Natural & Applied Sciences

Natural & Applied Sciences Research Papers/Topics

Anti-plasmodial Activity of Some Kenyan Medicinal Plant Extracts Singly and in Combination with Chloroquine

Abstract Sixty organic and aqueous extracts of eleven plants used for the control of malaria by local communities in Kisii District, Kenya were screened for in vitro anti-plasmodial activity. The plants selection was based on existing ethnobotanical information and interviews with local communities. The extracts were tested against chloroquine sensitive and resistant laboratory adapted strains of Plasmodium falciparum. The study revealed that 63.6% of the plants were active (IC50 ≤ 100 μg...

Complete genome sequence of Syntrophobotulus glycolicus type strain (FlGlyRT)

Abstract Syntrophobotulus glycolicus Friedrich et al. 1996 is currently the only member of the genus Syntrophobotulus within the family Peptococcaceae. The species is of interest because of its isolated phylogenetic location in the genome-sequenced fraction of tree of life. When grown in pure culture with glyoxylate as carbon source the organism utilizes glyoxylate through fermentative oxidation, whereas, when grown in syntrophic co-culture with homoacetogenic or methanogenic bacteria, it is...

Genotypic diversity of Dictyosphaerium–morphospecies (Chlorellaceae, Trebouxiophyceae) in African inland waters, including the description of four new genera

Abstract Trebouxiophytes of the Dictyosphaerium–morphotype from inland waters of Africa were studied using a polyphasic approach of SSU and ITS rDNA phylogeny, secondary structure of the ITS and observations made with a light microscope. Although the morphological criteria for differentiating species and genera are scarce, the genetic diversity of these algae was very high. Based on our genetic analysis findings, we described four new genera containing five new species: Compactochlorella d...

Fluctuating algal food populations and the occurrence of lesser flamingos (Phoeniconaias minor) in three Kenyan rift valley lakes

Abstract The last two decades have witnessed increasing episodes of lesser flamingo die-offs in East Africa. Based on data on phytoplankton composition, biomass, and flamingo population density in three alkaline-saline lakes of Kenya (Bogoria, Nakuru, and Oloidien) in 2001–2010, this study explored the link between sudden flamingo deaths and fluctuations in algal food quantity and quality. The phytoplankton biomass ranged from 13 to 768 mg Æ L)1. Similarly, flamingo numbers varied widely ...

Molecular detection of uncultured cyanobacteria and aminotransferase domains for cyanotoxin production in sediments of different Kenyan lakes

Abstract PCR-based denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA gene fragments was used to identify the cyanobacterial phylotypes in sediments and plankton of saline–alkaline and freshwater lakes of Kenya. The detection of the aminotransferase domain located on modules mcyE and ndaF using specific molecular markers confirmed the presence of potential toxin-producing cyanobacteria. The eight nucleotide sequences obtained from DGGE bands were placed in three divergent ...

Contribution of hot spring cyanobacteria to the mysterious deaths of Lesser Flamingos at Lake Bogoria, Kenya

Abstract Cyanobacterial mats at hot springs on the shore of the alkaline Lake Bogoria, Kenya, were investigated regarding species community and cyanobacterial toxin content. The hepatotoxins microcystin-LR, -RR, -LF and -YR, and the neurotoxin anatoxin-a were present. The mats were dominated by Phormidium terebriformis, Oscillatoria willei, Spirulina subsalsa and Synechococcus bigranulatus. The concentration of microcystins in mat samples, ranged from 221 to 845 microg microcystin-LR equival...

Mass developments of the cyanobacteria Anabaenopsis and Cyanospira (Nostocales) in the soda lakes of Kenya: ecological and systematic implications

Abstract The food web of the saline–alkaline lakes of East Africa is characterised by a unique interaction between the Lesser Flamingos as consumer birds and the cyanobacterium Arthrospira fusiformis as the primary producer. However, this interaction is disturbed frequently by alterations of the phytoplankton community. During the period 2001–2012, species of the cyanobacteria Anabaenopsis and Cyanospira were observed in four soda lakes of the African Rift Valley and compared to the enti...

Temporal changes in phytoplankton structure and composition at the Turkwel Gorge Reservoir, Kenya

Abstract Temporal changes in phytoplankton chlorophyll a, composition, diversity, biomass (density and fresh weight) and primary production were investigated at the Turkwel Gorge Reservoir (Kenya) over a two year period (1994 and 1995). The phytoplankton properties investigated revealed a seasonal pattern that was very distinct in 1994 and muted in 1995. The wet season was characterized by higher levels of chlorophyll a, biomass and primary production and a lower diversity. A prominent seaso...

Hepatitis B virus subgenotype A1, occurrence of subgenotype D4, and S gene mutations among voluntary blood donors in Kenya

Abstract Kenya is one of the high endemic zones for hepatitis B virus (HBV) infection. The consensuses on prevalence of the HBV genotypes and the existence of their variants have not been fully established in Kenya. Hence, there is a need to further monitor the diversity of HBV. This study aimed to extend the current molecular and epidemiological information about the geographical distribution of HBV genotypes and subgenotypes, as well as to describe the hepatitis B surface antigen (HBsAg) v...

Evaluation of an Antigen-Antibody “Combination” Enzyme Linked Immunosorbent Assay For Diagnosis Of Hepatitis C Virus Infections

Abstract BACKGROUND: Development of “combination” assays detecting in parallel, within a single test, Hepatitis C Virus (HCV) antigens and antibodies, not only reduces the window period in HCV-infection but also costs. Reduction of costs is important for developing countries where money and personal resources are limited. METHODS: We compared the Monolisa® HCV Antigen-Antibody Ultra (Bio-Rad Laboratories Limited, Marnes La Coquette, France) with the AXSYM HCV version 3.0 (Abbot Diagnost...

Comparing the yield components of three most popular commercial watermelon cultivars in Kenya with one newly introduced cultivar and one landrace

Abstract High yield is a major goal for watermelon (Citrullus lanatus) breeders. The objective of this study was to compare the yield components of some watermelon accessions available in Kenya and to identify high yielding accession(s) for recommendation to Kenyan growers and for use in breeding programs. A field trial involving five cultivated watermelon accessions in Kenya namely ‘Sugarbaby’, ‘Crimson Sweet’, ‘Charleston Gray’, ‘Yellow Crimson’; and one local landrace (GBK...

Fish Species Composition and Diversity of Small Riverine Ecosystems in the Lake Victoria Basin, Kenya

Abstract Riverine ecosystems in the Lake Victoria Basin (LVB) significantly contribute to the lake’s water budget and aquatic biodiversity. Despite their significance to the lakes fisheries, only limited biodiversity studies have been carried out, particularly in the smaller riverine ecosystems. This study investigated the fish species composition, diversity and distribution in two small riverine ecosystems (Rivers Awach Seme and Kisian) draining the Kenyan Lake Victoria Basin. Sampling wa...

INFLUENCE OF LARGE WOODY DEBRIS ACCUMULATIONS ON MACROINVERTEBRATE DISTRIBUTION IN A LOW ORDER FORESTED TROPICAL STREAM, SAGANA RIVER, KENYA

Abstract Woody debris accumulations are important ecological components in low order forested streams. They provide forage and refuge for a macroinvertebrates, which are key trophic components for riverine fish. The occurrence of woody debris in tropical streams is however threatened by large scale destruction of catchment forests thereby threatening the riverine biodiversity. Despite their importance, the current status of woody debris accumulations in tropical forested streams is unknown. ...

Morphological characterization of Kenyan native wood ear mushroom [Auricularia auricula (L. ex Hook.) Underw.] and the effect of supplemented millet and sorghum grains in spawn production

Abstract Utilization of mushrooms collected from the wild requires adequate description of useful phenetic features and domestication protocols. This study investigated morphological characters and spawn production procedures of three Kenyan native strains of wood ear mushroom [Auricularia auricula (L. ex Hook.) Underw.]. Nine basidiocarps were selected from collections made in three forest reserves within Kakamega Forest in Western Kenya and morphologically characterized. Mycelia were raise...

Morphological Characterization of Some Wild and Cultivated Watermelon (Citrullus Sp.) Accessions in Kenya

Abstract Genetic diversity and relatedness were assessed among three most common commercial watermelon cultivars in Kenya; one newly introduced commercial cultivar from the U.S., one Kenyan landrace and one wild (Citrullus colocynthis) accession. The six accessions were grown in the field for two seasons under sub humid tropical conditions. Randomized Complete Block Design (RCBD) with three replications was used. Data was collected on morphological features of watermelon which include vine, ...


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