Preparations are prepared, using completely clean slides and aqueous suspensions of young bacterial agar cultures. A drop of the suspension is placed on one end of the slide; the slide is then tipped, making the suspension drain down to the opposite end (Society of American Bacteriologists, Manual of Microbiological Methods, McGraw-Hill Book Co., New York, 1957). Both the mordanting and the sta...

This study involves the electro-oxidation of malachite green, a triphenyl methane dye, extensively used in industries and aquaculture, and later banned in most developed countries because of its potential carcinogenicity, mutagenicity and teratogenicity in mammals. The study is conducted in a batch electro-chemical reactor using the catalytic anode (made of noble oxide coated, RuOx-TiOx, titani...

The direct detection of pyrazinamide resistance in Mycobacterium tuberculosis is not routinely performed in many laboratories in the world because the drug is active only at acid pH, which also affects the growth of Mycobacterium tuberculosis. The pyrazinamidase enzyme, encoded by pncA gene, is necessary to convert prodrug pyrazinamide to its active form. Taking into account that nicotinamide, ...

The direct detection of pyrazinamide resistance in Mycobacterium tuberculosis is sufficiently difficult that many laboratories do not attempt it. Most pyrazinamide resistance is caused by mutations that inactivate the pyrazinamidase enzyme needed to convert the prodrug pyrazinamide to its active form. We evaluated two newer and simpler methods to assess pyrazinamidase activity, the nitrate redu...

Structures of the multidrug-binding repressor protein QacR with monovalent and bivalent cationic drugs revealed that the carboxylate side-chains of E90 and E120 were proximal to the positively charged nitrogens of the ligands ethidium, malachite green and rhodamine 6G, and therefore may contribute to drug neutralization and binding affinity. Here, we report structural, biochemical and in vivo e...

Growth of Salmonella enterica was studied in model mixed cultures with Citrobacter freundii or Escherichia coli in buffered peptone water (BPW) and in Rappaport-Vassiliadis medium with soya (RVS) with modified concentrations of MgCl2 and malachite green, and at modified incubation temperatures. Selected S. enterica strains were inoculated in BPW (10(0) cfu/ml) together with selected strains of ...

BACKGROUND Laccase-like multicopper oxidases have been reported in several Aspergillus species but they remain uncharacterized. The biocatalytic potential of the Aspergillus niger fungal pigment multicopper oxidases McoA and McoB and ascomycete laccase McoG was investigated. RESULTS The laccase-like multicopper oxidases McoA, McoB and McoG from the commonly used cell factory Aspergillus niger...