Synthesis of Heterologous Mevalonic Acid Pathway Enzymes in Clostridium ljungdahlii for the Conversion of Fructose and of Syngas to Mevalonate and Isoprene.

There is a growing interest in the use of microbial fermentation for the generation of high-demand, high-purity chemicals using cheap feedstocks in an environmentally friendly manner. One example explored here is the production of isoprene (CH), a hemiterpene, which is primarily polymerized to polyisoprene in synthetic rubber in tires but which can also be converted to C and C biofuels. The strictly anaerobic, acetogenic bacterium , used in all of the work described here, is capable of glycolysis using the Embden-Meyerhof-Parnas pathway and of carbon fixation using the Wood-Ljungdahl pathway.

A monoclonal antibody based capture ELISA for botulinum neurotoxin serotype B: toxin detection in food.

Botulism is a serious foodborne neuroparalytic disease, caused by botulinum neurotoxin (BoNT), produced by the anaerobic bacterium Clostridium botulinum. Seven toxin serotypes (A-H) have been described. The majority of human cases of botulism are caused by serotypes A and B followed by E and F.

Development and characterization of six monoclonal antibodies to hemagglutinin-70 of Clostridium botulinum and their application in a sandwich ELISA.

Botulinum neurotoxins (BoNT) are produced by Clostridium botulinum and cause severe neuroparalytic disease that if not treated quickly is often fatal. The toxin is produced as a 150 kDa precursor protein (holotoxin) that is enzymatically cleaved to form two subunits, heavy and light chains, linked by a single disulfide bond. Seven toxin serotypes are known.

Development and characterization of monoclonal antibodies against Shiga toxin 2 and their application for toxin detection in milk.

Human infection by Shiga toxin producing Escherichia coli (STEC) is one of the most prevalent foodborne diseases. Shiga toxin type 2 (Stx2) is the major contributor to hemolytic-uremic syndrome (HUS) and other systemic complications caused by STEC. Although outbreaks of HUS due to the consumption of dairy products occur frequently, very few reports are available on assays for the detection of Stx2 in milk.

Novel epitopes identified by anti-PrP monoclonal antibodies produced following immunization of Prnp0/0 Balb/cJ mice with purified scrapie prions.

Prions, or infectious proteins, cause a class of uniformly fatal neurodegenerative diseases. Prions are composed solely of an aberrantly folded isoform (PrP(Sc)) of a normal cellular protein (PrP(C)). Shared sequence identity of PrP(Sc) with PrP(C) has limited the detection sensitivity of immunochemical assays, as antibodies specific for the disease-causing PrP(Sc) isoform have not been developed.

Detection of botulinum neurotoxin serotype B at sub mouse LD(50) levels by a sandwich immunoassay and its application to toxin detection in milk.

Background: Botulinum neurotoxin (BoNT), the causative agent of botulism, a serious neuroparylatic disease, is produced by the anaerobic bacterium Clostridium botulinum and consists of a family of seven serotypes (A-H). We previously reported production of high-affinity monoclonal antibodies to BoNT serotype A.

Methods And Findings: Recombinant peptide fragments of the light chain, the transmembrane and receptor-binding domains of the heavy chain of botulinum neurotoxin type B (BoNT/B) were expressed in Escherichia coli as GST-fusion proteins and purified.

Characterization of the epitope region of F1-2 and F1-5, two monoclonal antibodies to Botulinum neurotoxin type A.

F1-2 and F1-5 are mouse IgG1 monoclonal antibodies that bind the heavy chain of Botulinum neurotoxin serotype A (BoNT/A). To characterize the epitopes of F1-2 and F1-5, three complementary experimental approaches were selected. First, recombinant peptide fragments of BoNT/A heavy-chain were used in Western blots to identify the epitope regions.

Epitope characterization and variable region sequence of f1-40, a high-affinity monoclonal antibody to botulinum neurotoxin type a (Hall strain).

Background: Botulism, an often fatal neuroparalytic disease, is caused by botulinum neurotoxins (BoNT) which consist of a family of seven serotypes (A-H) produced by the anaerobic bacterium Clostridium botulinum. BoNT, considered the most potent biological toxin known, is a 150 kDa protein consisting of a 100 kDa heavy-chain (Hc) and a 50 kDa light-chain (Lc). F1-40 is a mouse-derived, IgG1 monoclonal antibody that binds the light chain of BoNT serotype A (BoNT/A) and is used in a sensitive immunoassay for toxin detection.

Development and partial characterization of high-affinity monoclonal antibodies for botulinum toxin type A and their use in analysis of milk by sandwich ELISA.

Botulinum neurotoxins (BoNT), produced by the anaerobic bacterium Clostridium botulinum, cause severe neuroparalytic disease and are considered the most toxic biological agents known. While botulism is rare in the U.S.

Activity of abrB310 promoter in wild type and spo0A-deficient strains of Clostridium acetobutylicum.

In Clostridium acetobutylicum, abrB310 is transcribed from two transcription start sites (designated A1 and A2) forming an abundant large, and a five- to tenfold less abundant small transcript, respectively throughout exponential, acidogenic growth and early in the transitional period to stationary, solventogenic growth. beta-galactosidase reporter vectors were constructed to compare the transcriptional activity of the entire abrB310 promoter and the A1 and A2 transcription start sites individually. In stark contrast to the primer extension data, the A2 start site was threefold more active than the entire promoter, which was threefold more active than the A1 start site in wild type C.

Expression of abrB310 and SinR, and effects of decreased abrB310 expression on the transition from acidogenesis to solventogenesis, in Clostridium acetobutylicum ATCC 824.

The transcription factors sinR and abrB are involved in the control of sporulation initiation in Bacillus subtilis. We identified a single homologue to sinR and three highly similar homologues to abrB, designated abrB310, abrB1941, and abrB3647, in Clostridium acetobutylicum ATCC 824. Using reporter vectors, we showed that the promoters of abrB1941 and abrB3647 were not active under the growth conditions tested.

SpoIIE regulates sporulation but does not directly affect solventogenesis in Clostridium acetobutylicum ATCC 824.

Using gene expression reporter vectors, we examined the activity of the spoIIE promoter in wild-type and spo0A-deleted strains of Clostridium acetobutylicum ATCC 824. In wild-type cells, the spoIIE promoter is active in a transient manner during late solventogenesis, but in strain SKO1, where the sporulation initiator spo0A is disrupted, no spoIIE promoter activity is detectable at any stage of growth. Strains 824(pMSpo) and 824(pASspo) were created to overexpress spoIIE and to decrease spoIIE expression via antisense RNA targeted against spoIIE, respectively.

Sequences affecting the regulation of solvent production in Clostridium acetobutylicum.

The high solvent phenotype of Clostridium acetobutylicum mutants B and H was complemented by the introduction of a plasmid that contains either an intact or partially-deleted copy of solR, restoring acetone and butanol production to wild-type levels. This demonstrates that the solR open reading frame on pSOLThi is not required to restore solvent levels. The promoter region upstream of alcohol dehydrogense E (adhE) was examined in efforts to identify sites that play major roles in the control of expression.