![]() The results of this studyindicatede that strains Nostoc sp. N27P72, showed that strong Ni (II) removal capability could be associated with the high silicon containing heterocyclic compound and aromatic diacid compounds content. Results of Gas Chromatography-Mass Spectrometry (GC–MS) were used to determine the biochemical composition of Nostoc sp. FT-IR spectroscopy revealed that the treatment with Ni can change the functional groups and glycoside linkages in both strains. We found that using maltose as a carbon source can increase the production of EPS, protein, and carbohydrates content and it could be a significant reason for the high ability of metal absorbance. The crude EPS showed metal adsorption capacity assuming the order Ni (II) > Cu (II) > Cr (III) from the metal-binding experiments.Nickel was preferentially biosorbed with a maximal uptake of 188.8 ± 0.14 mg (g cell dry wt) ⁻¹ crude EPS. ![]() N27P72 which was isolated from lime stones.The cultures were evaluated for their ability to remove Cu (II), Cr (III), and Ni (II) in culture media with and without maltose. The production of EPS (9.1 ± 0.05 μg/ml) and increase in cell dry weight (1.01 ± 0.06 g/l) were comparatively high in Nostoc sp. FB71 was isolated from different habitats and thenthe results were compared and reported.Ĭultures of both strains, supplemented separately with either glucose, sucrose, lactose, or maltose showed that production of EPS and cell dry weight were boosted by maltose supplementation. Here, extracellular polymeric substances (EPS) production in strains Nostoc sp. ![]() Recently, most studies have been focused on different habitats using microalgae leads to a remarkable reduction of an array of organic and inorganic nutrients, but what takes place in the extracellular environment when cells are exposed to external supplementation with heavy metals remains largely unknown. As their photosynthetic machinery imposes high demands for metals, homeostasis of these micronutrients has been extensively considered in cyanobacteria. The data gathered here provide a first insight on the phylogenetic history of the EPS-related genes, and constitute a robust basis for subsequent studies aiming to optimize EPS production in cyanobacteria.Ĭyanobacteria are ecologically significant prokaryotes that can be found in heavy metals contaminated environments. However, it is necessary to identify other genes that may be related to this process, understand their genomic distribution, and reconstruct their evolutionary history. Our previous studies revealed that in cyanobacteria, the genes encoding these proteins occur in multiple copies, scattered throughout the genome, either isolated or in small clusters. Studies performed in other bacteria revealed that the mechanisms of EPS assembly and export are relatively conserved, generally following the Wzy-dependent or the ABC-dependent pathways, which require the involvement of polysaccharide copolymerase (PCP) and outer membrane polysaccharide export (OPX) proteins. ![]() Despite the increasing interest in these polymers, the information about their biosynthetic pathways is still limited. The particular characteristics of these EPS, such as the presence of two different uronic acids, sulphate groups and high number of different monosaccharides (up to 13), make them very promising for biotechnological applications. Many cyanobacterial strains produce extracellular polymeric substances (EPS), mainly composed of polysaccharides that can remain associated to the cell or be released into the surrounding environment (released polysaccharides (RPS)). ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |