Browsing by Author "Kwetegyeka, Justus"

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The fatty acid composition of edible grasshopper Ruspolia differens (Serville) (Orthoptera: Tettigoniidae) feeding on diversifying diets of host plants
(Wiley online Library: Entomological Research, 2018-12-12) Rutaro, Karlmax; Malinga, Geoffrey M.; Lehtovaara, Vilma J.; Opoke, Robert; Valtonen, Anu; Kwetegyeka, Justus; Nyeko, Philip; Roininen, Heikki
Ruspolia differens (Serville) (Orthoptera: Tettigoniidae) is a highly valued edible grasshopper species in Africa. However, the effects of plant diets on lipid content and fatty acid composition of R. differens are not well understood. We tested the effects of four diets on the total lipid content and fatty acid composition of R. differens. Sixth instar nymphs of R. differens were reared on one, and mixtures of two, three, and six natural plant inflorescences. Individuals collected from the field constituted a control treatment. We extracted lipids and analyzed the fatty acid methyl esters using gas chromatography–mass spectrometry. We analyzed if the total lipid content, body weight, and fatty acid composition differed among diets and between the sexes using two-way ANOVAs and a PERMANOVA model, respectively. The total lipid content and weight of R. differens did not differ among the diets. The nine common fatty acids were palmitic (mean across treatments, 26%), oleic (22%), palmitoleic (18%), linoleic (13%), stearic (7%), myristic (6%), myristoleic (4%), α-linolenic (2%) and arachidic acid (1%). The composition of fatty acids and the proportion of essential fatty acids significantly differed among the diets. The proportion of essential fatty acids was highest in the control treatment (21%) but low in less diversified (one to three feed) diets (12–13%). This study demonstrates that the fatty acid composition in R. differens can be influenced through diet. Thus, with dietary manipulations, using local plants in Africa, it is possible to produce R. differens with preferred high quality essential fatty acids for human consumption.
Fatty acid composition of muscle, liver, and adipose tissue of freshwater fish from Lake Victoria, Uganda
(Journal of Aquatic Food Product Technology., 2011) Masa, Justus; Ogwok, Patrick; Muyonga, John Herbert; Kwetegyeka, Justus; Makokha, Vincent; Ocen, Denis
Fish oils may differ in fatty acid (FA) composition depending on diet. Oils extracted from muscle, liver, and adipose tissue of Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus), silver fish (Rastrineobola argentea), lungfish (Protopterus aethiopicus), Victoria squeaker (Synodontis victoriae), and two catfishes (Clarias gariepinus and Bagrus docmac) from Lake Victoria, a tropical freshwater lake, were evaluated for FA composition. Oil contents of muscles, livers, and adipose tissues were in the range of 3.16 to 13.8%, 3.62 to 53.4%, and 28.8 to 42.4%, respectively. Omega-3 polyunsaturated FA, particularly alpha-linolenic (ALA), eicosapentaenoic (EPA), docosapentaenoic (DPA), and docosahexaenoic (DHA) acids, were found to be in substantial amounts in oils from all seven fish species. Ratios of polyunsaturated FA to saturated FA (0.79 to 1.18) were in the range considered adequate for normal health. Overall, the results show that the fish species studied are a rich source of omega-3 polyunsaturated FA.
Isolation, characterization and genome analysis of the orphan phage Kintu infecting Xanthomonas vasicola pv. musacearum
(BMC Microbiology, 2024-11-18) Nakayinga, Ritah; Ntulume, Ibrahim; Wagemans, Jeroen; Vallino, Marta; Kanaabi, Reagan; Kajubi, Ali; Kwetegyeka, Justus
Background Xanthomonas vasicola pv. musacearum is responsible for the widespread Banana Xanthomonas Wilt in banana cultivation regions across the globe. Biocontrol measures for disease management remain limited amidst increasing antimicrobial resistance and unsustainable conventional agricultural practices. The purpose of this study is to explore a viable alternative or adjunct strategy through the use of bacteriophages for disease management. Results Kintu was isolated from sewage and displayed clear and circular plaques measuring 3 mm. Based on transmission electron microscopy, Kintu displays siphovirus characteristics, including an icosahedral head and a non-contractile tail. Kintu infects 78% (22 out of 28) Ugandan Xvm strains, has an optimal multiplicity of infection of 1, a 10 min adsorption and latent period, a 35 min burst period, and a burst size of 15 particles per bacterium. Phage titers remain stable for two and half months (75 days) in SM buffer at -20 oC and − 40 oC but decrease significantly (p ≤ 0.0001) at 4 oC. Kintu is active at pH 3 and 11, maintains viability at temperatures between 25 oC and 120 oC and tolerates UV irradiation for up to 2 min and 20 s. Kintu inhibits Xvm growth at MOI ratios of 0.1, 1 and 10. The genome is a double stranded DNA molecule that consists of 48,985 base pairs and a G + C content of 51.71%. Antibiotic resistance genes or genes associated with a lysogenic life cycle are absent. There is limited sequence similarity of Kintu with other phages, making it a novel phage belonging to an unclassified genus of the class Caudoviricetes. Conclusion Kintu is a novel bacteriophage that infects and lyses Xanthomonas vasicola pv. musacearum, the causative agent for Banana Xanthomonas Wilt. Its stability across diverse temperatures and pH conditions highlights its potential as a biocontrol agent for managing the disease.