title: Biogenic Nanoparticles from Schwanniomyces occidentalis NCIM 3459: Mechanistic Aspects and Catalytic Applications.
abstract: When cells of Schwanniomyces occidentalis NCIM 3459 were incubated with 1 mM tetrachloroauric acid (HAuCl4) or silver nitrate (AgNO3), cell-associated nanoparticles were obtained. Their presence was confirmed by scanning electron microscope observations. The cell-free supernatant (CFS) of the yeast mediated the synthesis of gold nanoparticles. On account of the difficulties associated with the use of cell-bound nanoparticles, further work was restricted to extracellular nanoparticles. It was hypothesized that the CFS contained thermostable biomolecule(s) that mediated metal reduction reactions. Extraction of the CFS with chloroform/methanol (2:1) and subsequent separation by preparative thin layer chromatography led to the activity-guided purification of a glycolipid. The glycolipid was hydrolyzed and the glycone (glucose) and aglycone components (palmitic acid and oleic acid) were identified by gas chromatography-mass spectrometry. The purified glycolipid mediated the synthesis of gold and silver nanoparticles that were characterized by using an X-ray diffractometer and transmission electron microscope (TEM). The extracellular nanoparticles displayed catalytic activities and reduced 4-nitroaniline to benzene-1,4-diamine. This paper thus highlights nanoparticle synthesis by a hitherto unreported yeast culture, identifies the biomolecules involved in the process, and describes a potential application of the nanostructures.
authors.affiliation: Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007, India.
authors.forename: Pallavi
authors.initials: P
authors.lastname: Mohite
authors.affiliation: Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007, India.
authors.forename: Mugdha
authors.initials: M
authors.lastname: Apte
authors.affiliation: Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007, India.
authors.forename: Ameeta Ravi
authors.initials: AR
authors.lastname: Kumar
authors.affiliation: Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007, India. smita@unipune.ac.in.
authors.forename: Smita
authors.initials: S
authors.lastname: Zinjarde
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D001554:Benzene / Q000737:chemistry; D002384:Catalysis; D002474:Cell-Free System / Q000737:chemistry / Q000378:metabolism; D002712:Chlorides / Q000737:chemistry*; D006017:Glycolipids / Q000096:biosynthesis / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D017612:Gold Compounds / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D004718:Saccharomycetales / Q000737:chemistry* / Q000166:cytology; D012834:Silver / Q000737:chemistry; D012835:Silver Nitrate / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000814:Aniline Compounds; D002712:Chlorides; D006017:Glycolipids; D017612:Gold Compounds; C019498:4-nitroaniline; D012834:Silver; D006046:Gold; C024568:gold tetrachloride, acid; D012835:Silver Nitrate; D001554:Benzene
keywords: Catalysis; Glycolipid; Nanoparticles; Schwanniomyces occidentalis