Abstract: The disposal and the treatment of sewage sludge is an
expensive and environmentally complex problem. In this work, a
lipopeptide biosurfactant extracted from corn steep liquor was used
as ecofriendly and cost-competitive alternative for the mobilization
and bioremediation of fluorene in sewage sludge. Results have
demonstrated that this biosurfactant has the capability to mobilize
fluorene to the aqueous phase, reducing the amount of fluorene in the
sewage sludge from 484.4 mg/Kg up to 413.7 mg/Kg and 196.0
mg/Kg after 1 and 27 days respectively. Furthermore, once the
fluorene was extracted the lipopeptide biosurfactant contained in the
aqueous phase allowed the biodegradation, up to 40.5% of the initial
concentration of this polycyclic aromatic hydrocarbon.
Abstract: This research was undertaken to study enzymatic activity in the shoots, roots, and rhizosphere of alfalfa (Medicago sativa L.) grown in quartz sand that was uncontaminated and
contaminated with phenanthrene at concentrations of 10 and 100 mg kg-1. The higher concentration of phehanthrene had a distinct
phytotoxic effect on alfalfa, inhibiting seed germination energy, plant survival, and biomass accumulation. The plant stress response to the
environmental pollution was an increase in peroxidase activity. Peroxidases were the predominant enzymes in the alfalfa shoots and
roots. The peroxidase profile in the shoots differed from that in the roots and had different isoenzyme numbers. 2,2'-Azinobis-(3-ethylbenzo-thiazoline-6-sulphonate) (ABTS) peroxidase was
predominant in the shoots, and 2,7-diaminofluorene (2,2-DAF)
peroxidase was predominant in the roots. Under the influence of
phenanthrene, the activity of 2,7-DAF peroxidase increased in the
shoots, and the activity of ABTS peroxidase increased in the roots.
Alfalfa root peroxidases were the prevalent enzyme systems in the
rhizosphere sand. Examination of the activity of alfalfa root
peroxidase toward phenanthrene revealed the possibility of
involvement of the plant enzyme in rhizosphere degradation of the
PAH.
Abstract: Sediment and mangrove root samples from Iko River
Estuary, Nigeria were analyzed for microbial and polycyclic
aromatic hydrocarbon (PAH) content. The total heterotrophic
bacterial (THB) count ranged from 1.1x107 to 5.1 x107 cfu/g, total
fungal (TF) count ranged from 1.0x106 to 2.7x106 cfu/g, total
coliform (TC) count ranged from 2.0x104 to 8.0x104cfu/g while
hydrocarbon utilizing bacterial (HUB) count ranged from 1.0x 105 to
5.0 x 105cfu/g. There was a range of positive correlation (r = 0.72 to
0.93) between THB count and total HUB count, respectively. The
organisms were Staphylococcus aureus, Bacillus cereus,
Flavobacterium breve, Pseudomonas aeruginosa, Erwinia
amylovora, Escherichia coli, Enterobacter sp, Desulfovibrio sp,
Acinetobacter iwoffii, Chromobacterium violaceum, Micrococcus
sedentarius, Corynebacterium sp, and Pseudomonas putrefaciens.
The PAH were Naphthalene, 2-Methylnaphthalene, Acenapthylene,
Acenaphthene, Fluorene, Phenanthene, Anthracene, Fluoranthene,
Pyrene, Benzo(a)anthracene, Chrysene, Benzo(b)fluoranthene,
Benzo(k)fluoranthene, Benzo(a)pyrene, Dibenzo(a,h)anthracene,
Benzo(g,h,l)perylene ,Indeno(1,2,3-d)pyrene with individual PAH
concentrations that ranged from 0.20mg/kg to 1.02mg/kg, 0.20mg/kg
to 1.07mg/kg and 0.2mg/kg to 4.43mg/kg in the benthic sediment,
epipellic sediment and mangrove roots, respectively. Total PAH
ranged from 6.30 to 9.93mg/kg, 6.30 to 9.13mg/kg and 9.66 to
16.68mg/kg in the benthic sediment, epipellic sediment and
mangrove roots, respectively. The high concentrations in the
mangrove roots are indicative of bioaccumulation of the pollutant in
the plant tissue. The microorganisms are of ecological significance
and the detectable quantities of polycyclic aromatic hydrocarbon
could be partitioned and accumulated in tissues of infaunal and
epifaunal organisms in the study area.