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Journal ArticleDOI

Sustainable Production of Thermostable Laccase from Agro-Residues Waste by Bacillus aquimaris AKRC02

TL;DR: In this paper, a thermo-tolerant halophilic Bacillus aquimaris AKRC02 was isolated from pulp and paper mill waste sludge for efficient laccase production.
Abstract: Laccase is a versatile enzyme that plays a major role in the remediation of various environmental pollutants. In this work, a thermo-tolerant halophilic Bacillus aquimaris AKRC02 was isolated from pulp and paper mill waste sludge for efficient laccase production. Various agro-industrial waste residues, including potato peel, banana peel, sawdust, pea peel, wheat bran, orange peel, and rice bran, were screened to produce laccase using a submerged fermentation process. Among these, rice bran supported the maximum laccase production (4.58 U/mL). The optimized environmental conditions (incubation time 120 h; 4.58 U/mL), 35 0C; 6.624 U/mL) and pH 7.0; 10.142 U/mL) and nutritional sources (glucose 1.0%; 14.164 U/mL and peptone 0.5%; 18.124 U/mL) significantly enhanced the laccase production. Purified laccase showed a specific activity and purification fold of 228.34 U/mg and 38.08, respectively. The purified enzyme showed a molecular weight of 65 kDa and high thermal stability at 45 0C for 8 h. In conclusion, the remarkable properties of the newly isolated bacterium may provide a significant opportunity for degrading environmental contaminants, making it an attractive biocatalyst for industrial applications.
Citations
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Journal ArticleDOI
TL;DR: In this paper, the authors discuss the recent progress in the valorization of agro-industrial wastes as prospective microbial feedstocks to produce a spectrum of high-value products, such as microbial pigments, biopolymers, industrial biocatalysts, biofuels, biologically active compounds, bioplastics, biosurfactants, and biocontrol agents with therapeutic and industrial potentialities.

16 citations

Journal ArticleDOI
TL;DR: In this article , current advances in biotechnologies for valorizing plant lignocellulosic wastes to produce a wide range of high-value products such as bio fuels, biocatalysts, biologically active chemicals, and so on in this brief communication.
Abstract: Modern biorefinery technologies use a wide range of plant fibers/wastes and bioconversion techniques to produce a variety of biofuels and other goods. Plant waste, or lignocellulose, is one of the world's most easily accessible, sustainable, and biodegradable bioresources and has been identified as a valuable alternative raw material for the production of a variety of biofuels and chemicals. Furthermore, the generation of platform chemicals and biofuels from plant wastes benefits the environment and the economy. We will cover current advances in biotechnologies for valorizing plant lignocellulosic wastes to produce a wide range of high-value products such as biofuels, biocatalysts, biologically active chemicals, and so on in this brief communication. Furthermore, significant emphasis has been made on the green conversion of lignin into useful compounds, produced in large quantities as a by-product of paper and pulp or other industrial processes.

3 citations

Journal ArticleDOI
TL;DR: In this article, a review explores the adaptive mechanisms of extremophilic ligninolytic enzymes such as laccase, lignin peroxidase (LiP), and MnP.
Abstract: Extremophilic microbial communities have developed several physiological and molecular strategies to survive and grow in extreme environments. This review explores the adaptive mechanisms of extremophilic ligninolytic enzymes such as laccase, lignin peroxidase (LiP), and manganese peroxidase (MnP). The extremophilic ligninolytic enzyme adaptive features such as different compositions of amino acids, hydrophobic interaction, surface charges, tighter packing (compactness), a deleted loop, saturated/unsaturated fatty acid, salt bridge, disulfide bridge, hydrogen bond, several ions, and α-helical, as well as, cysteinyl-tRNA synthetase enzyme to maintain their active stability for catalytic functionalities in extreme conditions. The biochemical properties of extremophilic laccase are monomeric, dimeric, and trimeric glycoprotein with a molecular weight range of 50 to 97 kDa, while glycosylated haem proteins, LiP, and MnP, display a molecular weight ranging from 38 to 62.5 kDa (LiP: 38–46 kDa; MnP: 38–62.5 kDa). The optimum activity of laccase in bacteria and fungus was noted at pH 4.0–10.0. Moreover, the exquisite LiP and MnP activities in fungus occurred at pH 3.0–5.0, while bacteria adopted the diverse range of pH 4.0–9.0. Finally, concluding remarks, the current research needs to highlight the emerging applications of ligninolytic enzymes in broad range of industrial and biotechnological potentials.

2 citations

Book ChapterDOI
01 Jan 2022
TL;DR: In this article , the authors focused on the sources, catalytic reaction mechanisms and different biotechnological applications as well as highlighted the current scenario and updated information on the manganese peroxidase enzyme.
Abstract: Manganese peroxidase has gained much attention in many industrial applications due to key contributors in the microbial ligninolytic system. It mainly oxidizes Mn(II) ions that remain present in wood and soils, into a more reactive Mn3 + form, stabilized by fungal chelators like oxalic acids. However, Mn3 + acts as a diffusible redox intermediate, a low molecular weight compound, which breaks phenolic lignin and produces free radicals that tend to disintegrate involuntarily. It has a great application potential and ample opportunities in a diverse area, such as pulp paper, distillery, food, cosmetic, textile, biofuel, agriculture and industries. However, manganese peroxidases can degrade several xenobiotic compounds and produce polymeric products that have been formulated into useful bioremediation tools. In addition, lignin can also be transformed into biomass by microbial MnPs to convert the sugar into biofuels. This chapter is focused on the sources, catalytic reaction mechanisms and different biotechnological applications as well as highlighted the current scenario and updated information on the manganese peroxidase enzyme.

2 citations

Book ChapterDOI
01 Jan 2022
TL;DR: In this paper , the paper industry effluent characteristics, toxicity, and treatment using native dominant bacterial and fungal isolates were described using a variety of microorganisms such as bacteria and fungi with the help of various ligninolytic enzymes.
Abstract: Paper industry uses huge amount of freshwater during different steps of the papermaking process, and discharge highly contaminated toxic effluent in the environment. The paper and pulp industry effluent characteristics are alkaline pH, high biological oxygen demand, chemical oxygen demand, total dissolved solids, suspended solids, chloride, phenols, phosphate, sulfate, nitrate, lignin, and several toxic mutagenic pollutants along with various heavy metals. Moreover, paper and pulp industry effluent toxicity assessment on Phaseolus aureus seed germination and tubifex tubifex aquatic worms was done. While several studies have been conducted to eliminate the problems associated with paper and pulp industry effluent, but the problem still persists. Physical and chemical treatments are reliable, but they lack the cost effectiveness and residual effects of biological treatments. The biological treatment of paper industry effluent is thought to be effective in reducing organic load and toxic effects. The chemicals found in paper industry effluent have been degraded by several microorganisms such as bacteria and fungi with the help of various ligninolytic enzymes. This chapter described the paper industry effluent characteristics, toxicity, and treatment using native dominant bacterial and fungal isolates.

2 citations

References
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Journal ArticleDOI
15 Aug 1970-Nature
TL;DR: Using an improved method of gel electrophoresis, many hitherto unknown proteins have been found in bacteriophage T4 and some of these have been identified with specific gene products.
Abstract: Using an improved method of gel electrophoresis, many hitherto unknown proteins have been found in bacteriophage T4 and some of these have been identified with specific gene products. Four major components of the head are cleaved during the process of assembly, apparently after the precursor proteins have assembled into some large intermediate structure.

232,912 citations

Journal ArticleDOI
TL;DR: An advanced version of the Molecular Evolutionary Genetics Analysis software, which currently contains facilities for building sequence alignments, inferring phylogenetic histories, and conducting molecular evolutionary analysis, is released, which enables the inference of timetrees, as it implements the RelTime method for estimating divergence times for all branching points in a phylogeny.
Abstract: We announce the release of an advanced version of the Molecular Evolutionary Genetics Analysis (MEGA) software, which currently contains facilities for building sequence alignments, inferring phylogenetic histories, and conducting molecular evolutionary analysis. In version 6.0, MEGA now enables the inference of timetrees, as it implements the RelTime method for estimating divergence times for all branching points in a phylogeny. A new Timetree Wizard in MEGA6 facilitates this timetree inference by providing a graphical user interface (GUI) to specify the phylogeny and calibration constraints step-by-step. This version also contains enhanced algorithms to search for the optimal trees under evolutionary criteria and implements a more advanced memory management that can double the size of sequence data sets to which MEGA can be applied. Both GUI and command-line versions of MEGA6 can be downloaded from www.megasoftware.net free of charge.

37,956 citations

Book
01 Jan 1965
TL;DR: Manual for the identification of medical bacteria as discussed by the authors, Manual for identification of Medical bacteria, مرکز فناوری اطلاعات و اشعران رسانی
Abstract: Manual for the identification of medical bacteria , Manual for the identification of medical bacteria , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

5,115 citations

Journal ArticleDOI
TL;DR: Two new intermediates were identified in the protocatechuate pathway of Pseudomonas putida; β-Ketoadipate enol-lactone, which was isolated and physically characterized, is also an intermediate in the catechol pathway; thecatechol and protocate chuate pathways converge at this point.

477 citations

Journal ArticleDOI
Shraddha1, Ravi Shekher1, Simran Sehgal1, Mohit Kamthania1, Ajay Kumar1 
TL;DR: Laccase belongs to the blue multicopper oxidases and participates in cross-linking of monomers, degradation of polymers, and ring cleavage of aromatic compounds, and is widely distributed in higher plants and fungi.
Abstract: 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.

320 citations