Browsing by Author "Awotundun, Theresa Abimbola"
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Item Microbial gamma-aminobutyric acid synthesis: a promising approach for functional food and pharmaceutical applications(Letters in Applied Microbiology, 2024) Fashogbon, Racheal Oluwayemisi; Samson, Oyindamola John; Awotundun, Theresa Abimbola; Olanbiwoninu, Afolake Atinuke; Adebayo-Tayo, Bukola ChristianaGamma-aminobutyric acid (GABA) is a non-protein amino acid that is a main inhibitory neurotransmitter in the mammalian central nervous system. This mini-review emphasis on the microbial production of GABA and its potential benefits in various applications. Numerous microorganisms, including lactic acid bacteria, have been identified as efficient GABA producers. These microbes utilize glutamate decarboxylase enzymes to convert L-glutamate to GABA. Notable GABA-producing strains include Lactobacillus brevis, Lactobacillus plantarum, and certain Bifidobacterium species. Microbial GABA production offers numerous benefits over chemical synthesis, including cost-effectiveness, sustainability, and the potential for in situ production in fermented foods. Recent research has optimized fermentation conditions, genetic engineering approaches, and substrate utilization to enhance GABA yields. The benefits of GABA extend beyond its neurotransmitter role. Studies have shown its potential to reduce blood pressure, assuage anxiety, improve sleep quality, and improve cognitive function. These properties make microbial GABA production particularly attractive for developing functional foods, nutraceuticals, and pharmaceuticals. Future research directions include exploring novel GABA-producing strains, improving production efficiency, and investigating additional health benefits of microbially produced GABA.Item Mycological Assessment of Some Selected Fruits and Vegetables and Their Resistance Profile Against Some Antifungal Agents(2025) Olanbiwoninu, Afolake Atinuke; Awotundun, Theresa Abimbola; Olayiwola, John Olusola; Fashogbon, Racheal OluwayemisiFruits and vegetables offer distinct nutritional benefits and health-enhancing properties, driving their growing popularity. This research aimed to evaluate the mycological characteristics and investigate the antifungal resistance patterns of pathogens from selected fruits and vegetables. Samples, including watermelon, tomato, cucumber, and garden egg, were obtained from fruit markets and home gardens. They were subjected to microbiological analysis using standard procedures. The isolates were examined to determine their ability to cause disease, contribute to spoilage, and produce aflatoxins. Isolated pathogens were further subjected to antifungal sensitivity testing using the agar well diffusion method with three (3) antifungal agents. A total of eighteen (18) fungi were isolated from the genera Aspergillus (33.3 %), Candida (11.1 %), Cladosporium (5.6 %), Fusarium (5.6 %), Geotrichum (11.1 %), Penicillium (5.6 %), Pichia (16.6 %) and Saccharomyces (11.1 %). Isolates with haemolytic potential were 7, while 11 had spoilage potential, and 12 were pathogenic. Of the 12 pathogenic fungi, 9 (75%) were resistant to at least one antifungal agent while 3 (25%) showed no resistivity; however, among the Aspergillus spp., 5 (83%) were aflatoxigenic. The overall mycological quality of the analysed samples is low, improved hygienic practices should be encouraged among farmers, fruit and vegetable handlers and consumers.Item Polyphasic characterisation of Bacillus subtilis strains for iru fermentation and vitamin bioenrichment(2026) Awotundun, Theresa Abimbola; Greppi, Anna; Pugin, Benoit; Plüss, Serafina; Odunfa, Sunday Ayodele; Russo, Pasquale; Bokulich, Nicholas A; Olanbiwoninu, Afolake AtinukeBacillus subtilis plays a key role in traditional plant fermentations in Africa and Asia. Here, we characterised B. subtilis strains isolated from iru, a fermented condiment from Nigeria, and evaluated their potential as riboflavin- and folate-producers. Eighty-six Bacillus spp. were isolated through heat treatment and spore plating on nutrient agar. The isolates were phenotypically identified, assessed for enzymatic activity (proteases, amylases), and tested for safety (haemolysis, gelatinase, and biogenic amine production). Selected isolates were further screened for riboflavin and folate production in chemically defined media. Thirty-four strains were phenotypically identified as B. subtilis with riboflavin production ranging from 0.006 to 0.039 mg L−1, while nine produced folate between 0.300 and 1.940 mg L−1. These strains were submitted to the selective pressure of toxic analogues of riboflavin and folate in order to enhance their capability to synthesise these vitamins, with the best strain showing increases from 0.013 to 0.020 mg L−1 for riboflavin and 1.665 to 3.715 mg L−1 for folate. The most promising candidates were employed for lab-scale iru fermentation. In lab-scale iru fermentation using the improved strains, vitamin levels were enhanced by 38% for riboflavin (0.036 to 0.050 mg g−1 of iru) and 35% for folate (0.035 to 0.047 mg g−1 of iru), signifying that 10 g of iru fermented with these strains can provide 25% of daily riboflavin intake and 100% of folate intake. These results highlight the potential of selected B. subtilis strains as functional starter cultures for the dual purpose of iru fermentation and vitamin biofortification. Such strain selection and optimisation represent a promising biotechnological strategy to enhance the micronutrient profile of traditional fermented foods while preserving their sensory and cultural value.Item Pre- and post-storage evaluation of nutritional profiles and aflatoxin contamination in maize, millet, and wheat in Oyo town(Food Safety and Risk, 2026) Araoye, Martina Ivie; Awotundun, Theresa Abimbola; Oladipo, Iyabo Christianah; Olanbiwoninu, Afolake AtinukeCereal grains such as maize (Zea mays), millet (Pennisetum glaucum), and wheat (Triticum aestivum) are essential dietary staples in Nigeria, yet their nutritional quality and safety are often compromised by traditional storage practices. This study examined the impact of traditional storage on the nutritional quality and aflatoxin contamination of maize, millet, and wheat in Nigeria. Thirty grain samples (10 each) were collected, with one portion of each sample analysed immediately and the other stored for 7–8 months under traditional conditions. Proximate composition (protein, fat, ash, fibre, carbohydrate) and total aflatoxin levels were quantified using HPLC. Nutritional composition varied significantly (p < 0.05) between pre- and post-stored samples across all grains. Carbohydrate and protein contents generally declined after storage, while crude fibre and moisture showed variable trends. In maize, total aflatoxin content rose from 54.61 to 93.54 µg/kg pre-storage to 82.79–101.50 µg/kg post-storage. Millet ranged from 65.13 to 76.79 µg/kg to 81.89–99.24 µg/kg, while wheat increased from 56.22 to 58.20 µg/kg to 84.74–108.30 µg/kg. Aflatoxin B1 was the predominant toxin in all samples. These findings highlight the deterioration of nutritional quality and increased food safety risks in stored cereals, emphasising the need for improved storage systems, regular monitoring, and strict regulatory measures to safeguard consumer health.Item Viruses That Heal: Harnessing Bacteriophages in the Era of Antibiotic Resistance(Problems of Virology, 2026) Awotundun, Theresa Abimbola; Samson, Oyindamola John; Olanbiwoninu, Afolake AtinukeThe global rise in antimicrobial resistance (AMR) poses an urgent threat to public health, and novel alternatives to traditional antibiotics are needed. One of the most promising options is bacteriophages, viruses that infect and destroy bacteria. Once overshadowed by the discovery of antibiotics, phage therapy is now regaining attention, driven by advances in genomics, synthetic biology, and targeted medicine. This review examines the biology, diversity, and therapeutic use of bacteriophages in treating bacterial infections, especially those caused by multidrug-resistant pathogens. It also discusses how phages act through natural mechanisms, such as lytic enzymes (holins, endolysins, and muralysins), and highlights new genetic engineering techniques, such as CRISPR-Cas systems, phage recombineering, and synthetic genome reboots. In addition to clinical applications, we evaluate phages as biocontrol agents for food safety, environmental sanitation, and biofilm management. Additionally, the article explores key issues in phage therapy, including regulatory frameworks, formulation stability, dynamics of phage-host resistance, and the importance of rapid diagnosis. When properly integrated into modern health and biotechnology practices, bacteriophages offer significant potential and a sustainable solution to the global challenge of antimicrobial resistance.