Improved application of immobilized Enterobacter cloacae into a bio-based polymer for Reactive Blue 19 removal, an eco-friendly advancement in potential decolorizing systems.

The widespread use of highly complex synthetic dyes like reactive dyes in the textile industry has some adverse environmental impacts and deserves close attention. Biological treatment of these effluents utilizing various species of bacteria with remarkable efficiency in dye removal is still considered promising. Our current study deals with immobilizing an isolated bacterial strain into calcium alginate (Ca/Alg) gel beads and using it to treat pernicious pollutants like synthetic dyes. A potential Reactive Blue 19 (RB19)-degrading Enterobacter cloacae strain A1 was isolated from the Kashan textile industry and was characterized by 16S rDNA gene sequencing. The decolorization ability of strain A1 was assessed by time-based studies using free bacterial cells/immobilized in Ca/Alg. Based on the results of the 16S rDNA gene sequencing, it appears that strain A1 belonged to E. cloacae, with a 99.74% similarity. The findings suggest that immobilized strain A1 accomplished maximum decolorization activity compared with the free cells. The immobilized strain could utterly decompose and decolorize 0.05 mg/mL of RB19 within 48 h, while the free bacterial strain decolorized RB19 within 5 days. Moreover, Ca/Alg gel beads can maintain their efficiency for over three decolorization cycles. Further infrared spectroscopy (FTIR) and gas chromatograph mass spectrometer (GC/MS) investigation declared complete RB19 decomposition on reaction products. Artemia salina was used to investigate the toxicity of dye and its degraded metabolites. The LC50 values signified the pure dye as very toxic with 0.01 mg/mL concentration, while after-treatment products showed no toxic effect on larvae. This immobilization technique increased the applicability of bacterial strain for dye removal. It was beneficial for the decolorization of RB19 from textile wastewater due to a remarkable reduction in time. Notably, strain A1-immobilized beads can maintain their activity for three consecutive decolorization cycles without a considerable decrease in efficiency. PRACTITIONER POINTS: The remarkable capacity of immobilized Enterobacter cloacae strain A1 for Reactive Blue 19 (RB19) removal Immobilized A1 strain showed two-fold higher removal than free one over 48 h A promising method for enhancing RB19 decolorization Decolorization was due to degradation based on UV-Vis, FTIR, and GC/MS analysis Non-toxic posttreatment products for Artemia.

A novel combination of immobilized Enterococcus casseliflavus sp. nov. with silver nanoparticles into a reusable matrix of Ca-Alg beads as a new strategy for biotreatment of Disperse Blue 183: Insights into metabolic characterization, biotoxicity, and mutagenic properties.

Recent advances in immobilized biologic systems for decolorizing azo dyes are gaining great attention due to microorganisms like bacteria and nanoparticles that could stimulate decolorization. Enhanced decolorization performance was observed in this study, indicating the great potential of the immobilized complex of bacterial cells and AgNPs as an alternative to the traditional biological processes to improve the performance of biological systems. The biodegradation and decolorization of Disperse Blue183 (DB 183) were investigated utilizing a novel combination of Enterococcus casseliflavus strain A2 mediated by silver nanoparticles synthesized by Marinospirillum alkaliphilum strain N in three different conditions. Ⅰ: free bacterial strain A2 (100% dye removal in 72 h), Ⅱ: immobilized bacterial strain A2 in Ca-Alg beads (100% dye removal in 15 h), and Ⅲ: immobilized bacterial strain A2 with silver nanoparticles (AgNPs) as support in Ca-Alg beads (100% dye removal in 9 h). The presence of bacterial cells and nanoparticles in Ca-Alg beads was assessed and proved by scanning electron microscope (SEM) and X-ray energy diffraction (EDX) analysis. Moreover, DB 183 and its decolorization metabolites were evaluated by applying UV-Vis, infrared spectroscopy (FTIR), and GC/MS, and the results showed that the dye was degraded. The antimicrobial effect, brine shrimp toxicity (BST) test, and mutagenicity assay in the presence and absence of metabolic activation (+S9/-S9) were run to assess DB 183 and metabolite obtained from biodegradation. The antimicrobial activity of DB 183 disappeared after treatment. Further, the results of the BST test determined that the dye has moderate biotoxicity (LC50:0.064 mg/mL), and the after-treatment product was not toxic. According to the Ames test, DB 183 had mutagenicity effect (69-84%), and the metabolic activation increased the mutagenicity of the dye) 12-25%). However, the percentage mutagenicity of decolorization products decreased, ranging from 50 to 80% without activation (-S9) and 83-96% in present activation (+S9). This work used the immobilized bacterial cells and AgNPs Ca-Alg gel beads for the first time to introduce this kind of system as a suitable technique for rapid decolorization. Using this application enables a remarkable reduction in the time dedicated to the bioremediation of dyeing wastewater.

A new Bacillus Paralicheniformis sp. Tmas-01 as bioreactor for synthesis of Ag/AgCl composite-different effects of biological and Rodamin B dye decolorization, anticancer, genotoxic activity.

The Ag/AgCl composite can be synthesized using various chemical, physical, and biological methods. Biosynthesis of nanoparticles is a rapid technology and has advantages over physical and chemical synthesis methods. This research is based on the bacterial formation of silver nanoparticles by bacterial strain Tmas-01. The bacterial strain Tmas-01 was isolated from soil samples and screened for its potential to form Ag/AgCl composite. The formation of Ag/AgCl composite was investigated at the 300-800 nm range using UV-Vis spectrophotometer. Also, the structural and morphological synthesized nanoparticles were characterized using FTIR, SEM-EDS, and XRD. These results showed that Ag/AgCl composite have the SPR absorption peak at 410 nm and a size range of 10-30 nm with a spherical shape. The Ag/AgCl composite exhibited antibacterial and antibiofilm effects against uropathogenic organisms with a range of 5-100%. The results of the genotoxic effects of Ag/AgCl composite by Salmonella typhimurium reverse mutation bioassay (Ames test) indicated which Ag/AgCl composite had no mutation effect. Moreover, Ag/AgCl composite determined an anti-mutagenic effect with a percentage between 97 and 100%. Furthermore, the toxicity of biosynthesized nanoparticles was measured against brine shrimp to evaluate the cytotoxic effect and displayed LC50 (1 µg/ml). The Ag/AgCl composite could effectively photocatalytic degrade up to 64% of Rhodamine B dye. The phylogenetic analysis showed that strain Tmas-01 belonged to Bacillus paralicheniformis sp. with 99.29% similarity.

Halophilic Prokaryotes in Urmia Salt Lake, a Hypersaline Environment in Iran.

In this study, fluorescence in situ hybridization (FISH) and PCR-amplified fragments of the 16SrDNA gene were used to determine prokaryotes diversity in Urmia Salt Lake. Prokaryote cell population in Urmia lake range from 3.1 ± 0.3 × 106, 2 ± 0.2 × 108, 4 ± 0.3 × 108, and 1.8 ± 0.2 × 108 cells ml-1 for water, soil, sediment, and salt samples by DAPI (4́, 6-diamidino-2-phenylindole) direct count, respectively. The proportion of bacteria and archaea in the samples determinable by FISH ranged between 36.1 and 55% and 48.5 and 55.5%, respectively. According to the DGGE method, some bands were selected and separated from the gel, then amplified and sequenced. The results of sequences were related to two phyla Proteobacteria (16.6%) and Bacteroidetes (83.3%), which belonged to four genera Salinibacter, Mangroviflexus, Pseudomonas, and Cesiribacter, and the archaeal sequences were related to Euryarchaeota phyla and three genera Halonotius, Haloquadratum, and Halorubrum. According to our results, it seems that prokaryotic populations in this hypersaline environment are more diverse than expected, and bacteria are so abundant and diverse and form the metabolically active part of the microbial population inhabiting this extreme environment. Molecular dependent and independent approaches revealed a different aspect of this environment microbiota.

Decolorization of Reactive Black 5 and Reactive Red 152 Azo Dyes by New Haloalkaliphilic Bacteria Isolated from the Textile Wastewater.

Textile wastewaters are usually alkali and saline, so using haloalkaliphilic bacteria can be the best option for the treatment of wastewater. This study aimed at the decolorization of textile Reactive Black 5 and Reactive Red 152 dyes using new haloalkaliphilic bacteria isolated from the textile wastewater. Among 50 strains of bacteria isolated from the effluent of Kashan textile industry, three bacterial strains, namely D1, D2 and E49, exhibited high decolorization abilities for Reactive Black 5 and Reactive Red 152 dyes. Decolorization was evaluated through spectrophotometry at maximum absorbance wavelengths of 607 and 554 nm for Reactive Black 5 and Reactive Red 152, respectively. The highest decolorization percentage was observed at a dye concentration of 50 mg L-1. Aerobic conditions, 5% of the yeast extract and salt, 10% of peptone and glucose as nitrogen and carbon sources, respectively, and a pH range of 9-12 were considered as the optimal conditions for decolorization. The consortium of three haloalkaliphilic isolates showed a remarkable ability for decolorization of the Reactive Black 5 (87%) and Reactive Red 152 (85%) dyes. The consortium exhibited higher decolorization ability for the textile effluent, compared to individual bacterial inoculations. According to phenotypic characterization experiments and phylogenetic analyses based on comparing 16S rDNA sequence, the mentioned strains belonged to the genus Halomonas.

Isolation, characterization, and decolorization of Disperse Blue 60 by newly isolated bacterial strains from Kashan textile wastewater.

Wastewaters are a source of water pollution and the environment. Therefore, the decolorization ability of isolated strains from textile wastewater for Disperse Blue 60 dye was measured. After sampling from different parts of textile waste, four decolorizer strains were isolated. The effects of various factors were evaluated on decolorization. Decolorization ability of strains was measured after incubation up to 72 hr, the range of pH 6-9, different dye concentrations from 50 to 400 mg/L, and different carbon sources. The four newly bacterial strains showed high decolorization ability to dye. The highest decolorization (90%-95%) was observed after 72 hr, pH 7-9, 50 mg/L concentration of dye and glucose as carbon source. According to findings from the present study, the decolorization ability of F52, C43, C19, and C25 strains was 93%, 96%, 100%, and 98.33%, respectively. The phytotoxicity test confirmed the nontoxic effect of the dye decolorization products compared with the toxic Disperse Blue 60 on seeds of Raphanus sativus L. Based on the biochemical characterization and 16s rDNA gene sequencing analysis, the selected bacterial strains were identified as Alishewanella, Halomonas, Jonesia, and Pseudomonas genera. High decolorization ability of the bacterial isolates showed they could effectively use in the biological treatment of wastewater. PRACTITIONER POINTS: Isolation of powerful and effective strains from Kashan textile wastewater Increasing of decolorization by improving environmental conditions Alishewanella, Halomonas, Jonesia, and Pseudomonas genera can be used for biological treatment of wastewater.

Evaluation of antimicrobial activity of Malus domestica fruit extract from Kashan area.

OBJECTIVE: Many species of plants present noticeable potency against human bacterial and fungal pathogens. MATERIALS AND METHODS: In the current study, antimicrobial activity of the fresh fruits of 4 cultivars (A to D) of Malus domestica cultivated in the Qamsar area of Kashan, Iran was investigated. The disk diffusion and minimal inhibitory concentration (MIC) evaluation antimicrobial activity tests were performed. RESULTS: The samples showed moderate antimicrobial activities with inhibition zones from 11 to 16 mm in these tests. Cultivar D with inhibition zones of 16, 14, and 12 mm for E. coli, S. epidermidis and K. pneumoniae, respectively exhibited the best results in these tests. Cultivar A also showed a zone of inhibition of 11 mm against P. aerouginosa. CONCLUSION: Moderate antimicrobial activities were observed for the studied apple cultivars.