Impact of nanoparticles on transcriptional regulation of catabolic genes of petroleum hydrocarbon ‐degrading bacteria in contaminated soil microcosms

This study was conducted to determine what effects nanoparticles (NPs) like TiO2, ZnO, and Ag may pose on natural attenuation processes of petroleum hydrocarbons in contaminated soils. The solid NPs used were identified using x ‐ray diffraction technique and their average size was certified as 18.2, 16.9, and 18.3 nm for Ag‐NPs, ZnO‐NPs, and TiO2‐NPs, respectively. NPs in soil microcosms behave differently where it was dissolved as in case of Ag‐NPs, partially dissolved as in ZnO‐NPs or changed into other crystalline phase as in TiO2‐NPs. In this investigation, catabolic gene encoding catechol 2,3 dioxygenase (C23DO) was selected specifically as biomarker for monitoring hydrocarbon biodegradation potential by measuring its transcripts by RT‐qPCR. TiO2‐NPs amended microcosms showed almost no change in C23DO expression profile or bacterial community which were dominated byBacillus sp.,Mycobacterium sp.,Microbacterium sp.,Clostridium sp., beside uncultured bacteria, including uncultured proteobacteria,Thauera sp. andClostridia. XRD pattern suggested that TiO2‐NPs in microcosms were changed into other non‐inhibitory crystalline phase, consequently, showing the maximum degradation profile for most low molecular weight oil fractions and partially for the high molecular weight ones. Increasing ZnO‐NPs concentration in microcosms resulted in a reductio n in the expression of C23DO with a concomitant slight deteriorative effect on bacterial populations ending...
Source: Journal of Basic Microbiology - Category: Microbiology Authors: Tags: RESEARCH PAPER Source Type: research