Browsing by Author "Kawaka, Fanuel"

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    Fungi and Aflatoxin Levels in Traditionally Processed Cassava (Manihot esculenta Crantz) Products in Homa Bay County, Kenya
    (International Journal of Microbiology, 2020-08-26) Obong’o, Boniface Oure; Ayodo, George; Kawaka, Fanuel; Adalla, Morelly Kathy
    Cassava (Manihot esculenta Crantz) is a major source of carbohydrates, calcium, vitamins (B and C), and essential minerals and is the third most important source of calories in the tropics. However, it is not clear if the traditional processing methods expose the products to microbial contamination. This study assessed the levels of fungi and aflatoxin contamination in traditionally processed cassava products (Akuoga and Abeta). A total of 38 samples were collected from the local markets in 7 subcounties in Homa Bay County, Kenya. The levels of aflatoxin were determined using an indirect competitive ELISA protocol. Yeast and mould contamination was determined using ISO 21527-2 method. Mean aflatoxin levels in chopped, fermented, and sun-dried cassava (Akuoga) were 0.36 μg/kg compared to 0.25 μg/kg in chopped and sun-dried (Abeta) products. Aflatoxin contamination was detected in 55% of the samples and ranged from 0–5.33 μg/kg. These levels are within 10 μg/kg recommended by the CODEX STAN 193-1995. Yeast and mould counts in fermented and chopped sun-dried products were 3.16 log Cfu/g and 2.92 log Cfu/g, respectively. The yeast and mould counts were above standards set by East African Standard 739:2010 in 62% (Akuoga) and 58% (Abeta). The most prevalent fungal species were Saccharomyces cerevisiae (68.4%) and Candida rugosa (68%) followed by Candida parapsilosis (18.4%), Candida tropicalis (15.8%), Candida humilis (15.8%), and Aspergillus spp. (5.3%). Aspergillus spp. was the only mycotoxigenic mould isolated from the samples. The study shows that cassava consumers are exposed to the risk of aflatoxin poisoning. The study, therefore, recommends appropriate surveillance to ensure safety standards.
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    Phytochemical Analysis and Antibacterial Activity of selected Kenyan Wild Orchids
    (Research Square, 2022-04-25) Chagona, Polycarp; Kwamboka, Nancy; Gaya, Humphrey; Makonde, Huxley; Adem, Aggrey; Osano, Kenneth; Kawaka, Fanuel
    The current study evaluated antibacterial activity of dichloromethane and methanol (DCMMeOH) extracts of four Kenyan orchid species against three selected bacterial strains. Extracts of E1 (Ansellia africana), E2 (Trydactylescottelli), E3 (Polystachyabella) and E4 (Liparis bowkeri) were screened for antibacterial activity againstStaphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosausing agar disc diffusion. Ampicillin was included as a positive control.Qualitative analysis revealed the presence of flavonoids, saponins, alkaloids, tannins, terpenoids, steroids and glycosides. Trydactyle scottelli and Polystachyabella extracts revealed stronger presence of tannins and steroids respectively compared to the others. All extracts showed varying levels of antibacterial activity against the test bacteria. However, extracts of Polystachyabella and Liparis bowkeri against Bacillus subtilis and Ansellia africana against Pseudomonas aeruginosa exhibited higher activities similar to that of Ampicillin. The study further showedthat the DCM-MeOH extracts of the four orchids contain potential bioactive compounds that should be further analysed for conventional and traditional management of bacterial infections.
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    Phytochemical Analysis and Antibacterial Activity of the Kenyan Wild Orchids
    (Micro Environer, 2021-11-21) Chagona, Polycarp; Kwamboka, Nancy; Gaya, Humphrey; Makonde, Huxley; Adem, Aggrey; Osano, Kenneth; Kawaka, Fanuel
    The current study evaluated the antibacterial activity of dichloromethane and methanol (DCMMeOH) extracts of four Kenyan orchid species against three selected bacterial strains. Extracts of E1 (Ansellia Africana), E2 (Trydactylescottelli), E3 (Polystachyabella) and E4 (Liparis bowkeri) were screened for antibacterial activity against staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa using agar disc diffusion. Ampicillin was included as a positive control. Qualitative analysis revealed the presence of flavonoids, saponins, alkaloids, tannins, terpenoids, steroids and glycosides. Trydactyle scottelli and Polystachyabella extracts revealed a more substantial presence of tannins and steroids, respectively, compared to others. All extracts showed varying levels of antibacterial activity against the test bacteria. However, Polystachyabella and Liparis bowkeri against Bacillus subtilis and Ansellia Africana against Pseudomonas aeruginosa exhibited higher activities similar to that of Ampicillin. The study further showed that the DCM-MeOH extracts of the four orchids contain potential compounds that should be screened for conventional management of bacterial infections.
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    Publication
    Response of Common Bean (Phaseolus vulgaris L.) Cultivars to Water Hyacinth (Eichhornia crassipes [Mart.] Solms) Compost in Kisumu, Kenya along the Lake Victoria Basin
    (Journal of Experimental Agriculture International, 2018-09-06) Kawaka, Fanuel; Ombori, Omwoyo; Maingi, John M.; Amoding, Alice; Mukaminega, Dative; Muoma, John
    Aims: This study aimed at enhancing common bean production among the small holder farmers along the Lake Victoria basin, Kenya through the use of water hyacinth compost.Study Design: Randomized Complete Block Design with a split-plot structure with three replications. The bean cultivars formed the main plots while fertilizers formed the sub-plots.Place and Duration of Study: Field trials were conducted on small holder farms in Kisumu, Lake Victoria basin during the short and long rains in 2012/2013.Methodology: Fresh water hyacinth weeds were cut into smaller pieces and left to completely dry in the sun and allowed to decompose naturally for 45 days. The treatments consisted of control (no fertilizer), water hyacinth compost and diammonium phosphate (DAP) fertilizer (DAP). The fertilizers were applied at the rate of 46 kg ha-1 of DAP or 8 T ha-1 of compost along the rows and thoroughly mixed within the top 15 cm of soil to avoid direct contact with the seeds or the rhizobia inocula.Results: Water hyacinth compost significantly (P<0.05) increased nodulation and improved yield while diammonium phosphate also enhanced yield but suppressed nodulation of the beans. Other agronomic characteristics such as plant height, number of flowers and pods of beans were not significantly (P > 0.05) influenced with the application of either compost or diammonium phosphate.Conclusion: Application of water hyacinth compost has the potential for use as an alternative to expensive inorganic nitrogenous fertilizers in restoring soil fertility and improving bean crop productivity in Kenya.