Antibiotic sensitvity and plasmid profiles of bacteria isolated from water sources in Oproama community in the Niger Delta

The antibiotic sensitivity pattern and plasmid profile of Escherichia coli, Vibrio and Salmonella species isolated from well and river water sources in Oproama Community were investigated. Antibiotic sensitivity profiles of the bacteria (Escherichia coli, Vibrio sp. and Salmonella sp.) isolated from the water showed high sensitivity to oflaxicin, nalidixic acid and nitrofurantoin and high resistance to amoxicillin, augumentin, cotrimazole and tetracycline. Multi antibiotic resistant index (MARI) as high as 0.375 (Escherichia coli: E9; Vibrio spp.: V3, V4, V10; Salmonella spp.: S1, S9), 0.5 (Vibrio spp.: V2; Salmonella spp.: S2, S4) and 0.75 (Salmonella spp.: S7) were recorded after curing the plasmids with sodium deodecyl sulphate (SDS). The plasmid profiles revealed that 60% of the isolates harboured detectable plasmids with sizes up to 23.130 kb.Keywords: Antibiotics, Escherichia coli, Plasmid, Salmonella, Vibri

An Investigation of Oxygen Limitation in Microcosm Models in the Bioremediation of a Typical Niger Delta Soil Ecosystem Impacted With Crude Oil

Oxygen was investigated as a limiting factor in the bioremediation of a typical Niger delta soil impacted with crude oil under laboratory simulation conditions. Temperature, pH, moisture content and nutrients (N.P.K. 15: 15: 15) were maintained at optimal levels. Surfactant (S400) was added to aid emulsification of oil. Addition of hydrogen peroxide every four days and tilling were effected in some setups for enhanced oxygen supply. Hydrogen pyrogallol was added to create an anoxic environment in one set-up (experiment 4). Neat soil was used in the control experiment to avoid exogenous carbon sources. The bioremediation process was monitored for 50 days by periodic (10 days) measurements of oil and grease (O&G) and total organic carbon (TOC) levels. Enumeration of total heterotrophic bacteria, total hydrocarbon-utilizing bacteria, sulphate reducing bacteria (SRB) and nitrate utilising bacteria was done. The highest percentage loss in oil and grease level (>80%) and total organic carbon level (>95%) were recorded in the set-up treated with hydrogen peroxide and tilling. This set-up also recorded the highest titre of hydrocarbon-utilizing bacteria. Sulphate reducing bacteria and nitrate utilising bacteria were enumerated in the anoxic experiment 4. Experiment 3 (treated only with crude oil) recorded 57.7% hydrocarbon loss. This was attributed to remediation by natural attenuation processes. Aerobic bioremediation was estimated to be about 30 percentage points above anaerobic bioremediation. Aerobic degradation was found to be at least 30% more effective than anaerobic degradation. A combination of all possible aeration techniques is recommended for enhanced bioremediation

Enterotoxicigenicity profile of Escherichia coli , Vibrio , and Salmonella species isolated from well and river water sources in Oproama town in the Niger Delta, Nigeria

Well water is the only source of drinking water in Oproama Town in Rivers state, Nigeria. Water from these sources is consumed without treatment, and potentially poses a health risk to the local population. The Enterotoxigenicity profile of Escherichia coli , Vibrio and Salmonella species isolated from well and river water sources in Oproama were investigated using fluid accumulation (FA) ratio. The study revealed that Salmonella isolate (S9) from the river showed doubtful toxicity out of the ten Escherichia coli, ten Vibrio and ten Salmonella isolates. This study revealed a near-absence of enterotoxigenic Escherichia coli, Vibrio and Salmonella organisms from the waters in Oproama. More studies are required to further test the overall safety of these water sources due to the potential risk of consuming untreated water

Antibiotic sensitvity and plasmid profiles of bacteria isolated from water sources in Oproama community in the Niger Delta

The antibiotic sensitivity pattern and plasmid profile of Escherichia coli , Vibrio and Salmonella species isolated from well and river water sources in Oproama Community were investigated. Antibiotic sensitivity profiles of the bacteria (Escherichia coli, Vibrio sp. and Salmonella sp.) isolated from the water showed high sensitivity to oflaxicin, nalidixic acid and nitrofurantoin and high resistance to amoxicillin, augumentin, cotrimazole and tetracycline. Multi antibiotic resistant index (MARI) as high as 0.375 (Escherichia coli: E9; Vibrio spp.: V3, V4, V10; Salmonella spp.: S1, S9), 0.5 (Vibrio spp.: V2; Salmonella spp.: S2, S4) and 0.75 (Salmonella spp.: S7) were recorded after curing the plasmids with sodium deodecyl sulphate (SDS). The plasmid profiles revealed that 60% of the isolates harboured detectable plasmids with sizes up to 23.130 kb

Glucose And Hydrocarbon Utilization By Bacteria Isolated From Diesel Impacted Soil In The Niger Delta

Hydrocarbon utilizing bacteria were isolated from diesel impacted sites at the University of Port Harcourt using the vapour phase transfer method. The isolates were identified as Bacillus, Pseudomonas, Acinetobacter, Serratia, and Micrococcus species. Examination of cultures supplemented with glucose revealed that the total viable counts ranged from 1.7 x 104 to 5.9 x 105 cfu/ml. For cultures supplemented with kerosene the total viable counts ranged from 1.18 x 104 to 3.1 x 105 cfu/ml. Bacillus spp. and Micrococcus spp. gave the highest and lowest counts respectively in both media types within 96 h. The other isolates had counts in between these ranges in the respective supplemented media. The growth of the isolates in mineral salts solution supplemented with glucose or kerosene resulted in turbidity of the broth as compared to clear media solutions in controls. Higher turbidity was recorded in media supplemented with glucose than kerosene, and this was reflected in the total viable counts obtained. The ability of the bacterial isolates to utilize glucose and hydrocarbon as substrates for energy and carbon has beneficial application in bioremediation technology in the Niger Delta. KEY WORDS: Hydrocarbon utilization, glucose metabolism, bioremediation technology Global Journal of Pure and Applied Sciences Vol.11(2) 2005: 205-20

In vitro effects of petroleum refinery wastewater on dehydrogenase activity in marine bacterial strains

Toxicity of oil refinery effluent on four bacteria strains isolated from refinery effluent impacted river water sample was assessed via dehydrogenase assay. Pure cultures of the bacterial strains were exposed to various effluent concentrations [12.5 – 100% (v/v)] in a nutrient broth amended with glucose and TTC. The response of the bacterial strains to refinery effluent is concentration-dependent. At 12.5% (v/v), the effluent stimulated dehydrogenase activity in Streptococcus sp. RW3 and Pseudomonas sp. RW4. In all strains, dehydrogenase activity was progressively inhibited at concentrations greater than 12.5% (v/v). The IC50 ranges from 25.46 ± 4.75 to 31.30 ± 2.63% (v/v). The result of the in vitro study indicated that the bacterial strains are sensitive to oil refinery raw wastewater stress. Therefore, the improperly treated effluent when discharged would pose serious threat to the metabolism of the bacterial strains in natural environments

An Investigation of Oxygen Limitation in Microcosm Models in the Bioremediation of a Typical Niger Delta Soil Ecosystem Impacted With Crude Oil

Oxygen was investigated as a limiting factor in the bioremediation of a typical Niger delta soil impacted with crude oil under laboratory simulation conditions. Temperature, pH, moisture content and nutrients (N.P.K. 15: 15: 15) were maintained at optimal levels. Surfactant (S400) was added to aid emulsification of oil. Addition of hydrogen peroxide every four days and tilling were effected in some setups for enhanced oxygen supply. Hydrogen pyrogallol was added to create an anoxic environment in one set-up (experiment 4). Neat soil was used in the control experiment to avoid exogenous carbon sources. The bioremediation process was monitored for 50 days by periodic (10 days) measurements of oil and grease (O&G) and total organic carbon (TOC) levels. Enumeration of total heterotrophic bacteria, total hydrocarbon-utilizing bacteria, sulphate reducing bacteria (SRB) and nitrate utilising bacteria was done. The highest percentage loss in oil and grease level (>80%) and total organic carbon level (>95%) were recorded in the set-up treated with hydrogen peroxide and tilling. This set-up also recorded the highest titre of hydrocarbon-utilizing bacteria. Sulphate reducing bacteria and nitrate utilising bacteria were enumerated in the anoxic experiment 4. Experiment 3 (treated only with crude oil) recorded 57.7% hydrocarbon loss. This was attributed to remediation by natural attenuation processes. Aerobic bioremediation was estimated to be about 30 percentage points above anaerobic bioremediation. Aerobic degradation was found to be at least 30% more effective than anaerobic degradation. A combination of all possible aeration techniques is recommended for enhanced bioremediation

Biostimulation of Petroleum-Contaminated Soil Using Organic and Inorganic Amendments

The most common approaches for the in-situ bioremediation of contaminated sites worldwide are bioaugmentation and biostimulation. Biostimulation has often proved more effective for chronically contaminated sites. This study examined the effectiveness of optimized water hyacinth compost in comparison with other organic and inorganic amendments for the remediation of crude oil-polluted soils. Water hyacinth was found to be rich in nutrients necessary to stimulate microbial growth and activity. An organic geochemical analysis revealed that all amendments in this study increased total petroleum hydrocarbon (TPH) biodegradation by ≥75% within 56 days, with the greatest biodegradation (93%) occurring in sterilized soil inoculated with optimized water hyacinth compost. This was followed by polluted soil amended with a combination of spent mushroom and water hyacinth composts (SMC + WH), which recorded a TPH biodegradation of 89%. Soil amendment using the inorganic fertilizer NPK (20:10:10) resulted in 86% TPH biodegradation. On the other hand, control samples (natural attenuation) recorded only 4% degradation. A molecular analysis of residual polycyclic aromatic hydrocarbons (PAHs) showed that the 16 PAHs designated by the US EPA as priority pollutants were either completely or highly degraded in the combined treatment (SMC + WH), indicating the potential of this amendment for the environmental remediation of soils contaminated with recalcitrant organic pollutants

Biostimulation of Petroleum-Contaminated Soil Using Organic and Inorganic Amendments

The most common approaches for the in-situ bioremediation of contaminated sites worldwide are bioaugmentation and biostimulation. Biostimulation has often proved more effective for chronically contaminated sites. This study examined the effectiveness of optimized water hyacinth compost in comparison with other organic and inorganic amendments for the remediation of crude oil-polluted soils. Water hyacinth was found to be rich in nutrients necessary to stimulate microbial growth and activity. An organic geochemical analysis revealed that all amendments in this study increased total petroleum hydrocarbon (TPH) biodegradation by ≥75% within 56 days, with the greatest biodegradation (93%) occurring in sterilized soil inoculated with optimized water hyacinth compost. This was followed by polluted soil amended with a combination of spent mushroom and water hyacinth composts (SMC + WH), which recorded a TPH biodegradation of 89%. Soil amendment using the inorganic fertilizer NPK (20:10:10) resulted in 86% TPH biodegradation. On the other hand, control samples (natural attenuation) recorded only 4% degradation. A molecular analysis of residual polycyclic aromatic hydrocarbons (PAHs) showed that the 16 PAHs designated by the US EPA as priority pollutants were either completely or highly degraded in the combined treatment (SMC + WH), indicating the potential of this amendment for the environmental remediation of soils contaminated with recalcitrant organic pollutants