Toochukwu Ekwutosi OGBULIE, Ann Ijeoma OGOAMAKA, Justina Ugochi UDENSI
Abstract. Plasmid analysis of bacteria isolated from agricultural soil experimentally contaminated with crude oil was carried out and the resultant bands’ depicting the different molecular sizes of the plasmid DNA molecules per isolate was obtained. There was no visible band observed for Klebsiella indicating that the organism lack plasmid DNA that confers degradative ability to it, possibly the gene could be borne on the chromosomal DNA which enabled its persistence in the polluted soil. Molecular characterization was undertaken to confirm the identities of the possible microorganisms that may be present in crude oilcontaminated soil. The result of the DNA extracted and amplified in a PCR using EcoRI and EcoRV restriction enzymes for cutting the DNA of the bacterial cells indicated no visible band for cuts made with EcoRV restriction enzyme showing that the enzyme is not specific for bacterial DNA of isolates in the samples, hence there was no amplification. By contrast though, visible bands of amplicons were observed using EcoRI restriction enzymes. The resultant visible bands of microbial profile obtained using the universal RAPD primer with nucleotide sequence of 5’—CTC AAA GCA TCT AGG TCC A---3’ showed that only Pseudomonas fluorescens and Bacillus mycoides had visible bands at identical position on the gel indicating that both species possibly had identical sequence or genes of negligible differences coding for degradation of hydrocarbons as shown by similar values in molecular weight and positions in the gel electrophoresis field.
Keywords: Plasmid DNA; Polymerase chain reaction; crude oil; Agricultural soil, Nigeria.
BIOTECHNOLOGICAL ASPECTS CONCERNING THE ERGOSTEROL OBTAINING FROM YEASTS
Elena MOLODOI, Agafia USATÎI, Nadejda EFREMOVA, Natalia CHISELIŢA, Ludmila FULGA
Abstract. This paper reports on the experimental results for selection of Saccharomyces carlsbergensis CNMN-Y-15 yeast strain with high potential for ergosterol biosynthesis; determination of morpho-cultural and physiologo-biochemical characteristics of this yeast strain; establishment of the effect of low-intensity millimeter waves on ergosterol biosynthesis. Research results contributed to the elaboration of technological flow for obtaining of high yield of ergosterol from yeasts. The significant increasing of ergosterol content is possible due to the utililization of optimized nutritive medium with manganese acetate (0.012 g/L) and glucose (40.0 g/L); the treatment of inoculum with low-intensity millimeter waves for 20-30 minutes.
Keywords: yeast, Saccharomyces carlsbergensis, sterols, ergosterol, culture medium, millimeter waves.
EFFECT OF MENADIONE AND HYDROGEN PEROXIDE ON CATALASE ACTIVITY IN Saccharomyces YEAST STRAINS
Nadejda EFREMOVA, Elena MOLODOI, Agafia USATÎI, Ludmila FULGA, Tamara BORISOVA
Abstract. It has been studied the possibility of utilization of two important oxidant factors as regulators of catalase activity in Saccharomyces yeasts. In this paper results of the screening of some Saccharomyces yeast strains for potential producers of catalase are presented. Results of the screening for potential catalase producer have revealed that Saccharomyces cerevisiae CNMN-Y-11 strain possesses the highest catalase activity (2900 U/mg protein) compared with other samples. Maximum increase of catalase activity with 50-60% compared to the reference sample was established in the case of hydrogen peroxide and menadione utilization in optimal concentrations of 15 and 10 mM. This research has been demonstrated the potential benefits of application of hydrogen peroxide and menadione as stimulatory factors of catalase activity in Saccharomyces yeasts.
Keywords: Saccharomyces cerevisiae; antioxidant enzyme; catalase; oxidants.
Hasan Basri JUMIN
Abstract. Protoplasts isolated from embryogenic callus of Clausena harmandiana (Engl.) 'Swing. and M. Kell. were cultured in MT (Murashige and Tucker 1969) basal medium containing 5% sucrose supplemented with bezyladenine (BA), malt extract (ME) and 0.6 M sorbitol. The highest plating efficiency was obtained on MT basal medium containing 5% sucrose supplemented with 0.01 mg 1-1 BA and 600 mg 1-1 ME, MT basal medium containing 5% sucrose and supplemented with 0.01 mg 1-1 6(-y,y-dimethylallylamino)-purine was found to be a medium suitable for the development somatic embryos into heart-shaped somatic embryos. The highest percentage of shoot formation- was obtained using 0.1 mg 1-1 gibberellic acid (GA3) + 0.1 mg 1-1 zeatin. In this investigation 25 plants were survived and grew normally in the soil.
Keywords: Clausena harmandiana, cytokinin, protoplast, somatic embryo, sucrose
Abbreviations: BA - N6-benzyladenine, 2,4-D – 2, 4-dichlorophenoxyacetic acid, DAP – 6-(-y-y-dimethylallylamino)- purine, FDA - fluorescein diacetate, GA3 - gibberellic acid, ME - malt extract,
Mihaela-Liliana IONESCU, Gogu I. GHIORGHIŢĂ
Abstract. In this study we investigated the genetic diversity within Carassius genera, studying individuals from isolated aquatic populations in Romania, by analysing the sequences of three mitochondrial DNA genes: cytochrome b (Cyt b), mitochondrial control region (D-loop) and cytochrome c oxidase I (COX I). The nucleotide sequence variation of the three genes were used to study the mtDNA divergence for Carassius genera individuals and to examine the phylogenetic relationships within analyzed populations. Based on the alignment of cytochrome b gene sequences from individuals belonging to Carassius genera from analyzed populations, 21 haplotypes have been identified: two of them were found in four of the six analyzed populations and one in two of studied populations. Regarding the D-loop sequences there were identified 20 haplotypes: four of them were found in two or more populations. Following COX I sequence alignment, from individuals of the Carassius genera, in the six populations were identified 22 haplotypes, but only one was found in four of the analyzed populations. Phylogeographic aspects of the D-loop showed that there are common haplotypes between Buzău (Buzău River, Buzău County, Romania), Sofroneşti (Sofroneşti Lake, Vaslui County, Romania) Delta (Fortuna Lake, Danube Delta, Romania) and Băile Felix (Bihor County, Romania) populations, and for COX I between Buzău (Buzău River, Buzău County, Romania), Tăuteşti (Tăuteşti Lake, Iaşi County, Romania), Delta (Fortuna Lake, Danube Delta, Romania) and Băile Felix (Bihor County, Romania) populations. From the analysis of all sequences, it was found that the rate of occurrence of transitions is greater than the occurrence of transversions.
Keywords: D-loop; Cyt b; COX I (CO I); Carassius.
Valeriu Ioan VINŢAN, Petru BURESCU
Abstract. In the current paper we present a phytocoenologic study of the phytocoenoses of the association Pulmonario rubrae- Fagetum (Soó 1964) Täuber 1987, identified in the Orăştie river basin, situated in the central-western part of Romania. The characterisation of the association under analysis as well as the presentation of the synthetic table have been done by selecting the most representative relevés performed in the mixed broadleaf-needleleaf forests of beech (Fagus sylvatica subsp. sylvatica), fir (Abies alba) and spruce (Picea abies) with Pulmonaria rubra belonging to the Orăştie river basin. The phytocoenoses of these forests were analysed in terms of physiognomy and floristic composition, life forms spectrum, floristic elements, and ecological indices.
Keywords: Pulmonaria rubra; phytocoenoses; association; relevés; life forms; ecological indices; Orăştie river basin.
PHYTOCOENOLOGICAL RESEARCH CONCERNING THE FORESTS OF OAŞ MOUNTAINS (NORTH-WESTERN ROMANIA)
Ancuţa Mihaela JIBOC, Aurel ARDELEAN
Abstract. This paper aims to describe abaut the presence of the association Tilio argenteae-Quercetum petraeae-cerris Soó 1957, found in the studied area. In the Oas Mountains, it was located on the slopes of the Pustiu Mountain of the Turulung Vii village and it comprises 57 species. The scientific newness lies in approaching a habitat that wasn’t sufficiently explored and the results achieved, which involved the identification and the characterization of a association, which is now reported for the first time in the Oas Mountains. The association Tilio argenteae-Quercetum petraeae-cerris Soó 1957 was analyzed by us in terms of floristic composition, life forms spectrum, floristic elements and ecological indices.
Keywords: phytocoenoses, association, life forms, floristic elements, ecological indexes, Oaş Mountains.
Steliana CLAPCO, Cezara BIVOL, Alexandra CILOCI, Maria STRATAN, Eduard COROPCEANU, Janeta TIURIN, Andrei RIJA, Svetlana LABLIU, Ion BULHAC
Abstract. The supplementation of Co(III) and Cu(II) coordination compounds to the nutrient medium of Fusarium gibbosum CNMN FD 12 essentially increases fungal proteolytic activity. The maximal stimulatory effect was obtained on the 5th day of cultivation. Depending on type and concentration, the compounds stimulated the activity of neutral proteases with 17.5-96.0% and the activity of acid proteases with 12.1-71.7%. On the 6th day of cultivation fungal proteolytic activity decreased significantly, in most cases below the control sample. The direct supplementation of coordination compounds to cultural liquid containing enzyme indicated a neutral or inhibitory effect of just 21.2% compared to the control. This demonstrated the indirect stimulatory effect of coordination compounds on proteolytic activity, most likely due to the inclusion of them in cell metabolism and not direct - in enzyme structure. The chelating reaction with EDTA showed 81.8-78.8% remaining activity of neutral proteases at concentration of 1-10mM EDTA. This result allows us to suppose that most F. gibbosum exoproteases are not metalloproteases. They can belong to family of extracellular serine proteases and aspartic proteases.
Keywords: Fusarium gibbosum (Gibberella intricans), neutral and acid protease, coordination compounds, oxime ligands
