1st Edition

Bioreduction of Selenite and Tellurite by Phanerochaete Chrysosporium

By Erika Jimena Espinosa-Ortiz Copyright 2016
    180 Pages
    by CRC Press

    180 Pages
    by CRC Press

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    Selenium (Se) and tellurium (Te) are metalloids of commercial interest due to their physicochemical properties. The water soluble oxyanions of these elements (selenite, selenate, tellurite and tellurate) exhibit high toxicities; hence, their release in the environment is of great concern.
    This study demonstrates the potential use of fungi as Se- and Te-reducing organisms. The response of Phanerochaete chrysosporium to the presence of selenite and tellurite was evaluated, as well as its potential application in wastewater treatment and production of nanoparticles. Growth stress and morphological changes were induced in P. chrysosoporium when exposed to selenite and tellurite. Synthesis of Se0 and Te0 nanoparticles entrapped in the fungal biomass was observed, as well as the formation of unique Se0-Te0 nanocomposites when the fungus was cultivated concurrently with Se and Te. The response of P. chrysosporium to selenite exposure was investigated in different modes of fungal growth (pellets and biofilm). A bioprocess for selenite removal and Se0 nanoparticles recovery using an up-flow fungal pelleted reactor was developed. 70% selenite removal (10 mg Se L-1 d-1) was achieved under continuous mode. The use of Se0 nanoparticles immobilized in P. chrysosporium pellets as a new sorbent material for the removal of heavy metals from wastewater was demonstrated.

    1 General introduction
    1.1 Background
    1.2 Problem statement
    1.3 Research objectives
    1.4 Structure of the thesis
    1.5 References

    2 Literature review
    2.1 Introduction
    2.2 Fungal pellets
    2.2.1 Fungal pellets: formation and growth
    2.2.2 Factors influencing the characteristics and formation of pellets
    2.2.3 Fungal pellets in bioreactors
    2.3 Fungal pelleted bioreactors for wastewater treatment
    2.3.1 Potential applications and challenges
    2.3.2 Reactor configurations
    2.3.3 Reactor design for fungal pelleted reactors
    2.3.4 Sterile versus non‐sterile conditions
    2.3.5 Biomass recycle in fungal pelleted reactors
    2.4 Removal of organic and inorganic pollutants
    2.4.1 Removal of organic pollutants
    2.4.2 Removal of inorganic pollutants
    2.5 Scope for further research
    2.6 Conclusions
    2.7 References

    3 Effects of selenium oxyanions on the fungus Phanerochaete chrysosporium
    3.1 Introduction
    3.2 Materials and methods
    3.2.1 Fungal culture and medium composition
    3.2.2 Batch experiments
    3.2.3 Transmission electron microscopy (TEM) and electron‐energy loss spectroscopy (EELS) analysis
    3.2.4 Analytical methods
    3.3 Results
    3.3.1 Fungal interaction with selenium oxyanions
    3.3.2 Effect of glucose concentration
    3.3.3 Effect of pH
    3.3.4 Effects of selenium concentration
    3.4 Discussion
    3.4.1 Inhibition of fungal growth induced by selenium oxyanions
    3.4.2 Morphological effects induced by selenium oxyanions
    3.4.3 Removal of selenium oxyanions by P. chrysosporium
    3.4.4 Production of Se0 by P. chrysosporium
    3.4.5 Potential applications
    3.5 References

    4 Removal of selenite from wastewater in a Phanerochaete chrysosporium pellet based fungal bioreactor
    4.1 Introduction
    4.2 Materials and methods
    4.2.1 Strain, medium composition and pre‐cultivation of fungal cultures
    4.2.2 Bioreactor configuration and operating conditions
    4.2.3 Analytical methods
    4.2.4 Statistical analysis
    4.3 Results
    4.3.1 Bioreactor operation in batch mode
    4.3.2 Continuous bioreactor operation at constant selenium concentrations
    4.3.3 Bioreactor response to spikes of selenium concentration
    4.3.4 Evolution and growth of the fungal biomass
    4.4 Discussion
    4.4.1 Removal of selenite in a fungal pelleted bioreactor
    4.4.2 Response of the system to selenium spikes
    4.4.3 Fungal morphology in the bioreactor
    4.4.4 Operational advantages of fungal pelleted reactors
    4.4.5 Longevity of reactor operation
    4.5 Conclusions
    4.6 References

    5 Sorption of zinc onto elemental selenium nanoparticles immobilized in Phanerochaete chrysosporium pellets
    5.1 Introduction
    5.2 Experimental
    5.2.1 Biosorbent preparation
    5.2.2 Biosorbent characterization
    5.2.3 Batch adsorption experiments
    5.2.4 Analytical methods
    5.3 Results
    5.3.1 Characterization of biosorbent material
    5.3.2 Effects of operational parameters on sorption capacity of nSe0‐pellets
    5.3.3 Sorption kinetics
    5.3.4 Adsorption isotherms
    5.4 Discussion
    5.4.1 Sorption mechanisms of Zn onto nSe0 pellets
    5.4.2 Effects of operational parameters on sorption capacity of nSe0‐pellets
    5.4.3 Potential applications
    5.4.4 Conclusions
    5.5 References

    6 Effect of selenite on the morpholoy and respiratory activity of Phanerochaete chrysosporium biofilms
    6.1 Introduction
    6.2 Materials and methods
    6.2.1 Fungal strain and culturing conditions
    6.2.2 Biofilm growth and exposure experiments
    6.2.3 Microsensor measurements
    6.2.4 Biofilm sectioning and imaging
    6.2.5 Analytical methods
    6.3 Results
    6.3.1 Influence of short‐term SeO3 2‐ exposure on P. chrysosporium biofilm activity
    6.3.2 Influence of long‐term SeO3 2‐ exposure on P. chrysosporium biofilm activity
    6.4 Discussion
    6.4.1 Inhibition of developed P. chrysosporium biofilms by SeO3 2‐
    6.4.2 Influence of SeO3 2‐ on the physical and morphological properties of P. chrysosporium biofilms
    6.5 Conclusions
    6.6 References

    7 Biomineralization of tellurium and selenium‐tellurium nanoparticles by the white‐rot fungus Phanerochaete chrysosporium
    7.1 Introduction
    7.2 Materials and methods
    7.2.1 Fungal strain and culturing conditions
    7.2.2 Batch experiments
    7.2.3 Characterizations of fungal morphology
    7.2.4 Analytical methods
    7.3 Results
    7.3.1 Fungal interaction with chalcogen oxyanions
    7.3.2 Effect of Se:Te ratio on tellurite reduction
    7.3.3 Fungal morphology
    7.3.4 Electron microscopic analysis
    7.4 Discussion
    7.4.1 P. chrysosporium as a tellurite‐reducing organism
    7.4.2 Synergetic effect of selenite and tellurite on P. chrysosporium
    7.4.3 Morphological effects induced by tellurite and Se‐Te combinations
    7.4.4 Production of nTe0 and nSe‐Te
    7.5 Conclusions
    7.6 References

    8 Mycotechnology for the treatment of Se and Te contaminated effluents and biomineralization of Se0 and Te0 nanoparticles
    8.1 Mycotechnology
    8.2 Fungal technology in the removal of Se and Te from wastewater
    8.3 Fungi as Se0 and Te0 nanofactories
    8.4 Novel hybrid fungal sorbents containing nanoparticles for wastewater
    8.5 Fungal technology for the removal of selenium and potential applications of the Se0 nanoparticles immobilized in fungal pellets
    8.6 Conclusions and future perspectives
    8.7 References

    Appendix 1


    Erika Jimena Espinosa-Ortiz was born in Mexico City in 1984.  She received her Bachelor's Science degree, summa cum laude, in Environmental Engineering from the Autonomous Metropolitan University (UAM), Mexico, in 2006. Upon graduation, she worked for one year as environmental consultant, analyst and laboratory assistant in the Water Quality and Residues Laboratory at UAM. Erika obtained two Master degrees. The first one in Environmental Engineering, from the National Autonomous University of Mexico (UNAM) in 2009; during this period she investigated the biological contamination of source water supplies in the Tula Valley, Mexico, which is a region that has been irrigated with wastewater for over a hundred years. She was awarded with a Fulbright scholarship to complete the second Master, which she obtained from Purdue University, USA, in 2010 in Ecological Sciences and Engineering. Her research back then consisted on assessing the ecotoxicological effects of gallium and indium on soil microbial activities and plants.
    In 2012, Erika started her PhD programme at UNESCO-IHE, as part of an Erasmus Mundus Joint Doctorate Program on Environmental Technologies for Contaminated Solids, Soils and Sediments (ETeCoS3). Erika investigated the of the use of fungi as selenium and tellurium reducing organisms and their potential in wastewater treatment and nanotechnology. As part of her programme, Erika also performed research at Paris-Est University and at the Center for Biofilm Engineering in Bozeman, Montana, USA. She has nine years of laboratory experience and research-related work, participated in international conferences and has a number of scientific publications including a book chapter and peer-reviewed journals on her name. Currently, she works as a post-doc at the Center for Biofilm Engineering on the development of fungal biofilms (2016).