Distributive conjugal transfer (DCT) in mycobacteria results in transconjugant progeny with mosaic genomes more resembling chromosomes following meiotic recombination. Multiple, donor segments (blue) recombine into the recipient genome (yellow) resulting in both macro- and micro-mosaicism. Transconjugants can become donors if they inherit the mating identity locus. This review describes the unique features of DCT and compares it to other mechanisms of horizontal gene transfer.

Xenobiotic phthalates are industrially produced in the million ton scale. Their degradation by denitrifying bacteria proceeds via phthaloyl-CoA that is decarboxylated to benzoyl-CoA. We identified a CoA transferase that produces phthaloyl-CoA, an extremely instable CoA-ester with a half-life of minutes. Cells compensate for this instability by a massive overproduction of the decarboxylase for efficient phthaloyl-CoA decarboxylation at sub-micromolar concentrations. Anaerobic phthalate degradation is an unusual example for an evolving xenobiotic degradation pathway.

Drug-tolerant cells are a special subgroup of cells that can survive at high concentrations of drugs but without genetic mutations. Here we show a novel regulatory pathway for controlling the formation of isoniazid-tolerant cells in Mycobacterium smegmatis. The stress response sigma factor σ^B associates with its activator RbpA to regulate the expression of ppk1 gene, which encodes the polyphosphate kinase, to control the intracellular polyP levels and isoniazid-tolerance.

Mutating residues Tyr117 and Tyr119 of the N. crassa MOB2A protein revealed that in addition to the role MOB2A/B have in hyphal elongation/branching and conidiation, they are involved in regulation of conidial germination. The slow maturation of perithecia and a lack of ascus alignment in the mutants demonstrated a role in sexual development. We propose that the mentioned effects may be a result of the impaired interaction between MOB2A and the key MOB2A/B partner – COT1.

Mycobacterium smegmatis has three functional FurA paralogs that negatively regulate expression of genes related to peroxide detoxification. The FurA paralogs sense H₂O₂ by metal-catalyzed His oxidation mechanism.

Virulence and pathogenicity of Mycoplasma hyopneumoniae, the causative agent of enzootic pneumonia, has never been fully understood. We present in this work two interesting metabolic traits of M. hyopneumoniae that might be directly related to its enhanced virulence, especially regarding its ability to produce hydrogen peroxide.

Gene families with multiple copies of the same gene separately located on the chromosome are a frequent feature in prokaryotic and eukaryotic organisms. These gene families present a potential target site for integration of mobile genetic elements. Our results indicate that homologous recombination can protect genes within gene families from inactivation by mobile genetic elements, but for shorter gene sequences the efficiency of repair is very low.