Ashok Pandey

Role of humic acid entrapped calcium alginate beads in removal of heavy metals.

Most of the available techniques for removal of heavy metals from solution such as leachates from waste sites are very expensive. The technique described in this paper is designed to study the removal of humic acid by alginate beads and the subsequent binding of the metals within the beads thus decreasing the leachability of heavy metals from a hazardous waste site. The entry of 500 mg/l humic acid into 3% calcium alginate beads in 24 h showed a distinct fluorescence as compared to the fluorescence shown by the entry of 100 and 250 mg/l of humic acid into alginate beads. Further, on treatment of calcium alginate beads containing 500 mg/l humic acid with metals such as Cu, Mn, Zn, Cr and Fe, quenching of fluorescence was noticed, which was maximum with Cu and minimum with Fe.

Formation of Soluble Complexes of Metals with Humic Acid and Its Environmental Significance

Abstract In order to investigate the role of functional groups present in humic acid(s) (HA) during complex formation, water soluble complexes between HA isolated from soil and metals (Pb, Ca, As, Ni, Cr, Co, Cu, Cd, Fe, Mn, Mg and Zn) were prepared and subjected to infrared (IR) spectroscopy. the IR data revealed the involvement of the - OH group of humic acid in complex formation with all metals except copper and arsenic, whereas the - COOH group of HA was found to be the preferred site of binding for all the metals. the significance of findings in relation to detoxification of environmental pollutants is discussed in this paper.

Role of free radicals in the binding of organochlorine pesticides and heavy metals with humic acid

Abstract The formation of soluble complexes between humic acid (HA) and γ-HCH or different metals (Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn,Pb, Cd, As and Mg) was studied, along with any generation of free radicals by electron spin resonance spectroscopy. Free radical generation was noticed in case of interaction of humic acid with γ-HCH, Cu and Cr. A hyperfine splitting pattern was noticed only in case of Mn. However, with Ca, Cd, Pb, As, Ni, Co, Zn and Fe, neither free radicals were generated nor hyperfine splitting was observed. The possible significance of free radicals in the binding of environmental pollutants with humic acid is discussed together with ecotoxicological implications.

Biofuels: Production and Future Perspectives

Currently, the world is confronted with the twin crisis of fuel depletion and global environmental degradation, which resulted in rapid climate change. Indiscriminate extraction and lavish consumption of fossil fuels have led to the reduction of underground carbon resources. Moreover, the price of crude oil keeps on fluctuating and rising on a daily basis. Meanwhile, the scenario war for oil has already been started due to subsequent environmental concerns and political events in the Middle East. Over the globe, scientists have explored several fossil fuel alternatives (biofuels) of bio-origin, which have the potential to quench the ever-increasing thrust of today’s

Effect of dilute acid pretreatment of wild rice grass ( Zizania latifolia) from Loktak Lake for enzymatic hydrolysis

Zizania latifolia commonly known as wild rice grass which is available in huge quantities in Loktak Lake is a major concern as it occupies a large area of the Lake and causing a several environmental problems. The investigation of present study was to evaluate possibilities of using Zizania latifolia as feed stock for bioethanol production. The method involved the pretreatment with dilute acid or alkali followed by enzymatic hydrolysis with commercial cellulase. Acid pretreatment was performed with 10% biomass loading with different concentration of acids (0.4-2% w/v) and alkali (0.25-1.5% w/v). Maximum sugar release of 457 mg/g was obtained from 10% biomass loading and 2% w/v of acids. Alkali pretreatment is not effective for this grass. Physicochemical characterization of untreated and treated biomass was carried out by XRD, FTIR, SEM and corresponding alterations in the chemical composition were also monitored. Results showed the feasibility of this grass as biofuel (bioethanol) feed stock and can be potential approach to address the sustainable utilization phumdis grasses of Loktak Lake for the production of value added product.

Genomic and proteomic analysis of lignin degrading and polyhydroxyalkanoate accumulating β-proteobacterium Pandoraea sp. ISTKB

BackgroundLignin is a major component of plant biomass and is recalcitrant to degradation due to its complex and heterogeneous aromatic structure. The biomass-based research mainly focuses on polysaccharides component of biomass and lignin is discarded as waste with very limited usage. The sustainability and success of plant polysaccharide-based biorefinery can be possible if lignin is utilized in improved ways and with minimal waste generation. Discovering new microbial strains and understanding their enzyme system for lignin degradation are necessary for its conversion into fuel and chemicals. The Pandoraea sp. ISTKB was previously characterized for lignin degradation and successfully applied for pretreatment of sugarcane bagasse and polyhydroxyalkanoate (PHA) production. In this study, genomic analysis and proteomics on aromatic polymer kraft lignin and vanillic acid are performed to find the important enzymes for polymer utilization.ResultsGenomic analysis of Pandoraea sp. ISTKB revealed the presence of strong lignin degradation machinery and identified various candidate genes responsible for lignin degradation and PHA production. We also applied label-free quantitative proteomic approach to identify the expression profile on monoaromatic compound vanillic acid (VA) and polyaromatic kraft lignin (KL). Genomic and proteomic analysis simultaneously discovered Dyp-type peroxidase, peroxidases, glycolate oxidase, aldehyde oxidase, GMC oxidoreductase, laccases, quinone oxidoreductase, dioxygenases, monooxygenases, glutathione-dependent etherases, dehydrogenases, reductases, and methyltransferases and various other recently reported enzyme systems such as superoxide dismutases or catalase–peroxidase for lignin degradation. A strong stress response and detoxification mechanism was discovered. The two important gene clusters for lignin degradation and three PHA polymerase spanning gene clusters were identified and all the clusters were functionally active on KL–VA.ConclusionsThe unusual aerobic ‘-CoA’-mediated degradation pathway of phenylacetate and benzoate (reported only in 16 and 4–5% of total sequenced bacterial genomes), peroxidase-accessory enzyme system, and fenton chemistry based are the major pathways observed for lignin degradation. Both ortho and meta ring cleavage pathways for aromatic compound degradation were observed in expression profile. Genomic and proteomic approaches provided validation to this strain’s robust machinery for the metabolism of recalcitrant compounds and PHA production and provide an opportunity to target important enzymes for lignin valorization in future.

Introduction to Water Remediation: Importance and Methods

Water has always been one of the most essential entities for survival of living systems almost since the evolution of life form. It is pertinent to study water systems in respect of enhancing the quality of water as it can be a significant source affecting the living systems in a direct or indirect manner. Nowadays, increased level of water consumption and correspondingly high levels of pollution have generated a prominent need for managing the water quality by maintaining safe levels for the water to be used in specific applications. In this respect, water remediation methods have taken a forward thrust in order to increase the water quality of potable water as well as that of industrial grade water in order to prevent contamination of natural water resources due to the discharge of industrial effluents. Several methods of water remediation such as physical, chemical, electrochemical and biological are discussed and worked out worldwide. This monograph gives a review of the importance of water remediation, various methods that are employed to remediate and some automated techniques which have been breakthroughs in the field of water quality control.

Bioremediation by Microalgae: Current and Emerging Trends for Effluents Treatments for Value Addition of Waste Streams

The development of anthropogenic activities has lead to an excessive disposal of wastes into natural waterbodies, thus affecting the quality of water and polluting the entire environment due to the hazardous chemicals and other nutrients present in the waste, thereby it has a negative impact on the aquatic ecosystems. To avoid these harmful impacts associated with the discharge of wastes into waterbodies, effective remediation processes are required to reduce nutrients like nitrogen, phosphorus, other organic chemicals and heavy metals concentrations in discharged effluents. Current technologies applied for nutrients removal tend to be complex, energy demanding and costly process. Therefore, cultivation of microalgae has appeared as an emerging alternative approach for removing pollutants and heavy metals present in the waterbodies. Biomass production in the alga depends on rapid utilization of the organic content and other nutrients present in the effluent and can be considered as an attractive and eco-friendly means for treating waste streams, other than removing the pollution load, algal cultivation adds value to the process by production of commercially valuable products such as fuels and various chemicals from biomass. This chapter addresses the recent developments and perspectives in bioremediation of waste streams by algae for removal of various pollutants for value addition of waste.

Applications of Microbial Enzymes in Food Industry

The use of enzymes or microorganisms in food preparations is an age-old process. With the advancement of technology, novel enzymes with wide range of applications and specificity have been developed and new application areas are still being explored. Microorganisms such as bacteria, yeast and fungi and their enzymes are widely used in several food preparations for improving the taste and texture and they offer huge economic benefits to industries. Microbial enzymes are the preferred source to plants or animals due to several advantages such as easy, cost-effective and consistent production. The present review discusses the recent advancement in enzyme technology for food industries. A comprehensive list of enzymes used in food processing, the microbial source of these enzymes and the wide range of their application are discussed.

Sustainable Production of Chemicals and Energy Fuel Precursors from Lignocellulosic Fractions

From time immemorial, bioprocessing of lignocelluloses via chemical catalysis has been an impressive methodology of numerous value added commodities and energy fuel precursors (drop-in-fuel) synthesis. The most common technique for biomass fragmentation is catalytic hydrolysis using various acid catalysts covering inorganic or organic liquid acids as well as solid acids (heterogeneous). Most research in the past decade has been focused on cost-effective production of such biomass derived commodities with the aim of their commercialization. Till date, in order to improve final product yields and minimize production costs, various improvised production schemes have been developed like pretreatment methods for improved saccharification and displacement and/or reconstruction of recalcitrant biomass constituents, such as lignin to improve accessibility, employing multi-functional catalysts to promote single stage transformations, continuous extraction of desired product by use of specific solvents to improve product stability as well as to inhibit by-product formation, integration of physical processes for example microwave and ultrasonic irradiation resulting in decreased residence time, etc. With these technological advancements, researchers have overcome substantial limitations associated with lignocellulose transformation including mass-transfer hindrances and expensive downstream processing; as a result a wide array of commercially important chemicals and fuel precursors have been synthesised. The chapter provides an account of value addition to biomass via chemical catalysis of cellulosic, hemicellulosic and lignin fractions towards product chemicals synthesis.