title: Instability of protease production in a rel+/rel- -pair of Bacillus licheniformis and associated morphological and physiological characteristics.
abstract: A naturally occurring relaxed/protease-producing (A-type) versus stringent/not protease-producing (B-type) pair of an industrial Bacillus licheniformis has been characterized; either of the two types can convert into the other. Both types can sporulate, grow anaerobically, grow at 56 degrees C and reduce nitrate; morphologically, they can easily be distinguished by cell- and colony-shape. They differ in the ability to use 12 substrates, as determined in API-tests. The two types are remarkably different in their content of extrachromosomal elements (A-type: 2; B-type: 4); furthermore, they differ in their rel-status (A-type: relaxed; B-type: stringent). We propose that the differences in the ability of the two types to use different substrates probably are due to integration/extrusion of the extrachromosomal elements in and out of the chromosome, distorting or restoring a number of genes, together with induction of certain catabolic genes that are under control of the rel-system.
authors.affiliation: Dept. of Microbiology, Free University, Amsterdam, The Netherlands.
authors.forename: B A
authors.initials: BA
authors.lastname: Bulthuis
authors.forename: J
authors.initials: J
authors.lastname: Frankena
authors.forename: G M
authors.initials: GM
authors.lastname: Koningstein
authors.forename: H W
authors.initials: HW
authors.lastname: van Verseveld
authors.forename: A H
authors.initials: AH
authors.lastname: Stouthamer
mesh_terms: D000332:Aerobiosis; D001407:Bacillus / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D004926:Escherichia coli / Q000502:physiology; D007700:Kinetics; D010447:Peptide Hydrolases / Q000096:biosynthesis / Q000235:genetics*; D010957:Plasmids; D013045:Species Specificity
chemical_list: D010447:Peptide Hydrolases