The presented paper deals with the analysis of potential differences between organic waste compost (C_BD), vermicompost (C_VER) and mineral fertilizer (MF; 27% of N) applications affecting the quality of arable soil by influencing microbial activity therein. The selected types of compost represent alternatives to conventional organic fertilizers, which are, however, not available to Czech and Slovak farmers in sufficient amounts. Their mutual comparison and the comparison with organic fertilizers aim to provide farmers further information about their influence on arable land and thus to give them the possibility of deciding on the most suitable amendments. To demonstrate the effect of these amendments, six variants were prepared: one without the addition of fertilizers; two variants with the addition of 40 Mg/ha of C_VER and C_BD; one variant with the addition of double dosed C_VER (80 Mg/ha), and the remaining two variants were fertilized only with MF (0.22 Mg/ha) and with the combination of C_VER (0.20 Mg/ha) and MF (0.11 Mg/ha). Substrate induced respiration (SIR), basal respiration (BS), microbial carbon (C_mic) and enzymatic activities (hydrolysis of fluorescein diacetate—FDA, dehydrogenase activity—DHA, and phosphatase activity—PA) were used to evaluate the effect of C_BD, C_VER and MF application on the soil quality. Both organic and mineral amendments affected BS and SIR. The highest BS and SIR rates were found in variants with compost application (C_VER and C_BD). All variants treated with the mineral fertilizer showed the lowest level of enzyme activities; lower by about 30% in comparison with variants where C_VER, C_BD and the combination of MF and C_VER were applied. We found insignificant differences between the individual types of compost. More importantly, we compared the situation at the beginning of the experiment and after its end. It was found that the application of mineral fertilizers automatically led to the deterioration of all enzymatic parameters, on average by more than 25%, as compared with the situation at the beginning of the experiment. However, when the mineral fertilizer dose was supplemented with organic amendments (C_VER), this negative effect was eliminated or significantly reduced. Furthermore, both composts (C_VER and C_BD) positively affected plant biomass production, which reached a level of production enhanced by the MF. Results clearly showed that the application of both compost types could be used to improve soil quality in agriculture.

By serial dilution of samples on starch casein agar. The screening method consists of primary and secondary testing. The most active isolates were identified based on molecular and cultural methods. 42 out of 66 isolates displayed antimicrobial potential. 63% exhibited antibacterial activity, 16% antifungal activity, and 16% displayed both activities. Identified isolates, Streptomyces scabrisporus, Streptomyces sparsogenes, Streptomyces misakiensis, Streptomyces cirratus, Streptomyces lincolnensis, Streptomyces endophyticus, Streptomyces chartreusis, and Streptomyces alboniger showed a broad spectrum of enzymatic activities. The results indicated that these isolates may serve as antibiotic and enzyme-producing microbes....

Rapeseed is an important oil crop strongly dependent on high agrochemical inputs. Some pathogens, including Leptosphaeria maculans, cause blackleg disease and can drastically decrease yields. Microbial inoculants seem to be a promising solution to these problems. However, a selection of potent bacterial strains able to improve growth and/or suppress disease is needed. Endophytic bacteria (n = 38) isolated from rapeseed plants with exceptionally good growth were screened for plant growth promoting (PGP) traits and L. maculans antifungal activity. A majority of isolates (35) showed the ability to produce siderophores, 17 isolates solubilized phosphate, and 28 isolates inhibited the growth of L. maculans. The six most promising isolates belonging to Bacillus genera were characterized in detail and compared to two previously published PGP strains. Plant growth measured as total weight and root length of rapeseed seedlings was stimulated by all isolates in comparison to control. The best isolate, 1L6, preliminary identified as Bacillus pumilus showed the highest phosphate solubilization, IAA and HCN production, and growth promotion of plants. Isolates with high antifungal activity in screening showed good potential to suppress disease on plants, with 87% reduction of lesions caused by L. maculans. These strains are good candidates to be explored under field use either solely or in combination.

Fifty seven soil-borne actinomycete strains were assessed for the antibiotic production. Two of the most active isolates, designed as Streptomyces ST-13 and DK-15 exhibited a broad range of antimicrobial activity and therefore they were selected for HPLC fractionation against the most suppressed bacteria Staphylococcus aureus (ST-13) and Chromobacterium violaceum (DK-15). LC/MS analysis of extracts showed the presence of polyketides factumycin (DK15) and tetrangomycin (ST13). The taxonomic position of the antibiotic-producing actinomycetes was determined using a polyphasic approach. Phenotypic characterization and 16S rRNA gene sequence analysis of the isolates matched those described for members of the genus Streptomyces. DK-15 strain exhibited the highest 16S rRNA gene sequence similarity to Streptomyces globosus DSM-40815 (T) and Streptomyces toxytricini DSM-40178 (T) and ST-13 strain to Streptomyces ederensis DSM-40741 (T) and Streptomyces phaeochromogenes DSM-40073 (T). For the proper identification, MALDI-TOF/MS profile of whole-cell proteins led to the identification of S. globosus DK-15 (accession number: KX527570) and S. ederensis ST13 (accession number: KX527568). To our knowledge, there is no report about the production of these antibiotics by S.globosus and S. ederensis, thus isolates DK15 and ST13 identified as S. globosus DK-15 and S.ederensis ST-13 can be considered as new sources of these unique antibacterial metabolites.

The aim of the study was to evaluate the effect of nitrogen nutrition on the content of fatty acids and selected qualitative parameters (nitrogenous substances, ash, crude fiber) in winter oilseed rape (Brassica napus L.). The experiment was carried out at the Vígľaš—Pstruša Research and Breeding Station in 2008–2009 and 2009–2010 by complete block design with four repetitions. Nitrogen fertilization was applied at four levels, plus an untreated control (after agrochemical soil analysis) by DAN 27 (Dolomite Ammonium Nitrate): 100, 120, 140, and 160 kg/ha N. Application date was in BBCH scale phase 59–60. The fatty acid contents (MUFA—monosaturated fatty acids; PUFA—polyunsaturated fatty acids) were determined by gas chromatography in the extracted fat, which is determined by extraction method. Within the result evaluation, statistically significant increases in the contents of linoleic and linolenic acids were recorded in all variants treated by nitrogen fertilizer, which is positive in terms of the use of rapeseed oil for food and energy purposes. The statistically significant decrease of oleic acid after the application of nitrogen fertilizers is negative for industry use of rapeseed oil.