Journal Article•
Degradation of xenobiotic compounds by lignin-degrading white-rot fungi: enzymology and mechanisms involved.
TL;DR: Degradation of a number of environmental pollutants by ligninolytic system of white rot fungi is described in the present review.
Abstract: White-rot fungi (WRF) are ubiquitous in nature with their natural ability to compete and survive. WRF are the only organisms known to have the ability to degrade and mineralize recalcitrant plant polymer lignin. Their potential to degrade second most abundant carbon reserve material lignin on the earth make them important link in global carbon cycle. WRF degrade lignin by its unique ligninolytic enzymatic machinery including lignin peroxidase, manganese peroxidase, laccase, cellobiose dehydrogenase, H2O2-generating enzymes, etc. The ligninolytic enzymes system is non-specific, extracellular and free radical based that allows them to degrade structurally diverse range of xenobiotic compounds. Lignin peroxidase and manganese peroxidase carry out direct and indirect oxidation as well as reduction of xenobiotic compounds. Indirect reactions involved redox mediators such as veratryl alcohol and Mn2+. Reduction reactions are carried out by carboxyl, superoxide and semiquinone radicals, etc. Methylation is used as detoxification mechanism by WRF. Highly oxidized chemicals are reduced by transmembrane redox potential. Degradation of a number of environmental pollutants by ligninolytic system of white rot fungi is described in the present review.
Citations
More filters
TL;DR: In this paper, the authors provide an overview of bacterial decolorization/degradation of azo dyes and emphasize the application of these processes for the treatment of the azo dye-containing wastewaters.
Abstract: A variety of synthetic dyestuffs released by the textile industry pose a threat to environmental safety. Azo dyes account for the majority of all dyestuffs, produced because they are extensively used in the textile, paper, food, leather, cosmetics and pharmaceutical industries. Existing effluent treatment procedures are unable to remove recalcitrant azo dyes completely from effluents because of their color fastness, stability and resistance to degradation. Bacterial decolorization and degradation of azo dyes under certain environmental conditions has gained momentum as a method of treatment, as these are inexpensive, eco-friendly and can be applied to wide range of such dyes. This review mainly focuses on the different mechanisms of decolorization and discusses the effect of various physicochemical parameters on the dye removal efficiency of different bacteria. The enzymatic mechanisms involved in the bacterial degradation of azo dyes, the identification of metabolites by using various analytical techniques, and the nature of their toxicity has been investigated. This review provides an overview of bacterial decolorization/degradation of azo dyes and emphasizes the application of these processes for the treatment of azo dye-containing wastewaters.
1,226 citations
TL;DR: Even though some hybrid processes show promising micropollutant removals, further studies are needed to optimize these water treatment processes, in particular in terms of technical and economical competitiveness.
524 citations
Cites background from "Degradation of xenobiotic compounds..."
...LiP has been shown to eliminate several recalcitrant aromatic compounds such as PAH and phenolic compounds (Christian et al., 2005)....
[...]
TL;DR: This review will discuss the most important pretreatment methods available today and will highlight key criteria for the development of a future ideal pretreatment.
490 citations
TL;DR: Although ligninolytic enzymes have broad range of industrial application specially the degradation and detoxification of lignocellulosic waste discharged from various industrial activities, its large scale application is still limited due to lack of limited production.
212 citations
TL;DR: The response of three soil groups to anthropogenic perturbation is considered and the need for integrative studies which consider how environmental variables moderate interactions between functional groups, how this moderation affects biogeochemical processes and how these feedbacks ultimately drive ecosystem services provided by soil biota is suggested.
Abstract: The soil environment is essential to many ecosystem services which are primarily mediated by microbial communities. Soil physical and chemical conditions are altered on local and global scales by anthropogenic activity and which threatens the provision of many soil services. Despite the importance of soil biota for ecosystem function, we have limited ability to predict and manage soil microbial community responses to change. To better understand causal relationships between microbial community structure and ecological function, we argue for a systems approach to prediction and management of microbial response to environmental change. This necessitates moving beyond concepts of resilience, resistance and redundancy that assume single optimum stable states, to ones that better reflect the dynamic and interactive nature of microbial systems. We consider the response of three soil groups (ammonia oxidisers, denitrifiers, symbionts) to anthropogenic perturbation to motivate our discussion. We also present a network re-analysis of a saltmarsh microbial community which illustrates how such approaches can reveal ecologically important connections between functional groups. More generally, we suggest the need for integrative studies which consider how environmental variables moderate interactions between functional groups, how this moderation affects biogeochemical processes and how these feedbacks ultimately drive ecosystem services provided by soil biota.
205 citations
References
More filters
TL;DR: This paper presents a meta-analyses of IGNIN as a stimulus and its applications in medicine and physiology, and discusses the role that IGNIN plays in the development of disease and its role in medicine.
Abstract: INTRODUCTION ....................................................................................................................................... 465 LIGNIN AS A SUBSTRATE ............................................................................................................................... 466 MICROBIOLOGY OF LIGNIN BIODEGRADATI ON ........................................................................... 468 Anaerobic Conditions ............................................................................................................................... 469 Aerobic Conditions ................................................................................................................................... 469 LIGNIN DEGRADATION BY WHITEROT FUNGI ............................................................................. 471 Physiology .......................................................................................................................................................... 472 Biochemistry ............................................................................................................................................ 475 Genetics ..............................................................................................................................................................486 Molecular Biology .................................................................................................................................... 489 CONCLUSIONS AND RECOMMENDATIONS ..................................................................................... 491 ENZYMATIC “COMBUSTION” ........................................................................................................................ 493
2,556 citations
TL;DR: In this paper, the authors provide an outline of the microbial degradation of polycyclic aromatic hydrocarbons, including bacteria, fungi and algae, and the biochemical principles underlying the degradation.
Abstract: The intent of this review is to provide an outline of the microbial degradation of polycyclic aromatic hydrocarbons. A catabolically diverse microbial community, consisting of bacteria, fungi and algae, metabolizes aromatic compounds. Molecular oxygen is essential for the initial hydroxylation of polycyclic aromatic hydrocarbons by microorganisms. In contrast to bacteria, filamentous fungi use hydroxylation as a prelude to detoxification rather than to catabolism and assimilation. The biochemical principles underlying the degradation of polycyclic aromatic hydrocarbons are examined in some detail. The pathways of polycyclic aromatic hydrocarbon catabolism are discussed. Studies are presented on the relationship between the chemical structure of the polycyclic aromatic hydrocarbon and the rate of polycyclic aromatic hydrocarbon biodegradation in aquatic and terrestrial ecosystems.
1,839 citations
TL;DR: The intent of this review is to provide an outline of the microbial degradation of polycyclic aromatic hydrocarbons, a catabolically diverse microbial community, consisting of bacteria, fungi and algae, metabolizes aromatic compounds.
924 citations
TL;DR: A Mn(II)-dependent peroxidase found in the extracellular medium of ligninolytic cultures of the white rot fungus, Phanerochaete chrysosporium, was purified and the absorption spectrum of the enzyme indicates the presence of a heme prosthetic group.
716 citations
534 citations