Natural & Applied Sciences

Natural & Applied Sciences Research Papers/Topics

Detection of trypanosomes in small ruminants and pigs in western Kenya: important reservoirs in the epidemiology of sleeping sickness?

Abstract Background: Trypanosomosis is a major impediment to livestock farming in sub-Saharan Africa and limits the full potential of agricultural development in the 36 countries where it is endemic. In man, sleeping sickness is fatal if untreated and causes severe morbidity. This study was undertaken in western Kenya, an area that is endemic for both human and livestock trypanosomosis. While trypanosomosis in livestock is present at high levels of endemicity, sleeping sickness occurs at low...

Differential Induction of Proteins in Anopheles gambiae sensu stricto (Diptera: Cullicidae) Larvae in Response to Heavy Metal Selection

Abstract Investigations were conducted to establish the magnitude and pattern of differential expression of proteins due to generational selection of third instar An. gambiae s.s. larvae by cadmium, copper and lead heavy metals, three possible common urban pollutants. A susceptible strain of An. gambiae s.s. third instar larvae was separately placed under selection pressure with cadmium, copper and lead at LC30 and controls through five generations. First, third and fifth generation selectio...

Pathogenic Escherichia coli and food handlers in luxury hotels in Nairobi, Kenya

Abstract Background: The epidemiology and virulence properties of pathogenic Escherichia coli among food handlers in tourist destination hotels in Kenya are largely uncharacterized. Method: This cross-sectional study among consenting 885 food handlers working in nine luxurious tourist hotels in Nairobi, Kenya determined the epidemiology, virulence properties, antibiotics susceptibility profiles and conjugation abilities of pathogenic Escherichia coli. Result: Pathogenic Escherichia coli was ...

Characterization of algae oil (oilgae) and its potential as biofuel in Kenya

Abstract A survey of microalgae biodiversity in three Kenyan Rift valley lakes identified high oil yielding species abundantly distributed naturally. The species were cultured in BBM and BG-11 media to obtain pure clones and lipids (oil) extracted by the Bligh and Dyer method. The peak lipid content ranged from 1.5 – 10.5% of algal biomass with Chlorella species showing the highest yields (10.5%), followed by Euglena acus (5.88), Nitzschia (3.68%), Ankistrodesmus falcatus (1.58%) and Scene...

Analysis of genetic diversity in Eucalyptus grandis (Hill ex Maiden) seed sources using inter simple sequence repeats (ISSR) molecular markers

Abstract Eucalyptus grandis is an economically important tree species that is native to the Australian continent and its northern neighbours, where it is grown primarily for its hard wood timber and pulp for paper industries. It is widely grown in tropical countries such as South Africa, Kenya, Angola, Ghana, and Zimbabwe. Five ISSR primers generated 41 scorable polymorphic bands which were used to analyse genetic diversity between and within the seed sources and for construction of neighbou...

The Physico-chemical Conditions of Turkwel Gorge Reservoir, a New Man Made Lake in Northern Kenya

Abstract Variations in some physical, chemical, and nutrient conditions were investigated at Turkwel Gorge Reservoir and its inflowing river, Suam between 1994 and 1995. Seasonal changes in inflow volume had the greatest impact on the reservoir and river conditions investigated. A wide fluctuation in inflow volume combined with a regulated outflow independent of season resulted in a draw down of over 10 m in each year. Flood inflows during the wet season resulted in the lowest values of Secc...

Mass developments of a small sized ecotype of Arthrospira fusiformis in Lake Oloidien, Kenya, a new feeding ground for Lesser Flamingos in East Africa

Abstract The Lesser Flamingos constantly commute between the soda lakes of East Africa in search of food. Their preferred food, the cyanobacterium Arthrospira fusiformis, usually establishes dense populations in saline–alkaline habitats. However, the algal food resources are not stable and crash unexpectedly from time to time. Hence any site that provides food in suitable quality and quantity makes a valuable contribution to the survival of these nearly endangered birds. This paper reports...

Desertifilum fontinale sp. nov. (Oscillatoriales, Cyanobacteria) from a warm spring in East Africa, based on conventional and molecular studies

Abstract Desertifilum is a filamentous cyanobacterium of crusts and biofilms, recently described from the extreme hot and dry Thar Desert in north–western India. A new species was isolated from a warm spring near Lake Bogoria, Kenya and was characterised by light and electron microscopy and phylogenetically using the 16S rRNA gene, beta and alpha subunits including intergenic spacer (cpcBA–IGS) and 16S–23S internal transcribed spacer (ITS). The aquatic habitat of the new material from ...

An overview of advances in bioinformatics and its application in functional genomics

Abstract Bioinformatics is the scientific discipline that is concerned with the efficient management and useful interpretation of large scale biological information. Functional genomics aims at mapping DNA sequences and the components they encode for, to the function they perform. Initial efforts in bioinformatics were focused on the analysis of DNA sequence data. Presently, the scope and objectives of bioinformatics research and development have been broadened owing to the accelerating gene...

454 Pyrosequencing‑based assessment of bacterial diversity and community structure in termite guts, mounds and surrounding soils

Abstract Termites constitute part of diverse and economically important termite fauna in Africa, but information on gut microbiota and their associated soil microbiome is still inadequate. In this study, we assessed and compared the bacterial diversity and community structure between termites’ gut, their mounds and surrounding soil using the 454 pyrosequencing-based analysis of 16S rRNA gene sequences. A wood-feeder termite (Microcerotermes sp.), three fungus-cultivating termites (Macroter...

Haloleptolyngbya alcalis gen. et sp. nov., a new filamentous cyanobacterium from the soda lake Nakuru, Kenya

Abstract The food web of the saline-alkaline Lake Nakuru is dominated by the cyanobacterium Arthrospira fusiformis as the primary producer and a huge population of Lesser Flamingos as direct consumers. However, the dense blooms of Arthrospira are not stable, and collapse irregularly and unpredictably. During such periods they are replaced by other algae or cyanobacteria. The wide fluctuation in the cyanobacterial and algal populations of Lake Nakuru has a great influence on food availability...

Potential of indigenous bradyrhizobia versus commercial inoculants to improve cowpea (Vigna unguiculata L. walp.) and green gram (Vigna radiata L. wilczek.) yields in Kenya

Abstract Limited information is available on reduced cowpea (Vigna unguiculata L. Walp.) and green gram (Vigna radiata L.Wilczek.) yields in Kenya. Declining soil fertility and absence or presence of ineffective indigenous rhizobia in soils are assumptions that have been formulated but still require to be demonstrated. In this study, soils were collected from legume growing areas of Western (Bungoma), Nyanza (Bondo), Eastern (Isiolo), Central (Meru) and Coast (Kilifi) provinces in Kenya to a...

Hidden diversity of eukaryotic plankton in the soda lake Nakuru, Kenya, during a phase of low salinity revealed by a SSU rRNA gene clone library

Abstract A SSU rRNA gene clone library was constructed to establish the diversity of eukaryotic plankton in the African soda lake Nakuru during a phase of low salinity (9.7 ppt = hyposaline). Normally, the lake is mesosaline (up to 50 ppt) and its phytoplankton is dominated by few species of cyanobacteria, in particular Arthrospira fusiformis, which is the main food resource of Lesser Flamingos. Our study recovered a unique phytoplankton species composition characterized by a high diversity ...

Isolation and characterization of bacillus species from soil in Ngere tea catchment area of Murang’a county, Kenya

Abstract Bacteria are a very diverse group of organisms in soil, and major taxonomic groups are represented in most soils. The extent of the diversity of microorganisms in soil is seen to be critical to the maintenance of soil health and quality, since a wide range of bacteria are involved in the important soil functions. The objectives of this study were to isolate, characterise and identify groups of bacteria from Bacillus species that are associated with soil quality in tea growing areas ...

Isolation and characterization of bacteria isolates from soil feeding termites and soil from Juja and Kakamega forest in Kenya

Abstract In the last several years information on the gut ecosystem of termites has continued to be gathered. Most studies have been focused on wood feeding termites but studies on soil feeders remain sparse owing to their difficulty of establishing permanent laboratory cultures. The aim of this study was to isolate, characterize and identify bacteria resident in the soil feeding termite gut, mound and parent soil of Cubitermes species with the potential to produce antibiotics and enzymes fo...


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