Microbial solvent regeneration in biotreatment of air contaminated by styrene

[Abstract] In this study, the biodegradation of a styrene-polluted waste gas in a reactor containing 5 L of a biphasic mixture (10:90% v/v) of organic solvent (silicone oil) – water – biomass was investigated to establish the ability of a microbial solvent regeneration. Reproducible microbial solvent regenerations have been observed. The regeneration time, which increases with the increase of the styrene load (varying from 543 to 1800 mg), leads to elimination capacity up to 48 gstyrene.m-3 mixture.h-1. The solvent regeneration requires roughly 1.2 molecule of oxygen per molecule of styrene and corresponds to the first steps of the biodegradation of the styrene

Regulation of cellular zinc balance as a potential mechanism of EVER-mediated protection against pathogenesis by cutaneous oncogenic human papillomaviruses

Epidermodysplasia verruciformis (EV) is a genodermatosis associated with skin cancers that results from a selective susceptibility to related human papillomaviruses (EV HPV). Invalidating mutations in either of two genes (EVER1 and EVER2) with unknown functions cause most EV cases. We report that EVER1 and EVER2 proteins form a complex and interact with the zinc transporter 1 (ZnT-1), as shown by yeast two-hybrid screening, GST pull-down, and immunoprecipitation experiments. In keratinocytes, EVER and ZnT-1 proteins do not influence intracellular zinc concentration, but do affect intracellular zinc distribution. EVER2 was found to inhibit free zinc influx to nucleoli. Keratinocytes with a mutated EVER2 grew faster than wild-type keratinocytes. In transiently and stably transfected HaCaT cells, EVER and ZnT-1 down-regulated transcription factors stimulated by zinc (MTF-1) or cytokines (c-Jun and Elk), as detected with luciferase assays. To get some insight into the control of EV HPV infection, we searched for interaction between EVER and ZnT-1 and oncoproteins of cutaneous (HPV5) and genital (HPV16) genotypes. HPV16 E5 protein binds to EVER and ZnT-1 and blocks their negative regulation. The lack of a functional E5 protein encoded by EV HPV genome may account for host restriction of these viruses