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Silver-based nanomaterials have etched an indelible mark in multiple domains. The green synthesis of silver nanoparticles has received significant attention over the last few years vis-à-vis the conventional use of toxic chemicals and reagents in the preparatory stages. In this milieu, the work reported here highlights the use of an aqueous extract of teff (Eragrostis tef) flour to prepare silver nanoparticles (TSNPs). The compositional abundance of various phytochemicals, sunlight-induced bio-reduction of silver ions, and subsequent stabilization of the nanostructures by teff’s biomolecules were adroitly exploited. UV-visible spectroscopic analysis was employed to track the evolution of the TSNPs over time and their month-long storage stability. Exhibiting λmax at around 426 nm and energy gap (as revealed by Tauc’s plot) of 2.26 eV, the silver nanomaterial was employed for methylene blue dye degradation (50% degradation in less than 20 min) and DPPH scavenging (IC50 = 243.42 μL containing 410 μg of TSNPs), attesting their catalytic and anti-oxidant potency. On the other hand, anticoagulant action and a concentration-dependent variation were noted for radicle length post germination of Cicer arientinum seeds, treated with the TSNPs. The TSNPs could have profound implications in multiple domains. [ABSTRACT FROM AUTHOR]

The present research work was carried out on isolating lignocellulolytic enzyme-producing natural bacterial isolates of the Sundarban Mangrove ecosystem in West Bengal, India. Multiple bacterial isolations and qualitative as well as quantitative screening of the isolates was conducted by selective media plates and dye decolorization assay. Growth characterization of the top three isolates, namely GD1, GD2, and GD3, was determined in both nutrient broth and selective media. GD1 showed laccase activity in ABTS plate and decolorized congo red, malachite green, and methylene blue by 64.82%, 47.69%, and 33.33%, respectively, which is the inherent property of laccase. Along with the maximum laccase activity (9.72U/L), it also showed a little amount of cellulase (5.8U/ml) and pectinase (0.55U/ml) activity in the enzyme assay. GD2 showed maximum cellulase activity (6.56U/ml) with only 3.3% degradation of congo red and 39.43% degradation of malachite green. Like GD1, GD2 also bears 5.6U/L laccase and 0.12U/ml pectinase enzyme activity. The last isolate, GD3 specialized in pectinase production and having 4.4U/ml enzyme activity, degraded congo red by 66.75% and malachite green by 54.26%.All isolates showed activity between 30° and 37°C, and pH ranges from 4.5 to 7. The outcomes of this research will be useful in the fiber industry like jute or banana, dye industry, pulp-paper industry, and textile industry for waste remediation, recycling, and fiber modification.

The present research work was carried out on isolating lignocellulolytic enzyme-producing natural bacterial isolates of the Sundarban Mangrove ecosystem in West Bengal, India. Multiple bacterial isolations and qualitative as well as quantitative screening of the isolates was conducted by selective media plates and dye decolorization assay. Growth characterization of the top three isolates, namely GD1, GD2, and GD3, was determined in both nutrient broth and selective media. GD1 showed laccase activity in ABTS plate and decolorized congo red, malachite green, and methylene blue by 64.82%, 47.69%, and 33.33%, respectively, which is the inherent property of laccase. Along with the maximum laccase activity (9.72U/L), it also showed a little amount of cellulase (5.8U/ml) and pectinase (0.55U/ ml) activity in the enzyme assay. GD2 showed maximum cellulase activity (6.56U/ml) with only 3.3% degradation of congo red and 39.43% degradation of malachite green. Like GD1, GD2 also bears 5.6U/L laccase and 0.12U/ml pectinase enzyme activity. The last isolate, GD3 specialized in pectinase production and having 4.4U/ml enzyme activity, degraded congo red by 66.75% and malachite green by 54.26%. All isolates showed activity between 30° and 37°C, and pH ranges from 4.5 to 7. The outcomes of this research will be useful in the fiber industry like jute or banana, dye industry, pulp-paper industry, and textile industry for waste remediation, recycling, and fiber modification. [ABSTRACT FROM AUTHOR]

Dye-decolorization is one of the most important steps in dye-polluted wastewater treatment. The dye-decolorization bacteria were isolated from active sludge collected from wastewater treating pond of a dyeing and printing plant using serial dilution method. Among the 44 bacteria isolates from the active sludge, the strain Bacillus amyloliquefaciens W36 was found to have strong ability in dye-decolorization. The effects of carbon source, nitrogen sources, C/N, metal ions, temperature, pH, and rotation speed for dye-decolorization were investigated. The optimum decolorization conditions were that the strain was grown in enriched mineral salt medium (EMSM) using maltose 1 g/L, (NH4)2SO4 1 g/L as carbon and nitrogen source respectively, supplemented with 100 mg/L different dyes (pH 6.0), at 30 °C, 200 rpm from 48 to 96 h. The bacteria could aerobically decolorize dyes, such as Coomassie brilliant blue (95.42%), Bromcresol purple (93.34%), Congo red (72.37%) and Sarranine (61.7%), within 96 h. The dyes decolorization products were analyzed by ultra-violet and visible (UV–vis) spectroscopy before and after decolorization, which indicated that the four dyes were significantly degraded by the strain. The results indicated that the bacteria Bacillus amyloliquefaciens W36 could be used in dye-polluted wastewater treatment. [ABSTRACT FROM AUTHOR]

Trametes ljubarskyi produces multiple laccase isozymes under various physicochemical conditions. During co-cultivation condition Rhodotorula mucilaginosa showed inter-specific interactions with T. ljubarskyi and hypersecretion of laccases; however, the underlying molecular mechanism is less-known. The analysis of proteomics data of co-cultivated cultures revealed the mechanism of metabolic coupling during fungal-yeast interactions. The results suggested high score GO terms related to stimulus-response, protein binding, membrane components, transport channels, oxidoreductases, and antioxidants. The SEM studies confirmed the cellular communication and their inter-specific interactions. This study allows us to deepen and refine our understanding of fungal-yeast symbiotic interaction; further, it also establishes a mutual relation by metabolic coupling for 10-fold higher laccase isozyme secretion (6532 U/ml). The purified laccase isozymes showed acidic pH optima (pH 3–4), higher thermo-stability (60 °C), and broad enzyme kinetics (K m) values. Our study also provides an in-depth understanding of laccase isozymes and their potential to degrade synthetic dyes, which may help the fungi to survive in an adverse environment. • R hodotorula mucilaginosa stimulate laccase isozymes from T rametes ljubarskyi in co-culture. • Proteomic study suggests increase in stimulus-response, antioxidant and oxidoreductases. • SEM analysis showed inter-specific interaction between mycelial fungi and yeast. • Malachite green was completely decolorized by laccase isozymes from co-cultivation. [ABSTRACT FROM AUTHOR]

Hemoproteins are biotechnologically important heme-containing enzymes, and their production often requires optimal supply of precursors, such as 5-aminolevulinic acid (ALA) and hemin. In this work, endogenous ALA biosynthesis in Escherichia coli was increased as a strategy to improve catalytic activities of a recombinant dye-decolorizing peroxidase (DyP) from Bacillus subtilis . The positive effects of this expression system (pHemAL-DyP) are compared with individually expressed DyP strains grown with (pDyP + Hemin) and without (pDyP) the addition of hemin. The pHemAL-DyP plasmid increased intracellular ALA up to 117.5 mg/L, a 4.0-fold increased from control strain (pET22b, 29.7 mg/L of ALA). Soret peak in the UV–vis spectra was the highest for pHemAL-DyP strain with Reinheitszahl ( A 408 / A 280 ) value of 0.65 indicating higher heme content in the DyP produced compared to pDyP (0.39) and pDyP + Hemin (0.46). Peroxidase activity was increased up to 66.7 U/mg in the pHemAL-DyP strain compared to 39.0 and 43.4 U/mg for pDyP and pDyP + Hemin, respectively. Decolorization percentage of Reactive Blue 19 dye was the highest in the pHemAL-DyP strain with 84.7% as compared to the pDyP (69.9%) and pDyP + Hemin (72.8%) systems. In brief, enzymatic properties of recombinant DyP were successfully enhanced using this genetic engineering strategy thus eliminating the need for costly exogenous precursors. [ABSTRACT FROM AUTHOR]

The bacterial communities in the intestinal tracts of earthworm were isolated by culture-dependent approaches. In total, 72 cultures were isolated and purified from the gut of an earthworm under aerobic culture condition, out of which 25 isolates were laccase positive. Isolate 33, a good laccase producer was identified as Bacillus safensis DSKK5, using both biochemical and molecular approaches. It was found to produce maximum laccase activity at 0.75 % of wheat bran, 37 °C, and pH 6.2. Further, copper sulfate and copper chloride showed a maximum laccase production. In order to understand the affinity of binding and interaction between toxic dyes and bacterial laccase, homology models were generated. The resulted models were further validated and used for docking studies with commonly used industrial dyes. Molecular docking using CCDC GOLD software gave a good score with all the textile dyes. Further, validation using molsoft ICM software showed a good binding energy of −104.25, −106.00, −113.98, and −100.36, with commercial dyes, i.e., procion blue, procion green, procion red, and reactive yellow 86, respectively. Experimental data showed a maximum decolorization with procion green (85.66 %) and procion red (85.58 %), which validate the molsoft ICM results, i.e., −106.00 and −113.98, respectively. [ABSTRACT FROM AUTHOR]

Partial decolorization of two azo dyes (orange G and amaranth) and complete decolorization of two triphenylmethane dyes (bromophenol blue and malachite green) was achieved by cultures in submerged liquid culture producing laccase as the sole phenoloxidase. Enzyme production could be correlated with dye decolorization, with sorption of dye to mycelia accounting for less than 3% of dye removal. [ABSTRACT FROM AUTHOR]