Distribution of cyanotoxins in aquatic environments in the Niger Delta

The presence and types of cyanotoxins in some aquatic environments in the Niger Delta were investigated. Water samples surveyed in the study were surface water of Sombreiro, Nun and New Calabar Rivers. Others were groundwater from Abonnema and Kiama and pond water from Ogboro. Sampling locations of Sombreiro and the New Calabar rivers and the groundwater at Abonnema are all in the Rivers State while other locations were in Bayelsa State all in Nigeria. Cyanotoxins wereextracted using the rotary evaporator procedure. The toxins were intraperitoneally administered to mice. Pathological studies revealed that the extracts contained hepatotoxic peptides (microcystin andnodularin), cytotoxic alkaloids (cylindrospermopsin) and neurotoxic alkaloids (anatoxin-a, anatoxin-a(s) and saxitoxin). Cyanobacterial examination of the water samples revealed that Anabena was the mostpredominant cyanobacterium. Anabena and Microcystis were more predominant in the river and pond water while Anabena and Cylindrospermopsis were more predominant in the ground water. The nutrient load of water bodies influenced biomass (weight) of cyanobacteria. High nutrient load (BOD, COD, nitrates, sulphate, etc) produced high cyanobacterial biomass while low nutrient load producedcorrespondingly low cyanobacterial biomass. Nutrient load of river water were significantly higher than groundwater samples. The pond water produced intermediate values of most physicochemical parameters. The percentage hydrocarbon utilizing fungal counts (6.6 - 10.0%), total coliform (240 MPN/100 ml) and fecal coliform (92 to 160 MPN/100 ml) counts were greater than ground water samples (0%, 7.9 to 24 MPN/100 ml and 0.18 to 0.93 MPN/100 ml) respectively. These results suggested that though the conventional bacterial indicators were high, the presence of cyanobacteria and cyanotoxinsin these aquatic systems may also contribute to rendering these drinking water sources unfit for domestic consumption

Bioluminescent hydrocarbonclastic bacteria of the Niger Delta

Utilization of three petroleum hydrocarbons (Mobil SAE 40 Engine Oil, Diesel and Bonny light Crude Oil) by four bioluminescent bacteria (Vibrio harveyi, V. fisheri, Photobacterium leiognathi and P.Phosphoreum isolated from the Bonny estuary in the Niger Delta, Nigeria was investigated. Microbial utilization was monitored for an 8-week period using mineral salt medium containing the hydrocarbonsources as sole carbon source. Results showed that bioluminescent bacteria were widely distributed in the brackish and marine waters of the Niger Delta, representing 7.5-18.72% and 0-2-5% of the totalheterotrophic bacteria of the marine and brackish water systems, respectively. A hydrocarbon loss of 100% by week 7 for all four-test organisms was observed. These results indicated that the bacteriawere capable of utilizing the hydrocarbon sources as sole sources of carbon and energy. Increased phosphate concentrations (0.03-0.05 g/ml) in marine aquatic systems were also observed to stimulateincreases in bacterial population and the intensity of luminescence of the bacteria. The study revealed that increasing phosphate levels in phosphate depleted marine waters would encourage thegrowth of hydrocarbonoclastic bioluminescent bacteria which could serve as a potential tool for the remediation of petroleum polluted marine systems of the coast of the Niger Delta. Physiochemicalanalyses of water from the Bonny estuary (marine) and from Isaka (brackish) environments revealed that phosphate levels in the marine system was 0.04 mg/l while in the brackish environment nophosphate was recorded (0 mg/l)

Monitoring of microbial hydrocarbon remediation in the soil

Bioremediation of hydrocarbon pollutants is advantageous owing to the cost-effectiveness of the technology and the ubiquity of hydrocarbon-degrading microorganisms in the soil. Soil microbial diversity is affected by hydrocarbon perturbation, thus selective enrichment of hydrocarbon utilizers occurs. Hydrocarbons interact with the soil matrix and soil microorganisms determining the fate of the contaminants relative to their chemical nature and microbial degradative capabilities, respectively. Provided the polluted soil has requisite values for environmental factors that influence microbial activities and there are no inhibitors of microbial metabolism, there is a good chance that there will be a viable and active population of hydrocarbon-utilizing microorganisms in the soil. Microbial methods for monitoring bioremediation of hydrocarbons include chemical, biochemical and microbiological molecular indices that measure rates of microbial activities to show that in the end the target goal of pollutant reduction to a safe and permissible level has been achieved. Enumeration and characterization of hydrocarbon degraders, use of micro titer plate-based most probable number technique, community level physiological profiling, phospholipid fatty acid analysis, 16S rRNA- and other nucleic acid-based molecular fingerprinting techniques, metagenomics, microarray analysis, respirometry and gas chromatography are some of the methods employed in bio-monitoring of hydrocarbon remediation as presented in this review

Biodegradation of a simulated landfill leachate in tropical soil of depth 6.5 metres

No Abstract. Journal of Applied Science, Engineering and Technology Vol. 4(2) 2004: 6-1

Biodegradability of electrostatic photocopier toners

The biodegradability of two of the most popular brands of electrostatic photocopier toners (Minolta-Mt-Toner II and Sharp-Katun) in the Niger Delta and their reused forms was investigated. Heterotrophic soil microflora from the rain forest soil in the Niger Delta served as seed for biodegradation tests. The static shake flask method with toner as sole carbon source was used. Biodegradation was monitored over a 28-day period using changes total organic carbon (TOC), Dissolved organic carbon (DOC) ratio of DOC to TOC (Primary biodegradation) and Biochemical Oxygen Demand (BOD) measurements. At day 0 the BOD for Fresh Sharp, Reused Sharp, Fresh Minolta and Reused Minolta toners were 24.0, 22.4, 25.7 and 23.04 mg/l respectively. By day 28 BOD values were 7.4, 6.3, 6.0 and 8.0 mg/l respectively. At day 28 percentage loss of TOC for fresh Sharp, reused Sharp, fresh Minolta and reused Minolta were 85.0, 74.7, 86.7 and 75.8% respectively. During the same period percentage loss of DOC was 90.9, 77.3, 91.4 and 87.5% respectively. Primary biodegradation of toners was 52.4, 65.8, 100 and 63.0% during the same period. The pH and alkalinity increased from day 0 to day 14 and decreased by day 28. Nitrate, Sulphate and Phosphate levels decreased throughout the study. There was no significant difference at 95% confidence levels in these parameters between the two toner brands and their different states. However the reused toners showed slightly lower values of TOC and DOC than the fresh toners. The results showed that the toner brands and states were biodegradable. However the reuse of toners in photocopiers should be discouraged because of the production of modified products that are slightly more recalcitrant. Keywords: photocopier, toner, biodegradability, toxicity, water quality Tropical Freshwater Biology Vol. 14 2005: 95-10

Biodegradability of grounded cell phone recharge cards in two Niger Delta soils

The biodegradability of four commonly used Global System for Mobile Telecommunication (GSM) telephone recharge cards in rainforest (RS) and mangrove (MS) soils of the Niger Delta were examined. The effect of bio-stimulation with inorganic fertilizers (NPK 15:15;15 and Urea) was also examined. Biodegradation was monitored over 28-day period using changes in total organic carbon (TOC) and carbon dioxide evolution. Positive control consisted of filter paper plus test soil (rain forest soil or mangrove soil). Negative control consisted of recharge card and sterile soil. There was a rapid increase in total heterotrophic bacterial (THB) and fungal (TF) counts from a magnitude of 104 to107cfu/g for bacteria ad 103 to 104 cfu/g for fungi from day 0 to day 28 in the biodegradation test systems in rain forest and mangrove soils. There was no significant difference (

Optical study of the effect of gamma radiation and heavy metals on microorganisms (Bacteria)

Radionuclide and heavy metal pollution are the main concerns for the environment nowadays as thousands of waste sites around the world pose a serious threat to all living organisms and humans, in particular. Therefore, the focus of this study is on the development of novel-sensing technologies for the detection of radionuclides and heavy metals in water utilizing microorganisms. Several optical methods, i.e., fluorescence microscopy, fluorescence spectroscopy, and UV-vis spectrophotometer were exploited here for studying the effect of γ-radiation (from Co-57 source) and one of the heavy metal ions (Cd+2) on two types of bacteria, namely Escherichia coli (E. coli) and Deinococcus radiodurans (D. radiodurans). All three optical methods gave consistent and correlated results in regards to the gamma radiation. An exponential decay in bacterial counts with the increase in γ-radiation dose was observed in E. coli bacteria samples, while D. radiodurans bacteria appeared to be much less affected by γ-radiation and showed even a small increase in the bacteria counts at low-radiation doses followed by a rather moderate decay at intermediate and high doses. The effect of Cd2+ on bacteria is more complex, however, and the method of fluorescence microscopy gave the most reliable account in live bacteria concentration. Both E. coli and D. radiodurans bacteria showed similar effects of a moderate decay of bacteria counts with the increase in CdCl2 concentration. Comparative analysis of the results obtained shows a clear possibility of pattern recognition of the presence of γ-radiation and heavy metals using the above two bacteria

Characterization and bioremediation potential of marine Psychrobacter species

Three marine Psychrobacter strains were isolated from seawater and sediments in Mediterranean Sea, Egypt, using culture-dependent techniques. Genotypic characterization for the three strains was performed using 16S rDNA sequence analysis. The Psychrobacter strains were screened for some physiological, biochemical characters, resistance to some antibiotics and heavy metals. All tested Psychrobacter strains were able to resist and accumulate several metals (Pb2+, Cu2+ and Cd2+) with variable degrees, depending on bacterial strains and metal ion species. Lead ions were easier to be bioaccumulated than the other two metals. Psychrobacter sp. H41A was the most potent strain in accumulation of the different metals. Psychrobacter sp. H41A accumulated 91.47 mg Pb2+/g fresh cells at optimum conditions of 60 min contact time, at 600 ppm and 30 °C. Plackett–Burman experimental design was applied to optimize the nutritional factors. The growth of Psychrobacter sp. H41A strain in the optimized culture medium increased the lead bioaccumulation 1.12-fold. The Psychrobacter strains were monitored for their ability to decolorize three different azo-dyes (fast orange, methanil yellow and acid fast red). Psychrobacter sp. H62 and H65 recorded the highest decolorization percentages (85% and 65%) with fast orange and methanil yellow, respectively