Maxim BYRSA

Abstract. This study concerns the influence of a cianobacterial extract containing amino acids and oligopeptides on the growth, biomass and lipid accumulation, and quantitative and fractional lipid composition of Streptomyces canosus CNMN-Ac-02. The cyanobacterial extract was used as a supplement to growth liquid complex medium M-I. A significant increase of S. canosus CNMN-Ac-02 biomass yeld was registered for all concentrations in which the biological product was added. The best result was obtained using a concentration of 20.0 %/V of cyanobacterial extract, an increase by 81.38 % compared with control was recorded. Conversely, a larger amount of lipids (by 38.36 % compared with the control) was obtained using 0.1 %/V of cyanobacterial extract of amino acids and oligopeptides. Fraction of phospholipids in biomass of S. canosus CNMN-Ac-02 increased by 18.2 % - 25.39 % in comparison to the control, after cultivation on M-I medium with content of cyanobacterial extract of amino acids and oligopeptides, both in low concentrations (0.1-0.1 %/V). The cyanobacterial extract of amino acids and oligopeptides in concentration of 10.0-20.0 %/V, stimulate the accumulation of mono- and diglycerides by 8.91-16.2 % compared with the control. The fraction of sterols remained at the same level, but their esters increased by about 30 %.

Keywords: Streptomyces; cyanobacterial biological product; biomass; fractional lipid composition.




 Svetlana BURTSEVA, Oleg CHISELITSA, Maxim BYRSA, Natalia CHISELITSA

Abstract. The effect of cyanobacterial zinc sulfated polysaccharides from Arthrospira (Spirulina) platensis CNMN-CB-02, as a supplement added in complex liquid medium M-I, on accumulation of biomass, synthesis of total lipids and fractional lipid composition of strain S. canosus CNMN-Ac-02 was studied in laboratory conditions. Maximal quantity of biomass compared to control was obtained using 30.0 %/V Psh*ZnS (8.83 g/l) concentration, with an increase of 63.91 %. In the experiment total lipids were lower than in the control. However, no significant difference was observed at 5.0 %/V Psh*ZnS concentration (95.82 %) in comparison to control. At all concentrations of Psh*ZnS applied, fractions of phospholipids and sterols were higher than those observed in the untreated control. Significant increase of triglycerides (20.63 %) was obtained adding in the growth medium 10.0 %/V Psh*ZnS. All tested concentrations of Psh*ZnS had no effect on mono- and diglycerides in comparison to control, whereas waxes were significantly lower. Quantity of sterol esters was higher in comparison to control only at concentrations of 1.0-20.0 %/V Psh*ZnS. Total lipids were increased by the increase of biomass, by 15.9 % in comparison to control, after the addition of Psh*ZnS at 30.0 %/V concentration.

Keywords: Streptomyces; cyanobacterial zinc sulfated polysaccharides; biomass; fractional lipid composition.



Yulia BEREZIUK, Svetlana BOORTSEVA, Svetlana GARAEVA, Maxim BYRSA, Alexandr MANCIU

Abstract. The article deals with importance of proteins and amino acids in vital processes of all organisms and finding new ways for obtaining its in sufficient quantity to meet the growing demands. Because strains of genus Streptomyces are source of proteins and amino acids, the aim of research was to study changes of amino acid composition of the biomass of the strain Streptomyces fradiae CNMN-Ac-11, which was obtained during cultivation on medium R supplemented with bio products of cyanobacterial nature. Medium for cultivation R was improved by adding of cyanobacterial bio products BioR and Psh*ZnS. For analysis of amino acid composition were selected biomasses of experimental variants obtained after cultivation on medium R + 0.1 % BioR and medium R + 30.0 % Psh*ZnS, because of their benefic influence on lipogenesis. The addition of the BioR preparation in a concentration of 0.1 % had a significant effect on the productivity of the biomass of the strain and the synthesis of amino acids, increasing their yield by 24.2 %. The quantity of individual amino acids, such as asparagine, serine, valine, threonine and phenylalanine, has more than doubled. The addition of Psh*ZnS particularly affected the biosynthesis of methionine, increasing its yield by 83.8 %. The significant increase in the amount was mainly seen for essential amino acids.

Keywords: essential amino acids; proteins; Streptomyces; cyanobacterial bio products; biomass; lipids.



Zorica VOŞGAN, Lucia MIHALESCU, Marian JELEA, Monica MARIAN, Anca DUMUŢA, Flavia POP, Oana MARE ROŞCA, Cristian Felix BLIDAR

Abstract. The growth and multiplication of pathogenic bacteria in raw milk depend on various factors including animals` health and the environmental, hygienic and technological conditions during production. In this study, the incidence of coagulasepositive staphylococci (Staphylococcus aureus and other species) in raw goat milk collected each season (spring, summer, autumn) from a herd of goats bred in extensive system was monitored. The average growth rate of pathogens in milk was of 1.4 × 103 CFU/ml in the spring months when milk production was high, also with an increase in the contamination degree during summer of 3.2 × 103 CFU/ml, while in autumn the microbial population was quantified at 2.8 × 103 CFU/ml. The average results obtained in the spring months showed a low standard deviation. Seasonal variation indicated a higher contamination during summer in higher temperature conditions, but the 105 CFU/ml threshold considered relevant to the possibility of bacterial enterotoxins production was not exceeded. The microscopic examination performed on typical colonies revealed the presence of the specific cluster shape for staphylococcus bacteria. Multiplication of staphylococci in milk occurs by not following appropriate hygiene measures in correlation with environmental factors specific to each season. These germs were analyzed because their presence in the raw material (raw goat milk) influences the hygienic quality of the finished product.

Keywords: hygiene, milk raw, stapylococ, season.



Lucia MIHALESCU, Zorica VOŞGAN, Flavia POP, Monica MARIAN, Stela JELEA, Oana MARE ROŞCA, Anca DUMUŢA, Cristian Felix BLIDAR, Aurel MAXIM

Abstract. The purpose of the research was the monitoring of two tomato varieties behavior, Petula F1RZ and Gravitet F1 under the attack of Alternaria porri fungus, as well as determination of biologic efficiency for five fungicides, in order to recommend the most efficient products in treatment schedules. The experimental researches were carried out during 2014 and 2015 in the Sălsig village, Maramureş County, Romania. Ten products of plants protection were tested on the two varieties, and only 5 products were selected for their biologic efficiency, in 2014. The attack was calculated by determining the frequency and intensity of the disease. The linear-interrupted laying method was used. The obtained values showed that Gravitet F1 variety had a much higher sensitivity to the attack of the pathogen than Petula F1RZ variety. The data analysis showed that for Petula F1RZ variety the most efficient was V1, using the product Score 250EC, with the efficiency of 90.6%, followed by V2 – Cabrio TOP with 90.0%, and the last one, V5 – Pergado MZ with 84.5%. For Gravitet F1 variety, the scale was the same, but the efficiency of the products was diminished due to the sensitivity of the variety.

Keywords: alternariosis, attack, fungicide, tomato.