Abstract: The present invention provides a biological system for expanding the dethiazolidine ring of penicillins into the dehydrothiazine ring of cephalosporins or cephalosporin precursors. In particular, the invention defines reaction conditions under which expandase enzyme can convert penicillin substrates other than penicillin N into cephalosporins. The invention therefore provides a relatively inexpensive, uncomplicated, and environmentally friendly biological system for cephalosporin production from penicillins, which system can replace the synthetic chemical approaches currently utilized. In particular, the invention provides a system for producing DOAG and/or DAG, which can be enzymatically converted into 7-ADCA and 7-ADAC, which, in turn, can be enzymatically or chemically converted into valuable cephalosporins of commerce.

Abstract: A microorganism which does not form substantial foams during aerobic cultivation and which has an ability of producing erythritol is obtained by cultivating a microorganism having an ability of producing erythritol in a liquid medium, removing a microbial aggregate from the culture, collecting a microorganism which has physical properties such that when fractionated with water and a water-insoluble solvent the microorganism remains in a water layer in an amount of at least 20% or which has a hydrophobicity of 80% or less and further collecting a microorganism which does not form substantial foams during aerobic cultivation.

Abstract: The present invention provides a biological system for expanding the dethiazolidine ring of penicillins into the dehydrothiazine ring of cephalosporins or cephalosporin precursors. In particular, the invention defines reaction conditions under which expandase enzyme can convert penicillin substrates other than penicillin N into cephalosporins. The invention therefore provides a relatively inexpensive, uncomplicated, and environmentally friendly biological system for cephalosporin production from penicillins, which system can replace the synthetic chemical approaches currently utilized. In particular, the invention provides a system for producing DOAG and/or DAG, which can be enzymatically converted into 7-ADCA and 7-ADAC, which, in turn, can be enzymatically or chemically converted into valuable cephalosporins of commerce.

Abstract: A method of producing erythritol is disclosed, in which a microorganism having an ability of producing erythritol is cultivated for generation in a medium containing preferably 5 ppm or more of calcium, and erythritol is collected from the culture, thus producing erythritol efficiently.