Microbial community composition of different soil layers in an aged oil spill site in Bomu community. (Slide).

1. MICROBIAL COMMUNITY COMPOSITION OF DIFFERENT SOIL LAYERS IN AN AGED OIL-SPILL SITE IN BOMU COMMUNITY
Chikere, Chioma Blaise and Aggreh, Erhovwon Peter
University of Port Harcourt , P.M.B. 5323, Port Harcourt, Rivers State, Nigeria.
Email: choima.chikere@uniport.edu.ng
Phone: +2347030912861
Website: uniport.edu.ng
MethodsAbstract
Introduction
Results
References
Bioremediation: a cost effective , sustainable and eco-friendly approach in
crude oil clean up.
Several environmental factors affects biodegradation of contaminants by
microorganisms . Vidali, 2001.
The success of restoration project relies on proper understanding of the soil
composition and structure. Eldoado et al, 2016.
Soil microbial community composition is altered by the presence of
petroleum products. Janine et al, 2016.
The occurrence of crude oil spillage affects the microbial diversity and
composition of the soil micro-flora. Adesina and Adelasoye, 2013.
Microorganism play a central role in hydrocarbon degradation. Chikere et al.,
2011, 2012. Grupte and Sonawdekar, 2015.
Bioremediation is a cost-effective and sustainable approach for detoxifying
polluted soils. However, having a holistic knowledge of diverse microbial
composition colonizing different soil depths is essential in designing more
effective bioremediation strategies. Top soil (TS) and sub soil (SS) samples at 0
- 15 cm and 15 - 35 cm depths were collected from an aged crude-oil spilled site
in Bomu community, Rivers State characterized with microbiological and
physicochemical analytical methods. Samples were enriched in Bushnell Haas
broth and screened for the presence of oil-degrading bacteria and fungi. Total
petroleum hydrocarbon (TPH) and polycyclic aromatic hydrocarbon (PAHs)
constituents for TS and SS were 7439.59; 14.58 mg/kg and 8653.03; 1.21
mg/kg, respectively while mean values for hydrocarbon utilizing bacterial and
fungi counts for TS and SS were 1.9×105
; 0.5×103
cfu/g; and 4.3×105
; 0.4×103
cfu/g, respectively. Bacterial and fungal community compositions were
identified using phenotypic and microscopic techniques. A total of 24 bacterial
species encompassing 11 genera and 10 fungal species from 7 genera were
isolated and confirmed as oil degrading microorganisms using biodegradation
assay. The bacterial genera for TS included Proteus, Salmonella, Citrobacter,
Enterobacter, Klebsiella, Bacillus and Corynebacterium while SS were
Escherichia, Flavobacterium, Corynebacterium, Pseudomonas, and Bacillus.
Gammaproteobacteria were the dominant class across both soil layers. Fusarium
spp. and Rhizopus spp. were the dominant fungal isolates for SS and TS,
respectively. The different soil layers were variable in the microbial composition
and abundance as well as physical and chemical soil characteristics.
 Crude oil polluted site: Bomu community.
 Collection of soil samples. Top soil: 0-15cm, sub soil: 15-30cm.
 Determination of physicochemical parameters.
 Extraction of petroleum hydrocarbon with dichloromethane (dcm).
 Enumeration of Total Heterotrophic Bacteria (THB) and Fungi (THF).
 Enumeration and isolation of Hydrocarbon Utilizing Bacteria (HUB) and Fungi (HUF).
 Purification and characterization of hydrocarbon utilizing bacteria and fungi.
 Phenotyic typing of hydrocarbon utilizing bacteria morphology
 Biochemical characterization and identification of the hydrocarbon utilizing bacteria
 Determination of biodegradation potential for HUB and HUF by turbidometry
PRINCIPLES OF BIOREMEDIATION
Results
 The degrading ability demonstrated by the organisms is a clear indication that the
indigenous microorganisms present in an oil polluted environment are good and effective
oil degraders if the enabling environment/ constituents are provided for these organisms or
if there is a proper bio-augmentation strategy.
 The results gotten from this research are expected to increase the possibilities of
developing models and strategies for the bioremediation of hydrocarbon pollutants in both
soil layers.
Chikere, B.C. and Ekwuabu, C. B. (2014). Culture- dependent characterization of
hydrocarbon utilizing bacteria in selected crude oil- impacted sites in Bodo Ogoniland,
Nigeria. African Journal of Environmental Science and Technology. 8 (6): 401-405.
Eldoado A.C., Costantini., Christina, B., Alice, N., Gudrum, S., Ilan, S., Alejandro, V. and
Claudio, Z. (2016). Soil indicators to assess the effectiveness of restoration in dryland
ecosystem. Solid Earth. 7: 397-414.
Gupte, A. and Sonawdekar, S. (2015). Study of degrading bacteria isolated from oil
contaminated sites. International Journal for Research in Applied Science and
Engineering Technology. 3 (11): 345-349.
Janine, M., Alexander, G., Thomas, D. B., Franco, W. and Marcel., G. A. V. H. (2016). Effect
of nanoparticles on red clover and its symbiotic microorganisms. Journal of
Nanobiotechnology. 1-8.
.
Conclusions
Chikere, Chioma Blaise and Aggreh, Erhovwon Peter
University of Port Harcourt , P.M.B. 5323, Port Harcourt, Rivers State, Nigeria.
Email: choima.chikere@uniport.edu.ng
Phone: +2347030912861
Website: uniport.edu.ng
Fig 2. comparison of top soil and sub soil degradation potential.
Fig 1. Crude oil polluted site in Bomu
community.
Fig 3. Percentage degradation distribution of sub soil bacteria. Fig 5. Percentage degradation distribution for sub soil fungi.
.
Fig 4. Percentage degradation distribution of top soil fungi
Fig 6. Chromatogram of top soil polluted for total petroleum
hydrocarbon (TPH).
Fig 7. Chromatogram of top soil polluted sample for polycyclic
aromatic hydrocarbon (PAH).
Sample Mean Values of
THB
Mean Values of
HUB
Sub soil (cfu/g) 5.3 x 105
1.9 x 105
Top soil (cfu/g) 5.7 x 105
4.3 x 105
Table 2. Total heterotrophic fungi (thf) counts and hydrocarbon
utilizing fungal (huf) counts
Table 1. Total heterotrophic bacteria (THB counts and
hydrocarbon utilizing bacteria (HUB) counts
Sample Mean Values of
THF
Mean Values of
HUF
Sub soil (cfu/g) 1.0 x 103
0.4 x 103
Top soil (cfu/g) 2.1 x 103
0.5 x 103
Fig 9. Crude oil degradation as shown by increase in
turbidity.