TEXTILE DYE BIOREMEDIATION POTENTIAL OF SOME RHIZOBIAL STRAINS AND THEIR HEAVY-METAL AND HIGH SALINITY TOLERANCE

The discharge of untreated textile dye effluents enriched with toxic pollutants including dyes, heavy metals and other hazardous materials may cause negative impacts on the entire ecosystem. The proposed work aimed to isolate, molecularly identify and characterize the native rhizobial strains with textile dye biodegradation potential in relation with their tolerance to high salinity and heavy metals (usually meet in high concentrations in the textile dye effluents). Native rhizobial strains were isolated from various terrestrial ecosystems originated in Danube – Delta Biosphere Reserve. Most of the strains tolerated ≥ 2.0% NaCl. Our data showed that 3 strains (Agrobacterium sp.CR-B19; Rhizobium giardinii CR- B22 and Ensifer sp.CR-B26) were able to tolerate 15 ppm concentration of cadmium (Cd2+), whereas all strains identified as Rhizobium sp. (except R. leguminosarum CR-B10), and Agrobacterium sp. could tolerate 70 ppm of chromium (Cr6+).. Moreover, 3 indigenous strains (Rhizobium giardinii CR-B13; Rhizobium sp.CR-B15 and Agrobacterium sp. CR-B19) tolerated a concentration of 200 ppm of lead (Pb2+). In regard to azo-dye degrading potential, only Rhizobium leguminosarum CR-B10 was able to degrade the Reactive Orange 16 dye (90.18% decolorization) in stationary conditions, at 30°C. Comparatively, Agrobacterium sp. CR - B19 strain removed Reactive Orange 16 (sulphonic azo-dye) (78.92 % decolorization) and Reactive Blue 4 (antraquinonic dye) (12 % decolorization) by adsorbtion. Based on their bioremediation potential, the newly isolated rhizobial strains could be further used (in pure culture or in consortia) to develop a new environmental friendly and cost–effective biotechnology in order to reduce the toxicity of textile dyes effluents

TEXTILE DYE BIOREMEDIATION POTENTIAL OF SOME RHIZOBIAL STRAINS AND THEIR HEAVY-METAL AND HIGH SALINITY TOLERANCE

The discharge of untreated textile dye effluents enriched with toxic pollutants including dyes, heavy metals and other hazardous materials may cause negative impacts on the entire ecosystem. The proposed work aimed to isolate, molecularly identify and characterize the native rhizobial strains with textile dye biodegradation potential in relation with their tolerance to high salinity and heavy metals (usually meet in high concentrations in the textile dye effluents). Native rhizobial strains were isolated from various terrestrial ecosystems originated in Danube – Delta Biosphere Reserve. Most of the strains tolerated ≥ 2.0% NaCl. Our data showed that 3 strains (Agrobacterium sp.CR-B19; Rhizobium giardinii CR- B22 and Ensifer sp.CR-B26) were able to tolerate 15 ppm concentration of cadmium (Cd2+), whereas all strains identified as Rhizobium sp. (except R. leguminosarum CR-B10), and Agrobacterium sp. could tolerate 70 ppm of chromium (Cr6+).. Moreover, 3 indigenous strains (Rhizobium giardinii CR-B13; Rhizobium sp.CR-B15 and Agrobacterium sp. CR-B19) tolerated a concentration of 200 ppm of lead (Pb2+). In regard to azo-dye degrading potential, only Rhizobium leguminosarum CR-B10 was able to degrade the Reactive Orange 16 dye (90.18% decolorization) in stationary conditions, at 30°C. Comparatively, Agrobacterium sp. CR - B19 strain removed Reactive Orange 16 (sulphonic azo-dye) (78.92 % decolorization) and Reactive Blue 4 (antraquinonic dye) (12 % decolorization) by adsorbtion. Based on their bioremediation potential, the newly isolated rhizobial strains could be further used (in pure culture or in consortia) to develop a new environmental friendly and cost–effective biotechnology in order to reduce the toxicity of textile dyes effluents

RAPD-inferred genetic variability of some indigenous Rhizobium leguminosarum isolates from red clover (Trifolium pratense L.) nodules

The application of commercial rhizobial inoculants to legume crops is proving to be an alternative to synthetic fertilizer use. The challenge for sustainable agriculture resides in the compatibility between crop, inoculants and environmental conditions. The evaluation of symbiotic efficiency and genetic diversity of indigenous rhizobial strains could lead to the development of better inoculants and increased crop production. The genetic variability of 32 wild indigenous rhizobial isolates was assessed by RAPD (Random Amplified Polymorphic DNA). The strains were isolated from red clover (Trifolium pratense L.) nodules from two distinct geographical regions of Northern and Eastern Romania. Three decamer primers were used to resolve the phylogenetic relationships between the investigated isolates. Cluster analysis revealed a high diversity; most strains clustered together based on their geographical location

Molecular and Biochemical Characterization of the Parvulin-Type PPIases in Lotus japonicus1[C][W][OA]

The cis/trans isomerization of the peptide bond preceding proline is an intrinsically slow process, although important in many biological processes in both prokaryotes and eukaryotes. In vivo, this isomerization is catalyzed by peptidyl-prolyl cis/trans-isomerases (PPIases). Here, we present the molecular and biochemical characterization of parvulin-type PPIase family members of the model legume Lotus japonicus, annotated as LjPar1, LjPar2, and LjPar3. Although LjPar1 and LjPar2 were found to be homologous to PIN1 (Protein Interacting with NIMA)-type parvulins and hPar14 from human, respectively, LjPar3 represents a novel multidomain parvulin, apparently present only in plants, that contains an active carboxyl-terminal sulfurtransferase domain. All Lotus parvulins were heterologously expressed and purified from Escherichia coli, and purified protein verification measurements used a liquid chromatography-mass spectrometry-based proteomic method. The biochemical characterization of the recombinant Lotus parvulins revealed that they possess PPIase activity toward synthetic tetrapeptides, although they exhibited different substrate specificities depending on the amino acid amino terminal to proline. These differences were also studied in a structural context using molecular modeling of the encoded polypeptides. Real-time reverse transcription-polymerase chain reaction revealed that the three parvulin genes of Lotus are ubiquitously expressed in all plant organs. LjPar1 was found to be up-regulated during the later stages of nodule development. Subcellular localization of LjPar-enhanced Yellow Fluorescence Protein (eYFP) fusions expressed in Arabidopsis (Arabidopsis thaliana) leaf epidermal cells revealed that LjPar1- and LjPar2-eYFP fusions were localized in the cytoplasm and in the nucleus, in contrast to LjPar3-eYFP, which was clearly localized in plastids. Divergent substrate specificities, expression profiles, and subcellular localization indicate that plant parvulin-type PPIases are probably involved in a wide range of biochemical and physiological processes