Abstract: The present invention relates to a novel process for the genetic manipulation of myxobacteria, preferably of myxobacteria of the Sorangium/Polyangium group, which makes it possible for the first time specifically to apply recombinant DNA techniques to this group of organisms. The technical implementation of this process is based primarily on the preparation of recombinant DNA molecules which, by reason of their specific construction, are able to integrate genes or DNA sequences which code, where appropriate, for novel and desirable properties, with the aid of homologous recombination at sites, which are accurately defined by reason of the homologies present, within the bacterial genome, and on the insertion thereof into the myxobacterial cell.

Abstract: The present invention is directed to the production of an antipathogenic substance (APS) in a host via recombinant expression of the polypeptides needed to biologically synthesize the APS. Genes encoding polypeptides necessary to produce particular antipathogenic substances are provided, along with methods for identifying and isolating genes needed to recombinantly biosynthesize any desired APS. The cloned genes may be transformed and expressed in a desired host organisms to produce the APS according to the invention for a variety of purposes, including protecting the host from a pathogen, developing the host as a biocontrol agent, and producing large, uniform amounts of the APS.

Abstract: The present invention is directed to the production of an antipathogenic substance (APS) in a host via recombinant expression of the polypeptides needed to biologically synthesize the APS. Genes encoding polypeptides necessary to produce particular antipathogenic substances are provided, along with methods for identifying and isolating genes needed to recombinantly biosynthesize any desired APS. The cloned genes may be transformed and expressed in a desired host organisms to produce the APS according to the invention for a variety of purposes, including protecting the host from a pathogen, developing the host as a biocontrol agent, and producing large, uniform amounts of the APS.

Abstract: New antibiotically active compounds having the basic structure of rifamycin S, namely 3-hydroxyrifamycin S (formula A: X=>C.dbd.O; R.sup.1 =OH; R.sup.2 =H), 3,31-dihydroxy-rifamycin S (formula A: X=>C.dbd.O; R.sup.1 =R.sup.2 =OH) and 1-desoxy-1-oxarifamycin S (formula A: X=--O--; R.sup.1 =R.sup.2 =H) ##STR1## are formed by cultivating, under aerobic conditions, a strain of Nocardia mediterranei which is derived from Streptomyces mediterranei ATCC 13 685 as the parent strain and is characterized by the ability to produce at least one of the mentioned compounds. The recombinant strain Nocardia mediterranei DSM 1415 has proved suitable. The mentioned rifamycin S analogues have analogous antibiotic properties to this but have a wider range of action, especially against gram-negative bacteria.

Abstract: New antibiotically active compounds having the basic structure of rifamycin S, namely 3-hydroxyrifamycin S (formula A: X=<C.dbd.O; R.sup.1 =OH; R.sup.2 =H), 3,31-dihydroxyrifamycin S (formula A: X=<C.dbd.O; R.sup.1 =R.sup.2 =OH) and 1-desoxy-1-oxarifamycin S (formula A: X=--O--; R.sup.1 =R.sup.2 =H) ##STR1## are formed by cultivating, under aerobic conditions, a strain of Nocardia mediterranei which is derived from Streptomyces mediterranei ATCC 13 685 as the parent strain and is characterized by the ability to produce at least one of the mentioned compounds. The recombinant strain Nocardia mediterranei DSM 1415 has proved suitable. The mentioned rifamycin S analogues have analogous antibiotic properties to this but have a wider range of action, especially against gram-negative bacteria.

Abstract: New antibiotically active compounds having the basic structure of rifamycin S, namely 3-hydroxyrifamycin S (formula A: X.dbd.>C.dbd.O; R.sup.1 .dbd.OH; R.sup.2 .dbd.H), 3,31-dihydroxyrifamycin S (formula A: X.dbd.>C.dbd.O; R.sup.1 .dbd.R.sup.2 .dbd.OH) and 1-desoxy-1-oxarifamycin S (formula A: X.dbd.--O--; R.sup.1 .dbd.R.sup.2 .dbd.H) ##STR1## are formed by cultivating, under aerobic conditions, a strain of Nocardia mediterranei which is derived from Streptomyces mediterranei ATCC 13 685 as the parent strain and is characterized by the ability to produce at least one of the mentioned compounds. The recombinant strain Nocardia mediterranei DSM 1415 has proved suitable. The mentioned rifamycin S analogues have analogous antibiotic properties to this but have a wider range of action, especially against gram-negative bacteria.