There are increasing concerns over the harmful
effects of the phosphate industry on human health and
quality of life worldwide, including the Tunisian Chemical
Group (GCT) in Sfax, which generates various malodorous
gas fractions, such as hydrogen sulfide (H
2S) and fetid
mercaptans, causing nuisance to employees and local residents.
Accordingly, the present study aimed to investigate
the ability of an adapted microbial consortium isolated from
the gas-washing wastewaters (GWWs) generated from GCT
to degrade hazardous and malodorous mercaptans. A novel
mesophilic bacterial strain (SH6), which was noted to display
particularly high mercaptan degradation potential, was
isolated from the adapted consortium growing on those
GWWs and several malodorous mercaptans after enrichment
on 1-dodecanethiol. The results from 16 rRNA gene
sequencing and identity analysis revealed that the SH6
isolate belonged to
Staphylococcus
genus, with a high
sequence similarity to
Staphylococcus capitis
(99.7 %). The
SH6 strain was able to completely degrade 1-dodecanethiol,
used as the sole carbon and energy source, after 72 h of
incubation at 37 °C and 180 rpm. A decrease in the surface
tension of cell-free culture supernatants was observed during
the oxidation of dodecanethiol, suggesting the production
of surface-active compounds. The stain was also able to
grow on other mercaptans, such as 1,8-octanedithiol and
2,3-butanedithiol, which further supports its potential
candidacy for application in the bioremediation of mercaptan-
contaminated sites. Overall, the findings of the
present study indicate that the SH6 strain might offer
promising opportunities for the development of more
adapted, efficient and cost-effective bio-disodoration
strategies.
