Enterococcus faecium CCM4231, isolated from the rumen content of a calf, produced an antimicrobial agent active against Gram-positive and Gram-negative indicator organisms. After 100-fold concentration by ultrafiltration, the diameters of zones of inhibition ranged from 2 to 10 mm. The agent was sensitive to pronase and trypsin and resistant to heating at 60°C for 30 min.

The new bacteriocin, termed enterocin M, produced by Enterococcus faecium AL 41 showed a wide spectrum of inhibitory activity against the indicator organisms from different sources. It was purified by (NH₄)₂SO₄ precipitation, cation-exchange chromatography and reverse phase chromatography (FPLC). The purified peptide was sequenced by N-terminal amino acid Edman degradation and a mass spectrometry analysis was performed. By combining the data obtained from amino acid sequence (39 N-terminal amino acid residues was determined) and the molecular weight (determined to be 4 628 Da) it was concluded that the purified enterocin M is a new bacteriocin, which is very similar to enterocin P. However, its molecular weight is different from enterocin P (4 701.25). Of the first 39 N-terminal residues of enterocin M, valine was found in position 20 and a lysine in position 35, while enterocin P has tryptophane residues in these positions.

Aims: The partial characterization of bacteriocins produced by an environmental strain Enterococcus faecium EK13, isolated from cattle dung water. Methods and Results: A bacteriocin was partially pur...

We are experiencing rapid progress in all types of imaging techniques used in the detection of various numbers and types of mutation. In situ hybridization (ISH) is the primary technique for the discovery of mutation agents, which are presented in a variety of cells. The ability of DNA to complementary bind is one of the main principles in every method used in ISH. From the first use of in situ techniques, scientists paid attention to the improvement of the probe design and detection, to enhance the fluorescent signal intensity and inhibition of cross-hybrid presence. This article discusses the individual types and modifications, and is focused on explaining the principles and limitations of ISH division on different types of probes. The article describes a design of probes for individual types of in situ hybridization (ISH), as well as the gradual combination of several laboratory procedures to achieve the highest possible sensitivity and to prevent undesirable events accompanying hybridization. The article also informs about applications of the methodology, in practice and in research, to detect cell to cell communication and principles of gene silencing, process of oncogenesis, and many other unknown processes taking place in organisms at the DNA/RNA level.

Cancer chemoprevention is defined as the use of natural, synthetic or biological chemical agents to reverse, suppress or prevent carcinogenic progression of invasive cancer. Carcinogenesis is a complex multi-step process; therefore, it is nece...