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Effluents containing dyes from different industrial sectors pose a serious threat to the environment. Different physicochemical strategies are being carried out in industry to reduce the toxicity of dye-containing waste so that dye-mixed wastewater can be further utilized in agriculture or irrigation purposes in water-scarce areas. But those techniques are economically not feasible. There is an alternative mechanism present in biological systems that are biocatalysts which is eco-friendly, low cost, and sustainable. Lignin peroxidase, Laccase, Manganese peroxidase are oxidoreductase classes of enzymes with the ligninolytic ability and are potential biocatalysts for the degradation of environmental toxicants like dyes. Besides ligninolytic enzymes, cellulase, pectinase are also powerful candidates for dye decolourization. Most interestingly these biocatalysts are found in a variety of microbial monoculture as well as in mixed microbial consortia. The consortia are able to reduce the organic load of dye-containing industrial effluent at a higher rate rather than the monoculture. This article critically reviews the efficacy of lignocellulolytic enzymes in dye decolourization by both monoculture and consortia approaches. In addition, this review discusses the genetically and metabolically engineered microbial systems that contribute to dye decolourization as well as put forward some future approaches for the enhancement of dye removal efficacy.

The current scientific studies have shown that extensive quantities of synthetic pigments are used worldwide in diverse industries. Synthetic pigments have shown enormous toxicity issues compared to natural colorants and dyes in current industrial usage. Diverse microbial communities, including fungi, bacteria, archaea, and yeast are current biopigment producers. However, the aforementioned biopigments are expensive, least efficient, and less eco-friendly to attain industrial sustainability. Thus, algae-based bio pigments are one of the best natural resources to meet today’s challenges. Algal pigments increase the product’s marketability and carry multiple therapeutic properties, including antioxidant, anti-inflammatory, and neuroprotective actions. These multidimensional qualities of algal pigments have piqued the interest of the food, pharmaceutical, cosmetic, and nutraceutical industries resulting in most potential implementation. Thus, a paradigm shift requires identifying potential algal communities having a higher biopigment-producing ability for future manufacturing and commercialization as a sustainable way forward. Hence, the current study has been designed for effective isolation and screening of algal isolates (i.e. DS1, DS2, DS3, DS4, DS5) from a different region of sundarban water resources concerning the investigation of algal pigments (i.e. chlorophyll-a, chlorophyll-b and carotenoid). In a nutshell, the current study shows that DS2 isolate produces a significant quantity of carotenoid (9.729 mg/g DCW), chlorophyll a (7.872 mg/g DCW), and chlorophyll b (7.176 mg/g DCW) amongst all isolates. Hence, the present study reveals that DS2 algal isolates might be a potential predecessor of biopigment production, having pivotal applications in food, pharmaceutical, cosmetic, and nutraceutical industries in the near future.

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.