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The toxic effect of herbicide on some selected microbial populations from soil was investigated. Soil samples were collected from two unpolluted designated fields of Chukwuemeka Odumegwu Ojukwu University and later polluted with herbicides at different application rates (0.1 %, 0.2 %, 0.5 %, 1 % and 5 %) and periods using spraying method. Standard chemical processes were used for determining physico-chemical parameters of the soil while isolation, enumerating the population of the microorganisms and identification of the isolates were determined using standard microbiological methods. The result revealed that the soil samples are slightly acidic, sandy clay loam type, lower organic carbon content, higher total nitrogen and phosphorus contents and moderate water holding capacity. The isolatesPseudomonas aeruginosa, Bacillus vallismottis, Aeromonas hydrophilaandEnterobacter cloceawere selected using selective media and identified.Pseudomonas aeruginosaandBacillus vallismottishad the least (zero CFU/g) and maximum population counts (10 x 107CFU/g) during glyphosate exposure whilePseudomonas aeruginosaandEnterobacter cloceahad the least (zero CFU/g) and maximum population counts (2.50 x 107CFU/g) during 2, 4 - D amine exposure for 15 days, respectively. Thus, the application of glyphosate and 2, 4 - D amine herbicides on the soil have resulted into lower counts of the selected microbial groups. The inhibitions of their growths are dependent on concentration and exposure period, although 2, 4 - D amine had more inhibition than the glyphosate herbicide.&nbsp

The influence of physicochemical and microbiological properties on composting of agro wastes using cow dung as a booster was evaluated. The physicochemical parameters measured include pH, temperature and moisture. Titrimetric and spectrophotometric measurements of chemical nutrients as well as microbial assay using spread plating technique on several selective media were done. The results of pH, temperature and moisture content revealed lower pH (acidity) to higher pH (alkalinity) (7.5 – 9.0), slight temperature increased (24.9 – 27.3 °C), increased (20.33 – 66.00 %) and later declined in moisture content. The result of the chemical composition revealed significant increase in all nutrients except potassium with slight decrease (5.74 – 5.06 ppm). The result of the microbial analysis revealed that there were increased microbial count (0.413 X 105 – 6.78 X 105 cfu/ g) for all isolated microbial groups except total bacteria, fungi and anaerobes with numerous count. The cow dung which acts as booster improved the early maturity and nutrient contents of the composting depending on the levels of application. Statistically, there were significant differences detected among the four compost treatments throughout the composting period at p

Wastes generated by both agrobased industries and domestic units have high nutrient contents to support microbial growth but in Nigeria, these wastes are indiscriminately dumped and constitutes environmental and health hazards. Some of these wastes can be used to grow some bacterial species in microbial fuel cell to generate bioelectricity. The waste materials used in this work are, banana, and pineapple peels. Glucose was used for comparison. Bacterial species used were isolated from fluids collected from dustbins and soil, all within Chukwuemeka Odumegwu Ojukwu University, Uli campus. Microscopic characterization of the isolates by Grams reaction revealed the isolate to be Gram negative and Spore test were negative. Biochemical tests showed that the isolate were catalase positive, oxidase negative and citrate positive. By Bergys criteria, the isolate was shown to be Pseudomonas species. Genetic characterization confirmed the species to be Pseudomonas aeruginosa. Four (4) MFC’s were fabricated with a liter transparent plastic for the anode and cathode poles. The electrodes used was graphite for the production of graphite-graphite fuel cells. A 3.75% Sodium chloride, 2.2% agar salt bridge connected the chambers. Glucose, banana and pineapple peels were used as organic substrates and pure cultures of Pseudomonas aeruginosa were biocatalyst for the fuel cells. Result for effect of aeration with Pseudomonas aeruginosa by multimetric monitoring gave maximum power of 3.983 X 10-4 W, 7.1625 X 10-4W and 8.9920 X 10-4 W for glucose, banana peel and pineapple peel respectively, while non-aeration was 3.936 X 10-4 W, 7.059 X 10-4 W and 8.909 X 10-4 W for glucose, banana peel and pineapple peel. Population growth determination by spectrophotometric method at wavelength 540 nm gave these results 1.148, 1.572, 1.714 and 1.837 with Pseudomonas aeruginosa on days 1, 4, 7 and 10 respectively.