Environmental Engineering Reference
In-Depth Information
with 4 mm diameter plugs of the isolated fungal mycelia taken from agar inoculums
plate. The dishes were incubated at 25 ± 2 °C in an incubator. Fungal mycelia on the
plates (colony diameter) were measured using a measuring tape after 4 days and
compared with the control plates (Mohsenzade et al.
2009
).
S. glaucus
belonging to the family Asteraceae is a common plant on the oil pol-
luted sites in Abadan area, with a higher frequency than others, especially in the
central region of the oil-polluted areas. It is petroleum resistant, therefore its root-
associated fungi were chosen for this investigation. 80 pots were prepared and filled
with 2 kg sterile garden soil. These were divided in to 16 groups (depending on the
fungi isolated). Each group included five pots. The groups were containing follow-
ing agents separately as follows:
(1) Sterile soil, (2) Sterile soil+Plant, (3) Sterile soil+
Altenaria,
(4) Ster-
ile soil + Plant +
Altenaria,
(5) Sterile soil+
Fusarium acuminatum,
(6) Sterile
soil + plant +
F. acuminatum,
(7) Sterile soil +
F. equiseti,
(8) Sterile soil + plant +
F.
equiseti
, (9) Sterile soil+
F. reticulatum,
(10) Sterile soil + Plant +
F. reticulatum,
(11) Sterile soil +
penicilinium,
(12) Sterile soil + Plant +
Penicilinium,
(13) Sterile
soil
+ Rhizoctonia,
(14) Sterile soil + Plant +
Rhizoctonia,
(15) Sterile soil + all above
mentioned fungi
,
(16) Sterile soil + Plant + all above mentioned fungi
.
In the group with plants each pot had two seedlings. Crude oil was applied to
all pots, at a pollution level 5 % w/w. The pots were kept under same conditions
in greenhouse at Bu-Ali Sina University.
S. glaucus
plants were removed after 3
months at the end of the growing period. The soil of experimental and control pots
was homogenized separately and stored at 4 °C in the refrigerator until further anal-
ysis. At the end of experiment concentrations of oil were determined in the soil of
experimental and control pots (after 3 months) and decrease in the oil was compared
in the control and experimental pots.
The soil samples in the pots after 3 months were collected separately. Each soil
sample, without plant segments, was homogenized and stored at 4 °C until further
processing. TOG was analyzed according to the EPA method 9071A and EPA Meth-
od 3540B (USEPA
1994
). Fifteen grams of each soil sample were acidified with hy-
drochloric acid to pH 2 in two replicates and dehydrated with magnesium sulphate
monohydrate. After 15 min, samples were transferred to paper extraction thimbles
and placed in a Soxhlet type apparatus. TOG was extracted with dichloromethane
for 8 h and filtered through filter paper (Whatman No. 4) with 1 g sodium sulphate.
The solvent was evaporated with a rotary evaporator and the weight of dry extract
was determined. Percentage of TOG was calculated based on dry weight of soil and
its decrease was compared in the control and experimental pots.
The results were subjected to statistical analysis of variance (ANOVA) followed
by the least significant difference test (LSD) that was performed between control
and experimental groups (Chehregani et al.
2005
). Each data was represented as the
means ± SD of five samples for experimental and control groups.
