Browsing by Author "Chimwamurombe, Percy M."
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Item Bacteriological analysis of household water from hand-dug wells in the Cuvelai-Etosha basin of Namibia(University of Namibia, 2017) McBenedict, Billy M.; Wanke, Heike; Hang' ombe, B.M.; Chimwamurombe, Percy M.Communities in Oshikoto, Omusati, Ohangwena and Oshana regions of Namibia widely utilize the Cuvelai-Etosha Basin by constructing hand-dug wells to provide water to sustain agriculture and households. Since these regions lack a developed water pipeline system and deeper ground water maybe saline in large parts of the Basin, people rely on domestic water supply from private hand-dug wells which are near their houses for convenience and preference. However, the microbial water quality and safety of hand-dug wells being utilized for household consumption in the Cuvelai-Etosha Basin is unknown and this is undesirable since water is a habitat for some pathogenic microorganisms there by posing a health risk. Thus, a bacteriological water quality study that focuses on the identification of microbial contaminants was conducted on 25 wells in the Cuvelai-Etosha Basin of Northern Namibia during two sampling campaigns. Molecular methods indicated the presence of Bacillus aerophilus, Bacillus amyloliquefaciens, Bacillus aquimaris, Bacillus aryabhattai, Bacillus cereus, Bacillus licheniformis, Bacillus pumilus, Bacillus safensis, Bacillus samanii, Bacillussp.M37,Bacillussp. M26, Bacillus stratophericus, Bacillus subtilis, Pseudomonas mendocina, Staphylococcus haemolyticus and Streptomyces celuloflavus.Item Ethnomycology of indigenous trametes mushrooms from northern Namibia(University of Namibia, 2017) Ueitele, Isabella S.; Kadhila-Muandingi, Nailoke P.; Chimwamurombe, Percy M.To date there is no documented data available on the Namibian indigenous Trametes mushrooms. The objective of this study was therefore to generate information for the first time, on the ethnomycology of Trametes species in Northern Namibia. A questionnaire was used and the data captured were analysed in SPSS. Results show that 83.9% of respondents included in this study knew Trametes mushroom but only 70.4% used it for medicinal purpose. Indigenous Trametes mushrooms in Namibia are mostly used as a tranquiliser to calm bereaved people who are crying hysterically at burials. Other uses include treating cattle from lung disease. These uses for Trametes species have not been reported before in literature.Item Identification of putative vibrio species isolated from processed marine fish using Thiosulphate-Citrate-Bile-Sucrose (TCBS), Agar(School Domain International, 2012) Shikongo-Nambambi, Martha N.; Chimwamurombe, Percy M.; Venter, Stephanus N.Aims: To identify putative Vibrio isolates obtained from processed hake, pilchards and horse mackerel using Thiosulphate-Citrate-Bile-Sucrose (TCBS) agar.Place and Duration of Study: Sampling during April – June 2005 in Walvis Bay Namibia. Further analyses performed at the Department of Microbiology and Plant Pathology, University of Pretoria, South Africa between 2005 and 2007. Methodology: The 247 putative Vibrio isolates obtained from Thiosulphate-Citrate-Bile- Sucrose (TCBS) agar were initially grouped according to their Gram, oxidase and oxidation-fermentation reactions. Thereafter PCR was used to screen the isolates for genes specific to human pathogenic Vibrio species such as Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus. This was followed by sequencing the 16S rRNAgene for isolates of interest and drawing Neighbour Joining phylogenetic trees based on the data. All atypical isolates were further characterised by a combination of selected phenotypic tests and the V. alginolyticus specific collagenase gene PCR. Results: Of the 247 isolates obtained from TCBS, four were Gram positive. Many of the Gram negative isolates belonged to the family Enterobacteriaceae and others were members of the Pseudomonadaceae. Of the 91 isolates identified as belonging to the Vibrionaceae and related families, Vibrio alginolyticus was the dominant Vibrio species. None of the bacteria isolated from the processed fish belonged to the human pathogenic Vibrio species. Conclusion: This study again demonstrated that TCBS agar is not selective for the isolation of Vibrio species and that a wide range of bacteria could be isolated on this medium when analysing marine fish. The identity of putative Vibrio isolates obtained from this medium should therefore be confirmed employing a number of phenotypic and genetic techniques to accurately identify the atypical isolates.Item Molecular phylogeny of Trametes and related genera from northern Namibia(2018) Ueitele, Isabella S.; Chimwamurombe, Percy M.; Kadhila-Muandingi, Nailoke P.Trametes Fr. is widely characterized as a polyporoid cosmopolitan genus which is presented in almost any type of forest environments. It is characterized by a combination of pileate basidiocarp, porous hymenophore, trimitic hyphal system and thin-walled basidiospores which do not react in Melzer’s reagent. Dry polypores were collected from Northern Namibia and identified as Trametes species based on morphology. Molecular analysis of Internal Transcribed Spacer region 1 (ITS 1) and Internal Transcribed Spacer region 2 (ITS 2) of the collected material revealed inconsistency with morphological identification. The phylogenetic tree was reconstructed using the Neighbour Joining method and reliability for internal branches Assessment was done using the ML bootstrapping method with 500 ML bootstrap replicates applied to 44 unpublished sequences and sequences from GenBank database. Only specimens such as D1-D9, D11 and D13 and specimens F1, I2-I4 and K3-K6 were grouped in the trametoid clade together with Trametes species. Furthermore, the position of Trametes trogii (also known as Coriolopsis trogii) was confirmed to be outside the trametoid clade and more closely related to Coriolopsis gallica. The close relationships of Pycnoporus and Trametes were confirmed by grouping of Pycnoporus sanguineus in to trametoid clade. Alignment with GenBank sequences revealed identity to Trametes species with up to 99%. These results suggest that it is better to keep a single generic name of Trametes for the trametoid clade.Item Optimization of indigenous Ganoderma lucidum(University of Namibia, 2014) Ueitele, Isabella S.; Chimwamurombe, Percy M.; Kadhila-Muandingi, Nailoke P.Ganoderma lucidum is a mushroom which shows antitumor, anti-inflammatory and cytoxic activity and grows prolifically in warm climates on decaying hardwood logs and stumps. An experiment was done at the University of Namibia to cultivate the indigenous G. lucidum; however, compared to results from other countries the mushroom took much longer to grow. The objective of this study was to shorten the cropping cycle of the indigenous G. lucidum under cultivation at the University of Namibia. The indigenous mushroom was cultivated according to the established protocol. A suitable indigenous Ganoderma mushroom was selected to make tissue culture, which was used to make the spawn that was inoculated into the woodchips substrate. New ideas were introduced to induce fast growth and optimum yield. The grains were inoculated with more pieces of tissue culture; the substrate was inoculated with increased layers of spawn and mixed with pearl millet husk instead of wheat bran to accelerate the colonization of the substrates. In addition to the hanging bag method used in the previous study, the buried wood log method was also introduced. Temperature and moisture were closely controlled during the experiment. A major highlight of this study was the significant reduction (p < 0:05) in the time it took for the substrate to reach fruiting stage. The substrate mixed with pearl millet husk was completely colonized by the mycelia, two weeks faster than the substrate that was mixed with wheat bran. Since Pearl millet is readily available in Northern Namibia, individuals and communities can substitute the wheat bran with pearl millet husk, which allows the substrate to be ready for fruiting faster, thus shortening the cropping cycle and also reducing the production cost as they no longer have to purchase wheat bran. The buried wood logs did not yield any fruiting bodies, but the hanging bags did produce G. lucidum. The study was successful in producing fruiting bodies in a shorter period. There was no significant improvement in the yield obtained.Item Physicochemical and functional characteristics of starch extracted from Marama bean tuber (Tylosema esculentum Burchell A. Schreiber)(University of Namibia, 2015) Nepolo, Emmanuel; Llyod, J.R.; Chimwamurombe, Percy M.Marama bean (Tylosema esculentum Burchell A. Schreiber) is a highly nutritious plant and is currently regarded as a prospective crop for the future in arid zone agri-ecologies of the world. Starch is a major storage component in higher plants and it is used in both food and non-food industries. The marama bean plant is a creeper with stems that lie prostrate on the ground in several directions up to six metres long in length which spread from a tuberous root below the ground. The tuber has a reddish brown bark and it can weigh about 1 kg and up to more than 10 kg. The plant produce attractive bright yellow flowers along the stems, each with erect petals and stamens, and are followed by marama fruits or bean. Mature marama bean cotyledons are white to cream in colour, encapsulated in hard, woody seed coats, reddish to brownish black in colour. Until recently, the basic knowledge of the physicochemical and functional properties of marama tuber starch is has not been yet reported. The present study reports for the first time the physicochemical and functional properties of marama tuber starch and makes a possible provision for a new starch source. Native marama starch content was 87.38 mg starch/gram fresh weight and the total amylose content was 35%. Phosphate at the C-6 position determined as Glucose-6-Phosphate was 0.788 nmol G6P/mg. The starch granules were round to elliptical with smooth surfaces and their sizes ranged from 8 -20 μm. The pasting properties of pasting temperature, host paste, peak, final viscosity, breakdown and set back showed higher values for marama starch in contrast to commercial potato starch. This study has clearly contributed to starch biology by making known for the first time the physicochemical and functional properties of marama tuber starch. It is hoped that by further exploring the potential of marama starch as a raw material, it can be applied in various applications in both industry and food processing that will produce high valued products.Item Science: An all encompassing field(University of Namibia, 2013) Kazembe, Lawrence N.; Archibong, Edet F.; Chimwamurombe, Percy M.; Singh, Shyam; Chinsembu, Kazhila C.What unites science, as Sir David Cox mentioned, is not the subject matter we all work in, but the methodology and the thought process that help solve the problems that arise [1]. Put differently, it is the replicability of its methods, the validity of its findings and reliability of its instruments and techniques. The diversity in science now emphasizes that not a single subject matter will work alone in isolation - especially if you are working in applied sciences, but has to learn from others. Even so, contemporary applied sciences have extended this collaboration to the social sciences [2]. For instance, in implementation science they have learnt to involve social sciences to inform human behaviour if scaling-up of interventions is to be a success.