Laccase belongs to the blue multicopper oxidases and participates in cross-linking of monomers, degradation of polymers, and ring cleavage of aromatic compounds. It is widely distributed in higher plants and fungi. It is present in Ascomycetes, Deuteromycetes and Basidiomycetes and abundant in lignin-degrading white-rot fungi. It is also used in the synthesis of organic substance, where typical substrates are amines and phenols, the reaction products are dimers and oligomers derived from the coupling of reactive radical intermediates. In the recent years, these enzymes have gained application in the field of textile, pulp and paper, and food industry. Recently, it is also used in the design of biosensors, biofuel cells, as a medical diagnostics tool and bioremediation agent to clean up herbicides, pesticides and certain explosives in soil. Laccases have received attention of researchers in the last few decades due to their ability to oxidize both phenolic and nonphenolic lignin-related compounds as well as highly recalcitrant environmental pollutants. It has been identified as the principal enzyme associated with cuticular hardening in insects. Two main forms have been found: laccase-1 and laccase-2. This paper reviews the occurrence, mode of action, general properties, production, applications, and immobilization of laccases within different industrial fields.

/pdf/laccase-microbial-sources-production-purification-and-2m9gfovgsa.pdf

Laccase: Microbial Sources, Production, Purification, and Potential Biotechnological Applications

Microbial laccases and their applications: a review.

One of the major problems facing the industrialized world today is the contamination of soils, ground water, sediments, surfacewater and air with hazardous and toxic chemicals. The application of microorganisms which degrade or transform hazardous organic contaminants to less toxic compounds has become increasingly popular in recent years. This review, with approximately 300 references covering the period 2005-2008, describes the use of fungi as a method of bioremediation to clean up environmental pollutants.

https://www.itqb.unl.pt/~imartins/Pinedo_Rivilla_etal_2009.pdf

Pollutants Biodegradation by Fungi

Heavy metals are dense chemicals with dual biological role as micronutrients and intoxicants. A few hypersaline environmental systems are naturally enriched with heavy metals, while most metal-contaminated sites are a consequence of human activities. Numerous halotolerant and moderately halophilic Bacteria possess metal tolerance, whereas a few archaeal counterparts share similar features. The main mechanisms underlying heavy metal resistance in halophilic Bacteria and Archaea include extracellular metal sequestration by biopolymers, metal efflux mediated by specific transporters and enzymatic detoxification. Biotransformation of metals by halophiles has implications both for trace metal turnover in natural saline ecosystems and for development of novel bioremediation strategies.

Heavy metal resistance in halophilic Bacteria and Archaea.

Degradation of chlorophenols by sequential biological-advanced oxidative process using Trametes pubescens and TiO2/UV.

. Aerosol black carbon (BC) mass concentrations were continuously monitored over a period of 2 years (April 2010 to May 2012) from a high-altitude location Ooty in the Nilgiris Mountain range in southern India to characterize the distinct nature of absorbing aerosols and their seasonality. Despite being remote and sparsely inhabited, BC concentrations showed significant seasonality with higher values (~ 0.96 ± 0.35 μg m−3) in summer (March to May), attributed to increased vertical transport of effluents in the upwind valley regions, which might have been confined to the surrounding valley regions within the very shallow winter boundary layer. The local atmospheric boundary layer (ABL) influence in summer was further modulated by the long-range transported aerosols from the eastern locations of Ooty. During monsoon (June–August), the concentrations were far reduced (~ 0.23 ± 0.06 μg m−3) due to intense precipitation. Diurnal variations were found conspicuous mainly during summer season associated with local ABL. The spectral absorption coefficients (αabs) depicted, in general, flatter distribution (mostly

https://angeo.copernicus.org/articles/32/1361/2014/angeo-32-1361-2014.pdf

Aerosol black carbon characteristics over a high-altitude Western Ghats location in Southern India

Nanotechnology is expected to open new avenues to fight and prevent disease using atomic scale tailoring of materials. Among the most promising nanomaterials with antibacterial properties are metallic nanoparticles, which exhibit increased chemical activity due to their large surface to volume ratios and crystallographic surface structure. In this work we conducted batch experiments to assess the efficiency of silver nanoparticles synthesized by citrate reduction method for their antimicrobial property. The antimicrobial activity of silver nanoparticles and AgNO3 was compared in terms of Escherichia coli growth rate, zone of inhibition and time dependent antimicrobial activity. Silver nanoparticles showed 100 per cent growth reduction of E. coli when treated with 30 µg ml–1 concentrations, whereas the effect was much less at this concentration of AgNO3. Zone of inhibition test was also done for identification of degree of inhibition by using different concentration of AgNO3 and silver nanoparticles. It was found that, 10 µg ml-1 concentration was able to inhibit bacterial growth and created a zone of 0.8 cm by AgNO3 and 1.7 cm by Ag nanoparticles. Thus Ag nanoparticles are found to be efficient candidate for antimicrobial activity than AgNO3.

The bactericidal potential of silver nanoparticles

/pdf/biodegradation-of-phenols-by-ligninolytic-fungus-trametes-399fn1orlc.pdf

Biodegradation of Phenols by Ligninolytic Fungus Trametes versicolor

Decolorization and Degradation of Phenolic Paper Mill Effluent by Native White Rot Fungus Phanerochaete chrysosporium

A 90 day study was conducted to evaluate the efficiency of an exotic earthworm species (Eudrilus eugeniae) for decomposition of different types of organic substrates (mixed liquor suspended solids, cow dung and leaf litter) into valuable vermicompost. Mixed liquor suspended solids (MLSS) and leaf litter (LL) were mixed with cow dung (CD) in eight different ratios with three replicates for each treatment. All vermibeds expressed a significant decrease in pH, organic carbon, C:N ratio and an increase in total nitrogen, phosphorus and potash. Overall, earthworms could maximize decomposition and mineralization efficiency in bedding with lower proportions of MLSS. Maximum value for earth worm zoo mass and higher concentration of nutrient content was observed in CD + MLSS + LL in 1:1:2 ratios. Earthworm mortality tended to increase with increasing proportion of MLSS and maximum mortality in E. eugeniae was recorded for MLSS treatment alone. Results indicate that vermicomposting might be useful for managing the energy and nutrient of MLSS on a low-input basis. Products of this process can be used for sustainable land restoration practices.

C. Udayasoorian

Papers

Aerosol black carbon characteristics over a high-altitude Western Ghats location in Southern India

The bactericidal potential of silver nanoparticles

Biodegradation of Phenols by Ligninolytic Fungus Trametes versicolor

Decolorization and Degradation of Phenolic Paper Mill Effluent by Native White Rot Fungus Phanerochaete chrysosporium

Vermicomposting of paper mill solid waste using epigeic earthworm Eudrilus eugeniae.