title: Exploring the fungal protein cadre in the biosynthesis of PbSe quantum dots.
abstract: While a large number of microbial sources have recently emerged as potent sources for biosynthesis of chalcogenide quantum dots (QDs), studies regarding their biomimetic strategies that initiate QD biosynthesis are scarce. The present study describes several mechanistic aspects of PbSe QD biosynthesis using marine Aspergillus terreus. Scanning electron microscopic (SEM) studies indicated distinctive morphological features such as abrasion and agglomeration on the fungal biomass after the biosynthesis reaction. Further, the biomass subsequent to the heavy metal/metalloid precursor was characterized with spectral signatures typical to primary and secondary stress factors such as thiol compounds and oxalic acid using Fourier Transform Infra-Red Spectroscopic (FTIR) analysis. An increase in the total protein content in the reaction mixture after biosynthesis was another noteworthy observation. Further, metal-phytochelatins were identified as the prominent metal-ion trafficking components in the reaction mixture using Liquid Chromatography Mass Spectroscopic analysis (LCMS). Subsequent assays confirmed the involvement of metal binding peptides namely metallothioneins and other anti-oxidant enzymes that might have played a prominent role in the microbial metal detoxification system for the biosynthesis of PbSe QDs. Based on these findings a possible mechanism for the biosynthesis of PbSe QDs by marine A. terreus has been elucidated.
authors: Department of Chemical Engineering, National Institute of Technology, Karnataka, Surathkal 575 025, India.
authors: Jaya Mary
authors: JM
authors: Jacob
authors: Department of Chemical Engineering, National Institute of Technology, Karnataka, Surathkal 575 025, India.
authors: Sumit
authors: S
authors: Sharma
authors: Department of Chemical Engineering, National Institute of Technology, Karnataka, Surathkal 575 025, India. Electronic address: rajmohanbala@gmail.com.
authors: Raj Mohan
authors: RM
authors: Balakrishnan
mesh_terms: D001230:Aspergillus / Q000737:chemistry / Q000378:metabolism; D018533:Biomass; D002614:Chelating Agents / Q000737:chemistry; D005656:Fungal Proteins / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D008668:Metallothionein / Q000032:analysis; D010070:Oxalates / Q000737:chemistry; D054811:Phytochelatins; D045663:Quantum Dots / Q000737:chemistry*; D017382:Reactive Oxygen Species; D012623:Seawater / Q000382:microbiology; D018036:Selenium Compounds / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013482:Superoxide Dismutase / Q000032:analysis
chemical_list: D002614:Chelating Agents; D005656:Fungal Proteins; D010070:Oxalates; D017382:Reactive Oxygen Species; D018036:Selenium Compounds; D013438:Sulfhydryl Compounds; C088065:lead selenide; D007854:Lead; D008668:Metallothionein; D054811:Phytochelatins; D013482:Superoxide Dismutase
keywords: Aspergillus terreus; Biosynthesis; Metallothionein; PbSe quantum dots; Phytochelatin