Low ÃŽ- Irradiation Doses on Saccharomyces Cerevisiae

Low - Ir radiation Doses on genus genus genus Saccharomyces CerevisiaeRESULTS OF LOW - scape DOSES ON SACCHAROMYCES CEREVISIAE FERMETATION PROCESSLetiia OPREAN1, Dan CHICEA2, Enik GASPAR, Ecaterina LENGYELAbstract Four different strains of Saccharomyces cerevisiae yeast samples were irradiated utilise a 90Sr nuclear source. The results of this ongoing conduct release that the small slam doses dod in the work reported hither produce measurable changes in the fermentation parameters and in the lipid and phospholipid levels. profound words Saccharomyces cerevisiae, small doses, fermentation.1. INTRODUCTIONYeasts be a addition form of eukaryotic microorganisms classified in the kingdom Fungi. Approximately 1500 species of yeasts score been described, just about of which reproduce asexually by bud, although in a a couple of(prenominal) cases by binary fission. Yeasts are uni carrellular, although some species with yeast forms may commence multicellular through the formation of a string of connected budding cells known as pseudohyphae, or true hyphae as seen in most moulds. Industrial yeasts are of special interest for microbiology and biotechnology because they have a big content of lipids and phospholipids that are currently used in naturist products preparation.Nowadays, comprehensive research is being done with respect to the methods of obtaining lipids and phospholipids from lipid biocomponents, in order to identify new methods for obtaining liposomal substances, needed by the pharmaceutical, cosmetic and medical examination industry. At present, egg lecithin is being used instead but the use of this source has several drawbacks, such as for example the fact that it oxidizes easily. Eukaryotes (yeasts, fungi, algae) are the main microorganisms that produce lipids and phospholipids. Of great interest to microbiology and biotechnology are the researches conducted in the field of phospholipids synthesis, of obtaining phospholipids from microorganisms and of optimizing culture media for their cultivation.During the last decades, ionizing radiations have been investigated to determine their influence on living organisms. Radionuclides are released into the environment from various sources nuclear accidents, as plan discharges from the nuclear power industry, disposal of radioactive waste, medical use, nuclear weapons exploitation or recycling. Ionizing radiations are able to cause toxically and genetic effects on organisms, because radionuclides do accumulate in biotic and abiotic components of the environment 1. atomic radiation can stimulate morphogenetic changes manifest in the early development stages 2, 3. Nuclear radiation can directly disturb metabolic processes, such as photosynthesis, growth, plant respiration, active transport as well as bonce balance and enzyme synthesis 4. The literature reveals that low doses of ionizing radiations can stimulate cell proliferation 5, 6. In this study, we investigated the low dose s of beta radiation influence on the 4 Saccharomyces cerevisia string section, mainly the influence on the fermentation process.The enlarge of the samples spear and fermentation analysis are presented in sections 2 and 3.2. SAMPLE scapeThe samples were irradiated one at a time in an dick bedroom that was build for this purpose. The hole in the upper part fits a rubbish tube than can be easily inserted and extracted. The tube is used to buttocks the sample in the proximity of the beta lance source. The schematic of the irradiation chamber is presented in Fig.1. The dose debit through the glass tube, in the very location w present the yest samples were placed one by one, was measured using a RFT KD27012 dosimeter with an ion chamber.Fig. 1 The beta-irradiation chamberThe - source was 90Sr and decays by the contrivance (1)having E=546 keV, with a branching ratio of 100% 7. The daughter nucleus, 90Y, is unsteady as well. It decays by the scheme (2)with the energies, branch ing ratios and half-lives presented in mesa 1. circuit board 1The energies, branching ratios and half-lives of the 90Y 7.E (keV)I (%)Half-life, hours93.830.000001464.00519.390.011564.00642.770.00183.192280.199.988564.00Four strings of Saccharomyces cerevisiae yeast samples were used. The first string, label SCP, was separated from Turkish yeast having the hallmark Pakmaya. The second string was labeled SCO and was separated from yeast having the trademark Dr.Oetker. The trey string, labeled SCSL, was separated from French yeast having the trademark Saff Levure. The quadrupleth string, labeled SCH, was separated from Dutch yeast having the trademark Hollandia.Two sample of to each one string were prepared, having a suffix 1, for the control, nonirradiated samples and 2 for the irradiated samples. The yeast sample type, irradiation time and irradiation dosis are presented in Table 2Table 2The sample type, irradiation time and irradiation dosisNr.Sample radio beam time (h)Irradia tion Dosis, (Gray)1SCP1002SCP25123SCO1004SCO25125SCSF1006SCSF25127SCH1008SCH25123. Fermentation detailsBoth the control and the irradiated samples were cultivated in malt agar-agar. Malt agar-agar is used for isolating and cultivating yeasts and molds from food and for cultivating yeast and mold stock cultures 8, 9. Malt Agar contains malt extract which provides the carbon, protein and nutrient sources required for the growth of microorganisms. Agar is the solidifying agent. The acidic pH of Malt Agar allows for optimal growth of molds and yeasts while restricting bacterial growth.The eight samples described above were compositors case to a fermentation process conducted in identical conditions, in an providence 20 fermenter. The temperature was kept up(p) constant at 28C. The acidity was maintained at pH=5.8. The maltasic bodily process (which is defined as catalysis of the hydrolysis of maltose by an alpha-D-glucosidase-type action) and the CO2 emission were monitored for 96 hours 10. The results of the fermentation activity, measured as CO2 emission and the maltasic activity measured at 24 hours separation are presented in Table 3. The CO2 emission at 24 hours interval is presented in Fig. 2 and the maltasic activity in Fig. 3.Table 3Results of the fermentation activityNr.crt.Yeast stringCO2-24hmaltasic activity24 hCO2-48hmaltasic activity48 hCO2-72hmaltasic activity72 hCO2-96hmaltasic activity96 h1SCP10.57801.58101.38000.37602SCP20.812201.612401.512000.512003SCO10.78401.38501.18300.28204SCO20.912801.712901.512800.412505SCSL10.67601.47801.27500.37506SCSL20.711901.512101.311600.311807SCH10.78601.49201.19000.48508SCH20.812301.612401.412200.21220Fig. 2 The CO2 emission for the four Saccharomyces cerevisiae yeast stringsExamining Table 1, Fig. 2 and 3 we honor that the fermentation process produced by the irradiated samples (batch having the suffix 2) is more intense, which is proved by the increased CO2 emission and by the increased maltasic activit y.4. Conclusions and discussionsOne of the high-octane procedures to select high productivity yeasts is irradiating the samples with nuclear radiation. To our knowledge, results of irradiation on yeast have not been reported yet and the literature is poor in yeast irradiation 11.Examining the results we can conclude that for all four Saccharomyces cerevisiae yeast strings the low 12 Gray irradiation dosis had a stimulating effect in respect of the fermentation process. The SCO and SCH strings had the high stimulation effect.Fig. 3 The maltasic activity for the four Saccharomyces cerevisiae yeast stringsWe believe that the differences are produced by the yeast genome changes produced by irradiation.The results of this ongoing study revealed that the small irradiation doses used in the work reported here produce measurable improvement in the fermentation parameters. Special supervise must be taken in evaluating the side effects of the irradiationREFERENCESV.I. Kryukov, V.I. S hishkin, S.F. Sokolenko, Radiacionnaja biologija. Radioekologija, 36, 209, (1996).I.W. Mericle, R.P. Mericle, Radiat. Botany, 7, 449, (1967).D. Chicea, M. 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