Biodecolorization and biodegradation of Reactive Green 12 textile industry dye and their post-degradation phytotoxicity-genotoxicity assessments.

The employment of versatile bacterial strains for the efficient degradation of carcinogenic textile dyes is a sustainable technology of bioremediation for a neat, clean, and evergreen globe. The present study has explored the eco-friendly degradation of complex Reactive Green 12 azo dye to its non-toxic metabolites for safe disposal in an open environment. The bacterial degradation was performed with the variable concentrations (50, 100, 200, 400, and 500 mg/L) of Reactive Green 12 dye. The degradation and toxicity of the dye were validated by high-performance liquid chromatography, Fourier infrared spectroscopy analysis, and phytotoxicity and genotoxicity assay, respectively. The highest 97.8% decolorization was achieved within 12 h. Alternations in the peaks and retentions, thus, along with modifications in the functional groups and chemical bonds, confirmed the degradation of Reactive Green 12. The disappearance of a major peak at 1450 cm-1 corresponding to the -N=N- azo link validated the breaking of azo bonds and degradation of the parent dye. The 100% germination of Triticum aestivum seed and healthy growth of plants verified the lost toxicity of degraded dye. Moreover, the chromosomal aberration of Allium cepa root cell treatment also validated the removal of toxicity through bacterial degradation. Thereafter, for efficient degradation of textile dye, the bacterium is recommended for adaptation to the sustainable degradation of dye and wastewater for further application of degraded metabolites in crop irrigation for sustainable agriculture.

Cyanobacteria as biochemical energy source for the synthesis of inorganic nanoparticles, mechanism and potential applications: a review.

Green synthesis of nanoparticles (NPs) has gained great concern among researchers due to their unique properties, excellent applications and efficient route of synthesis. From the last decades, the number biologicals such as plants, fungus, bacteria, yeast, algae, and cyanobacteria and their products are using by various researchers for the synthesis of different NPs. However, the pillar of green chemistry keeps touching new heights to improve the performance. This review paper unveils almost recent cyanobacteria-assisted greener NP synthesis technique, characterization and application. The enormous potency of cyanobacteria in NP synthesis (silver, gold, copper, zinc, palladium, titanium, cadmium sulfide, and selenium) and significance of reducing enzymes were summarized. The extracellular and intracellular entity such as metabolites, enzyme, protein, pigments in cyanobacteria play a significant role in the conversion of metal ions to metal NPs with unique properties discussed briefly. The green synthesis of nanomaterials is valuable because of their cost-effective, nontoxic and eco-friendly prospects as well as the potential application metal NPs such as antibacterial, antifungal, anticancerous, catalytic, drug delivery, bioimaging, nanopesticide, nanofertilizer, sensing properties, etc. Therefore, in the present review, we have systematically discussed the mechanisms of synthesis and applications of cyanobacteria-assisted green synthesis of NPs.

Enhanced growth and yield of oyster mushroom by growth-promoting bacteria Glutamicibacter arilaitensis MRC119.

Promotion of mushroom growth by means of biological agents replacing chemicals is an emerging and highly demanded issue in the sector of mushroom cropping. The present study was aimed to search for a novel bacterium potentially able to enhance mushroom growth and yield. A total of 2165 bacterial isolates purified from different samples were scrutinized through various growth-promoting attributes. As a consequence of rigorous screening, 26 isolates found exhibiting positive traits of mushroom growth promotion. Thereafter, in response to the cocultivation (fungus and bacteria), a potent bacterial strain was isolated capable to improve significantly the mycelial growth. In cocultivation the highest radial and linear growth rate was 7.6 and 8.1 mm/day on 10th and 11th days, respectively. The fruitbody yields and biological efficiency (BE) of the inoculated sets were 28% and 58% higher than the uninoculated control sets. The bacterium was molecularly identified based on 16S ribosomal RNA sequencing and confirmed as Glutamicibacter arilaitensis MRC119. Therefore, the bioinoculant of the current bacterium can be potentially useful as an ecofriendly substitute stimulating the production of mushroom fruit bodies with improved BE.

Decolorization of synthetic brilliant green carpet industry dye through fungal co-culture technology.

Aim of the present study was to evaluate the efficiency of fungal co-culture for the decolorization of synthetic brilliant green carpet industry dye. For this purpose two lignocellulolytic fungi Pleurotus florida (PF) and Rhizoctonia solani (RS) were employed. The study includes determination of enzyme profiles (laccase and peroxidase), dye decolorization efficiency of co-culture and crude enzyme extracts. Both fungi produced laccase and Mn peroxidase and successfully decolorized solutions of different concentrations (2.0, 4.0, 6.0, & 8.0(w/v) of dye. The co-culture resulted highest 98.54% dye decolorization at 2% (w/v) of dye as compared to monocultures (82.12% with PF and 68.89% with RS) during 12 days of submerged fermentation. The lower levels of dyes were rapidly decolorized, while higher levels in slow order as 87.67% decolorization of 8% dye. The promising achievement of the study was remarkable decolorizing efficiency of co-culture over monocultures. The direct treatment of the mono and co-culture enzyme extracts to dye also influenced remarkable. The highest enzymatic decolorization was through combined (PF and RS) extracts, while lesser by monoculture extracts. Based on the observations and potentiality of co-culture technology; further it can be exploited for the bioremediation of areas contaminated with hazardous environmental pollutants including textile and other industry effluents.

Differential response of oyster shell powder on enzyme profile and nutritional value of oyster mushroom Pleurotus florida PF05.

Oyster mushroom Pleurotus florida was cultivated on different combinations of wheat straw (WS) as basal substrate and oyster shell powder (OSP) supplement. The OSP supplementation considerably responded to different cultivation phases. The mycelium grew fast and showed rapid growth rate (8.91 mmd(-1)) in WS + OSP (97 + 3) combination while WS + OSP (92 + 8) showed maximum laccase (3.133 U/g) and Mn peroxidase (MnP) activities (0.091 U/g). The climax level of laccase (5.433 U/g) and MnP (0.097 U/g) was recorded during fruit body initiation in WS + OSP (97 + 3) and WS + OSP (98 + 2) combinations, respectively. The WS + OSP (97 + 3) combination represented the best condition for mushroom cultivation and produced the highest biological efficiency (147%). In addition, protein and lipid contents in fruit bodies were slightly improved in response to OSP. The carbohydrate was significantly increased by raising concentration of OSP. The highest values of protein, carbohydrate, and lipid noted were 31.3 µg/g, 0.0639 (g/g), and 0.373 (g/g) correspondingly. Conclusively it was evident that lower concentrations of OSP acted positively and relatively to higher concentrations and improved nutritional content which may suitably be used to enhance both yield and nutritional values of mushroom.

Studies on in vitro degradability of mixed crude enzyme extracts produced from Pleurotus spp.

A preliminary investigation was conducted to assess lignocellulolytic efficiency of crude extracts from three white-rot fungi, Pleurotus florida PF05 (PF), Pleurotus sajor-caju PS07 (PS) and Pleurotus eryngii PE08 (PE). The activities of CMC-ase, xylanase, beta-glucosidase, beta-xylosidase, laccase and Mn peroxidase in extracts were evaluated. PF produced its highest CMC-ase (317 UL(-1)'), beta-glucosidase (62 UL(-1)), beta-xylosidase (37 UL(-1)) and laccase (347 UL(-1)) activities while, PS produced highest xylanase (269 UL-(1)) and Mn peroxidase (69 UL(-1)) activities. In addition, crude extracts extracted were employed for their in vitro degradability assessment; and were evaluated with mono and mixed extracts separately to corn cob substrate. The losses in cell wall components and dry matter during 5 and 10 days incubations were analyzed after treatments of extracts. Maximum 8.2, 4.4 and 2.8% loss were found respectivelyin hemicellulose (HC), cellulose (C) and lignin (L) with mono extract of PF within 10 days. The influence of mono extract of each strain (PF PS and PE) and their mixed extracts (PF+PS, PF+PE, PS+PE and PF+PS+PE) on degradation of cell wall constituents were remarkably differed. The mixed extract treatment proved maximum 13.6% HC loss by PF+PS+PE extract, 9.2% loss in C by PF+PS extract and 5.2% loss of L by the PF+PS+PE extract treatment. The highest dry matter loss (8.2%) was recorded with PF+PS+PE mixed extract combination.

Removal of chromium (VI) through biosorption by the Pseudomonas spp. isolated from tannery effluent.

Heavy metal contamination of the rivers is a world wide environmental problem and its removal is a great challenge. Kanpur and Unnao two closely located districts of Uttar Pradesh India are known for their leather industries. The tanneries release their treated effluent in the near by water ways containing Cr metal that eventually merges with the river Ganges. Untreated tannery effluent contains 2.673 +/- 0.32 to 3.268 +/- 0.73 mg l(-1) Cr. Microbes were isolated, keeping the natural selection in the view, from the tannery effluent since microbes present in the effluent exposed to the various types of stresses and metal stress is one of them. Investigations include the exposure of higher concentrations of Cr(VI) 1.0 to 4.0 mg l(-1) to the bacteria (presumably the Pseudomonas spp.) predominant on the agar plate. The short termed study (72 h) of biosorption showed significant reduction of metal in the media especially in the higher concentrations with a value from 1.0 +/- 0.02, 2.0 +/- 0.01, 3.0 +/- 0, and 4.0 +/- 0.09 at zero h to 0.873 +/- 0.55, 1.840 +/- 1.31, 2.780 +/- 0.03 and 3.502 +/- 0.68 at 72 h respectively. The biosorption of metal show in the present study that the naturally occurring microbes have enough potential to mitigate the excessive contamination of their surroundings and can be used to reduce the metal concentrations in aqueous solutions in a specific time frame.