Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XX
Written by Gabriela POPA, Catalina VOAIDES, Matilda CIUCA, Calina Petruta CORNEA

Pleurotus eryngii is an edible mushroom with important biological functions, such as anticancer, antiviral, immune potentiating, and hypolipidemic activities. Due to its importance from economically, medicinal and ecologically point of view, a special attention was given to this species worldwide. Analyses via molecular markers revealed that Pleurotuseryngii is a species complex comprises at least six varieties (natural isolates and commercial strains). Improvement of culture technologies as well as the increase of biological compounds content involves a better knowledge of the genetic properties of each isolate, candidate for specific applications. For this reason, in this study several strains of Pleurotus eryngii collected from different geographical locations were analyzed in correlation with a wild Pleurotus ostreatus isolate, in order to determine the genetic variability and relationship between species. The genetic diversity of biological material was analyzed using a TBP (tubulin-based polymorphism) molecular marker that relies on the presence of intron-specific DNA polymorphisms of the plant β-tubulin gene family. For the fungal DNA extraction mycelium obtained on plates with PDA was used. Our results revealed that TBP amplification profile of intron 1 showed eight polymorphic bands while TBP amplification profile of intron 2 indicated nine polymorphic bands.The multiple length polymorphism of β-tubulin intron 2 generated amplification profiles which resulted highly specific for each of the analyzed species. However, these results suggested that TBP molecular markers could be used for highlighting the genetic diversity both intra- and inter-specific and the genetic diversity was closely related to the geographical distribution of this fungus.

[Read full article] [Citation]

SPUPOPUPNO1

Read full article 

Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXI
Written by Gabriel Florin ANTON, Maria JOIȚA-PĂCUREANU, Luxiţa RÎŞNOVEANU, Călina Petruţa CORNEA, Mihaela POPA

The virulence of the downy mildew pathogen increased during the last period and new virulent races of this fungus appear. Thus it is essential to know data about the presence and distribution of the pathotypes. In Europe, an increasing number of the pathotypes, have been identified. In Romania we identified eight races of the pathogen. They are not present in all areas cultivated with sunflower, in some areas being present only five races, in other six or seven. Using the sources of resistance to Plasmopoara halstedii pathogen, for the most virulent races present now in Europe we have introduced genes of resistance in the best lines from our germplasm collection. The testing of some sunflower hybrids with different degree of resistance to downy mildew has showed that there is difference in the pathogen attack degree, depending on the climatic conditions in the years and locations.

[Read full article] [Citation]

SPUPOPUPNO1

Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXI
Written by Cristian MOISA, Lucian COPOLOVICI, Georgeta POP, Dana COPOLOVICI

Mountain or winter savory Satureja montana L. is one of the most cultivated aromatic plant from Lamiaceae family. As most of the species from their genus, Satureja montana L. contains essential oils which differ in chemical composition as plants are from different origin or has been dried in different regime. This study has been shown that chemical composition and antioxidant capacity are different for dry and fresh herba and even has been varying if the herba was dried in air or in the oven. It has been demonstrated that the major compound, carvacrol, of volatile oils from dry herba was found to be in higher percent than in volatile oils extracted from fresh herba. In contrast, different sesquiterpenes concentrations were higher for fresh herba. The antioxidant capacity was two times bigger for the oil extracted from dry herba. This surprising feature could be explained by the higher carvacrol concentration and lower thymol concentration determined in volatile oil extracted from dry herba.

[Read full article] [Citation]

SPUPOPUPNO1

Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXI
Written by Giorgiana M. CĂTUNESCU, Ioan ROTAR, Roxana VIDICAN, Ancuţa M. ROTAR

Vitamin C and total polyphenols are quality markers used to assess the effect of treatments and storage on foodstuffs. Although, the effect of other conventional shelf-extension method is well established, refrigeration was taken for granted and rather neglected. The present study aims to describe its influence on three minimally processed herbs stored at 4°C for 12 days: parsley (Petroselinum crispum), dill (Anethum graveolens) and lovage (Levisticum officinale). The content of ascorbic acid and total polyphenols was determined on methanolic extracts. Ascorbic acid was separated, identified and dosed using HPLC coupled with an UV–VIS detector. Total polyphenols were determined spectrophotometrically, following Folin-Ciocalteu method. On the first day of storage, the content of vitamin C was above 170 mg/100 FW for the three herbs: dill had the highest content, followed by parsley and lovage, statistically similar. During the 12 days of storage, the content of vitamin C decreased by 18% for parsley, by 8% for lovage and by 3% for dill. At the beginning of the study, lovage had the highest content of total phenols followed by parsley and dill. On day 5 of storage, the content increased, reaching the maximum values for the three herbs and then it decreased below the levels of the first day. It was noted that during the 12 days of study, the evolution of total polyphenols at refrigeration temperature was given by a function of second degree. Thus, the present study confirms that vitamin C can be successfully used as a quality marker for herbs due to its low stability during storage. The evolution of total phenols is polynomial, reaching its peak during the shelf-life of herbs.

[Read full article] [Citation]

SPUPOPUPNO1

Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXI
Written by Evelina GHERGHINA, Florentina ISRAEL-ROMING, Daniela BĂLAN, Gabriela LUŢĂ

Sweet potato (Ipomoea batatas L.) is an important food crop around the world, being cultivated in more than 100 countries as the crop can be a rich source of energy and have been recognized as healthy foods because of their significant content of phytonutrients. In recent years, the use of bioregulators in sustainable agriculture has been growing because it leads to higher content of nutrients in the plant tissues and positive metabolic changes. It appears that using abscisic acid in controlling the mechanisms of plant evolution is a good alternative for an ecologic agriculture given that recent studies on the mechanism of the abscisic acid action have shown its great importance as a bioregulator for plants. The objective of this work was to to study the influence of the abscisic acid treatment on some quality characteristics of sweet potato. For this purpose abscisic acid solutions in different concentrations were used as foliar treatments on sweet potato leaves and comparative results concerning some morphological and biochemical changes in the tuberous roots were studied. The experiment was conducted starting with the first leaves appearance until the harvesting of the roots, while determination of the sugars and proteins content were made on the tuberous root harvested in the maturity stage.

[Read full article] [Citation]

SPUPOPUPNO1

Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XX
Written by Osman Kadir TOPUZ, Adem KAYA, Ali Can Alp

Microalgae are a recognized source of fatty acids and fatty acid-based lipids of potential interest in preparation of functional health products. Unlike terrestrial crops, these photoautotrophic microorganisms can directly produce polyunsaturated fatty acids (PUFA) and, although microalgae are not suitable for direct human consumption, their nutritional value can also be exploited if added to animal feeds. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) belongs to the omega-3 fatty acids group. In recent years, omega-3 fatty acids rich oil has attracted much attention because of its recognized beneficial effect on human health. In this study, response surface methodology was used to investigate the effect of ultrasound-assisted extraction variables including extraction temperature (25-6°C), extraction time (30-90 min.) and solvent: microalga ratio (10:1-30:1 ml:mg) on the omega-3 EPA content of N. oculata microalga. The experimental results showed that the extraction temperature and time were the significant parameters for the EPA rich oil extraction, while the solvent:microalga ratio was insignificant. The optimum oil extraction parameters for the maximum omega-3 EPA content were as follows: extraction temperature, 27.6°C; extraction time, 34.00 min. and solvent:microalga ratio, 21:3 ml:mg. Under the above predicted optimum conditions, the experimental oil yield and omega-3 EPA content were 62.8 % and 16.25%, respectively. The drying of algal biomass by freeze dryer improved the green color intensity and omega-3 EPA content.

[Read full article] [Citation]

SPUPOPUPNO1

Read full article 

Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXII
Written by Maria PETRESCU, Mihaela-Carmen EREMIA

This work aims to study the effect of gamma radiation on the inulinase production by the fungus Aspergillus terreus. The fungus was screened for the ability to produce enzymes from other strains belonging to the Collection of Microorganisms of Industrial Importance of the National Institute of Chemical-Pharmaceutical Research and Development. Subsequently, the fungi were irradiated at 3 doses (500, 1000 and 1500 Gy), using the vegetative form of the fungi. A fermentation assay for enzyme production was made using the DNS method. The best enzyme activity was 770.7 U/L, obtained from the media with orange peels. The use of gamma radiation increased the production of enzymes compared to tests without radiation. Statistically, the best dose of radiation was 1000 Gy.

[Read full article] [Citation]

SPUPOPUPNO1

Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXI
Written by Hülya GÜL, Hicran ŞEN

The effects of rosehip seed flour (RSF) on the rheological properties of bread dough were investigated. RSF was substituted with bread wheat flour at the proportions of 5, 7.5 and 10%. RSF was found to have 7.4 % protein, 4.6% lipid, 79.4% dietary fiber, 97.60 g/kg GAE total phenolic, and 759.48 IC50=μg/ml antiradical activity. Among farinograph parameters: water absorption, development time and softening value of RSF added doughs were found lower than the control dough while stability was showed slightly increase as the RSF level increases from 5% to %7.5. However it began to decrease after this level. Textural measurements by using Kieffer dough and gluten extensibility rig studies showed that inclusion of RSP did not cause any significant change at the maximum resistance to extension and extensibility of doughs when 5% of RSP was added. As the level of RSF increased from 5 to 7.5 and 10% respectively, a decrease in extensibility of doughs was observed. The addition of RSF resulted in significant effects on pressure, extensibility and energy of doughs measured with Dobraszczyk/Roberts dough inflation system of the texture analyser. A significant increase was observed in pressure and energy of doughs who were positively correlated with increased level of RSF. On the other hand a weakening was noted at higher levels (from 5% to 10%) when compared with control dough. As a result; substitution at 5 % of RSF gives rheological parameter values at least as good as the control sample and it can be used as valuable ingredient to enhance the functional properties of bakery products.

[Read full article] [Citation]

SPUPOPUPNO1

Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XXI
Written by Suleyman KIZIL, Tahsin SOGUT, Umit ACAY, Berfin SARIHAN, Ugur SESIZ, Khalid Mahmood KHAWAR

In vitro regenerated bulblets of Hyacinthus orientalis L., improved their size using MS medium containing different sucrose concentrations. The sucrose concentrations showed higher growth and better development of the bulblets on MS medium stored at 24°C. Sucrose showed the highest performance rate at 9 % concentration for both small and large bulblets. Sucrose treatments showed positive effects of induction of bulb diameter, number of shoots per bulb, shoot length and bulb weight in the culture medium.

[Read full article] [Citation]

SPUPOPUPNO1

Published in Scientific Bulletin. Series F. Biotechnologies, Vol. XX
Written by Gianina Antonela BADEA, Arina Oana ANTOCE

The colour of wine is an important characteristic which contributes to the construction of the quality profile of a wine. This parameter is extremely important especially for white wines, a close connection being present in the consumer’s perception between the colour of the wine and its quality level. The appearance of brown shades due to oxidation reactions is equivalent to a decrease in the quality level of the white wine and may indicate even an irreversible degradation of the wine. The present study evaluates the colour evolution of a Sauvignon Blanc wine during storage in bottles after being treated just before bottling with different combinations and doses of sulphur dioxide (SO2), ascorbic acid (AA) and reduced glutathione (GSH).The use of various antioxidants aims to reduce and prevent the browning evolution of white wine colour, and many hopes are expressed regarding the newly OIV approved reduced glutathione. However, this preliminary study results indicate that, in certain conditions, these antioxidants may not confer the expected protection and could even damage the final colour of white wine.

[Read full article] [Citation]

SPUPOPUPNO1

Read full article