Advances in Microbe-assisted Phytoremediation of Polluted Sites



Copyright
Contents
Contributors
PART 
1 - Overview of microbe-assisted phytoremediation
Chapter
1 - Microbe-assisted phytoremediation of environmental contaminants
	1.1 Introduction
	1.2 Environmental contaminants: Types, nature, and sources
	1.3 Impact of environmental contaminants on the environment and human health
	1.4 Plant-microbe association/interaction and its role in phytoremediation of environmental contaminants
		1.4.1 Phytoremediation of organic and inorganic contaminants
		1.4.2 Phytoremediation of wastewater
		1.4.3 Role of constructed wetlands in treatment of wastewaters
	1.5 Mechanisms involved in the phytoremediation of environmental contaminants
		1.5.1 Phytostabilization
		1.5.2 Phytovolatilization
		1.5.3 Phytodegradation
		1.5.4 Phytoaccumulation
		1.5.5 Phytoextraction
		1.5.6 Rhizoremediation
			1.5.6.1 Plant growth promoting rhizobacteria (PGPR)
			1.5.6.2 Arbuscular mycorrhizal fungi
	1.6 Economic importance of microbe assisted phytoremediation of environmental contaminants
	1.7 Conclusion
	References
Chapter
2 - Microbial augmented phytoremediation with improved ecosystems services
	2.1 Introduction
	2.2 Concept of phytoremediation
	2.3 Need of augmentation of substances in phytoremediation
		2.3.1 Chemical augmentation
		2.3.2 Biological augmentation
	2.4 Role of microbes in soil ecosystem
		2.4.1 Nutrient bioavailability in the soil
		2.4.2 Contaminant bioavailability in the soil
		2.4.3 Stress tolerance
			2.4.3.1 Role of microbes in plants tolerance to drought
			2.4.3.2 Role of microbes in plants tolerance to salinity stress
			2.4.3.3 Role of microbes in plants tolerance to temperature stress
		2.4.4 Biocontrol of pathogens
		2.4.5 Microbes enhances overall plant growth
	2.5 Mechanism of microbe-assisted phytoremediation
	2.6 Conclusion and future recommendation
	References
Chapter
3 - Role of genetic engineering in microbe-assisted phytoremediation of polluted sites
	3.1 Introduction
	3.2 Microbe-assisted phytoremediation
		3.2.1 Mechanism of phytoremediation using microorganism
			3.2.1.1 Direct mechanism
			3.2.1.2 Indirect mechanism
		3.2.2 Advantages of microbe-assisted phytoremediation
	3.3 Genetic engineering of microbes for assisting phytoremediation
		3.3.1 Plant growth-promoting bacteria
		3.3.2 Rhizospheric bacteria
		3.3.3 Endophytic bacteria
	3.4 Genetic engineering of plants for microbe-assisted phytoremediation
		3.4.1 Engineering plants to enhance growth
		3.4.2 Rhizosphere competence
		3.4.3 Examining effects of the root targeted modification
	3.5 Conclusions and future prospects
	Acknowledgments
	References
PART 
2 - Microbe-assisted phytoremediation of inorganic contaminants
Chapter
4 - Phytoremediation potential of genetically modified plants
	4.1 Introduction
	4.2 Heavy metal contamination
	4.3 Technologies used in the remediation of HMs
		4.3.1 Excavation
		4.3.2 Composting
		4.3.3 Electrokinetic remediation (EKR)
		4.3.4 Bioreactors
	4.4 Phytoremediation
	4.5 Factors affecting phytoremediation
	4.6 Advantages and disadvantages of phytoremediation
	4.7 Role of genetic engineering in phytoremediation
	4.8 Conclusion and future prospects
	References
chapter
5 - The role of bacteria in metal bioaccumulation and biosorption
	5.1 Introduction
	5.2 Microbial bioremediation
		5.2.1 Biosorption
			5.2.1.1 Extracellular adsorption
			5.2.1.2 Cell surface adsorption
		5.2.2 Bioaccumulation
	5.3 Mechanisms underlying microbial metal biosorption and bioaccumulation
		5.3.1 Extracellular adsorption
		5.3.2 Cell surface adsorption or complexation
			5.3.2.1 Ion exchange mechanism
			5.3.2.2 Surface complex mechanism
			5.3.2.3 Bioaccumulation/Intracellular adsorption
	5.4 Main factors influencing the bioaccumulation efficiency
		5.4.1 pH
		5.4.2 Temperature
		5.4.3 The presence of other metal ions
		5.4.4 Physical and chemical pretreatment
	5.5 General conclusions and future perspectives
	Acknowledgments
	References
Chapter
6 - Plant-microbe association to improve phytoremediation of heavy metal
	6.1 Introduction
		6.1.1 Phytoremediation
	6.2 Metal resistance and uptake in microorganisms
	6.3 Plant growth and metal uptake by plant growth-promoting bacteria (PGPB)
		6.3.1 Phytoremediation assisted by soil bacteria
		6.3.2 Effects of microorganisms on bioavailability of metals/metalloids and mobilization
		6.3.3 Low-molecular-mass organic acids
		6.3.4 Release of carboxylic acid anions
		6.3.5 By secretion of siderophores
		6.3.6 Other trace element chelators
		6.3.7 Microbial-induced metal immobilization in phytostabilization
	6.4 Effects of microorganisms on nutrients’ uptake
	6.5 Approach of genetic engineering for improved metal uptake
	6.6 Current scenario and future perspective
	References
Chapter
7 - Bacterial-mediated phytoremediation of heavy metals
	7.1 Introduction
	7.2 Heavy metals effects on living organisms
	7.3 Remediation strategies to reduce the HM pollutants
		7.3.1 Physicochemical approaches
		7.3.2 Biological approaches/bioremediation
	7.4 Phytoremediation
		7.4.1 Phytoextraction
		7.4.2 Phytostabilization
		7.4.3 Phytodegradation
		7.4.4 Phytovolatilization
		7.4.5 Phytofiltration
		7.4.6 Rhizodegradation
		7.4.7 Phytotransformation
	7.5 Microbial remediation
		7.5.1 Fungal remediation
		7.5.2 Bacterial remediation
	7.6 Mechanisms of bacterial-assisted phytoremediation
		7.6.1 Plant growth promotion
		7.6.2 Bacterial-assisted biodegradation
		7.6.3 Biotransformation of HM
		7.6.4 Bioleaching
		7.6.5 Mobilization
		7.6.6 Solubilization
		7.6.7 Volatilization
		7.6.8 Sequestration/accumulation
	7.7 Case studies of PGP bacteria-assisted phytoremediation
	References
Chapter
8 - Recent advances in microbial-aided phytostabilization of trace element contaminated soils
	8.1 Introduction
	8.2 Phytostabilization
		8.2.1 TE behavior in soils - speciation and mobility
		8.2.2 TE uptake and transfer in plant tissues
		8.2.3 Plant tolerance to TE toxicity
		8.2.4 Plant’s selection
	8.3 Aided phytostabilization
		8.3.1 Effect of microbial amendments on soil properties
		8.3.2 Microbial amendment’s effect on TE immobilization.
		8.3.3 Microbial amendment’s effect on plant growth and development
	8.3.4 Combined use of amendments
	8.4 Future scope
		8.4.1 Limitations of aided phytostabilisation
		8.4.2 Future scope: Phytomanagement of TE-contaminated soils
	8.5 Conclusion
	Acknowledgments
	References
Chapter
 9 - Phytoremediation of heavy metal contaminated soil in association with arbuscular mycorrhizal fungi
	9.1 Introduction
	9.2 Sources of HMs in soil
		9.2.1 Natural processes
		9.2.2 Anthropogenic processes
	9.3 Adverse impacts of HMs
		9.3.1 Impacts on the environment
		9.3.2 Impact on the soil microbes and its enzymatic activity
		9.3.3 Impact on the plants and animals
		9.3.4 Impact on human health
	9.4 Remediation of metal contaminated soil
		9.4.1 Phytoremediation
	9.5 Arbuscular mycorrhizal fungi
		9.5.1 AMF as mediators of phytoremediation processes
		9.5.2 Mechanisms of detoxification involving the association of mycorrhizal fungi and plants
		9.5.3 Mechanisms involving the retention by fungal structures
	9.6 Biochemical mechanisms
		9.6.1 Chelating agents and enzymes
		9.6.2 Gene expression mediated by AMF
	9.7 Conclusion
	References
chapter
10 - Role of Pb-solubilizing and plant growth-promoting bacteria in Pb uptake by plants
	10.1 Introduction
	10.2 Presence and forms of Pb in soil
	10.3 Phytoextraction of Pb from contaminated soils
	10.4 Microbe-assisted Pb phytoextraction
	10.5 Pb solubilization mechanisms by bacteria
		10.5.1 Acidolysis
		10.5.2 Redoxolysis
			10.5.2.1 Bio-reduction
			10.5.2.2 Bio-oxidation
		10.5.3 Complexolysis
			10.5.3.1 Low molecular weight organic acids
			10.5.3.2 Siderophores
			10.5.3.3 Biosurfactants
	10.6 Effect of bacteria on plant growth in Pb-contaminated soils
		10.6.1 Production of phytohormones
			10.6.1.1 Auxins
			10.6.1.2 Cytokinins
			10.6.1.3 Gibberellins
		10.6.2 Improvement of plant nutrition
			10.6.2.1 Phosphorus solubilization
			10.6.2.2 Siderophore production
			10.6.2.3 Nitrogen fixation
			10.6.2.4 Improvement of nutrient uptake
		10.6.3 ACCD production
		10.6.4 Triggering plant antioxidant system
	10.7 Effects of bacterial inoculations on Pb phytoextraction
		10.7.1 Effects of PGPBs on Pb phytoextraction
		10.7.2 Effects of Pb-solubilizing PGPBs on Pb phytoextraction
	10.8 Conclusions
	References
Chapter
 11 - Role of Cd-resistant plant growth-promoting rhizobacteria in plant growth promotion and alleviation of the p ...
	11.1 Introduction
		11.1.1 Plant growth promoting rhizobacteria and their classification
		11.1.2 Loading of Cd in the environment
		11.1.3 Toxic effects of Cd on plants, humans, and microorganisms
	11.2 Cadmium-resistant PGPR
	11.3 Cadmium-resistance mechanisms in PGPR
		11.3.1 Cd removal by several efflux systems
		11.3.2 Intra/extracellular Cd binding
			11.3.2.1 Intracellular Cd sequestration
			11.3.2.2 Extracellular Cd sequestration
	11.4 Role of Cd-resistant PGPR to alleviate Cd toxicity in plants
		11.4.1 Nitrogen fixation
		11.4.2 Phosphate solubilization
		11.4.3 ACC deaminase activity
		11.4.4 Production of phytohormones
		11.4.5 Siderophore production
		11.4.6 Production of organic acids
		11.4.7 Production of exopolymers
	11.5 Alleviation of Cd-induced oxidative stress by Cd-resistant PGPR
	11.6 Biotechnological approaches toward Cd-bioremediation
	11.7 Bioformulation of Cd-resistant bacteria
	11.8 Conclusion and future perspectives
	Acknowledgments
	References
Chapter
12 - Beneficial plant microbiome assisted chromium phytoremediation
	12.1 Introduction
	12.2 Chromate ecoavailability
	12.3 Chromium toxicity
	12.4 Phytoremediation of Cr(VI)
		12.4.1 Phytoaccumulation/phytoextraction/phytosequestration
		12.4.2 Phytostabilization/phytorestoration/phytoimmobilization
		12.4.3 Phytodegradation/phytotransformation/phytodetoxification
		12.4.4 Phytovolatilization
		12.4.5 Rhizofiltration
	12.5 Mechanisms of chromate tolerance in plants
		12.5.1 Cr extrusion or restriction
		12.5.2 Root exudates
		12.5.3 Phytoreduction
		12.5.4 Cr chelation
		12.5.5 Enzymatic antioxidant system
		12.5.6 Nonenzymatic antioxidant system
		12.5.7 Plant hormones
		12.5.8 Heat shock proteins (HSP) and DNA methylation
		12.5.9 Plant microbiome
	12.6 Microbes-enhanced phytoremediation mechanisms
		12.6.1 Microbial reduction of chromate toxicity
			12.6.1.1. Biosorption
			12.6.1.2 Bioaccumulation
			12.6.1.3 Bioreduction
			12.6.1.4 Bioprecipitation
			12.6.1.5 Efflux pumps
			12.6.1.6 Chromate resistance determinants (CRD)
		12.6.2 Plant growth promoting products (PGPP)
	12.7 Microbe-assisted phytoremediation studies
	12.8 Genetically engineered plants and microbes for chromate bioremediation
	12.9 Challenges and future perspectives
	Acknowledgment
	Conflict of interest
	References
Chapter
13 - Toxic potential of arsenic and its remediation through microbe-assisted phytoremediation
	13.1 Introduction
	13.2 Chemical and environmental properties of arsenic
	13.3 Biological properties of arsenic and its toxicity
	13.4 Root-associated microorganisms
	13.5 Phytoremediation with plant-associated microbes
		13.5.1 Endophyte-assisted bioremediation
		13.5.2 Application of genetic engineering to enhance phytoremediation potentiality
	13.6 Mechanism of As accumulation
	13.7 Conclusion
	Acknowledgments
	References
Chapter
14 - Microbe-assisted phytomanagement of fly ash spoiled sites
	14.1 Introduction
	14.2 Fly ash properties
	14.3 Fly ash generation and utilization
	14.4 Multiple uses of fly ash
	14.5 Problems due to fly ash
	14.6 Fly ash management
	14.7 Microbial remediation
	14.8 Multiple benefits of fly ash phytomanagement
	14.9 Limitations of phytomanagement in fly ash spoiled sites
	14.10 Conclusion
	References
Chapter
15 - Role of microorganism in phytoremediation of mine spoiled soils
	15.1 Introduction
	15.2 Mine spoiled soils
		15.2.1 Characteristics of mine spoiled soils
		15.2.2 Problems associated with mine spoiled soils
	15.3 Strategies for management of mine spoiled soil
	15.4 Phytorestoration of mine spoiled soils
	15.5 Potential plant species suitable for phytorestoration of mine spoiled soils
	15.6 Microbial-assisted phytoremediation of abandoned mine sites
		15.6.1 Factors affecting microbe-assisted phytoremediation of mining abandoned sites
	15.7 Conclusion and future prospects
	References
PART 
3 - Microbe-assisted phytoremediation of organic contaminants
Chapter
16 - Rhizobacteria assisted phytoremediation of oily sludge contaminated sites
	16.1 Introduction
	16.2 Role of plants on remediation of contamination
	16.3 Role of rhizobacteria on remediation of contaminates
	16.4 Potentiality of rhizobacteria assisted phytoremediation to clean up oily sludge contaminated sites
	16.5 Conclusion
	References
Chapter
17 - Bioremediation of oil-contaminated sites using biosurfactants
	17.1 Introduction
	17.2 Oil contaminants
	17.3 Bioremediation
	17.4 Biosurfactant
		17.4.1 Types of biosurfactant
		17.4.2 Microorganisms produce biosurfactants
	17.5 Mechanisms associated with biosurfactant-mediated bioremediation
	17.6 Current scenario and future outlooks
	17.7 Conclusions
	References
Chapter
18 - Association of plants and microorganisms for degradation of polycyclic aromatic hydrocarbons
	18.1 Introduction
	18.2 PAHs and plants
		18.2.1 PAH toxicity to plants
		18.2.2 PAH uptake, translocation, and accumulation in plants
		18.2.3 Factors affecting PAH phytoavailability
		18.2.4 PAH effects on plant antioxidant protection
		18.2.5 PAH effects on the plant photosynthetic system
		18.2.6 Biochemical transformation of PAHs in plants
	18.3 The rhizosphere
		18.3.1 Root exudate composition and significance
		18.3.2 Factors affecting root exudate composition
		18.3.3 Root exudate enzymes
	18.4 PAH and microorganisms
		18.4.1 Microbial communities of PAH-contaminated soil
		18.4.2 PAH-degrading bacteria
		18.4.3 Pathways for microbial degradation of PAHs
	18.5 Plant-microbial cooperation for degradation of PAHs
		18.5.1 Coupled metabolism of PAHs
		18.5.2 Microbe-assisted phytoremediation of PAH contaminated soil
	18.6 Conclusion
	References
Chapter
19 - The potential of engineered endophytic bacteria to improve phytoremediation of organic pollutants
	19.1 Introduction
	19.2 Uptake mechanism of OPs by plants from soil and water
	19.3 Ecology of endophytic bacteria
	19.4 Niche of endophytic bacteria
	19.5 Host and endophytic diversity
	19.6 Interaction between plant and associated endophytic bacteria
	19.7 Potential of endophytic bacteria to improve phytoremediation of soil contaminated with OP
	19.8 Potential of endophytic bacteria to improve phytoremediation of water contaminated with OPs
	19.9 Factor affecting the activity of engineered endophytic bacteria
		19.9.1 Properties of soil
		19.9.2 Selection of plant
		19.9.3 Pollutant concentration
		19.9.4 Inoculation methods
	19.10 Conclusion
	References
Index