The fear of depletion of fossil fuels and their attendant ecological effects and the high cost of renewable energy technology in Nigeria has triggered a need to develop alternative sources of energy, among which is biogas production. A slurry of 1 kg mixture of agro-waste feed stocks (plantain peel/rice husk, PP/RH; banana peel/plantain peel, BP/PP; and banana peel/rice husk, BP/RH) in 1:1 ratio was co-digested in locally fabricated digesters (10 L capacity). The experiment was run for 50 days and assessed for proximate content, biogas generation, organic matter, and mineral content in the digested and undi-gested agro-waste materials. The proximate composition showed that while banana peel had the highest moisture (56%), rice husk was highest in the content of ash (64%), crude protein (6.94%), and volatile solids (20%). The weekly cumulative biogas generation increased from 852.6 cm3 for BP/PP sample to 1049.7 cm3 for PP/RH sample for the 7 weeks at the experimental room temperature range of 29 oC to 35 oC. Sample PP/RH generated the highest volume of gas (biogas, methane, and others) compared to BP/RH and BP/PP samples.  In each case the volume of gas production decreased in week 7 from 271.4 cm3 to 152.0 cm3 (for biogas), 161.4 cm3 to 97.1 cm3 (for methane), and 110.0 cm3 to 54.9 cm3 (for other gases). The nutritional concentrations of the digested and undigested mixture of the waste samples after Atomic Absorption Spectrophotometer (AAS) and Flame Photometry showed that the digested samples had higher contents of the nutritional elements than the undigested samples. The mineral elements ranged from 0.554 mg/g in the undigested rice husk to 18.155 mg/g in the digested banana peel samples. Fermentation of agricultural wastes to generate biogas and sludge with agricultural value offers an al-ternative and efficient method of agricultural wastes and energy management in Nigeria.

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It was reported in 2005 during WHO survey that about 70-80% of the world population use medicinal plants either in their crude unmodified form or partially in their modified semi-synthetic form of plant sources in their primary healthcare. The present study investigated the phytochemicals and antimicrobial activities of the leaf extracts of Cerathoteca sesamoides and Chromolaena odorata to ascertain their potentials in herbal medicine. Fresh leaf of the plants obtained from Lafia in Nasarawa State, Nigeria were dried, powdered, and subjected to methanolic extraction, partition, phytochemical, and antimicrobial analyses using standard methods. Partitions from n-hexane, methanol, ethyl acetate, chloroform, and residue extracts were tested against clinical bacteria Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, Staphylococcus aureus, and fungus Candida albicans. Among the four different solvents used in partitioning methanolic and ethyl acetate extracts of both plants contain flavonoids, tannins, alkaloids, terpenoids, saponins, steroids, and cardiac glycosides. Saponins were absent in the n-hexane and chloroform extracts of C. odorata and the ethyl acetate extract of C. sesamoides. While flavonoids were present in the n-hexane extracts of C. odorata, they were absent in C. sesamoides. Anthraquinone and reducing sugar were absent in all the solvent extracts of both medicinal plants. The antimicrobial susceptibility tests showed that n-hexane and residue extracts of both plants had no activity against the tested microorganisms. The chloroform and ethyl acetate extracts of C. sesamoides and C. odorata (at 12.5 mg/ml) were active against all the tested clinical bacteria K. spp., E. coli, P. aeruginosa, S. aureus, and C. albicans. The methanolic extracts of both plants were active against the bacterial isolates but inactive against C. albicans. The minimum bactericidal concentration of these plant extracts was ≥50 mg, while the minimum inhibition concentrations ranged between 12.5 mg and ≥50 mg. The findings showed that the chloroform or ethyl acetate extracts of the leaves of these plant drugs could be used to treat urinary tract infections.