Acta Microbiologica et Immunologica Hungarica, 62 (Suppl), pp. 127–241 (2015) DOI: 10.1556/030.62.2015.Suppl.2 INVESTIGATION OF THE FUNCTION AND STRUCTURE OF ACE2P - A CONSERVED REGULATOR OF CELL SEPARATION LAJOS ÁCS-SZABÓ, BIANKA BALOGH, MATTHIAS SIPICZKI and IDA MIKLÓS Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary During cytokinesis, a three-layered cell wall has to be produced allowing the separation of daughter cells in the fission yeasts Schizosaccharomyces. The formation and cleavage of the septum requires strict coordination to prevent cell lysis. These processes are under the control of complex networks of genes and proteins. The transcription factors Sep1p and Ace2p play essential roles in cell separation through regulation of numerous genes such as agn1 and eng1 that encode enzymes of septum degradation. It has been proven that the mentioned regulators are conserved as their putative orthologs can be found in many fungi. However, they are diverse in the protein and gene sequence length. The zinc-finger transcription factor Ace2p has some Schizosaccharomyces specific structural characteristics. The aim was to deepen our knowledge on the structure and function of the Ace2p by further analysis of its sequence characteristics with bioinformatical and experimental methods. As more genome sequences of related species became recently available, we performed BLAST search using the protein sequence of Sch. pombe. After generating phylogenetic trees we analysed the sequences deeply for finding new conservative blocks. Then we examined the protein sequences with the IUPred algorithm to find intrinsically disordered regions. As the protein sequences from the N-terminus to the first conserved blocks seem to be ordered but diverse among the species, we created a trunked version of Ace2p to learn its role. The transformation of this product to our Sch. pombe ace2Δ strain is underway. HOW COULD MEIOTIC DNA BREAKS DEFINE THE FATE OF GENE ORDER IN RELATED SPECIES? LAJOS ÁCS-SZABÓ, ZSUZSANNA HADHÁZI, MATTHIAS SIPICZKI and IDA MIKLÓS Department of Genetics and Applied Microbiology, University of Debrecen, Debrecen, Hungary Most sexually reproducing organisms have recombination processes during meiosis, which could contribute to the rearrangement of gene order on their chromosomes. This phenomenon could be advantageous for the organism as the new gene order being formed can elevate its fitness. Otherwise it could lead to complete disaster, if it occurs near the centromeres or within repetitive DNA. Henceforth, in proper circumstances recombination occurs just in specific regions, called hotspots. Meiotic hotspots are often motif associated, initiated by transcription factors (Tfs) such as Atf1- Pcr1, Rst2 and Php2-Php3-Php5 complex in Schizosaccharomyces pombe. It is supposed that Tfs play a role in shaping and evolving DNA double strand breaks (DSBs), but forming of DSBs are not caused directly by them. In Sch. pombe, developmentally programmed DSBs are generated by a topoisomerase-related protein called Rec12 (Spo11 in Saccharomyces cerevisiae). A near single- nucleotide resolution DSB map has been made by other laboratories. As this DSB landscape and sequence motifs are available, we are able to examine how meiotic DNA breaks could affect the reshuffling of gene order in the fission yeasts. 1217-8950/$ 20.00 2015 Akadémiai Kiadó, Budapest 128 17TH INTERNATIONAL CONGRESS OF THE HUNGARIAN SOCIETY FOR MICROBIOLOGY First, we analysed the synteny relationships in the four Schizosaccharomyces species by finding conserved collinear blocks that consist of at least five genes. Second, we compared the positions of those blocks and of Rec12 cleavage sites in the genome of Sch. pombe. After that we examined the association of DSB sites and local clustering of essential genes. Moreover, we were curious about the function and co-expression rate of genes located near the cleavage sites. At last, we compared the locations of known meiotic hotspot motifs with our map of conserved collinear blocks. ROLE OF MALDI-TOF METHOD TO IDENTIFY BACTERIAL SPECIES FROM INFLAMED PERIODONTAL POCKETS 1 2 2 1 ANDRÁS ÁDÁM , SZILVIA KAJÁRI , PÉTER VÁLYI and EDIT URBÁN 1Institute of Clinical Microbiology, Faculty of Medicine; 2Department of Periodontology, Faculty of Dentistry, University of Szeged, Szeged, Hungary All forms of periodontitis are multifactorable diseases, but the role of strict anaerobic bacteria is obvious in the procession of the diseases. In the subgingival biofilm, we can group the component bacteria into complexes. We worked with two patient groups: 10 people had aggressive periodontitis and 6 people had chronic periodontitis. The aim of this study was to compare the presence of bacterial species in this two disease forms. We also proposed to compare a rapid biochemical identification system and MALDI TOF mass spectrometry (Bruker Daltonik, Germany) in the identification of anaerobic bacteria. Samples were collected in the Department of Periodontology, in our University. All patients underwent general dental examinations, including pocket depth and bleeding measuring, according to criteria established by WHO. The microbiological sample collection was performed with sterile paper points at isolated and dried pockets. Sample preparation and microbiological culture were carried out according to the routine microbiological practice. After the cultivation procedures all of the isolated bacteria were identified by biochemical and by MALDI- TOF methods. In patients with aggressive periodontitis the average periodontal pocket depth is 6.2 mm (5-8 mm) and the average isolated bacterial species number is 8.2/pocket (4-16/pocket), while in case of patients who had chronic periodontitis the average periodontal pocket depth is 6.8 mm (6- 9 mm) and the average isolated bacterial species number is lower: 5.5/pocket (3-10/pocket). Altogether 189 bacterial strains were isolated in the two groups: 111 (58.7%) obligate anaerobic and 59 (31.2%) facultative anaerobic bacteria. Using the biochemical identification method, only 31.1% of the strains were identified at species level. In contrast, using the MALDI-TOF method 172 isolates (91%) were identified at species level, and in case of 19 isolates (10.1%) identification was not reliable. In this study we used MALDI-TOF mass spectrometry to study the presence of various bacterial species from periodontal pocket samples in cases of aggressive and chronic periodontitis patients. We managed to identify at species and at genus level difficulty identifiable obligate anaerobic bacteria using MALDI TOF. Our result also emphasize that this identification method can be useful for the rapid identification of bacteria from clinical samples. We also managed to identify 7 bacterial strains at species level, which are hardly or not identifiable by biochemical methods. Acta Microbiologica et Immunologica Hungarica 62, 2015 ABSTRACTS 129 THERMOPHILIC BIOFILM AND WELL WATER PROKARYOTIC COMMUNITIES FROM BUDA THERMAL KARST SYSTEM REVEALED BY SEM AND MOLECULAR CLONING 1 1 1 1 1 DÓRA ANDA , JUDIT MAKK , GERGELY KRETT , LAURA JURECSKA , KÁROLY MÁRIALIGETI , 2 1 JUDIT MÁDL-SZŐNYI and ANDREA BORSODI 1Department of Microbiology; 2Department of Physical and Applied Geology, Faculty of Science, Eötvös Loránd University, Budapest, Hungary Phylogenetic approaches and chemical-physical analyses have been used to investigate the diversity of thermophilic archaea and bacteria in a geothermal karst system located in Budapest (Hungary). Karstic thermal water of 73.7 °C and 6.2 pH and biofilm extracted from an outflow pipeline have been analyzed with the help of molecular cloning and scanning electron microscopy (SEM). On the scanning electron microscopic observations it can be clearly seen that calcium carbonate minerals serve as surface for colonization for bacteria and the cross-section of the hollow morphology suggests that bacteria may have played a role in the formation of minerals accumulated in their cell surface. The vast majority of the bacterial clones proved the dominance of the chemolithoautotrophic sulfur oxidizer Betaproteobacteria in the water sample, while that of the hydrogen oxidizer Aquificae in the biofilm. The most abundant phylotypes both in water and biofilm archaeal clone libraries were closely related to thermophilic ammonia oxidizer Nitrosocaldus and Nitrososphaera but phylotypes belonging to methanogens were also detected. The results show that in addition to the bacterial sulfur and hydrogen oxidation, mainly archaeal ammonia oxidation may play a decisive role in the studied thermal karst system. This research was supported by the Hungarian Scientific Research Fund (OTKA NK101356). DIVERSITY OF EXTREMOPHILIC BACTERIA IN THE HIGH- ALTITUDE LAKES OF OJOS DEL SALADO VOLCANO, DRY ANDES 1 1 1 1 2 JÚLIA MARGIT ASZALÓS , GERGELY KRETT , DÓRA ANDA , KÁROLY MÁRIALIGETI , BALÁZS NAGY and 1 ANDREA K. BORSODI 1Department of Microbiology; 2Department of Physical Geography, Faculty of Science, Eötvös Loránd University, Budapest, Hungary Bacterial communities inhabiting the high altitude lakes in a mountain desert area of volcano Ojos del Salado (Dry-Andes) were revealed by molecular biological and cultivation dependent methods. Water and sediment samples from lakes located between 3770 and 6500 meters above sea level were taken in February 2014. Diversity of the bacterial communities was investigated with 16S rRNA based molecular methods. General diversity