Perception of small farmers in Serbia regarding the use of ICT and possibilities of organic agriculture

During the last two decades there is a growing awareness of the importance of introducing organic agricultural production in Serbia due to issues of health, environmental protection and need for more sustainable agriculture. There is a need for education of small farmers on the possibilities of organic production and significance of information technologies for education, production and marketing. This paper aims to examine the perception on the possibilities of organic production and ICT use concerning their level of education. The study has included 143 farmers from Raška district, municipality Kraljevo. The statistical ANOVA analysis has been done by using the software package SPSS18 to explore an impact the education has on the perception of small farmers on the use of information technologies in education, production, and marketing of agricultural products. The results show statistically significant difference in the perception of small farmers on the usage of information technologies regarding their level of education.Publishe

Different coordination abilities of 1,7- and 4,7-phenanthroline in the reactions with copper(II) salts: Structural characterization and biological evaluation of the reaction products

The reactions between equimolar amounts of CuX2 (X = NO3− and CF3SO3−) and two aromatic nitrogen-containing heterocycles differing in the position of nitrogen atoms, 1,7- and 4,7-phenanthroline (1,7- and 4,7-phen), were performed in ethanol/methanol at room temperature. When CuX2 salts were mixed with 4,7-phen, two copper(II) complexes, [Cu(NO3)2(4,7-Hphen)2](NO3)2 (1) and [Cu(CF3SO3)(4,7- phen)2(H2O)2]CF3SO3 (2), were formed. On the other hand, in the reaction of CuX2 salts with 1,7-phen, only 1,7-HphenNO3 (3a/b) and 1,7-HphenCF3SO3 (4) were obtained as the final products. The obtained products 1–4 were characterized by spectroscopic and X-ray diffraction techniques. In the copper(II) complexes 1 and 2, the coordination geometry around the Cu(II) ion is distorted octahedral and square pyramidal, respectively. The antimicrobial potential of the copper(II) complexes 1 and 2 and corresponding compounds used for their synthesis were assessed against four different bacterial species and Candida albicans, displaying moderate growth inhibiting activity. The cytotoxic properties of the investigated complexes were also evaluated against the normal human lung fibroblast cell line (MRC-5) indicating moderate, yet more pronounced cytotoxicity than antimicrobial properties

Genomics-Based Insights Into the Biosynthesis and Unusually High Accumulation of Free Fatty Acids by Streptomyces sp NP10

Schneider O, Ilic-Tomic T, Rückert C, et al. Genomics-Based Insights Into the Biosynthesis and Unusually High Accumulation of Free Fatty Acids by Streptomyces sp NP10. FRONTIERS IN MICROBIOLOGY. 2018;9: 10.Streptomyces sp. NP10 was previously shown to synthesize large amounts of free fatty acids (FFAs). In this work, we report the first insights into the biosynthesis of these fatty acids (FAs) gained after genome sequencing and identification of the genes involved. Analysis of the Streptomyces sp. NP10 draft genome revealed that it is closely related to several strains of Streptomyces griseus. Comparative analyses of secondary metabolite biosynthetic gene clusters, as well as those presumably involved in FA biosynthesis, allowed identification of an unusual cluster C12-2, which could be identified in only one other S. griseus-related streptomycete. To prove the involvement of identified cluster in FFA biosynthesis, one of its three ketosynthase genes was insertionally inactivated to generate mutant strain mNP10. Accumulation of FFAs in mNP10 was almost completely abolished, reaching less than 0.01% compared to the wild-type strain. Cloning and transfer of the C12-2 cluster to the mNP10 mutant partially restored FFA production, albeit to a low level. The discovery of this rare FFA biosynthesis cluster opens possibilities for detailed characterization of the roles of individual genes and their products in the biosynthesis of FFAs in NP10

Expression and purification of the Sgm protein from E. coli

The sgm gene from Micromonospora zionensis, the producer of the aminoglycoside antibiotic G-52, encodes for Sgm methylasewhich modifies the target site on 16S rRNA and thus protects the producer against its own toxic product. The sgm gene wasmodified by polymerase chain reaction (PCR) and cloned in the QIAexpress pQE-30 vector in order to make a construct that places the (His)6 tag at the N-terminus of the protein. The resulting expression construct was transformed in the E. coli strain NM522 and the functional activity of the Sgm-His fusion protein was confirmed in vivo. Purification of the (His)6-tagged Sgm protein by Ni-NTA affinity chromatography was performed under native conditions and the protein was detected on a sodium dodecyl sulfate polyacrylamide gel. Sgm methylase was purified to homogeneity > 95 %. Polyclonal antibodies raised to purified (His)6-tagged Sgm protein were used to identify this protein byWestern blot analysis

Expression and purification of the Sgm protein from E. coli

The sgm gene from Micromonospora zionensis, the producer of the aminoglycoside antibiotic G-52, encodes for Sgm methylasewhich modifies the target site on 16S rRNA and thus protects the producer against its own toxic product. The sgm gene wasmodified by polymerase chain reaction (PCR) and cloned in the QIAexpress pQE-30 vector in order to make a construct that places the (His)6 tag at the N-terminus of the protein. The resulting expression construct was transformed in the E. coli strain NM522 and the functional activity of the Sgm-His fusion protein was confirmed in vivo. Purification of the (His)6-tagged Sgm protein by Ni-NTA affinity chromatography was performed under native conditions and the protein was detected on a sodium dodecyl sulfate polyacrylamide gel. Sgm methylase was purified to homogeneity > 95 %. Polyclonal antibodies raised to purified (His)6-tagged Sgm protein were used to identify this protein byWestern blot analysis

Eco‑friendly dyeing of polyamide and polyamide‑elastane knits with living bacterial cultures of two Streptomyces sp. strains

Given the environmental burden of textile industry, especially of dyeing processes and the volume of synthetic dyes and surfactants, the intensive development of the greener approaches is under way. Herein, an environmentaly-friendly dyeing of polyamide (PA) and PA/Elastane (PA/EA) knits using live bacterial approach in water environment, completely eliminating usage of textile auxiliaries is described. A total of 12 pigment-producing Streptomyces strains were isolated and purified from soil and rizoshere or bark of smoke tree Cotinus coggygria samples. The antibacterial, antifungal and cytotoxic effects of crude bacterial extracts were tested. Antimicrobial effect was obtained by the majority of extracts but only two streptomycetes extracts, 11–5 and BPS51, showed moderate cytotoxicity against HaCaT human cell line. This was the reason to select 11–5 and BPS51 strains for the dyeing of the textile materials. Excellent properties of dyeing wool, silk and PA are achieved initially using live cultures, and the bioprocess is optimized on commercial PA and PA/EA knits used for stockings production. Satisfactory coloration of both knits is achieved with dynamic conditions (culture shaking at 180 rpm over 5–14 days at 30 ºC) giving the best coloration results, except in the case of the PA sample dyed with a bacterial strain 11–5. The prolongation of dyeing time leads to higher color yields independently of fabric and bacteria strain. Although the color differences between the samples before and after washing are observed, washing fastness after three washing cycles can be considered as satisfactory

Critical Residues for Cofactor Binding and Catalytic Activity in the Aminoglycoside Resistance Methyltransferase Sgm▿ †

The 16S rRNA methyltransferase Sgm from “Micromonospora zionensis” confers resistance to aminoglycoside antibiotics by specific modification of the 30S ribosomal A site. Sgm is a member of the FmrO family, distant relatives of the S-adenosyl-l-methionine (SAM)-dependent RNA subfamily of methyltransferase enzymes. Using amino acid conservation across the FmrO family, seven putative key amino acids were selected for mutation to assess their role in forming the SAM cofactor binding pocket or in methyl group transfer. Each mutated residue was found to be essential for Sgm function, as no modified protein could effectively support bacterial growth in liquid media containing gentamicin or methylate 30S subunits in vitro. Using isothermal titration calorimetry, Sgm was found to bind SAM with a KD (binding constant) of 17.6 μM, and comparable values were obtained for one functional mutant (N179A) and four proteins modified at amino acids predicted to be involved in catalysis in methyl group transfer. In contrast, none of the G135, D156, or D182 Sgm mutants bound the cofactor, confirming their role in creating the SAM binding pocket. These results represent the first functional characterization of any FmrO methyltransferase and may provide a basis for a further structure-function analysis of these aminoglycoside resistance determinants

Halochromic cellulose textile obtained via dyeing with biocolorant isolated from Streptomyces sp. strain NP4

Halochromic (pH-responsive) material was obtained by dyeing functionalized viscose fabric with a crude extract from Streptomyces sp. strain NP4. The functionalization of the fabric before dyeing was performed to make cellulose susceptible to coloration with NP4 extract. Two combined pre-treatment steps were used, oxidation to obtain dialdehyde cellulose and chitosan deposition after oxidation. Chitosan was deposited onto untreated fabric as well, while only oxidized viscose was also investigated for dyeing. Functionalization by both protocols made viscose susceptible to dyeing with the notion that the deposition of chitosan onto oxidized viscose produced the darkest shade on the material. Dyed fabrics showed visual pH responsiveness in the range pH 4-10, with a color change from pink to red (pH 4-pH 7) and a major color change from red to blue (pH 7-pH 10) whereby fabric was tested and could withstand 10 color-changing cycles. Cytotoxicity assay confirmed the non-toxic nature of dyed material, which indicates its possible use as wound dressing's indicators

Antimicrobial Nanocomposites Based on Oxidized Cotton Fabric and in situ Biosynthesized Copper Oxides Nanostructures Using Bearberry Leaves Extract

The aim of this study was to develop antimicrobial nanocomposite textile material comprising of Cu-based nanostructures synthesized on oxidized cotton fabric using Arctostaphylos uva-ursi (L.) Spreng., Ericaceae (bearberry leaves) as a green reducing agent for adsorbed Cu2+-ions. In order to provide sufficient number of carboxyl groups for complexation with Cu2+-ions a two-step oxidation process with NaIO4 and NaClO2 was carried out. The influence of NaIO4 concentration on content of carboxyl groups and Cu-based nanoparticles was studied by FTIR and AAS. HPLC analysis identified the gallic acid known as a reducing agent in bearberry leaves extract. FESEM and XRD analyses revealed that using bearberry leaves extract and gallic acid solution as reducing agents led to a formation of spherical Cu2O/CuO nanoparticles and CuO nanosheets, respectively. These nanoparticles and nanosheets provided excellent antibacterial activity against Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus. Cytotoxicity on human keratinocyte cells was shown to depend on their copper content