John Maingi

Kenyatta University · Department of Microbiology

In agroecosystems, microbial communities play a crucial role in delivery of various ecosystem services. These microbial communities are affected by several factors such as soil physicochemical properties which contribute to the diversity of bacterial and fungal communities. In this study, we investigated the soil physicochemical parameters and the...

Background: Global food supply is highly dependent on field crop production that is currently severely threatened by changing climate, poor soil quality, abiotic, and biotic stresses. For instance, one of the major challenges to sustainable crop production in most developing countries is limited nitrogen in the soil. Symbiotic nitrogen fixation of...

Fish products are highly vulnerable to microbial contamination due to their soft tissues, making them perishable and harmful to consumers. The clinical and subclinical infections reported by fish consumers are mainly associated with pathogenic microorganisms in fish products. Therefore, this study aimed at establishing the molecular profiles and di...

Grain legumes play a significant role in smallholder farming systems in Africa because of their contribution to nutrition and income security and their role in fixing nitrogen. Biological Nitrogen Fixation (BNF) serves a critical role in improving soil fertility for legumes. Although much research has been conducted on rhizobia in nitrogen fixation...

The use of antibiotics for prophylaxis and growth enhancement in livestock farming is on the increase globally. This practice has led to the emergence and spread of antimicrobial-resistant bacteria in livestock. Only limited research has been done to establish the role of cattle farming in antimicrobial resistance. The current study sought to estab...

Pseudomonas aeruginosa is a pathogen of great clinical importance to both humans and animals. It causes pneumonia in cystic fibrosis patients, and it is responsible for the infections of blood and lungs during surgery. Increased antibiotic use has led to the emergence of multidrug-resistant strains of P. aeruginosa. Recently, phage therapy has attr...

Ensuring safe aquaculture products has been one of the major challenges and concerns for many fish farmers, traders and consumers in developing countries. This is attributed to contamination of fish and fish products by pathogenic and spoilage microorganisms that are resistant to multiple antibiotics. Additionally, the use of antibiotics in fish fa...

Background: Hepatitis A and B causes morbidity and mortality among patients. This study determined the proportion of hepatitis A, B viruses (HAV, HBV) and genetic diversity of HBV among jaundice patients at the Coast General Hospital, Mombasa County, Kenya. Methods: A cross-sectional study was conducted among 222 patients; recruited and screened...

Globally, organic farming and bradyrhizobia inoculation are gaining popularity as agronomically and environmentally sound soil management strategies with great potential to alleviate declining soil fertility, maintain environmental quality and enhance soybean production. However, the role of bradyrhizobia in organic farming system is poorly underst...

Objectives: Hepatitis B virus (HBV) infection and emergence of drug resistance have remained one of the major public health puzzles. This study determined circulating HBV genotypes and nucleoside analog resistance to provide information in choosing the best therapy. Methods: A cross-sectional study was conducted among jaundiced patients visiting...

Smallholder agroecosystems play a key role in the world's food security providing more than 50% of the food produced globally. These unique agroecosystems face a myriad of challenges and remain largely unsupported, yet they are thought to be a critical resource for feeding the projected increasing human population in the coming years. The new chall...

Cowpea (Vigna unguiculata (L.) Walp) is an important multipurpose legume crop grown in arid and semi-arid areas of sub-Saharan Africa. The crop associates with a wide diversity of high ecological value rhizobia bacteria, improving biological soil fertility and crop production. Here, we evaluated the symbiotic efficiency (SE) and genetic diversity o...

Soil amendment with beneficial microorganisms is gaining popularity among farmers to alleviate the decline of soil fertility and to increase food production and maintain environmental quality. However, farm management greatly influence soil microbial abundance and function, which overly affects crop growth and development. In this work, greenhouse...

The diverse community of endophyte and rhizobacteria is a critical resource in enhancing plant growth and resistance against abiotic and biotic stress. These microbes include various bacterial communities dominated by Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes. They inhabit and proliferate in plant tissues forming beneficial assoc...

Banana (Musa acuminate L) is the world’s most widely known and distributed fruit and is a great contributor to food security in the developing world. However, many limiting factors affect banana farming, which cut across sociodemographic factors and agronomic and management practices. The current study was carried in three counties, including Kisii...

Background: In Cameroon, common bean (Phaseolus vulgaris L) is amongst the legumes which are greatly consumed. Farmers in Cameroon especially the Menoua Division grow different common bean cultivars which after harvest, are stored to be used as food over the storage period or for sale. Stored common bean after harvest in Cameroon are prone to funga...

Organic farming systems are gaining popularity as agronomically and environmentally sound soil management strategies with potential to enhance soil microbial diversity and fertility, environmental quality and sustainable crop production. This work aimed at understanding the effect of organic and conventional farming on the diversity of soybean nodu...

Common bean is a legume grown globally especially in developing countries including Cameroon for human consumption. In Cameroon it is grown in a wide variety of agro ecological zones in quantities enough to last through the off growing season after harvest. Stored common bean after harvest in Cameroon are prone to fungal spoilage which contributes...

Promiscuous soybeans are grain legumes that nodulate with diverse strains of indigenous Bradyrhizobium and play a significant role in biological nitrogen fixation through symbiosis. However, experiments on the potential use of promiscuous soybean varieties have recorded very low nodulation and poor nitrogen fixation probably due to ineffective nati...

The coronavirus health crises is really changing the way people say goodbye to their loved ones. This is because corpses of victims who died as a result COVID-19 disease are recognised to be highly infectious and contagious with a great risk of the virus being transmitted by direct contact with the dead bodies.Memorial services are not allowed to b...

The coronavirus health crises is really changing the way people say goodbye to their loved ones. This is because corpses of victims who died as a result COVID-19 disease are recognised to be highly infectious and contagious with a great risk of the virus being transmitted by direct contact with the dead bodies.Memorial services are not allowed to b...

farmers growing different cultivar types. Upon harvest, these cultivars are stored to be used as food over the storage period or for sale. Unfortunately appropriate facilities for storing the cultivars after harvest are not available hence predisposing the grains to fungi infection. The knowledge of cultivar resistant to damage by storage fungi wou...

In sub-Saharan Africa, crop production has continued to decline due to soil infertility, limited arable land, among other factors. This has necessitated the use of inorganic farm inputs, which are expensive and have detrimental environmental effects. Rhizobia technology can enhance legume crop production. The present study aimed at assessing the po...

Purpose: To screen nine available bean genotypes for resistance to common bacterial blight disease under green house and field conditions.Methodology: Experiments were conducted in randomized complete block design with three replications in a 9×2×2 factorial factor of 9 bean genotypes, grown in sterile or non-sterile soil and inoculated or non-inoc...

Introduction: COVID-19 (coronavirus) has become a global threat to the human population. The virus which originated from China in December, 2019 has swept across continents in the world. Cameroon has been one of the countries with a high infectious rate. Lack of awareness plays a major role in the rise of COVID-19 cases. Studies have shown that the...

Beneficial soil microbiota, such as arbuscular mycorrhizal fungi (AMF) and rhizobia, provide essential agroecosystem services in smallholder farming systems. Such microorganisms have great potential to promote crop production and resilience under a changing climate in sub-Saharan Africa. However, their function is affected by agronomic management p...

Green gram (Vigna radiata L. Wildzek) is a neglected crop with great potential to boost food security among small scale farmers. Inoculation of this crop with beneficial soil microbiota can sustainably improve its production especially under water stress conditions. Here, we aimed at determining the effect of bradyrhizobia and arbuscular mycorrhiza...

Objective Increase in antimicrobial resistance is a threat to health sector globally. Surveillance on the spread and emergence of antimicrobial resistance is therefore invertible. This study investigated prevalence of Salmonella and Escherichia coli, molecularly characterized their antimicrobial resistance patterns and spread among resistant isolat...

Aims: The aim of this study was to establish the effect of field treatment with selected soil amendments on bacterial wilt incidences in Tomatoes, Capsicum and Potatoes. Study Design: The study was laid out as randomized complete block design (RCBD) in split plot arrangement for two seasons in the field. Place and Duration of Study: The experiment...

Aims: This study was carried out to evaluate the influence of organic and inorganic soil amendments on soil moisture content and micronutrients in semi and arid areas. Methodology: The study was laid out as randomized complete block design (RCBD) in split plot arrangement for two seasons. The treatments were ChalimTM, Super-hydro-grow polymer and M...

Aims: The aim of this study was to establish the effect of selected soil amendments on Ralstonia solanacearum isolates in greenhouse on selected solaneceous crops. Study Design: The study was laid out as randomized complete block design (RCBD) in split pot arrangement for two seasons in the greenhouse. Place and Duration of Study: The experiment wa...

Aims: The aim of this study was to characterize bacteria isolated from circulating Kenyan banknotes and also antibiotic susceptibility profiles within Nyeri County. Study Design: This was a cross-sectional study and simple random sampling was used to collect 25 of each paper currency denomination. Place and Duration of Study: Samples analyses were...

The popularity of using the Inorganic and organic soil amendments is based on the current status of soil degradation that led to decline in fertility of soils, resulting to low yields. The objective of current study was to evalute different organic and inorganic soil amendments and their effects on soil pH and macronutrients. The study was laid out...

Purpose Traditional methods of composting are limited in timely production of good-quality compost due to recalcitrant nature of materials of plant origin. This study focused on evaluating the use chicken and donkey manure as starter cultures to biostimulate bioconversion of rice straw into bioorganic fertilizer. Use of starter cultures would enhan...

A study was carried out to hasten maturity, improve nutrient content and determine agronomic performance of water hyacinth-based composts. Water hyacinth (WH) was composted using pile method and six treatments: WH + cattle manure (WH+CM), WH + poultry manure (WH+PM), WH + effective microorganisms, WH + molasses at 25% total sugar content, WH + mola...

Biological nitrogen fixation (BNF) in legumes plays a critical role in improving soil fertility. Despite this vital role, there is limited information on the genetic diversity and BNF of bacteria nodulating common bean (Phaseolus vulgaris L.). This study evaluated the genetic diversity and symbiotic nitrogen fixation of bacteria nodulating common b...

Arbuscular mycorrhizal fungi (AMF) and rhizobia associate with majority of agricultural crops conferring their hosts with nutritional and protective benefits in exchange for photosynthetic carbohydrates. Although the potential of AMF and rhizobia to improve crop production and quality has been demonstrated in many parts of the world, their utilizat...

Within the rhizospheric soil, rhizobia frequently encounter various abiotic stresses that affect their growth, initial steps of symbiosis with legumes, and their capacity of nitrogen fixation. In sub-Saharan Africa (SSA), acidic soils that characterize many agroecosystems are a major impediment to biological nitrogen fixation. Moreover, this is exa...

Because water hyacinth-based compost contains substantial amounts of nitrogen (N), phosphorus (P) and potassium (K) its application can boost crop production. We evaluated the agronomic performance of water hyacinth-based composts using field experiments and five treatments which were; water hyacinth compost made using cattle manure (WH+CM), poultr...

Rhizobia inoculants are soil bacteria that promote biological nitrogen fixation (BNF). Understanding of rhizobia-host genotype association is a critical step in enhancing legume productivity. Questionnaires were used to identify the common bean varieties cultivated in Eastern Kenya. The native rhizobia were isolated from the root nodules of MAC 13...

Depletion of soil nutrients due to continuous cultivation without adequate external fertilization is one of the challenges facing many smallholder farmers in western Kenya. This study was conducted to assess the effects of organic (water hyacinth compost), inorganic (urea) nitrogen (N) sources, and commercial Rhizobia inoculant on the yield of comm...

The increasing interest in the use of rhizobia as biofertilizers in smallholder agricultural farming systems of the Sub-Saharan Africa has prompted the identification of a large number of tropical rhizobia strains and led to studies on their diversity. Inoculants containing diverse strains of rhizobia have been developed for use as biofertilizers t...

Linner CS, Birgen JK, Maingi J. 2017. In vitro response of Phomopsis theae to the products of Azadirachta indica and extracts of Warburgia ugandensis. Bioteknologi 14: 37-46. This study was done to determine the use of plant products and extracts to manage the disease. Among the products used were Nimbecidine and Trilogy which are products of neem...

Climbing bean (Phaseolus vulgaris L.) production in Kenya is greatly undermined by low soil fertility, especially in agriculturally prolific areas. The use of effective native rhizobia inoculants to promote nitrogen fixation could be beneficial in climbing bean production. In this study, we carried out greenhouse and field experiments to evaluate s...

Background:This study aimed at determining the prevalence of bacterial agents causing upper respiratory tract infections and their susceptibility patterns to commonly used antibiotics among outpatients in Kitui District Hospital. Methods: A total of 237 throat swabs were collected between November, 2012 to April, 2013 and innoculated onto Blood aga...

Background: With the increasing world population, there is increasing demand for food. This has led to overuse of agricultural farms causing reduced soil fertility and accumulation of phytopathogens. Inorganic fertilizers and pesticides have been extensively used in response to these challenges. Extensive integration of inorganic fertilizers and pe...

Climbing bean (Phaseolus vulgaris L.) production in Kenya is greatly undermined by low soil fertility, especially in agriculturally prolific areas. The use of effective native rhizobia inoculants to promote nitrogen fixation could be beneficial in climbing bean production. In this study, we carried out greenhouse and field experiments to evaluate s...

The bacterial family Enterobacteriaceae and fungal genus Candida have continued to be a great challenge worldwide including resistance to antibiotics and relapse of infections mediated by them. Among these organisms, Salmonella typhi, Shigella species, Klebsiella pneumoniae and Escherichia coli strains have emerged as the most frequent cause of dia...

Background Globally, there is great concern about expanding agricultural activities due to their impact in the conservation of agrobiodiversity. African continent is known for its richness in biodiversity. In Kenya, there is a continuous unabated expansion of agriculture into natural habitats due to demographic and economic pressures posing a signi...

Rhizobia inoculants are soil bacteria that promote biological nitrogen fixation (BNF). Understanding of rhizobia-host genotype association is a critical step in enhancing legume productivity. Questionnaires were used to identify the common bean varieties cultivated in Eastern Kenya. The native rhizobia were isolated from the root nodules of MAC 13...