@unilorin.edu.ng
Professor, Faculty of Life Sciences
Dean, Faculty of Life Sciences
University of Ilorin
Professor in the Department of Microbiology, University of Ilorin, Nigeria. Dean, Faculty of Life Sciences 2022- to date
Ph.D. (Ilorin) Microbiology 1992
Agricultural and Biological Sciences, Food Science, Biotechnology, Applied Microbiology and Biotechnology
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
El-Imam Amina Ahmed, Mardhiyah A. Sanusi, Eromosele Ighalo, Mushafau A. Oke, and Patricia F. Omojasola
World Researchers Associations
Microbial fermentation of lignocellulosic biomass into lactic acid (LA) has received considerable attention because it ensures the valorisation of wastes and reduces dependence on fossil sources. First, the proximate and phytochemical compositions of Prosopis africana pods (PAP) were determined. Previous biologically-pretreated pods of Prosopis africana were then saccharified using dilute acid hydrolysis following a full factorial design. The factors optimized were acid type (HCl and H2SO4), acid concentration (1 %, 3 % and 5 %), solid loading ratio (5 %, 10 % and 20 %) and reaction time (15, 30 and 60 minutes). Several Rhizopus oryzae isolates were screened for LA production and the most prolific was molecularly identified. The factors affecting LA yield from PAP hydrolysate were screened using a half-factorial design. The significant factors were then optimised using Box-Behnken Design of Response Surface Methodology (RSM). The proximate analysis showed high levels of protein, lipid, ash and carbohydrates. The phytochemical analysis of PAP revealed the presence of flavonoids, alkaloids, saponins, phenols, tannins, glycosides and terpenoids. The hydrolysis conditions of 3 % HCl, 20 % solid loading and 15 minutes hydrolysis time yielded the highest reducing sugars of 42.5 g/L. The most promising isolate, identified as R. oryzae strain AK-22, produced 19.7 g/L after RSM optimization, a 38.1 % increase over yields from non-optimised conditions. These findings are on the biotechnological production of LA from the pods of Prosopis africana, an abundant yet under-utilised tree crop.
J. A. Amao, P. F. Omojasola, A. A. Ayandele, and A. G. Adewoyin
Allerton Press
John Ayobami Amao, Madhumita Barooah, and Patricia Folakemi Omojasola
Springer Science and Business Media LLC
John Ayobami AMAO, Patricia Folakemi Omojasola, and Madhumita Barooah
Elsevier BV
C. O. Oladoye, I. F. Connerton, R. M. O. Kayode, P. F. Omojasola, and I. B. Kayode
Zhejiang University Press
Microbial attacks during storage are one of the primary causes of product deterioration, and can limit the process of prolonging the shelf-life of harvested food. In this study, sweet potatoes were stored at temperatures of 13, 21, and 29 °C for 4 weeks. Samples were collected during storage and plated on potato dextrose agar, from which axenic mold cultures were obtained and identified using 26S rRNA gene sequences. Physiological changes of potato tubers were assessed with respect to pathogenicity, enzyme activity, and atmospheric storage conditions. Six fungal species were identified, namely Penicillium chrysogenum (P. rubens), P. brevicompactum, Mucor circinelloides, Cladosporium cladosporiodes, P. expansum, and P. crustosum. The following fungal isolates, namely P. expansum, P. brevicompactum, and Rhizopus oryzae, were recovered from the re-infected samples and selected according to their levels of enzyme activity. This study revealed high levels of activity for cellulase and pectinase, which were most notable during the initial three days of testing, and were followed by a steady decrease (P<0.05). Polygalacturonase activity was prominent with values ranging from 12.64 to 56.79 U/mg (P. expansum) and 18.36 to 79.01 U/mg (P. brevicompactum). Spoilage was obvious in the control group, which had a 100% decay at the end of the experimental period compared with samples treated with iprodione and sodium hypochlorite, in which the decay rates were 5% and 55%, respectively. The data for the iprodione- and sodium hypochlorite-treated samples at the end of the 3-month storage period showed that they were significantly different (P=0.041), with the sodium hypochlorite-treated samples producing twice the rate of infection compared to the iprodione-treated samples. The comparative rate of the progression of decay in the treated samples can be expressed as iprodione<sodium hypochlorite<control. This study demonstrates that sweet potato tissue damage is due to the activities of microbial enzymes and, in particular, the pectinases of the organisms isolated from the infected potato tissues, and suggests the advantages of utilizing iprodione as a curing agent for potato tubers before storage.
Joshua A. Obaleye, Adedibu C. Tella, Wahab A. Osunniran, Nzikahyel Simon, and Patricia F. Omojasola
Springer Science and Business Media LLC
P.F. Omojasola and O.P. Jilani
Science Alert
The wastes materials from the sweet orange (Citrus sinensis) were used as substrate for the production of cellulase. The rind, the pericarp or albedo and the pulp were hydrolyzed by cellulolytic enzymes of Trichoderma longibrachiatum, Aspergillus niger and Saccharomyces cerevisiae after they were treated with alkali and steam. The amount of glucose released from the substrates following the secretion of cellulase by the three microorganisms was measured. The orange wastes released amounts of glucose ranging from 0.76-0.96 mg mL(-1) by Trichoderma longibrachiatum, 0.90-1.08 mg mL(-1) by A. niger and 0.60-0.76 mg mL(-1) by S. cerevisiae after five days of fermentation. The conditions of the fermentation were then varied to determine their effect on cellulase production. Fermentation parameters varied were time, pH, substrate concentration, temperature and inoculum size. After this, conditions that produced highest amounts of glucose were combined in an optimization experiment. Glucose production under optimized conditions were 0.94 mg mL(-1) by T. longibrachiatum, 0.83 mg mL(-1) by A. niger and 0.67 mg mL(-1) by S. cerevisae. The activity of the test organisms' cellulase against CMC on the orange wastes was also determined with T. longibrachiatum producing 3.86 mg mL(-1), A. niger 2.94 mg mL(-1) and S. cerevisiae 2.30 mg mL(-1) glucose amounts all from orange pulp.