UTICAJ NPK ĐUBRIVA NA RAZVOJ SAPROFITNIH GLJIVA U ALUVIJUMU

The influence of different NPK fertilizer rates on the developement of the saprophytic fungi of the alluvial soil planted with plum culture has been studied over the three-year period (2003 – 2005). The trial was set up in the experimental plum orchard established by Fruit Research Institute Čačak (Serbia) and at the laboratory of Department of Microbiology, Faculty of Agronomy Čačak (Serbia). The soil was treated with 8:16:24 + 3% of MgO mineral fertilizer in the following treatment variants: variant N1 – 400 kgha-1; variant N2 – 600 kgha-1; variant N3 – 800 kgha-1 and variant N4 –1000 kgha-1, all treatment variants being applied in three replications. Unfertilized soil served as the control. The size of the trial plot was 68 m2. The effect of the studied mineral fertilizer rates was determined three times over the growing season. It was checked by identification of the number of saprophytic fungi by the indirect rarefaction method on Czapek nutritive medium. The results of the study suggested that the number of the saprophytic fungi varied by different fertilizer rates, periods of sampling and years of study. The application of fertilizers brought about increase in the number of the saprophytic fungi. Of all studied treatment variants, the one with highest nitrogen rate (variant N4) exhibited the strongest effect. The influence of the applied fertilizer was highest over the third sampling period. Furthermore, the effect thereof was highest in 2003. The application of 600 kgha-1 of mineral fertilizer resulted in the highest plum yield.Tokom trogodišnjih proučavanja (2003-2005) praćen je uticaj različitih doza NPK na razvoj saprofitnih gljiva u aluvijumu pod zasadom šljive. Ogled je izveden u eksperimentalnom zasadu šljiva, Instituta za voćarstvo i u Odeljenju za Mikrobiologiju Agronomskog fakulteta u Čačku. Zemljište je tretirano mineralnim đubrivom formulacije 8:16:24 + 3 % MgO i to: varijanta N1 – 400 kgha-1; varijanta N2 – 600 kgha-1; varijanta N3 – 800 kgha-1 i varijanta N4 –1000 kgha- 1. Kao kontrola korišćeno je zemljište koje nije đubreno. Svaka od navedenih varijanti đubrenja bila je zastupljena u tri ponavljanja. Veličina osnovne ogledne parcele iznosila je 68 m2. Efekat primenjenih đubriva određivan je tri puta tokom vegetacije, a praćen je putem utvrđivanja brojnosti saprofitnih gljiva indirektnom metodom razređenja na Čapekovoj hranljivoj podlozi. Rezultati istraživanja su pokazali da su na brojnost saprofitnih gljiva uticale primenjene varijante đubrenja, periodi uzimanja uzoraka i godine istraživanja. Primena mineralnih đubriva je izazvala povećanje brojnosti gljiva. Od svih ispitivanih varijanti đubriva najizraženiji uticaj pokazala je N4 varijanta (varijanta sa najvišom dozom azota). Uticaj primenjenih đubriva je bio najizraženiji u trećem periodu uzimanja uzoraka. Takođe, može se primetiti najizraženije dejstvo tokom 2003. godine. Najznačajnije povećanje prinosa šljive ostvareno je primenom mineralnog đubriva u količini od 600 kgha-1

UTICAJ NPK ĐUBRIVA NA RAZVOJ SAPROFITNIH GLJIVA U ALUVIJUMU

The influence of different NPK fertilizer rates on the developement of the saprophytic fungi of the alluvial soil planted with plum culture has been studied over the three-year period (2003 – 2005). The trial was set up in the experimental plum orchard established by Fruit Research Institute Čačak (Serbia) and at the laboratory of Department of Microbiology, Faculty of Agronomy Čačak (Serbia). The soil was treated with 8:16:24 + 3% of MgO mineral fertilizer in the following treatment variants: variant N1 – 400 kgha-1; variant N2 – 600 kgha-1; variant N3 – 800 kgha-1 and variant N4 –1000 kgha-1, all treatment variants being applied in three replications. Unfertilized soil served as the control. The size of the trial plot was 68 m2. The effect of the studied mineral fertilizer rates was determined three times over the growing season. It was checked by identification of the number of saprophytic fungi by the indirect rarefaction method on Czapek nutritive medium. The results of the study suggested that the number of the saprophytic fungi varied by different fertilizer rates, periods of sampling and years of study. The application of fertilizers brought about increase in the number of the saprophytic fungi. Of all studied treatment variants, the one with highest nitrogen rate (variant N4) exhibited the strongest effect. The influence of the applied fertilizer was highest over the third sampling period. Furthermore, the effect thereof was highest in 2003. The application of 600 kgha-1 of mineral fertilizer resulted in the highest plum yield.Tokom trogodišnjih proučavanja (2003-2005) praćen je uticaj različitih doza NPK na razvoj saprofitnih gljiva u aluvijumu pod zasadom šljive. Ogled je izveden u eksperimentalnom zasadu šljiva, Instituta za voćarstvo i u Odeljenju za Mikrobiologiju Agronomskog fakulteta u Čačku. Zemljište je tretirano mineralnim đubrivom formulacije 8:16:24 + 3 % MgO i to: varijanta N1 – 400 kgha-1; varijanta N2 – 600 kgha-1; varijanta N3 – 800 kgha-1 i varijanta N4 –1000 kgha- 1. Kao kontrola korišćeno je zemljište koje nije đubreno. Svaka od navedenih varijanti đubrenja bila je zastupljena u tri ponavljanja. Veličina osnovne ogledne parcele iznosila je 68 m2. Efekat primenjenih đubriva određivan je tri puta tokom vegetacije, a praćen je putem utvrđivanja brojnosti saprofitnih gljiva indirektnom metodom razređenja na Čapekovoj hranljivoj podlozi. Rezultati istraživanja su pokazali da su na brojnost saprofitnih gljiva uticale primenjene varijante đubrenja, periodi uzimanja uzoraka i godine istraživanja. Primena mineralnih đubriva je izazvala povećanje brojnosti gljiva. Od svih ispitivanih varijanti đubriva najizraženiji uticaj pokazala je N4 varijanta (varijanta sa najvišom dozom azota). Uticaj primenjenih đubriva je bio najizraženiji u trećem periodu uzimanja uzoraka. Takođe, može se primetiti najizraženije dejstvo tokom 2003. godine. Najznačajnije povećanje prinosa šljive ostvareno je primenom mineralnog đubriva u količini od 600 kgha-1

Bacteriocins produced by lactic acid bacteria - A review

Lactic acid bacteria (LAB) have an essential role in the production of fermented products. With their metabolic activity, they influence the ripening processes - leading to desired sensory qualities while at the same time inhibiting the growth of undesired microorganisms. Because of their dominant role during fermentation and because of a long tradition of utilization, LAB have been designated as safe microbiota. Biological protection of LAB, as a naturally present and/or selected and intentionally added microflora, is realized through the production of non-specific (lactic acid, acetic acid and other volatile organic acids, hydrogen peroxide, diacetyl, etc) and specific metabolites, bacteriocins. Bacteriocins are extracellularly released proteins or peptides which possess certain antibacterial activity towards certain types of microorganisms, usually related to the producing bacteria. Today, bacteriocins represent a very interesting potential for their application in the food industry. Their application can reduce the use of synthetic preservatives and/or the intensity of thermal treatment during food production consumer's need for safe, fresh and minimally-processed food. With the intention of realizing this potential to the fullest, it is necessary to understand the nature of bacteriocins, their production mechanisms, regulations and actions, as well as the influence of external factors on the their antimicrobial activity. The composition of food, i.e. its characteristics (pH, temperature, ingredients and additives, types and quantities of epiphytic microbiota) and the actual technological process used in production, can all influence the stability and activity of the added bacteriocins. The future research in this field should also aim to clarify this unknown aspect of the application of bacteriocins, to provide the necessary knowledge about the optimization of the external conditions and open up the possibility of discovering their new producers

Scientific and pedagogical life an outstanding Russian microbiologist of the 20th century

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Effect of Biofertilizers on Soil Microbial Activity and Basic Morphological Characteristics of Camellia Sp. and Cupressus Sp.

This paper examines the effect of Enteroplantin and Slavol on soil mi- crobial activity (count of microorganisms, numbers of azotobacter, oligoni- trophiles, soil fungi and actinomycetes) and growth (length of underground and aboveground plant parts) of Camellia sp. and Cupressus macrocarpa gold crest, grown in vegetative pots. Microbial counts were determined by an indirect method of growth on specific selective media. Enteroplantin and Slavol induced an increase in the number of all examined groups of microorganisms, except soil fungi. Enteroplantin was found to be particularly effective in this respect, hav-ing a more stimulating effect on the growth of roots and aboveground parts of both plants, in the course of the entire study period (2006–2008). The observed growth of the aboveground parts and roots of both plants, the established val-ues of soil microbial parameters, and potential economic and environmentaleffects suggest that Enteroplantin and Slavol can be recommended for use in cultivating Camellia sp. and Cupressus macrocarpa gold crest..This work is supported by the Ministry of Education and Science of the Republic of Serbia, Projects TR-31057 and TR-31093.Author's versio

Microorganisms and Technogenic Polution of Agroecosystem

This paper deals with the reactions of the soil microbial community to the effects of agrochemicals (pesticides, heavy metals), oil pollution and other possible xenobiotics.. Pesticides and heavy metals change the physicochemical properties of the soil and lead to a distribution in the qualitative composition of the soil microbial community, which is characterized by a wide range of phenomena (stimulation, repression, resistant species). Some compounds of S, N and CI cause soil and groundwater acidification, which results in Ca, Mg and K losses, higher content and greater activity of AI, Fe and Mo as well as in the activation of toxic elements Hg, Pb and Cd, which reduce the number of bacteria and actinomycetes and enhance the presence of bacilli and fungi in the soil. Low oil pollution level may cause fluctuating changes in the soil microbial cenosis, whereas a higher one may result in serious disorders of the microbial community and even in its completely restrained activity.Publishe

Microorganisms as indicators of soil pollution with Heavy metals

Since indication geobotany and indication biology have not succeeded to identify microorganisms for early indication of soil pollution yet, microbiological indication has been approached differently - analysing diagnostic signs of isolated levels of soil pollution with heavy metals. In this regard, the distribution occurring in the amylolytic microbial community under the effect of the anthropogenic soil loading and particular indicators of biochemical activity of soil microorganisms (nitrogen fixing activities) should be analysed when studying responses of higher plants and the occurrence of microorganisms, which are resistant to soil pollution with heavy metals.Publishe

INFLUENCE OF SOLVENT TYPE ON THE PHENOLIC CONTENT AND ANTIMICROBIAL AND ANTIOXIDANT PROPERTIES OF ECHIUM VULGARE L. EXTRACTS

The aim of this study was to investigate influence of solvent type on the phenolic content and antimicrobial and antioxidant properties of Echium vulgare L. extracts. The following solvents were used in the study: ethanol, acetone, chloroform, petroleum and ethyl acetate. The content of phenols, flavonoids and tannins was determined by spectrophotometric methods, while the identification and quantification of polyphenolic compounds was performed by chromatographic method. Determination of antimicrobial activity was done by microdilution method, while several methods were used in the evaluation of antioxidant activity of plant extracts. The ethanolic extract had the highest content of phenols and flavonoids, while chloroform extract had the highest content of tannins. The ethanolic extract exhibited the best antioxidant potential compared to other extracts, and ethanolic and chloroform extracts manifested the best antimicrobial activity

Effect of bread dough mixing method on rye bread quality

The objective of this study was to evaluate the effect of sourdough (indirect bread dough mixing method) on the quality of rye/wheat bread (TYPE 500 wheat flour and whole grain rye flour - 60:40) and determine its advantages over the straight dough method. Three bread dough mixing methods were used: I - indirect bread dough mixing using flour scalding; II - indirect bread dough mixing without flour scalding; III - straight dough mixing. The study involved the monitoring of the following: microbial characterristics of the flour and dough (yeasts and lactic acid bacteria) and of the bread (presence of Enterobacteriaceae, yeasts and moulds); chemical properties of the dough and the bread (pH and degree of acidity); organoleptic attributes of bread (volume, porosity according to Dallman, crumb elasticity, pore structure fineness, bread crumb score, external appearance, crumb appearance, flavour of both the crust and the crumb). The results showed the highest counts of lactic acid bacteria and yeasts in the indirect bread dough mixing method using rye flour scalding. The rye/wheat bread made with sourdough had a mild sourish flavour, an intense aroma, a prolonged shelf life, and reduced crumbliness. The study suggests that the technological process of sourdough-type rye/wheat bread making is an important requirement in improving bread quality and assortment that can be used in any bakery facility

The quality of noncarbonated nonalcoholic beverages during their shelf life

The manufacture of safe products that have important quality parameters and the preservation of these requirements during the specified shelf life are the main tasks of any manufacturer. To meet these requirements, it is necessary to implement appropriate manufacturing practices and adhere to the prescribed regulations. The aim of this study was to investigate the microbiological safety and sensory properties of seven types of non-carbonated non-alcoholic beverages (I - VII), produced by the Knjaz Miloš AD Company, Arandjelovac, Serbia, containing different ingredients (I: peach flavouring, citric acid, a mixture of vitamin B, sugar, potassium sorbate and sodium benzoate; II: herbal extracts of guarana and lemon grass, apple, grape and lemon juices, citric acid, caffeine, vitamins and lemon flavouring; III: inulin and extract of Aloe vera, apple, orange, pineapple, mango, passion fruit, kiwi and papaya juices, citric acid, L-ascorbic acid, melon flavouring and preservatives; IV: concentrated apple, grape and lemon juices, citric and L-ascorbic acids, juniper, gentian and lavender flower extracts, cherry flavouring and preservatives; V: Cambogia Garcinia extract, fructose, L-carnitine, Mg-citrate, vitamins, lemon, lime juice, green tea, and caffeine flavourings; VI: sugar, Mg and Ca-lactate, citric acid, preservatives and flavouring agents; VII: concentrated apple juice, Mg and Ca-lactate, sugar, citric acid, preservatives and flavourings). Samples were kept in the original packaging, at different storage temperatures (20, 25, 30 and 42 0C). Microbiological tests were carried out according to the national legislation on safety and non-alcoholic beverages, which is in accordance with both ISO methodology (Enterobacteriaceae, yeasts, fungi, aerobic mesophilic bacteria) and internal control requirements set down by the company (coagulase positive staphylococci, sulphate- reducing clostridia, E. coli, acid-tolerant microorganisms). All analyses were carried out at succesive ten-day intervals, during three months. At the end of the production, all samples were microbiologically safe. The presence of lactic acid bacteria wasnot recorded in the tested samples during the three months of storage. The number of aerobic mesophilic microorganisms significantly increased in beverage I (20 days at 25 0C), IV (20 and 50 days at 20 0C and 90 days at 25 0C), and V (50 and 80 days at 20 0C). The total numbers of mould and yeast, and acid-tolerant microorganisms significantly increased only in the samples of beverage I (90 days at 25 0C) and III (10 days at 25 0C). Other microbiological results were within the prescribed limits. Throughout the study, sensory test results for all samples showed normal quality.Publishe