Comparison of three screening methods to select mixed-microbial inoculum for mixed-acid fermentations.

Using a mixed culture of microorganisms, the carboxylate platform converts biomass into hydrocarbons and chemicals. To develop a method that identifies the highest performing inoculum for carboxylate fermentations, five bacterial communities were screened and ranked by three fermentation performance tests: (1) 30-day batch screen, (2) 28-day continuum particle distribution model (CPDM), and (3) 5-month continuous countercurrent fermentation trains. To screen numerous inocula sources, these tests were used sequentially in an aseptic environment.

Mineralization of acephate, a recalcitrant organophosphate insecticide is initiated by a pseudomonad in environmental samples.

An aerobic bacterium capable of breaking down the pesticide acephate (O,S-dimethyl acetyl phosphoramidothioic acid) was isolated from activated sludge collected from a pesticide manufacturing facility. A phylogenetic tree based on the 16 S rRNA gene sequence determined that the isolate lies within the Pseudomonads. The isolate was able to grow in the presence of acephate at concentrations up to 80 mM, with maximum growth at 40 mM.

Organophosphorus hydrolase as an in vivo catalytic nerve agent bioscavenger.

The use of proteins as a treatment for organophosphorus intoxication has been investigated since A. R. Main demonstrated protective efficacy against parathion with an exogenously administered arylesterase in the late 1950s.

Thermodynamic prediction of hydrogen production from mixed-acid fermentations.

The MixAlco™ process biologically converts biomass to carboxylate salts that may be chemically converted to a wide variety of chemicals and fuels. The process utilizes lignocellulosic biomass as feedstock (e.g.

Improved pharmacokinetics and immunogenicity profile of organophosphorus hydrolase by chemical modification with polyethylene glycol.

A catalytic bioscavenger with broad substrate specificity for the therapeutic and prophylactic defense against recognized chemical threat agents has been a long standing objective of civilian and military research. A catalytic bioscavenger utilizing the bacterial enzyme organophosphorus hydrolase (OPH) is characterized in these studies, and has potential application for both military and civilian personnel in threat scenarios involving either nerve agents or OP pesticides. The present study examines the effects of PEGylation on the biochemical and pharmacological characteristics of OPH.

Orientation specific positioning of organophosphorus hydrolase on solid interfaces for biosensor applications.

Protein immobilization on solid interfaces is a crucial aspect of their successful application in technologies such as biosensing, purification, separation, decontamination, etc. Although immobilization can improve the long-term and operational stability of proteins, this is often at the cost of significant losses in the catalytic activity of the tethered enzyme. Covalent attachment methods take advantage of reactive groups on the amino acid side chains.

Physicochemical characterization of stealth liposomes encapsulating an organophosphate hydrolyzing enzyme.

The present studies were focused on the preparation and characterization of stericaly stabilized liposomes (SLs) encapsulating a recombinant organophosphorus hydrolyzing phosphotriesterase (OPH) enzyme for the antagonism of organophosphorus intoxication. Earlier results indicate that the liposomal carrier system provides an enhanced protective effect against the organophosphorus molecule paraoxon, presenting a more effective therapy with less toxicity than the most commonly used antidotes. Physicochemical characterization of the liposomal OPH delivery system is essential in order to get information on its in vitro stability and in vivo fate.

Electron beam irradiation as protection against the environmental release of recombinant molecules for biomaterials applications.

In biomaterials applications there exists a need to protect against the environmental release of recombinant microorganisms and transmissible genetic material and to prevent the recovery of proprietary genetic information. Irradiation technologies have long been used to eliminate microorganisms associated with spoilage and contamination and recent studies have demonstrated that moderate doses of irradiation may be used to sterilize medically important proteins without causing adverse effects in their desirable biological properties. Recombinant Escherichia coli cells expressing organophosphate hydrolase (OPH, E.

Modeling allosteric regulation of de novo pyrimidine biosynthesis in Escherichia coli.

With the emergence of multifaceted bioinformatics-derived data, it is becoming possible to merge biochemical and physiological information to develop a new level of understanding of the metabolic complexity of the cell. The biosynthetic pathway of de novo pyrimidine nucleotide metabolism is an essential capability of all free-living cells, and it occupies a pivotal position relative to metabolic processes that are involved in the macromolecular synthesis of DNA, RNA and proteins, as well as energy production and cell division. This regulatory network in all enteric bacteria involves genetic, allosteric, and physiological control systems that need to be integrated into a coordinated set of metabolic checks and balances.