title: Yeast-based self-organized hybrid bio-silica sol-gels for the design of biosensors.
abstract: The methylotrophic Pichia angusta VKM Y-2559 and the oleaginous Cryptococcus curvatus VKM Y-3288 yeast cells were immobilized in a bimodal silica-organic sol-gel matrix comprised of tetraethoxysilane (TEOS), the hydrophobic additive methyltriethoxysilane (MTES) and the porogen polyethylene glycol (PEG). Under carefully optimized experimental conditions, employing basic catalysts, yeast cells have become the nucleation centers for a silica-organic capsule assembled around the cells. The dynamic process involved in the formation of the sol-gel matrix has been investigated using optical and scanning electron microscopic techniques. The results demonstrated the influence of the MTES composition on the nature of the encapsulation of the yeast cells, together with the architecture of the three-dimensional (3D) sol-gel biomatrix that forms during the encapsulation process. A silica capsule was found to form around each yeast cell when using 85 vol% MTES. This capsule was found to protect the microorganisms from the harmful effects that result from exposure to heavy metal ions and UV radiation. The encapsulated P. angusta BKM Y-2559 cells were then employed as a biosensing element for the detection of methanol. The P. angusta-based biosensor is characterized by high reproducibility (Sr, 1%) and operational stability, where the biosensor remains viable for up to 28 days.
authors.affiliation: Department of Biotechnology, Tula State University, Pr. Lenina 92, Tula 300012, Russia. Electronic address: olgaponamoreva@mail.ru.
authors.forename: O N
authors.initials: ON
authors.lastname: Ponamoreva
authors.affiliation: Department of Chemistry, Tula State University, Pr. Lenina 92, Tula 300012, Russia.
authors.forename: O A
authors.initials: OA
authors.lastname: Kamanina
authors.affiliation: Department of Chemistry, Tula State University, Pr. Lenina 92, Tula 300012, Russia.
authors.forename: V A
authors.initials: VA
authors.lastname: Alferov
authors.affiliation: Laboratory of Cytology of Microorganisms, G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pr. Nauki 5, Pushchino, Moscow Region 142290, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Machulin
authors.affiliation: Department of Chemistry, Tula State University, Pr. Lenina 92, Tula 300012, Russia.
authors.forename: T V
authors.initials: TV
authors.lastname: Rogova
authors.affiliation: Department of Chemistry, Tula State University, Pr. Lenina 92, Tula 300012, Russia.
authors.forename: V A
authors.initials: VA
authors.lastname: Arlyapov
authors.affiliation: Department of Biotechnology, Tula State University, Pr. Lenina 92, Tula 300012, Russia.
authors.forename: S V
authors.initials: SV
authors.lastname: Alferov
authors.affiliation: Laboratory of Cytology of Microorganisms, G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pr. Nauki 5, Pushchino, Moscow Region 142290, Russia.
authors.forename: N E
authors.initials: NE
authors.lastname: Suzina
authors.affiliation: Faculty of Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, Hawthorn, Victoria 3122, Australia.
authors.forename: E P
authors.initials: EP
authors.lastname: Ivanova
mesh_terms: D015374:Biosensing Techniques; D002384:Catalysis; D003454:Cryptococcus / Q000737:chemistry*; D000432:Methanol / Q000302:isolation & purification*; D010843:Pichia / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry; D016062:Porosity; D012821:Silanes / Q000737:chemistry; D058428:Silica Gel / Q000737:chemistry
chemical_list: D012821:Silanes; C071718:methyltrimethoxysilane; D011092:Polyethylene Glycols; D058428:Silica Gel; D019904:Polymethyl Methacrylate; D000432:Methanol
keywords: Encapsulation of living cells; Methanol biosensor; Methylotrophic yeast; Sol–gel silica; Whole-cell biosensor