Dr. Billy A Makumba | Moi University (original) (raw)

Uploads

Papers by Dr. Billy A Makumba

American Journal of Microbiological Research, 2019

Net-blotch and scald are important foliar diseases of barley. In the present study, the biocontro... more Net-blotch and scald are important foliar diseases of barley. In the present study, the biocontrol activity of Paenibacillus polymyxa KaI245 was evaluated against Drechsclera teres f. sp teres and Rhynchosporium commune causing net-form-net-blotch and scald respectively. In-vitro efficacy of the bacterial isolate entailed dual culture technique, use of cell-free supernatant and test for volatile-compounds-mediated inhibition. Greenhouse studies were further conducted to evaluate the efficacy of crude bacterial extracts against net-blotch pathogen in barley plants. In dual culture technique, the mycelial growth of D. teres f. sp teres was impeded by approximately 47.3% while there was no any observable effect in R. commune colonies. Food-poison technique was u sed to test the antifungal activity of cell-free supernatant. The cell free supernatant inhibited the growth of D. teres by approximately 24.1%. R. commune colonies were impeded by 52.9% via volatile organic compounds while D. ...

CRC Press eBooks, May 5, 2022

Journal of Advances in Microbiology, 2019

University of Eldoret, 2016

Frontiers in Plant Science

Recent decades have witnessed increased agricultural production to match the global demand for fo... more Recent decades have witnessed increased agricultural production to match the global demand for food fueled by population increase. Conventional agricultural practices are heavily reliant on artificial fertilizers that have numerous human and environmental health effects. Cognizant of this, sustainability researchers and environmentalists have increased their focus on other crop fertilization mechanisms. Biofertilizers are microbial formulations constituted of indigenous plant growth-promoting rhizobacteria (PGPR) that directly or indirectly promote plant growth through the solubilization of soil nutrients, and the production of plant growth-stimulating hormones and iron-sequestering metabolites called siderophores. Biofertilizers have continually been studied, recommended, and even successfully adopted for the production of many crops in the world. These microbial products hold massive potential as sustainable crop production tools, especially in the wake of climate change that is p...

Agriculture, 2022

Biofertilizer technology continues to be derailed by the short shelf life of inoculants. The pres... more Biofertilizer technology continues to be derailed by the short shelf life of inoculants. The present study investigated the suitability of wheat-bran (WB), rice-husks (RH), farmyard-manure (FYM), bagasse (BG), and sawdust (SD) in the formulation of potato-derived Klebsiella grimontii (MPUS7), Serratia marcescens (NGAS9), and Citrobacter freundii (LUTT5) under refrigerated (8 °C) and room (25 ± 2 °C) storage. The physicochemical properties of the materials were assessed before sterilization and introduction of the inoculants and assessment of their viability for 8 months. Most of the physicochemical properties of the materials varied significantly (p < 0.05). Bagasse supported the maximum growth of MPUS7 (5.331 log CFU g−1) under refrigeration and LUTT5 (4.094 log CFU g−1) under both conditions. Under room storage, the maximum growth of MPUS7 (3.721 log CFU g−1) occurred in WB. Formulations that remained viable under room storage can easily be integrated into existing agricultural...

Potato Research, 2019

Potato (Solanum tuberosum L.) is one of the most important food crops worldwide but its cultivati... more Potato (Solanum tuberosum L.) is one of the most important food crops worldwide but its cultivation is affected by numerous challenges including pests, diseases and high fertiliser requirements which have associated environmental problems. The exploitation of plant rhizospheres and their associated rhizobacterial interactions has gathered momentum worldwide in search of environmentally-friendly approaches to crop cultivation. A lot of literature exists on rhizobacterial associations and their biofertilisation or bioprotection roles in many plants. However, very scanty information is available on rhizobacterial functions and communities of the potato, an indication that they are still understudied. In this regard, more research is needed to understand and exploit them for the successful application of rhizobacteria-based technology in potato cropping. This review updates our knowledge of the beneficial rhizobacteria of the potato and documents their roles in its bioprotection, phytostimulation and biofertilisation while highlighting their potential in enhancing its production and productivity. The future prospects regarding the research on these important potato microflora are further discussed as a guide and a baseline for future research on them. This review shows that rhizobacteria-based technology is a viable option for potato biofertilisation and bioprotection and could be the missing link in its sustainable cropping. The adoption and full exploitation of this technology can be fast-tracked if we increase our understanding of the subject matter.

Microbiological Research, 2018

Conventional agricultural practices often rely on synthetic fertilizers and pesticides which have... more Conventional agricultural practices often rely on synthetic fertilizers and pesticides which have immense and adverse effects on humans, animals and environments. To minimize these effects, scientists world over are now deeply engaged in finding alternative approached for crop production which are less dependent on chemical inputs. One such approach is the use of rhizospheric bacteria as vital components of soil fertility and plant growth promotion (PGP) through their direct and indirect processes in plant rhizospheres. Among the most studied rhizobacteria are the Bacilli, particularly for production of antibiotics, enzymes and siderophores all of which are important aspects of PGP. Despite this, little information is available especially on their potentiality in crop production and their direct application only involves a few species, leaving a majority of these important rhizobacteria exploited. This paper gives an overview of the unique properties of Bacilli rhizobacteria as well as their different PGP mechanisms that if mined can lead to their successful application and agricultural sustainability. It further points out the missing aspects with regards to these important rhizobacteria that should be considered for future research. This information will be useful in analyzing the PGP abilities of Bacilli rhizobacteria with an aim of fully mining their potential for crop production and environmental sustainability.

Plant and Soil, 2015

Background and aim Fungal endophytes are commonly associated with plants, and are considered an i... more Background and aim Fungal endophytes are commonly associated with plants, and are considered an important component of crop production. They can influence plant growth and tolerance to biotic and abiotic stresses. The aim of this study was to analyse and identify endophytic fungi associated with rice roots in irrigated and upland ecosystems in Kenya, as an inventory for a future search for biological control and growth promoting agents. Methods Fungi were isolated from the roots and selected based on culture characteristics. All selected isolates were sequenced using primers targeting the internal transcribed spacer (ITS) region, intergenic spacer (IGS) region and the gene encoding the translation elongation factor (TEF-1α). The species were determined by comparing their sequences with those of well characterised or type strains. Phylogenetic relationships among the species were used to identify their taxonomic groups, and distribution in the agroecosystems, especially for the Fusarium spp. Results Based on sequencing of the ITS region, 75 fungal isolates were identified as Fusarium-like, while the remaining 98 isolates were found to belong to different species representing other genera than Fusarium. A further analysis of the Fusarium spp., using concatenated IGS and TEF-1α sequences showed that these isolates belong to the Fusarium oxysporum (FOSC) and Gibberella fujikuroi (GFSC) species complexes. Within the FOSC isolates, a clear divergence was observed between isolates from irrigated and upland ecosystems, while in the GFSC this phenomenon was not observed. When the total number of species was considered, 27 species were identified in the irrigated ecosystems, while only 18 species were found in the upland ecosystems. Conclusions More fungal species were found in the irrigated ecosystems than in the upland ecosystems. We propose that flooding may affect the assembly of endophytic fungi in rice roots, however, other factors such as rice cultivars, geographical locations and soil types could also be important.

Agriculture & Food Security, 2021

Agricultural intensification continues in Africa in attempts to meet the rising food demands of t... more Agricultural intensification continues in Africa in attempts to meet the rising food demands of the equally rising population. However, most arable lands in the region are characterized by nutrient deficiency and over-reliance on synthetic fertilizers which consequently contributes to increased production costs, environmental pollution, and global warming. Decades of research on plant–rhizobacterial interactions have led to the formulation and commercialization of rhizobacterial biofertilizers globally for sustainable soil and crop health. Nevertheless, this promising technology has not received much attention in Africa and remains largely unexplored due to several constraints. This article discusses the practical applications of rhizobacterial biofertilizers for sustainable crop production in sub-Saharan Africa. The challenges of soil infertility and the use of conventional synthetic fertilizers in crop production in Africa are critically evaluated. An overview of the potential of ...

Endophytes: Mineral Nutrient Management, Volume 3

Microbiology Resource Announcements

We present here the complete genome sequences of plant growth-promoting Klebsiella sp. strain MPU... more We present here the complete genome sequences of plant growth-promoting Klebsiella sp. strain MPUS7, Serratia sp. strain NGAS9, and Citrobacter sp. strain LUTT5, isolated from rhizosphere soils and tubers of potato (Solanum tuberosum L.) plants growing in the northern and southern highlands of Tanzania.

The world’s population is increasing and so are agricultural activities to match the growing dema... more The world’s population is increasing and so are agricultural activities to match the growing demand for food. Conventional agricultural practices generally employ artificial fertilizers to increase crop yields, but these have multiple environmental and human health effects. For decades, environmentalists and sustainability researchers have focused on alternative crop fertilization mechanisms to address these challenges, and biofertilizers have constantly been researched, recommended, and even successfully-adopted for several crops. Biofertilizers are microbial formulations made of indigenous plant growth-promoting rhizobacteria (PGPR) which can naturally improve plant growth either directly or indirectly, through the production of phytohormones, solubilization of soil nutrients, and production of iron-binding metabolites; siderophores. Biofertilizers, therefore, hold immense potential as tools for sustainable crop production especially in the wake of climate change and global warmin...

African Handbook of Climate Change Adaptation

The global rise in human population has led to the intensification of agricultural activities to ... more The global rise in human population has led to the intensification of agricultural activities to meet the ever-rising food demand. The potato (Solanum tuberosum L.) is a crop with the potential to tackle food security issues in developing countries due to its short growth cycle and high nutrient value. However, its cultivation is heavily dependent on artificial fertilizers for yield maximization which culminates in global warming and other environmental problems. There is need, therefore, for its alternative fertilization technologies to mitigate climate change. This study evaluated the potential of indigenous rhizobacteria for potato cropping in Tanzania. Ten potato rhizobacterial isolates belonging to Enterobacter, Klebsiella, Citrobacter, Serratia, and Enterobacter genera were obtained from a previous collection from different agro-ecological areas in Tanzania. The isolates were characterized culturally, microscopically, biochemically, and by their carbohydrate utilization patter...