Kenyatta University Repository
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Isolation and Characterization of L-Asparaginase Producing Endophytic Fungi Inhabiting Prunus africana and Periploca linearifolia
(Kenyatta University, 2025-09) Cheruiyot, Dennis Kipngenoh
The clinical use of L-Asparaginase derived from bacterial sources has been hindered by various challenges, including toxicity and repression. This has prompted the exploration of alternative sources, particularly eukaryotic microorganisms like fungi, in an effort to enhance the safety and effectiveness of therapeutic ASNase. In this study, endophytic fungi isolated from medicinal plants, Periploca linearifolia (Apocynacease family) and Prunus africana (Rosaceae family), were investigated for their potential as a source of novel ASNase for therapeutic applications. These isolates were screened for L-Asparaginase production using the plate assay method on modified Czapex dots agar medium. L-Asparaginase activity of the fungal endophytes was determined using the nesslerization method. Identification of the fungal endophytes was performed using morphological characteristics and DNA barcoding with ITS sequencing, followed by BLAST analysis. Additionally, a phylogenetic tree was constructed using MEGA version X software. Twenty-four percent of the fungal endophytes exhibited positive reaction for L-ASNase activity and were identified as Penicillium ubiquetum, Penicillium pancosmium, Phoma sp, Penicillium. crustosum, Fusarium sporotrichioides, Cercospora canescens, Penicillium commune, septoria sp, Fusarium solani, and Colletotrichum sydowii. The fungal endophytes exhibited significant variation in production of L-asparaginase under the inflence of time of incubation and pH. It was observed that the fungal endophytes showed L-asparaginase activity at different day of incubation with Penicillium ubiquetum (2.63±0.47UI/mL), Penicillium pancosmium (1.44±0.1UI/mL), Phoma sp (2.6±0.47UI/mL), Penicillium crustosum (3.80±0.37 UI/mL), Penicillium commune (2.52±0.29 UI/mL), Fusarium sporotrichioides (3.47±0.24 UI/mL), Cercospora canescen (2.24±0.12 UI/mL) showed highest enzyme activity on the 6th day of incubation. Septoria sp and Colletotrichum sydowii exhibited best L-asparaginase activity of 12.6±0.81UI/mL and 4.06±0.23 UI/mL on the 9th day of incubation, respectively. While Fusarium solani showed atmost L-asparaginase activity of 12.4±1.12 UI/mL on the 12th day of incubation. In addition, the ten identified fungal endophytes records the highest activity at pH range 5.0-6.0 with Fusarium solani recording the highest enzyme activity of (6.14±0.01 UI/mL) at pH 6.0. The study revealed that fungal endophytes inhabiting plants with medicinal properties are potential source of L-Asparaginase. Among the fungal isolates, Fusarium solani and Septoria sp. showed the highest ASNase activity under optimized conditions (pH 5-6, incubation 9-12 days), indicating their potential as safer alternative to bacterial L-Asparaginase for anticancer therapy.
Bioethanol Production from Dilute Acid-Pretreated Rice and Sorghum Biomass via Enzymatic Hydrolysis and Fermentation
(Kenyatta University, 2025-09) Nyang’au, Agatha Kemunto
The world has a massive energy need, and bioethanol is a viable clean energy substitute for the
fast-depleting fossil fuel supply. Large volumes of crop leftovers generated and left in the field
for burning can be used in an affordable, dependable, and steady way thanks to production of
bioethanol from lignocellulose biomass. However, because of the variations in lignocellulosic
biomass, biochemical composition and lignin’s recalcitrance, producing ethanol from it is still
difficult. This study evaluated the effects of pre-treating selected agro wastes with dilute acid
on ethanol yields via microbial hydrolysis and fermentation. Nerica husk (NH), Nerica straw
(NS), Basmati 370 husk (BH), Basmati 370 straw (BS), sorghum from KALRO plot 8 (SP08)
and Sorghum from KALRO plot 17 (SP17) were used in this study. Biomass samples were
dried to a constant moisture content, milled into fine powder, and treated at 121oC for 60 min
with sulphuric acid (1.2%(w/w) or 2.25%(w/w) at a solid to liquid ratio of 1:10. This was
followed by enzyme hydrolysis using cellulase from Aspergillus niger at 5% substrate loading.
High performance liquid chromatography (HPLC) with a reverse phase column and refractive
index detector was used to evaluate the resultant sugars. The cellulase hydrolysed substrate
solution was fermented with Saccharomyces cerevisiae, and the alcohol production was
measured by HPLC. An analysis of the statistics was done through the analysis of variance
(ANOVA), considering a 95% confidence level using SPSS software. Simple sugars including
glucose, sucrose, maltose, and specific sugars such as xylose, arabinose, and mannose were
detected, with glucose being the sugar that was found to be most prevalent in all samples.
Glucose yields were consistently higher in samples pre-treated with 2.25%(w/w) dilute
sulphuric acid than in biomass samples pre-treated with 1.2%(w/w) sulphuric acid, which
yielded between 12.8%(w/v) and 26.7%(w/v) glucose across all biomass samples. In contrast,
cellulase hydrolysis after 2.25%(w/w) acid pre-treatment, yielded 32.3%(w/w), 30.6%(w/w),
31.6%(w/w), 30.3%(w/w), 29.3%(w/w), and 13.4%(w/w) glucose from NH, NS, BH, BS,
SP08, and SP17 samples, respectively. Biomass samples pre-treated with 2.25%w/w dilute acid
and subjected to microbial fermentation produced ethanol ranging from 5.8%(v/v) to
8.9%(v/v). These findings demonstrate that 2.25%(w/w) sulphuric acid pre-treatment
significantly enhances the release of fermentable sugars, particularly glucose from selected
agro-wastes, supporting their potential as viable low-cost feedstocks for sustainable bioethanol
production in Kenya
Prevalence and Risk Factors Associated with Geohelminths and Intestinal Protozoa Infections among Pupils Aged 7–12 Years in Nyeri County, Kenya
(Kenyatta University, 2025-10) Muthee, Anthony Menaine
Helminths and protozoa are the two categories into which intestinal parasites fall. Schoolage children are highly susceptible to intestinal protozoa and soil-transmitted helminth
(STH) infections. Geo-helminth and intestinal protozoa infections remain a significant
public health burden in many parts of Kenya, especially among school-going children in
rural and peri-urban regions. Despite the implementation of Mass Drug Administration
(MDA) programs, the prevalence of these infections among school-aged children
continues to rise. The study aimed to determine the prevalence and associated risk factors
of STH and intestinal protozoa infections among school-going children in selected
primary schools in Konyu area. The Specific Objectives were: To determine the
prevalence of geohelminths and intestinal protozoa infection among school children; to
identify the risk factors associated with geohelminths and intestinal protozoa infection
among pupils, and To identify the environment related risk factors associated with
geohelminths and intestinal protozoa infection in Nyeri County. The Epidemiological
Triangle Model (ETM) guided this study. A cross-sectional study design was employed
involving 164 pupils from Kihuro, Gathuini, and Gikumbo primary schools. The study
was conducted in 3 primary schools which were purposively selected and the study
population comprised pupils in Grades 1 to 6, aged between 7 and 12 years. This study
employed a cluster random sampling technique to select participants from public primary.
Using the Cochran formula, a total number of 178 study subjects was calculated, though
only 164 pupils provided complete date. Pre-testing of the research instruments was
conducted in a school setting, to ensure consistency with the actual study environment.
The reliability of the study tools and laboratory procedures, quality control measures
were implemented and a coefficient of 0.84 was obtained. The data collection process
began with a community sensitization meeting supported by local leaders, followed by a
focus group discussion involving key stakeholders. Pupils and their guardians completed
structured questionnaires on hygiene and environmental risk factors before being given
labeled containers for stool sample collection. Samples were collected and analysed using
the Kato-Katz technique for helminths and the Formal Ether Concentration technique for
protozoa. Laboratory SOPs were rigorously followed, with quality checks to ensure
accuracy and confidentiality. Data were cleaned, coded, and analysed using SPSS version
28.0. Descriptive statistics were used to summarize participant characteristics, while Chisquare tests evaluated associations between risk factors and infection prevalence. The
prevalence of intestinal protozoa was 21.4%, 33%, and 20.4% in Kihuro, Gathuini, and
Gikumbo, respectively, while STH prevalence was 10.7%, 13%, and 13%. There was a
significant association between pupil and environmental risk factors and the prevalence
of infections (p < 0.05). Risk factors related to hygiene practices, sanitation, and
environmental exposure were significantly associated with infection rates, underscoring
the need for integrated interventions beyond routine deworming. The study concluded
that infection prevalence was high and significantly linked to personal and environmental
risk behaviours, leading to targeted recommendations for health education, hygiene
infrastructure, regular deworming, and improved WASH practices in schools.
Role of Risk Assessment Strategies on Success of Sports Tourism Events in Nairobi City County, Kenya
(Kenyatta University, 2025-08) Chengo, Moses
Kenya’s sports tourism industry faces a significant obstacle due to the absence of long-term,
sustainable strategic planning and development. A key indicator of this challenge is the spread of
numerous small and medium-sized accommodation facilities across the country, many of which
operate outside the formal tourism development framework and contribute little to regional
growth. Compared to other branches of tourism, sports tourism remains underdeveloped and
undervalued in Kenya and across much of Africa. One critical component in managing sporting
events is risk assessment, which involves the combined efforts of organizers, municipal authorities,
police, and safety agencies to ensure secure and successful events. The purpose of this study was
to assess the effect of risk assessment methodologies on the success of sports tourism events.
Specifically, the study sought to: profile sports tourism events and venues in Nairobi City County,
Kenya; examine the influence of risk assessment and risk management strategies on sports tourism
events and evaluate the moderating role of financial capability in the relationship between risk
assessment, risk management strategies, and sports tourism events within Nairobi City County. A
descriptive research design was employed, focusing on 17 major sporting venues in the county.
The study engaged a total of 340 participants and 69 managers, with 17 managers and 105 athletes
selected purposively. Data collection was conducted through questionnaires and interview guides,
which allowed respondents to share their views freely. Both descriptive and inferential statistics
were used to analyze the data. Linear regression modeling was applied to establish the relationship
between the independent variables (risk assessment and risk management strategies) and the
dependent variable (success of sports tourism events). Results were presented in tables, charts, and
bar graphs. Findings from the multiple linear regression analysis showed a coefficient of
determination (R²) of 0.700, indicating that 70% of the variation in the success of sports tourism
events could be explained by risk assessment and risk management strategies. Moreover, the
relationship between these strategies and event success was found to be positive and statistically
significant (β = 0.837, p = 0.000 < 0.05). The study further revealed that financial capability had
a moderating effect on the relationship between risk assessment strategies and the success of sports
tourism events. Based on these findings, it was concluded that effective risk assessment and
management practices play a crucial role in the success of sports tourism. The study therefore
recommends the adoption of a multi-agency approach to enhance risk assessment procedures and
protocols, ensuring that sporting events are managed more effectively and sustainably in Nairobi
City County
Meanings of Health and Disease and their Implication on Health Behaviours among Preadolescents and Guardians in Nairobi City County, Kenya
(Kenyatta University, 2025-10) John, Dennis Kiilu
The rising global prevalence of non-communicable diseases (NCDs) presents a critical public health challenge, particularly in low and middle-income countries (LMICs) like Kenya. Understanding lay conceptualizations of health and disease, especially among preadolescents and their guardians, is crucial for addressing NCD determinants, yet remains underexplored. This study, therefore, conducted a secondary qualitative analysis of existing data from the Kenya-Finland Education and Research Alliance (KENFIN-EDURA) project, originally conducted in two sub-counties of Nairobi. The study aimed: (1) to identify factors determining preadolescents' and guardians' meanings of health and disease; (2) to establish their meanings of obesity and NCDs; and (3) to explain the implications of these meanings on health behaviours. Guided by William Cockerham's Health Lifestyle Theory and the Health Belief Model, the research employed thematic analysis on eight in-depth interviews (IDI) and six focus group discussions (FGD) transcripts. Data saturation informed transcript selection, and ethical considerations for secondary analysis were strictly observed. Findings revealed that health and disease meanings are profoundly shaped by complex socio-cultural (e.g., family environment, maternal influence), economic (socioeconomic status, parental education), and contextual (e.g., obesogenic environments, parental work) factors. Participants largely conceptualized obesity and NCDs as direct outcomes of unhealthy diet and physical inactivity, recognizing links to chronic illnesses. However, a significant finding was the low perceived vulnerability to NCDs among adolescents, who often attributed these conditions to old age, highlighting a critical barrier to behaviour change from a Health Belief Model perspective. Despite this, preadolescents demonstrated a foundational understanding of health-protective behaviours, indicating their potential as change agents. The study concludes that while basic knowledge of health and NCDs exists, effective prevention requires moving beyond simple education. Public health strategies must address the social construction of health meanings, prioritize fostering positive parental healthy-eating attitudes and behaviours due to the family's central role in health socialization, and leverage the potential of preadolescents themselves. This research offers nuanced, context-specific insights into lay health conceptualizations in urban LMIC settings, informing more effective and culturally sensitive NCD prevention programs.