Michigan State University

Pbs Biotech, Inc.

Michigan Biotechnology Institute

J Gregory Zeikus

Claire Vieille

Pil Sung Kim

Maris Laivenieks

Thomas A Post

Michael Bagdasarian

Karla I Ziegelmann-Fjeld

Dinlaka Sriprapundh

Kyungnam Kim

Chanyong Lee

Menghsiao Meng

Seung Hoon Song

Keith E Johnson

A pneumatic bioreactor includes a vessel containing a fluid to be mixed and at least one mixing device driven by gas pressure. A first embodiment includes a floating impeller that rises and falls in the fluid as gas bubbles carry it upward to the surface where the gas is then vented, permitting the impeller to sink in the fluid. The floating impeller may be tethered to a second impeller with a flexible member and pulley. The mixing speed is controlled with electromagnets in the vessel acting upon magnetic material in the impeller or its guides. In another embodiment, floating pistons mix the fluid, pushing it through a mixing plate with one or more apertures. In a third embodiment, the mixing device is a rotating drum with bubble-catching blades and rotating mixing plates with apertures. The top of the vessel for these mixers may include a closed top and sterile filters.

Vertical wheel bioreactors

Methods of using pneumatic bioreactors

Nucleic acids encodingmannitol dehydrogenase and themannitol dehydrogenase polypeptide are disclosed. Further provided are an electrochemical bioreactor system and a bioreactor electrode that can be used to convert glucose or fructose to mannitol.

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Pneumatic bioreactor

The present invention relates to compositions and methods utilizing thermostable and novel alcohol dehydrogenase enzymes for biosynthesizing chiral specific molecules for use as precursor molecules in synthesizing pharmaceutical compounds. Particularly, in preferred embodiments, the invention relates to directed engineering of an enzymatic catalytic site of an alcohol dehydrogenase enzyme gene for enhancing enantioselectivity for (S)-enantiomer substrate catalytic activity for providing aryl (S)-enantiomer products in stereomeric excess.

Molecular design of thermostable alcohol dehydrogenase for synthesis for chiral aromatic alcohols

A pneumatic bioreactor having a containment vessel which includes a semi-cylindrical concavity defined by the vessel bottom. A mixing apparatus includes a rotational mixer rotatably mounted within the containment vessel about a horizontal axis. The rotational mixer has buoyancy-driven mixing cavities which are fed by a gas supply beneath the rotational mixer. The mixing apparatus extends into the semi-cylindrical concavity to substantially fill that concavity. The rotational mixer is divided into two wheels with outer paddles extending axially outwardly and inner paddles extending axially inwardly on either side of each wheel. Blades between the outer and inner paddles form impellers in the wheels to induce axial flow through the wheels in opposite directions. Stationary baffles fixed relative to the containment vessel are inclined toward the rotational mixer in the direction of rotation. The containment vessel may be of film and supported by a structural housing also having a semi-cylindrical concavity defined by the housing bottom.

The present invention provides novel isolated polynucleotides encoding a novel xylose isomerases capable of catalyzing the conversion of glucose to fructose and nucleic acids encoding for such isomerase. The present invention also provides a method of producing the xylose isomerase enzymes employing DNA encoding for the enzymes, plasmids containing the DNA, and bacteria into which the plasmids have been inserted and which produce the enzymes.

Anplasmid vector which provides a means to overexpress proteins in. The plasmid can be transformed efficiently by electroporation, and replicates in a stable manner in. The plasmid comprises at least one marker gene, operably linked to a first promoter functional in, an origin of replication functional in, a second promoter isolated from, and a cloning site downstream from the second promoter. Plasmids pLGZ901, pLGZ920, pLGZ921, and pLGZ922 are disclosed. The pckA gene polypeptide sequence and nucleic acid sequence of, including the promoter and ribosome binding site, is disclosed. Furthermore, a method for producing a recombinantis described, including a method of transformation. Additionally, a recombinantis disclosed and a method for producing succinate utilizing this recombinantis described.

Anplasmid vector which provides a means to overexpress proteins inThe plasmid can be transformed efficiently by electroporation, and replicates in a stable manner inThe plasmid comprises at least one marker gene, operably linked to a first promoter functional inan origin of replication functional ina second promoter isolated fromand a cloning site downstream from the second promoter. Plasmids pLGZ901, pLGZ920, pLGZ921, and pLGZ922 are disclosed. The pckA gene polypeptide sequence and nucleic acid sequence ofincluding the promoter and ribosome binding site, is disclosed. Furthermore, a method for producing a recombinantis described, including a method of transformation. Additionally, a recombinantis disclosed and a method for producing succinate utilizing this recombinantis described.

A genetically engineered glucose isomerase with improved affinity for D-glucose and the method of preparation of such a glucose isomerase are disclosed. The glucose isomerase is obtained by mutagenizing the gene of a naturally occurring glucose isomerase such that a smaller amino acid replaces a larger amino acid in the catalytic site. In an especially advantageous embodiment of the present invention, the Clostridium glucose isomerase sequence is mutated and the residue replaced with a smaller amino acid is either Trp.sub.139 or Val.sub.186.

Growing community of inventors

Okemos, MI, United States of America

J Gregory Zeikus