reductase (which converts L-xylulose to xylitol). The genes encoding these enzymes were cloned behind the araBAD promoter in tandem so that they were polycistronically transcribed from the single promoter, like an operon.

Isolation of an operon involved in xylitol metabolism from a xylitol-utilizing Pantoea ananatis mutant.

An operon involved in cryptic xylitol metabolism of Pantoea ananatis was cloned by transposon tagging. A xylitol negative mutant with a transposon insertion in the xylitol 4-dehydrogenase gene (xdh) was isolated and genomic DNA around the transposon was sequenced. Consequently, six consecutive genes, xytB-G are located downstream of xdh in the same strand.

Expression and characterization of recombinant C-terminal biotinylated extracellular domain of human receptor for advanced glycation end products (hsRAGE) in Escherichia coli.

The receptor for advanced glycation end products (RAGE) is a multi-ligand receptor involved in the development of diabetic complications. Using an Escherichia coli expression system, we have successfully expressed and purified the C-terminal biotinylated extracellular domain of human RAGE (hsRAGE), which consists of three immunoglobulin-like domains carrying three putative disulfide bonds. Over 90% of hsRAGE was expressed in soluble form in trxB and gor mutant E.

Production of D-arabitol by a newly isolated Zygosaccharomyces rouxii.

A newly isolated Zygosaccharomyces rouxii NRRL 27,624 produced D-arabitol as the main metabolic product from glucose. In addition, it also produced ethanol and glycerol. The optimal conditions were temperature 30 degrees C, pH 5.

Lectin-like oxidized low-density lipoprotein receptor (LOX-1) functions as an oligomer and oligomerization is dependent on receptor density.

Lectin-like oxidized low-density lipoprotein (LDL) receptor (LOX-1) exists as a homodimer formed by an intermolecular disulfide bond. Although the dimer is the minimum structural unit of LOX-1 on cell membranes, LOX-1 can form larger noncovalent oligomeric complexes. But, the functional unit of LOX-1 is not known.

In vitro system for high-throughput screening of random peptide libraries for antimicrobial peptides that recognize bacterial membranes.

Antibacterial peptides have been isolated from a wide range of species. Some of these peptides act on microbial membranes, disrupting their barrier function. With the increasing development of antibiotic resistance by bacteria, these antibacterial peptides, which have a new mode of action, have attracted interest as antibacterial agents.

Human lectin-like oxidized low-density lipoprotein receptor-1 functions as a dimer in living cells.

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a unique scavenger receptor that plays important roles in atherogenesis and has been thought to function as a monomer. Using coimmunoprecipitation studies, we demonstrate that human LOX-1 (hLOX-1) forms constitutive homo-interactions in vivo. Western blot analysis of cell lysates under nonreducing or reducing conditions revealed one clear immunoreactive species corresponding to the size of a putative receptor dimer or a monomer, respectively, consistent with the presence of disulfide-linked hLOX-1 complexes.

alpha-Galactosidase from cultured rice (Oryza sativa L. var. Nipponbare) cells.

The alpha-galactosidase from rice cell suspension cultures was purified to homogeneity by different techniques including affinity chromatography using N-epsilon-aminocaproyl-alpha-D-galactopyranosylamine as the ligand. From 11 l of culture filtrate, 28.7 mg of purified enzyme was obtained with an overall yield of 51.

Characterization of DNA polymerase delta from a higher plant, rice (Oryza sativa L.).

DNA polymerase delta (pol delta), which is comprised of at least two essential subunits, is an important enzyme involved in DNA replication and repair. We have cloned and characterized both the catalytic and small subunits of pol delta from rice (Oryza sativa L. cv.