A technical evaluation of stillage characterization, treatment, and by-product recovery in the ethanol industry was performed through a review of the scientific literature, with particular emphasis on solutions pertinent to a cellulosic-based ethanol production system. This effort has generated substantial information supporting the viability of anaerobic digestion for stillage treatment followed by land application on biomass crops for nutrient recovery. Generally, the characteristics of stillage from cellulosic materials appear comparable to those of conventional sugar- and starch-based feedstocks. However, the data on cellulosic stillage characteristics and treatment parameters are extremely limited and highly variable. This has significant impacts on the capital costs and biogas recovery of anaerobic treatment systems predicted from these data. In addition, technical questions remain unanswered with regard to stillage toxicity from untested feedstocks and the impact of heavy metal leaching when acid hydrolysis reactors are fabricated from corrosion-resistant alloys. Thermophilic anaerobic digestion of ethanol stillage achieves similar treatment efficiencies and methane yields compared to mesophilic treatment, but at almost twice the organic loading rate. Therefore, application of thermophilic anaerobic digestion would improve process economics, since smaller digesters and less stillage cooling are required. Downstream processes for stillage utilization and by-product recovery considered worthy of continued investigation include the production of feed (from single cell protein and/or algae production), color removal, and production of calcium magnesium acetate. This study finds that sustainable and economically viable solutions are available for mitigating the environmental impacts which result from large-scale biomass-to-ethanol conversion facilities. However, further research in some areas is needed to facilitate successful implementation of appropriate technology options.

Stillage characterization and anaerobic treatment of ethanol stillage from conventional and cellulosic feedstocks

Plants are subjected to various abiotic stresses, such as drought, extreme temperature, salinity, and heavy metals. Abiotic stresses have negative impact on the physiology and morphology of plants through defects in the genetic regulation of cellular pathways. Plants employ several tolerance mechanisms and pathways to avert the effects of stresses that are triggered whenever alterations in metabolism are encountered. Phytohormones are among the most important growth regulators; they are known for having a prominent impact on plant metabolism, and additionally, they play a vital role in the stimulation of plant defence response mechanisms against stresses. Exogenous phytohormone supplementation has been adopted to improve growth and metabolism under stress conditions. Recent investigations have shown that phytohormones produced by root-associated microbes may prove to be important metabolic engineering targets for inducing host tolerance to abiotic stresses. Phytohormone biosynthetic pathways have been identified using several genetic and biochemical methods, and numerous reviews are currently available on this topic. Here, we review current knowledge on the function of phytohormones involved in the improvement of abiotic stress tolerance and defence response in plants exposed to different stressors. We focus on recent successes in identifying the roles of microbial phytohormones that induce stress tolerance, especially in crop plants. In doing so, this review highlights important plant morpho-physiological traits that can be exploited to identify the positive effects of phytohormones on stress tolerance. This review will therefore be helpful to plant physiologists and agricultural microbiologists in designing strategies and tools for the development of broad spectrum microbial inoculants supporting sustainable crop production under hostile environments.

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Phytohormones and Beneficial Microbes: Essential Components for Plants to Balance Stress and Fitness.

Preface. 1. Introduction. 1.1 Fungal Biodegradation and Biodeterioration. 1.2 How a Fungus Escapes Water to Grow in Air? 1.3 Fungal Morphology, Analysis and Growth Measurement. 1.4 Mass Transfer, Growth Kinetics, and Bioreactors. 1.5 Methods for Detection of Degradative Fungi. 1.6 Fungi as Environmental Indicators. 1.7 Fungal Attack on Coal. 1.8 Thermophilic, Alpine, and Lichen-Forming Fungi. 1.9 Mycoremediation: Fungal Bioremediation. 1.10 Ecology of Mycoremediation. 1.11 Genetic Engineering of Mycoremediation References. 2. Fungal Treatment of Industrial Wastewaters. 2.1 Introduction. 2.2 Alternative Industrial Wastewater Bioreactors. 2.3 Fungal Treatment of Industrial Wastewaters. 2.4 Biotechnology. 2.5 Conclusions and Future Perspectives References. 3. Fungal Treatment of Distillery and Brewery Wastes. 3.1 Introduction. 3.2 Composition and Characteristics of Stillage. 3.3 Alternative Industrial Stillage Treatment Reactors. 3.4 Fungal Treatment of Distillery and Brewery Wastes. 3.5 Fungal Fermentation and Decolorization. 3.6 Molasses Toxicity to Fungi. 3.7 Factors Affecting Fungal Fermentation and Decolorization. 3.8 Mechanisms of Melanoidin Degradation. 3.9 Fungal Bioreactors for Distillery and Brewery Wastes. 3.10 Modeling. 3.11 Economic Importance. 3.12 Biotechnology. 3.13 Conclusions and Future Perspectives References. 4. Fungal Metabolism of Petroleum Hydrocarbons. 4.1 Introduction. 4.2 Fate of Oil in the Environment. 4.3 Composition of Petroleum Hydrocarbons. 4.4 Methods of Analysis of Petroleum Hydrocarbons. 4.5 Alternative Treatment Technologies. 4.6 Hydrocarbon-Utilizing Yeasts and Fungi. 4.7 Fungal Methods for Assessment. 4.8 Hydrocarbon Metabolism by Yeasts and Fungi. 4.9 Taxonomic Relationship of Hydrocarbon-Utilizing Yeasts and Fungi. 4.10 Factors Affecting Metabolism of Petroleum Hydrocarbons. 4.11 Fungal Mechanisms of Metabolism of Petroleum Hydrocarbons. 4.12 Oxidation of Petroleum Hydrocarbons by Fungal Enzymes. 4.13 Cytochrome P450 Enzyme Systems. 4.14 Economic Importance. 4.15 Biotechnology and Bioengineering. 4.16 Conclusions and Future Perspectives References. 5. Fungal Degradation of Polychlorinated Biphenyls and Dioxins. 5.1 Introduction. 5.2 Nomenclature. 5.3 Bioaccumulation and Toxicity. 5.4 Alternative PCB Remediation Technologies. 5.5 Analysis of Polychlorinated Biphenyls. 5.6 Bioavailability of Polychlorinated Biphenyls. 5.7 Fungal Degradation of Polychlorinated Biphenyls. 5.8 Fungal Degradation of Dioxins. 5.9 Genetic Manipulation. 5.10 Conclusions and Future Perspectives References. 6. Fungal Degradation of Pesticides. 6.1 Introduction. 6.2 Classification. 6.3 Biosensors for Detection of Pesticides. 6.4 Fungal Degradation of Insecticides. 6.5 Fungal Degradation of Herbicides. 6.6 Fungal Degradation of Fungicides. 6.7 Biotransformation of Pesticides by Fungal Enzymes. 6.8 Genetic Manipulation. 6.9 Conclusions and Future Perspectives References. 7. Fungal Metabolism of Phenols, Chlorophenols and Pentachlorophenol. 7.1 Introduction. 7.2 Alternative Treatment Technologies. 7.3 Fungal Biosensors for Determination of Various Types of Phenols. 7.4 Methods of Analysis of Various Types of Phenols. 7.5 Fungal Bioreactors for Removal of Various Types of Phenols. 7.6 Fungal Metabolism of Phenols, Chlorophenols and Pentachlorophenol. 7.7 Factors Affecting Fungal Metabolism of Various Types of Phenols. 7.8 Physiological Alterations of Fungi by Phenols. 7.9 Taxonomic Relationship of Phenol-Utilizing Yeasts and Fungi. 7.10 Mechanisms of Metabolism, Metabolic Pathways, and Metabolites. 7.11 Degradation of Phenols by Fungal Enzymes. 7.12 Fungal Transformation of Pentachlorophenol in Soils. 7.13 Cytochrome P450 Systems in Degradation of Phenols. 7.14 Conclusions and Future Perspectives References. 8. Fungal Metabolism of Polycyclic Aromatic Hydrocarbons. 8.1 Introduction. 8.2 Occurrence of PAHs in the Environment. 8.3 Alternative PAH Metabolism. 8.4 Fungal Metabolism of PAHs. 8.5 Mutagenicity of Fungal Metabolites of PAHs. 8.6 Fungal Bioreactors for Removal of PAHs. 8.7 PAH Degradation by Fungal Enzymes. 8.8 Cytochrome P450 in Degradation of PAHs. 8.9 Fungal Degradation of PAHs in Soils. 8.10 Fungal Metabolism of Complex PAH Mixtures. 8.11 PAH Degradation by Fungal-Bacterial Co-cultures. 8.12 Biotechnology and Bioengineering. 8.13 Conclusions and Future Perspectives References. 9. Fungal Lignin Degradation and Decolorization of Pulp and Paper Mill Effluents. 9.1 Introduction. 9.2 Distribution and Structure of Lignin. 9.3 Lignin-Degrading Microorganisms. 9.4 Fungal Lignin-Degrading Enzymes. 9.5 Mechanisms of Fungal Lignin Degradation and Metabolic Products. 9.6 Fungal Decolorization of Pulp and Paper Mill Effluents. 9.7 Fungal Bioreactors for Decolorization of Pulp and Paper Mill Effluents. 9.8 Factors Affecting Decolorization of Pulp and Paper Mill Effluents. 9.9 Effect of Fungal Treatment on Chlorophenols and Chloroaldehydes in Effluents. 9.10 Decolorization of Effluents by Fungal Enzymes. 9.11 Wetlands Treatment. 9.12 Conclusions and Future Perspectives References. 10. Fungal Decolorization and Degradation of Dyes. 10.1 Introduction. 10.2 Classification, Structure, and Color Measurements. 10.3 Legislation and Regulations. 10.4 Alternative Decolorization Treatment Technologies. 10.5 Fungal Decolorization and Degradation of Dyes. 10.6 Yeast Decolorization and Degradation of Dyes. 10.7 White-Rot Fungal Decolorization and Degradation of Dyes. 10.8 Mechanisms of Fungal Decolorization and Degradation of Dyes. 10.9 Metabolic Products and Pathways. 10.10 Factors Affecting Fungal Decolorization and Degradation of Dyes. 10.11 Fungal Dye Decolorization and Degradation Bioreactors. 10.12 Decolorization and Degradation of Dyes by Fungal enzymes. 10.13 Decolorization of Artificial Textile Effluent. 10.14 Sequential Dye Decolorization. 10.15 Conclusions and Future Perspectives References. 11. Fungal Biosorption of Heavy Metals. 11.1 Introduction. 11.2 Biosorption and Bioaccumulation of Heavy Metals. 11.3 Evaluation of Sorption Performance. 11.4 Mechanisms of Fungal Biosorption of Heavy Metals. 11.5 Fungal Biosorption Reactors for Heavy Metals. 11.6 Applications of Fungal Biosorption of Heavy Metals. 11.7 Fungal Biosorption of Herbicides and Phenols. 11.8 Fungal Biosorption of Dyes. 11.9 Fungal Binary and Ternary Biosorption Systems. 11.10 Biosorption of Heavy Metal Anions. 11.11 Metal Ion Resistance. 11.12 Conclusions and Future Perspectives References. 12. Mycorrhizal Fungi in Rhizosphere Remediation. 12.1 Introduction. 12.2 Classification of Mycorrhizal Fungi. 12.3 Functions of Mycorrhizal Mycelium. 12.4 Methods for Studying Mycorrhizal Fungi. 12.5 Molecular Mechanisms of Mycorrhizal Symbiosis. 12.6 Metabolism of Mycorrhizal Fungi. 12.7 Uptake of Toxic Metals. 12.8 Petroleum Hydrocarbon Degradation. 12.9 Lignin and Phenolic Degradation. 12.10 PAH and TNT Degradation. 12.11 PCB Degradation. 12.12 Herbicide Degradation. 12.13 Comparison of Mycorrhizal and White-Rot Fungi. 12.14 Conclusions and Future Perspectives References. Index.

Mycoremediation: Fungal Bioremediation

Soil salinity has emerged as a serious issue for global food security. It is estimated that currently about 62 million hectares or 20 percent of the world's irrigated land is affected by salinity. The deposition of an excess amount of soluble salt in cultivable land directly affects crop yields. The uptake of high amount of salt inhibits diverse physiological and metabolic processes of plants even impacting their survival. The conventional methods of reclamation of saline soil which involve scraping, flushing, leaching or adding an amendment (e.g., gypsum, CaCl2, etc.) are of limited success and also adversely affect the agro-ecosystems. In this context, developing sustainable methods which increase the productivity of saline soil without harming the environment are necessary. Since long, breeding of salt-tolerant plants and development of salt-resistant crop varieties have also been tried, but these and aforesaid conventional approaches are not able to solve the problem. Salt tolerance and dependence are the characteristics of some microbes. Salt-tolerant microbes can survive in osmotic and ionic stress. Various genera of salt-tolerant plant growth promoting rhizobacteria (ST-PGPR) have been isolated from extreme alkaline, saline, and sodic soils. Many of them are also known to mitigate various biotic and abiotic stresses in plants. In the last few years, potential PGPR enhancing the productivity of plants facing salt-stress have been researched upon suggesting that ST-PGPR can be exploited for the reclamation of saline agro-ecosystems. In this review, ST-PGPR and their potential in enhancing the productivity of saline agro-ecosystems will be discussed. Apart from this, PGPR mediated mechanisms of salt tolerance in different crop plants and future research trends of using ST-PGPR for reclamation of saline soils will also be highlighted.

Salt-Tolerant Plant Growth Promoting Rhizobacteria for Enhancing Crop Productivity of Saline Soils.

Inoculation of abscisic acid-producing endophytic bacteria enhances salinity stress tolerance in Oryza sativa

In this study, auxin (indole-3-acetic acid), gibberellin, cytokinin (zeatin) and abscisic acid production were investigated in the culture medium of the bacteria Proteus mirabilis, P. vulgaris, Klebsiella pneumoniae, Bacillus megaterium, B. cereus, Escherichia coli. To determine the levels of these plant growth regulators, high performance liquid chromatography (HPLC) technique was used. Our findings show that the bacteria used in this study synthesized the plant growth regulators, auxin, gibberellin, cytokinin and abscisic acid.

Auxin, gibberellin, cytokinin and abscisic acid production in some bacteria

In this study, olive oil mill and alcohol factory wastewaters have been tested as growth media for the production of plant growth hormones Funalia trogii ATCC 200800 and Trametes versicolor ATCC 200801 have been tested Gibberellic acid (GA3), abscisic acid (ABA), indole acetic acid (IAA), and cytokinin were determined in the culture media of these fungi Both organisms produced enhanced levels of all three hormones in the presence of either of the wastewaters

S.F. Topcuoglu

Papers

Auxin, gibberellin, cytokinin and abscisic acid production in some bacteria

Plant growth hormone production from olive oil mill and alcohol factory wastewaters by white rot fungi