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Prokaryotic diversity and composition within equatorial lakes Olbolosat and Oloiden in Kenya (Africa)
(ELSEVIER :www.sciencedirect.com/journal/current-research-in-microbial-sciences, 2021-12-26) Wafula, Eliud N.; et.al
Total community 16S rDNA was used to determine the diversity and composition of bacteria and archaea within lakes Olbolosat and Oloiden in Kenya. The V3-V4 hypervariable region of the 16S rRNA gene was targeted since it’s highly conserved and has a higher resolution for lower rank taxa. High throughput sequencing was performed on 15 samples obtained from the two lakes using the Illumina Miseq platform. Lakes Olbolosat and Oloiden shared 280 of 10,523 Amplicon Sequence Variants (ASVs) recovered while the four sample types (water, mi crobial mats, dry and wet sediments) shared 4 ASVs. The composition of ASVs in lake Olbolosat was highly dependent on Cu+, Fe2+, NH4+, and Mn2+, while L. Oloiden was dependent on Mg2+, Na+, Ca2+, and K+. All the alpha diversity indices except Simpson were highest in the dry sediment sample (EC1 and 2) both from lake Oloiden. The abundant phyla included Proteobacteria (33.8%), Firmicutes (27.3%), Actinobacteriota (21.2%), Chloroflexi (6.8%), Cyanobacteria (3.8%), Acidobacteriota (2.8%), Planctomycetota (1.9%) and Bacteroidota (1.1%). Analysis of similarity (ANOSIM) revealed a significant difference in ASV composition between the two lakes (r =0.191, p =0.048), and between the sample types (r =0.6667, p =0.001). The interaction network for prokaryotic communities within the two lakes displayed Proteobacteria to be highly positively connected with other microbes. PERMANOVA results suggest that temperature controls the functioning of the two ecosystems.
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Potential Role of African Fermented Indigenous Vegetables in Maternal and Child Nutrition in Sub-Saharan Afric
(Hindawi International Journal of Food Science, 2021-12-15) Wafula, Eliud N.; et.al
Hunger and malnutrition continue to affect Africa especially the vulnerable children and women in reproductive age. However, Africa has indigenous foods and associated traditional technologies that can contribute to alleviation of hunger, malnutrition, and communicable and noncommunicable diseases. The importance of African indigenous vegetables is undeniable, only that they are season-linked and considered as “food for poor” despite their high nutritional contents. The utilization of African indigenous vegetables (AIVs) is hindered by postharvest losses and antinutrients affecting the bioavailability of nutrients. In Africa, fermentation is among the oldest food processing technologies with long history of safe use. Apart from extending shelf life and improving food organoleptic properties, fermentation of African indigenous vegetables (AIVs) is known to improve food nutritional values such as proteins, minerals, vitamins, and other beneficial phytochemicals. It can also increase bioavailability of various vitamins, minerals, and phytochemicals and increase synthesis of vital blood pressure regulators thus protecting against cardiovascular diseases and cancer and further helping fight certain malnutrition deficiencies. Some lactic acid bacteria (LAB) involved in food fermentation are known to produce exopolysaccharides with cholesterol-lowering, immunomodulator, antioxidant, and anticancer properties. Fermented foods (vegetables) are superior in quality and safety since most microorganisms involved in fermentation are good starter cultures that can inhibit the growth of foodborne pathogens and detoxify harmful compounds in foods. Thus, fermented foods can boost growth and well-being in children and women due to their higher nutritional contents. Therefore, fermentation of AIVs can contribute to the attainment of food and nutrition security especially among women and children who rely on these vegetables as a staple source of micronutrients and income. These benefits have a positive impact on the implementation of the second sustainable development goals and African Union agenda 2063. This review is aimed at shedding light on the potential of African fermented indigenous vegetables in combating maternal and child malnutrition in Sub-Sahara Africa
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Phenotypic and genotypic characterization of lactic acid bacteria isolated from spontaneously fermented vegetable amaranth
(African Journal of Food Science, 2021-05-25) Wafula, Eliud N.; et.al
Lactic acid bacteria (LAB) are Gram-positive, non-spore-forming, catalase-negative cocci or rod-shaped bacteria that produce lactic acid as a major fermentation product. They are also involved in the production of fermented foods. They have applications in industry and human health, such as food preservation and probiotics. The aim of this research was to isolate, characterize, and classify indigenous lactic acid bacteria from fermented vegetable amaranth, a leafy vegetable native to Africa. The isolates' 16S rRNA gene was amplified using bacterial universal primers 27F and 1492R. From fermented vegetable amaranth, a total of 15 LAB were isolated were grouped into the genera Lactobacillus, Lactococcus, and Weissella based on 16S rRNA gene analyses. Lactobacillus plantarum dominated vegetable amaranth fermentation, accounting for 60% of all isolates.
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Isolation and Identification of Bacteriocin-Producing Bacillus spp from Rastrineobola argentea (Omena) with Activity against Bovine Mastitis Bacterial Pathogens
(Journal of Food Security, 2021-04-19) Wafula, Eliud N.; et.al
Rampant use of antibiotics has increased resistance of pathogenic bacteria in both animals and humans. This has triggered the investigation of novel antimicrobial agents produced by a bacterial strain of low virulence with antimicrobial activity with a wide range of clinical significance. This study sought to extract bacteriocins from Bacillus spp that were isolated and identified from Omena (Rastrineobola argentea) and to evaluate the in vitro antimicrobial effect of the obtained bacteriocin against bovine mastitis pathogens. Samples were collected from Lake Victoria using a completely randomized design method followed by isolation of the bacteriocin producing Bacillus spp. Characterization and identification of isolates was done by Gram staining, morphology and Biochemical tests which included catalase, nitrate reduction, methyl Red,-Voges-Proskauer, indole, motility and hydrogen sulphide, growth on Simmons citrate agar, triple sugar iron agar and starch hydrolysis. Antimicrobial activity was done using disc diffusion methods on the nutrient agar and zone of the inhibition measured after 24hours. An analytical profile index system (API 50CH BE, Biomerieux, Inc, France), was also used for identification. Molecular characterization was done by extracting genomic DNA using Qiagen DNA isolation Kit (Qiagen Germany) using the manufacturer's instructions. The gene encoding the 16S rRNA was amplified by PCR using universal bacterial primers pair combination of forwarding primer 27F forward (5′-AGA GTT TGA TCC TGG CTC AG-3′) and 1492R reverse, (5′-GGT TAC CTT GTT ACG ACT T-3′) about Escherichia coli gene sequence. A total of 60 pure isolates were obtained from Omena samples from Lake. Victoria. Morphological characteristics showed varied colour, form, shape and elevation of the pure colonies. About 54 isolates (90%) were gram-positive with spores, while 6 (10%) were gram-negative. Biochemical tests showed varied results among the bacterial isolates. 28 isolates showed antimicrobial activity on E. coli and S. aureus with inhibition measuring between 17-30mm. Analytical profile index system also showed that 20 isolates (71%) were identified as Bacillus subtilis, three isolates (11%) identified as Bacillus pumilus and five isolates (18%) Bacillus mycoides. The Blast analysis of the partial sequences showed100% of the strains of genus Bacillus within the Firmicutes in the domain bacteria. Twenty (20) isolates belong to Bacillus subtilis, Bacillus mycoides represent 18% (5 isolates) while Bacillus pumilus constituted 11% (3 isolates). This study contributes to understanding the use of bacteriocin in the control of diseases in dairy animal farming in Kenya.