Significant scientific results 2016

DNA integrity control

Alexandra Mayer, Vladimír Baran

The ongoing collaboration with the Institute of Animal Biology and Genetics of the CAS, Liběchov (Czech Republic) focused on the study of processes controlling the integrity of the DNA molecule. The published results showed that during maturation of female germ cells the nuclear protein MRE11 is more important in the recognition of DNA molecule damage than ATM kinase. It was also confirmed that this endonuclear protein (MRE11) is very important for the subsequent maintenance of chromosome integrity throughout oocyte maturation.

MAYER, Alexandra – BARAN, Vladimír – SAKAKIBARA, Yogo – BRZÁKOVÁ, A. – MOTLIK, J. – KITAJIMA, T. – SCHULTZ, R.M. – ŠOLC, Peter. DNA damage response during mouse oocyte maturation. In Cell Cycle, 2016, vol. 15, no. 4, p. 546-558. (2015: 3.952 – IF, Q2 – JCR, 2.259 – SJR, Q1 – SJR, karentované – CCC). (2016 – Current Contents). ISSN 1538-4101.

Manganese in animal nutrition

Ľubomíra Grešáková, Katarína Venglovská, Klaudia Čobanová

In order to enhance the performance of livestock, the enrichment of feed with trace elements is frequently in excess of the animals’ requirements. The enhanced bioavailability of manganese from its organic forms may facilitate increased deposition in animal tissues. The enrichment of sheep feed with manganese chelate glycine, as an organic source of Mn, and inorganic MnSO₄ up to the maximum concentration permitted in the EU (150 mg Mn/kg), over a period of four months, resulted in elevated Mn concentrations in sheep plasma and liver. Additionally, the activity of the antioxidant enzymes manganese superoxide dismutase (MnSOD) and arginase in sheep liver was observed to increase. These parameters reflect the quantity of Mn ingested with the feed, irrespective of the form in which it is ingested. The higher manganese concentrations observed in the kidneys of sheep receiving feed enriched with the organic chelate glycine suggest differences in manganese distribution between its sources. As the enzyme activity and the content of Mn, Zn and Cu in other tissues of sheep were not altered, it can be concluded that there is no difference between these Mn compounds used as additives in animal diets. However, the results demonstrated that the enrichment of sheep diets with Mn at these doses may result in a reduction in plasma Cu levels in sheep, which is likely due to increased Cu accumulation in the liver.

GREŠÁKOVÁ, Ľubomíra – VENGLOVSKÁ, Katarína – ČOBANOVÁ, Klaudia. Dietary manganese source does not affect Mn, Zn and Cu tissue deposition and the activity of manganese-containing enzymes in lambs. In Journal of Trace Elements in Medicine and Biology, 2016, vol. 38, special iss. SI, p. 138-143. (2015: 2.550 – IF, Q3 – JCR, 0.639 – SJR, Q2 – SJR, karentované – CCC). (2016 – Current Contents). ISSN 0946-672X.

Unknown bacteria from the extreme environment of the brown sludge landfill near Žiar nad Hronom

Stramanová Zuzana, Peter Javorský, Peter Pristaš

Brown sludge is a waste product generated during the production of aluminium via the Bayer process. As a consequence of the extensive utilisation of sodium hydroxide in this process, the landfill site for brown sludge and the drainage water from the aforementioned landfill site, situated in the vicinity of Žiar nad Hronom, represents one of the most significant ecological burdens in Slovakia. The pH of the landfill drainage water is greater than 13, and it contains a considerable amount of dissolved salts and heavy metals. Despite the challenging conditions for microbial life, we observed a relatively diverse bacterial population with an abundance of 80 colony-forming units (cfu) per milliliter in the drainage water of the brown sludge landfill through culture-based methods. A combination of MALDI-TOF and 16S rDNA analysis was employed to identify alkali-tolerant heterotrophic isolates. The dominant species identified in the drainage water were actinobacteria (specifically, Microbacterium spp. and Micrococcus spp.) and gram-positive bacteria with low G+C pair content (specifically, Bacillus spp.). Of the isolates identified, only two were gram-negative bacteria, belonging to the species Brevundimonas. Phylogenetic and biochemical analyses suggest that approximately half of the isolates obtained represent new bacterial species. The brown sludge landfill, therefore, represents an interesting source of bacterial taxa applicable in biotechnological and bioremediation products.

STRAMOVÁ, Zuzana – REMENÁR, Matej – JAVORSKÝ, Peter – PRISTAŠ, Peter. Heterotrophic microflora of highly alkaline (pH13) brown mud disposal site drainage water near Ziar nad Hronom (Banska Bystrica region, Slovakia). In Environmental science and pollution research, 2016, vol. 23, no. 5, p. 4199-4206. (2015: 2.760 – IF, Q2 – JCR, 0.906 – SJR, Q1 – SJR, karentované – CCC). (2016 – Current Contents). ISSN 0944-1344.