The aim of the research was to examine the effect of rhizospheric bacteria Azotobacter chroococcum, Pseudomonas fluorescens (strains 1 and 2) and Bacillus subtilis on the growth and yield of onion and on the microorganisms in the rhizosphere of onion. The ability of microorganisms to produce indole-acetic acid (IAA), siderophores and to solubilize tricalcium phosphate (TCP) was also assessed. The experiment was conducted in field conditions, in chernozem type of soil. Bacillus subtilis was the best producer of IAA, whereas Pseudomonas fluorescens strains were better at producing siderophores and solubilizing phosphates. The longest seedling was observed with the application of Azotobacter chroococcum. The height of the plants sixty days after sowing was greater in all the inoculated variants than in the control. The highest onion yield was observed in Bacillus subtilis and Azotobacter chroococcum variants. The total number of bacteria and the number of Azotobacter chroococcum were larger in all the inoculated variants then in the control. The number of fungi decreased in most of the inoculated variants, whereas the number of actinomycetes decreased or remained the same.

The effect of inoculation with Pseudomonas fluorescens and Bacillus subtilis on the yield of fresh and dry mass of English ryegrass (Lolium perenne L.) as well as on the number of rhizospheric microorganisms was studied. The microorganisms were introduced into the soil before sowing. The control plots were not inoculated. The number of microorganisms was determined after the third mowing. The yield was determined after the first, second and third mowing. In comparison with the control, after the first and second mowing, there was a statistically significant increase in the fresh and dry mass in both inoculated variants whereas after the third mowing, a statistically significant increase in the yield of fresh mass was recorded only in the variant with B. subtilis. The use of B. subtilis had a better effect on the total yield of the fresh and dry mass of English ryegrass. The number of the investigated groups of microorganisms, apart from actinomycetes, increased in the inoculated variants. Inoculation of P. fluorescens affected the increase of total number of bacteria and aminoheterotrophs whereas inoculation of B. subtilis affected the increase of the number of azotobacter and fungi.

The aim of this study was to determine the microbiological activity in soil under beans in organic and conventional production. Organic production was conducted on the field in the village Pivnice (Serbia), while conventional production was conducted in the village Curug (Serbia) during 2014 on the chernosem type soil. Cultivars of beans Belko, Dvadesetica, Maksa, Slavonac, Sremac, Zlatko were used. Before sowing, the bean seeds were inoculated by biofertilizers NS-Nitragin. NS-Nitragin contains a mixture of selected strains of symbiotic bacteria Rhizobium leguminosarum bv. phaseoli. The total number of actinomycetes, ammonifiers, Azotobacter, bacteria and fungi were determined. At the end of vegetation period in conventional production the highest number of actinomycetes (5.83) and fungi (4.87) was recorded in cultivar Dvadesetica. In organic production the highest number of ammonifires was in cultivar Sremac (9.91). The highest number of bacteria was in cultivar Dvadesetica (9.08) and the highest number of fungi was in cultivar Zlatko (5.14). The results have shown that number of microorganisms was higher in organic production.

Microalgae application in agriculture is an alternative measure that could be highly beneficial to plants. The application of microalgae Chlorella vulgaris S45 and its effect on plant growth and pigment content in Swiss chard were investigated. In the treatments, 5% and 10% algal suspensions were applied by spraying on plants and in soil, respectively. C. vulgaris S45 affected the initial growth of Swiss chard and the content of photosynthetic pigments positively. The correlation analysis proved the existence of statistically significant interdependency between chlorophyll a (Chl a) content and leaf number (r = 0.876 at p < 0.05), and chlorophyll b (Chl b) content and fresh leaf weight (r = 0.783 at p < 0.05).

The presence of porcine circovirus 2 and porcine parvovirus was examined in forty clinical samples of spleen, lymph nodes and lungs originating from non-vaccinated swine by polymerase chain reaction. All animals were reared in extensive livestock farming systems in different geographical districts of Republic of Srpska, Bosnia and Herzegovina. Porcine circovirus 2 DNA was detected in four lymph node and two spleen samples (15%), while porcine parvovirus DNA was identifi ed in fi ve lymph node samples (12.5%). The presence of both viruses was detected in three lymph node samples (7.5%). Partial nucleotide sequence of ORF1 gene of 2 porcine circovirus 2 and VP2 gene of 2 porcine parvovirus isolates was determined. The nucleotide sequences of two PCV2 isolates from RS-BIH included in phylogenetic typing are similar and cluster together with the strain Mantova isolated from domestic pigs in Italy, strains DE006-14 and DE222-13 isolated from pigs in Germany as well as with the strain Jvnan isolated from pigs in China. Also, analyzed PCV2 isolates were partially similar to the strain NIV-C SRB isolated from pigs in Serbia. The nucleotide sequences of two PPV isolates that were included in phylogenetic typing showed a high level of similarity with the strain Challenge isolated from pigs in UK, strain Kresse isolated from pigs in USA and strains 77 and LZ isolated from pigs in China.

The present study was carried out to investigate the influence of crop rotation and fertilization on the number of different groups of microorganisms. Soil samples were taken from the following treatments: 1. Monoculture of maize, 2. Maize-wheat (without fertilization), 3. Maize-wheat (with fertilization), 4. Maize-soybean-wheat (with fertilization), 5. Pasture soil, 6. Forest soil under oak, from three depths: 0-10 cm, 10-20 cm, and 20-30 cm in May and October 2012. Microbiological analyses included the determination of total number of bacteria, number of fungi, actinomycetes, aminoheterotrophs, and azotobacter. The number of investigated groups of microorganisms was higher in May on average. Fertilization did not affect the number of investigated groups of microorganisms. Crop rotation positively affected the total number of bacteria and the number of aminoheterotrophs in soil under maize.

Honey bee mite Varroa destructor and microsporidium Nosema ceranae are currently considered the most important threats to honey bees and beekeeping. It has been believed that both N. apis and N. ceranae invade exclusively epithelial cells of the honey bee ventriculus. However, some fi ndings suggest that these microsporidia may infect other tissues of honey bees. There are indications that these pathogens could be found in honey bee haemolymph, as the medium for its distribution to anatomically distant tissues. Knowing that V. destructor being an ectoparasitic mite feeds on the honey bee's haemolymph, the aim of this study was to investigate if DNA of Nosema spp. microsporidia could be found in honey bee haemolymph and in V. destructor.The study was conducted on bee haemolymph and V. destructor mites from 44 Apis mellifera colonies. From each hive fi ve mite individuals and 10 μL of haemolymph (from 4-5 bees) were used as samples for DNA isolation and PCR detection of Nosema spp.The DNA of N. ceranae was confi rmed in 61.36% of V. destructor mites and 68.18% of haemolymph samples. This is the fi rst report of N. ceranae DNA in honey bee haemolymph and in V. destructor mites. The fi nding of DNA of N. ceranae in V. destructor could be interpreted as the result of mite feeding on N. ceranae infected bee haemolymph. However, for a full confi rmation of the vector role of V. destructor in spreading of nosemosis, further microscopy investigations are required for the detection of spores in both investigated matrices (haemolymph and V. destructor internal tissues).

Within the field of green chemistry, a noticeable results were obtained in the solvent-free synthesis of amide derivatives of naphthenic acids under microwave irradiation. Naphthenic acid amides, anilides, and morpholides were synthesized directly from free carboxylic acids and amines in the absence of solvent and catalyst under high-temperature heating in a closed-vessel system of microwave reactor. With this new and efficient method, different primary, secondary, and tertiary amide derivatives of naphthenic acids were obtained in good to excellent yields. Synthesized derivatives were assayed as plant rooting agents for their stimulative effects on the formation of adventitious roots in sunflower cuttings and susceptibility for growth stimulation of Pseudomonas sp. strains.