Jatropha curcas is an ornamental plant which is also employed to cure various infections in traditional medicine. The hexane, ethanolic and aqueous extracts and latex of this plant were analysed phytochemically and screened against different microorganisms responsible for various human infections. Phytochemical analysis of the extracts and latex revealed the presence of many secondary metabolites including steroids, alkaloids and saponins. Ethanolic extract was found to be richer than hexane extract and aqueous extract as well as latex. The extracts and latex displayed potent antimicrobial activity against Staphylococcus aureus, Neisseria gonorrhoea, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, and Aspergillus flavus, giving minimum inhibitory concentration as low as 0.5 mL. The results confirmed the potency of this plant in treating human infections including sexually transmitted diseases.

Primary screening of ethanolic and aqueous extracts of Anacardium occidentale (bark and leaf) for antimicrobial activity against Escherichia coli, Pseudomonas auroginosa, Shigella dysenteriae, Salmonella typhi and Staphylococcus aureus showed that ethanolic extract was more effective than aqueous extract. The minimum inhibitory concentration ranged from 0.05 g/ml to 0.2 g/ml .The ethanolic extract was found to be bactericidal to all the test bacteria, while the aqueous extract was found to be bacteriostatic to the test bacteria with the exception of the aqueous leaf extract that was bactericidal to Salmonella typhi. The greater the concentration of the extract, the higher the antibacterial activities exerted on the isolates. Salmonella typhi was the most sucesceptible organism to the leaf extract, while Pseudomonas auroginosa was the least sucesceptible organism. Staphphylococcus aureus was the most sucescephple to the ethanolic bark extract and Escherichia coli was the least suceptible organism.

The significance of preservatives in food preparations lies in their ability to inhibit or retard the growth of microorganisms which in turn reduces their deteriorative effects on food. The preservative effects at varying concentrations (1%, 3%, 5% v/v) of sodium benzoate was compared with extracts of ginger, cloves and a combination of the two extracts on soymilk at refrigerated temperature. Indices for measurement of shelf life included drop in pH, protein and fat contents, changes in colour and odour, as well as changes in microbial counts. The protein, fat contents and pH decreased more with storage time and these were concentration dependent. The bacterial counts during 25 days of storage ranged from 1.0 x 104 to 6.4 x 105, while fungal counts ranged from 8.0 x 103 to 18.4 x 104. At all concentrations, sodium benzoate exhibited the best preservative effect on the soymilk samples. Reduction in total microbial count was more pronounced in samples treated with clove extract than those treated with ginger extract, while the extracts’ combination exhibited the best preservative effect of all the spice treated samples. The use of ginger as a preservative increased shelf life of soymilk by 7 days, cloves extended shelf life by 10 days, while the combination of the extracts maintained a longer shelf life of 13 days. The bacterial isolates include Bacillus cereus Strain KWS2, Bacillus subtilis strain BTBS, Bacillus amyloliquefaciens strain PJ-5, Bacillus safensis strain SABA5 and Lactobacillus fermentum strain SABA5, while the fungal isolates were Aspergillus niger, Aspergilus fumigatus, Fusarium moniliforme and Saccharomyces cerevisae. The phytochemicals found in ginger and cloves include tannins, phenol, alkaloid, flavonoid, terpenoids, steroids, glycosides, coumarin and saponins, which might be responsible for the antimicrobial properties. The results of the study showed that a combination of ginger and cloves extracts is a better preservative of soymilk than the single extracts, as natural preservatives.

Garlic has been used throughout all of recorded history for culinary and medicinal reasons. The portion of the plant most often consumed is an underground storage structure called a head. The antimicrobial effects of Allium sativum (garlic) against some bacterial isolates were investigated using the agar diffusion well method. Standard methods were used to carry out the investigation. Photochemical analyses of the ethanolic extracts showed the presence of many secondary metabolites such as saponins, tannins, alkaloid steroids and glycosides. The minimum inhibitory concentration and minimum bactericidal concentration of the agent (garlic) was determined for both the aqueous and ethanolic extract. The ethanolic extract was more effective than the aqueous extract, inhibiting all the test organisms. While the aqueous extracts was effective against Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. Garlic extracts are strictly broad-spectrum with immune boosting phytonutrients from Allium ‘family’. Further research will need to be done to carry out the purification of the active ingredients which have potential for combating human disease. Also, toxicological studies need to be evaluated.

This research work investigated cellulase production potentials of the microbial profile of three sugarcane bagasse dumping sites at Zango area, Ilorin, Nigeria. The microbial isolates were screened for cellulase production with a view to select the best organism for eventual cellulase production. Pour Plate method was used for the isolation and a total of thirteen (13) different organisms including both fungal and bacterial species were isolated and screened. Six (6) fungal isolates identified as Mucor racemosus Aspergillus niger, Aspergillus flavus, Neurospora sitophilus, Penicillium oxalicum and Penicillium citrinum were isolated, while seven (7) different bacterial species isolated include Clostridium cellobioparum, Clostridium thermocellum, Bacillus subtilis, Bacillus pumillus, Lactobacillus spp, Pseudomonas flavescens and Serratia spp. Generally, bacterial isolates were more in abundance than fungal species. However; fungal isolates were constant and were isolated through the experimental period of three weeks. All the isolates showed cellulase production potential in varying degrees as reflected in the clearance zone around their colonies. Fungal isolates produced more cellulase than the bacterial isolates. Mucor racemosus had the highest clearance zone (75.0 mm) among the fungal isolates while Clostridium cellobioparum (35.0 mm) were the best producer among bacterial isolates. The least producer among fungal isolates, Penicillium citrinum (40.0 mm), is a little more than the bacterial cellulase producer (35.0 mm) and is far greater than the least bacterium Serratia spp (14.0 mm).