Abstract: The present invention relates to an isolated mutant eubacterium comprising at least one mutation resulting in a substitution of at least one amino acid in the beta-subunit of the RNA-polymerase encoded for by the rpoB-gene providing an altered production of a product of interest when said production of a product of interest is compared to the production of the same product in an isogenic wild type strain grown at identical conditions, wherein the substitution of at least one amino acid occurs at any of the positions 469, 478, 482, 485, or 487 of SEQ ID NO:2, or at the equivalent positions in any eubacterial RNA-polymererase beta-sub-unit family member. Another aspect of the invention relates to a process for producing at least one product of interest in a mutant eubacterium and to a use of the mutant eubacterium according to the invention for producing at least one product of interest.

Abstract: The present invention relates to a method for screening for compounds secreted by an organism, comprising (a) raising antibodies against secreted products of a donor organism, (b) providing a gene library from the donor organism, (c) cloning the gene library into a suitable host organism, (d) expressing the cloned genes in the host organism, and (e) detecting positive clones, which upon expression of the cloned genes secretes a compound, using the antibodies of (a) to identify such positive clones. The invention also relates to compounds, nucleotide sequences and microorganisms identifiable by said method.