Fatty Acids Effect on Lipase and Biosurfactant Induction in Rhodotorula Glutinis CMGB-RG5

Fatty acids represent important substrates for obtaining microbial lipases and biosurfactants. The yeast strain CMGBRG5 was identified as Rhodotorula glutinis using the BIOLOG MicroLog System. The opacity screening tests showed that R. glutinis CMGB-RG5 was able to produce lipases in presence of 1% Tween 80 after three days of incubation. Lipase induction was estimated as cell growth in presence of Tween 80, Tween 20, olive oil and tributyrin. After 48 hours, best results were obtained in presence of butyric acid, respectively, oleic acid: 2.2 × 107cells/ml on tributyrin and 1.0 × 107cells/ml on olive oil. Biosurfactant production was evaluated as emulsification index (E24%). After one week, high E24 values were obtained on fried sunflower oil (53%) and olive oil (35%). Crude and concentrated biosurfactants were tested against nine Candida strains. Best antimicrobial activity was observed for [20X] biosurfactants against C. tropicalis, C. guilliermondii and C. krusei. In conclusion, R. glutinis CGB-RG5 shows high potential for using fatty acids from various sources as unique carbon substrates for synthesis of biocompounds with high economic and biotechnological value.

Antibacterial Activity of Magnetite Nanoparticles Coated with Bee Pollen Extracts

In a nanobiotechnology world with many applications in biomedicine, a novel combination of inorganic-organic materials is needed to prove a novel functionality. Natural compounds from bee pollen extract coated on magnetite nanoparticles could open up a new way in apitherapy field. Iron oxide nanoparticles have proved special requirements for biological applications like superparamagnetic properties, high biocompatibility and nontoxic material. Magnetite nanoparticles functionalized with natural bioactive substances extracted from bee pollen have been characterised and investigated for antimicrobial activity. Previous findings demonstrate that magnetite nanoparticles (MNPs) and pollen ethanolic extracts (PEE) exhibited antimicrobial activity against a large antimicrobial spectrum, including Grampositive, Gram-negative and antifungal microorganisms.

The Influence of Climatic Variations on the Stability of Wheat Plant Height

The decrease of variability sources and the genotypes instability as a result of climate changes from the last years were issues addressed in the breeding programs. For breeders the stability of some parameters like plant height is very important in selection process, therefore the influence of climatic variations it is aimed to be reduced by genetic response of the genotypes. Semi-dwarf genotypes are preferred by breeders because in this way is avoided the lodging risk. A set of 307 mutant and mutant/recombinant wheat DH lines, along with parental genotypes, was analyzed in three different years for plant height and the semi-dwarf selected lines were evaluated for stability of this parameter. The material was also analyzed for the presence of Lr34, or genes and 1A/1R translocation. In our study the reduced plant height and its stability was not associated with any of the genetic background

The Potential of New Streptomyces Isolates as Biocontrol Agents Against Fusarium Spp

The excessive use of synthetic pesticides for plant pathogens control could cause possible harmful side-effects to humans and animals, environmental pollution, residual toxicity, affects soil characteristics or induce the development of fungal resistance. Alternative ways for fungal contamination control involve natural products, based on microorganisms, many of them being already available for use. The selection and characterization of new biological agents useful for plant pathogens control are permanent goals for plant protection researches. In the last decade, several studies revealed that Streptomyces species are promising biocontrol agents against a wide range of phytopathogenic fungi, including Fusarium spp., one of the most important wheat pathogens. In our study, 60 strains of Streptomyces spp. were isolated from soil or compost and evaluated for in vitro antifungal abilities by dual confrontation method. At least 30% of the isolates presented inhibitory activity against F. culmorum and F. graminearum. The bacterial strains were also tested for their ability to produce various bioactive compounds, possible involved in fungal inhibition. The capacity of some of the bacterial isolates to produce cellulases, amylases, lipases and volatile metabolites was proved. In addition, a new screening method for chitinases production was developed, based on the use of a combination of Congo red and Lugol solutions, which allowed the detection of chitinases in several Streptomyces spp. strains. Moreover, the reduction of the level of some Fusarium mycotoxins was detected by HPTLC analysis. As a conclusion, antagonistic interactions between Streptomyces isolates and fusaria could involve antibiosis, competition and parasitism and suggested that at least some of the selected isolates could be used in obtaining biological control products.

Study of Heavy Metals in the Soils of Two Localities in Dolj County

The study was conducted in two neighboring localities located in the northern county of Dolj, namely Murgasi and Bulzesti. The purpose of the study was twofold: namely, the study of heavy metal loading in order to identify possible pollution areas and to know the soil content of these localities in heavy metals in order to be able to give the verdict on the use of sludge from Craiova wastewater treatment plant as fertilizer on these soils. In order to determine the suitability of sewage sludge from the Craiova wastewater treatment plant as a fertilizer, physical and chemical properties and heavy metal content of the soils in these areas were analysed, as well as the chemical composition of sludge, according to Order 344/2004 of the Ministry of Environment and Water Management of Romania, respectively 13 physical and chemical parameters of the soils in these localities and the chemical composition of the sludge and respectively the quantity of heavy metals to be introduced annually into the soil by using it.

The Accumulation of Nutrients and Contaminants in Aromatic Plants Grown in a Hydroponic System

Hydroponic systems are highly appreciated today, due to their potential to protect the environment and ensure a high level of food safety. In general, aromatic plants play a very important role in the food, pharmacy, cosmetics, perfumery and aromatherapy industries, all these products being highly appreciated by consumers. Due to their importance, different hydroponic systems are put in place to grow at different levels, these aromatic plants. In the present study, is analyzed the influence of three different hydroponic systems (two vertical and one horizontal) on minerals content and nutritional quality of two varieties of Occimum basilicum and one Mentha piperita variety. In this study are presented dry matter content, ash, micro and macro elements and contaminants content of leaves are presented. The results showed that the vertical system without foil had the best results, followed by the vertical system with foil comparative to the horizontal system that had the lowest content in nutritious principles. The vertical eco-sustainable systems proved to be a promising innovation for growing aromatic plants at the household level and a promising start for the intensive growing.

Evolution of Vegetation Fraction Cover in Agricultural Areas Affected by Prellonged Draughts in the South Regions of Romania

The draught phenomena affecting the traditional agricultural areas in south of Romania has been increasing in intensity over the time, leading to the desertification of several thousands of hectares in the south part of the country. In this study we have computed the vegetation fraction cover for the South-West and South - East regions of Romania, based on the minimum and maximum NDVI extracted from MODIS satellite images. The time frame to refer to is 2000 - 2017, perennially, with special significance given the numerous and prolonged draught intervals these areas have been facing and the social economic evolution, from small farms to large agricultural holdings. The resulted vegetation fraction cover (fc) is correlated to the SPI values in order to determine a pattern to be used in anticipating deviations from the seasonal vegetation productivity. As a conclusion, the study presents a fair balance, indicating the most sensitive areas in soil vegetation cover, due to the SPI change.

Farms Typologies and Their Impact on the Development of Rural Areas in Moldova

For Moldova’s agriculture are characterized the existence of many small family farms and only a small number of corporate holdings (limited liabilities companies, agricultural production cooperatives etc). Most of individual farms, small by size produce only for own family consumption and cannot find their way to the market place. The accentuated poverty makes rural economy to flow more and more to a natural subsistence economy, isolating itself from the market economy. The goal of this paper is to delimitate different types of farms based on selected indicators and to appreciate their level of development. Differences in farms levels of development are appreciated through cluster analysis. The research includes the analysis of farms survey data. This research was carried as a part of the Academy of Sciences project “Sustainable rural development in Republic of Moldova in the context of EU accession”. In the project were surveyed 938 individual farms from nine districts across the country. As a result, we distinguish three types of farms: natural, family and market household. The cluster analysis allows to characterize the farms level development, to determine the main priority directions, and to elaborate measures for the individual farms further sustainable development.

Comparative Assessment of the Analytical Parameters in Ascorbic Acid and Sulphite Assay at a Spectrographic Carbon Working Electrode

The aim of this study is the comparative investigation of spectrographic carbon electrode’s viability as working electrode, in ascorbic acid and sulphite asssessment. Cyclic voltammetry involves a linear sweeping of the potential, the analytical signal being represented by the anodic oxidation /cathodic reduction peak of the analyte. For both analytes, the electro-oxidation resulted in an anodic peak, correlable with ascorbic acid / sulphite concentration. The analytical range of linear response corresponded to 0.07 - 10 mM for ascorbic acid and to 15.5 mg/L - 4 g/L for sulphite. The relative standard deviation RSD (%) was 2.71 % for ascorbic acid and 2.88 % for sulphite. The sensitivities, given by the slopes of the calibration graphs were 88.88 μA/mmole/L for ascorbic acid and 477.37 μA/g/L for sulphite.

Polychlorinated Biphenyls in Soil: Exposure and Health Risk

The paper presents an original research regarding the risk for human health in the area of Ploiesti city using SADA software - Spatial Analysis and Decision Assistance. Due to the high level of toxicity, international legislation provides the list of PCBs compounds to be monitored: PCB28, 52, 101, 118, 138, 153, 180. Sample collection was made in 22 points including public green gardens, residential areas, roadsides and industrial areas. The chemical analyses were conducted in the Laboratory of National Research and Development Institute for Soil Science, Agro-Chemistry and Environment from Bucharest, according to an own analytical method adapted after EPA. According to the Romanian standards, PCBs were elevated across industrial regions near urban and industrial sources. The concentrations of PCBs overcome the normal values in the most sampling points and the area presents a potential of risk for people. Local authorities should address the human health threats from urban and industrial soils in Ploiesti city.