Abstract: The invention relates to a variant of a parent Fungamyl-like fungal alpha-amylase, which exhibits improved thermal stability at acidic pH suitable for, e.g., starch processes.

Abstract: Polymeric hollow particles for delivery of an agent are provided that change permeability in response to a change in an external stimulus such as pH, temperature, light, ionic strength, electric field, magnetic field and/or solvent composition. The particles can have a shell formed of an amphiphilic triblock ABA or BAB copolymer, where A is a hydrophilic block and B is a hydrophobic block. Low permeability particles with a reversibly permeable shell expand and increase permeability in response to a stimulus so that an active agent such as a therapeutic, prophylactic or diagnostic agent can be introduced. Removing the stimulus allows the particles to return to a low permeability state to form particles loaded with the active agent. Surfaces of the particles can be modified with specific ligands that allow the particles to be directed to a specific target via molecular recognition.

Abstract: Butanol and acetone are major end products of a bacterial fermentation process carried out by anaerobic saccharolytic clostridia such as Clostridium acetobutylicum. However, these organisms degenerate upon repeated subculture of growing cells, thereby losing their capacity to produce solvents and to develop into spores. A novel class of degeneration-resistant mutants of C. acetobutylicum, generated by transposon insertion mutagenesis, has been produced employing a novel selection procedure. Upon subculture the mutant cells survive significantly longer than the parental cells without altered solventogenic characteristics. The mutant organism, the technique for its isolation and its use are provided.

Abstract: A method for producing butanol by fermentation is provided. The method is carried out by culturing a butanol-producing microorganism in a culture medium containing a fluorocarbon selected from the group consisting of monofluorotrichloromethane, monofluorodichloromethane, monochloroheptafluoroethane, dichlorodifluoromethane, dichlorotetrafluoroethane and mixtures thereof in an amount sufficient to increase butanol production, and by separating the butanol from the culture medium.

Abstract: A novel asporogenic strain of Clostridium acetobutylicum is produced by growing a spore-forming strain in a continuous culturing reactor. Culturing is conducted at a dilution rate which prevents accumulation of butanol and acetone in the medium. Culturing at this dilution rate is continued until the asporogenic strain is obtained.