Water and sanitation facilities in sub-Saharan Africa and Africa in general are appalling and for the most part absent. Progress continues with respect to the development of plant materials as potent adsorbents, disinfectants, coagulants, flocculants, wetland species and lots more as substitutes for the dangerous chemical disinfectants.
This research presents the potential of phyto-active components of Zanthoxylum zanthoxyloides and Gongronema latifolium as effective biocides against water microbial contaminants. Dry powder of Zanthoxylum zanthoxyloides and Gongronema latifolium were extracted and prepared into different concentrations with ethyl acetate and chloroform, ranging from 25 to 500 mg/ml. These fractions were then examined for antimicrobial activities against inherent bacterial and fungal water contaminants using disc diffusion assay. Fractions were afterwards screened for phytochemical active compounds using standard methods. Crude extracts of the different plant examined selectively comprise saponins, tannins, reducing sugars, anthraquinones, flavonoids, terpenoids, phlobatanins and alkaloids. All plant extracts showed broad spectrum antibiosis against selected gram positive and gram negative bacteria including E. coli, P. aeruginosa, Klebsiella sp, S. pneumoniae and B. cereus, as well as tested fungi, including A. niger, A. flavus, Trichoderma sp and Candida sp. While all extracts exhibited maximum antibiosis at 500 mg/ml, the chloroform extracts compared well than ethyl acetate extracts. The overall results revealed that antimicrobial activities of the plant extracts are dose dependent with comparative activity greater than that of commercial antibiotics at the concentration of extracts tested. E.coli was the most susceptible microbial isolate tested and represents the potential of the extract against a group of coliform which are important indicators of microbial pollution in water. Other microbial isolates also recorded sensitivity to extracts tested at varying degrees. The findings indicate that microbes tested were mostly susceptible to chloroform extract of Z. zanthoxyloides and G. latifolium except for the activity of ethyl acetate extract of Z. zanthoxyloide against E.coli. Results of phytochemical screening of the extract also showed the varied presence of alkaloids, saponins, tannins, flavonoids, terpenoids and anthraquinones The results indicated that plant materials investigated can be developed as effective biocides against water microbial contaminants