TITLE:
Uptake of Polycyclic Aromatic Hydrocarbons across Bacterial Membrane
AUTHORS:
Shaomin Yan, Guang Wu
KEYWORDS:
Bacteria, Polycyclic Aromatic Hydrocarbon, Transport Mechanisms
JOURNAL NAME:
Advances in Microbiology,
Vol.10 No.7,
July
22,
2020
ABSTRACT: Polycyclic aromatic hydrocarbons (PAHs) are
important pollutants, whose biodegradation and bioremediation with
microorganisms are the promising ways to clean environments and reduce their
exposure to humans. Although the transportation of PAHs across bacterial membrane
is the first step forwards their biodegradation, it receives less attention. In
this mini-review, we explore which transport system for uptake of carbon
sources can serve for uptake of PAHs in
bacteria, and try to uncover some patterns in their transport mechanisms. Collectively,
1) the major carbohydrate transport system, PTS, is unlikely to take PAHs
because PAHs lack a hydroxy group for phosphorylation but aromatic acids are
good candidates; 2) PAHs could probably go through H+ symporters, especially
the low-molecular-weight PAHs, which are partially dissolvable in water; 3) it
is unlikely that PAHs can produce chemiosmotic ion gradients to go through
uniporters; and 4) antiporters could serve as transporters to transport PAHs across
bacterial membrane only after the metabolism of PAHs generates extra H+ inside cell. Accordingly, the basic mechanism for uptake of PAHs is whether
they can donate H+ in order to generate an electrochemical proton gradient
to go through symporters.