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  • Area of Specialization: Molecular Biotechnology
  • Department of Biochemistry

  • Studies associating fungi with cassava have focused on postharvest processing techniques to increase the protein content and quality of ready-to-eat cassava products as well as to decrease their cyanide contents. There are a number of biotechnological industries in which fungi associated with cassava spoilage can be used for cassava digestion to release glucose. These include sugar and glucose industries, bread and alcohol industry, detergent, building product and feed industries. We have isolated and identified amylase from Aspergillus species growing on cassava products that will have useful applications in food, detergent, paper, textile, and pharmaceutical industries, where microbial a-amylases would be required for efficient and cost-effective hydrolysis of cassava starch, cassava flour and or its products. We are currently characterizating of solid state fermented cassava (Manihot esculanta Crentz) using Rhizopus oligophorus and and applying it in poultry feed production. Our results have shown that solid state fermentation can reduce and eliminate the cyanide, increase the protein content and improve the digestibility of cassava. Solid state fermented cassava can wholly replace maize (Zea mays) in broiler starter feed with a view of having a cost-effective yet nutritious and health friendly ration. My group is also involved in medicinal plants research. In addition to characterizing various medicinal plants, we are currently focused on the determination of the genetic relatedness, antioxidant activities and antigenotoxic properties of bitter leaf (Vernonia amygdalina) collected from the different geographical locations in Nigeria. We have isolated, characterize and compared the Rubisco gene DNA sequence present in the V. amygdalina collection using various bioinformatics software. Detailed determination of the antioxidant activities and antigenotoxic properties of the V. amygdalina collection using Allium cepa is ongoing. Nyerhovwo John Tonukari obtained his Ph.D. in Biochemistry, in 2000 from the Michigan State University, East Lansing, Michigan, USA. He was also trained in protein analysis at the University di Napoli, Italy in 1992 and in DNA sequencing at the Washington University, St. Louis, MO, USA in 1994. He is a recipient of the Thoman Fellowship (USA) (1999 – 2000) and the Rockefeller Foundation Fellowship (USA) (May – October 1994). He obtained his B.Sc. in Biochemistry (First Class Honours) from the University of Maiduguri, Nigeria in 1987 and M.Sc. from the University of Ibadan also in Nigeria in 1990. Prof. Tonukari is the immediate past Dean of Science (2020 to 2022), Delta State University, Abraka, Nigeria. Some of the other numerous positions he has occupied include: Head, Department of Biochemistry, Delta State University, Editor, African Journal of Biotechnology (2002 to present), Acting Director, ICT, Delta State University, Abraka (2010), Acting Director, Pre-Degree Programme, Delta State University, Abraka (2007 to 2010), Associate Scientist (Molecular Biology), East Coast Fever Vaccine Project, International Livestock Research Institute (ILRI), Nairobi, Kenya (2002 to 2004), Fungal Molecular Biologist (Strain improvement), James R. Randle Research Center, Archer Daniels Midland Co, Decatur, IL 62521, USA (October 2000 – 2002), and Research Associate, Biotechnology Unit, International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria September 1991 to 1995. Nyerhovwo Tonukari founded Academic Journals in 2002 to enable African scholars have access to high quality peer reviewed articles, and also to enable researchers across the globe have access to articles published by Africans researchers without any form of restriction. Prof. Tonukari have been a strong proponent of scientific journals adopting the open access model especially as this model of publication is the most effective way to distribute research output, bridge the information gap between developing and advanced countries and help improve research productivity worldwide. He has encouraged and assisted several African journals to adopt the open access publishing model. He is also Chairman of Tonukari Biotechnology Company, and has several publications and two patents to his credit. Prof. Tonukari is a member of the Nigerian Society of Biochemistry and Molecular Biology, Biotechnology Society of Nigeria, International Society of African Biotechnologists and Bioscientists, and the Sapele Chamber of Commerce and Industry.
    My Publications
  1. Avwioroko, O. J., Anigboro, A. A., Ejoh, A. S., Atanu, F. O., Okeke, M. A., & Tonukari, N. J. (2019) Characterization of a-amylases isolated from Cyperus esculentus seeds (tigernut): Biochemical features, kinetics and thermal inactivation thermodynamics. , Biocatalysis and Agricultural Biotechnology Vol.21 Pages: 101298

  2. Apiamu, A., Asagba, S. O., & Tonukari, N. J. (2019) Role of Anthocleista vogelii in serum antioxidant defence system in cadmium-induced oxidative stress in Wistar rats., Beni-Suef University Journal of Basic and Applied Sciences Vol.8 Pages: 12

  3. Orororo, O. C., Asagba, S. O., Tonukari, N. J., Okandeji, O. J., & Mbanugo, J. J. (2018) Cadmium-Induced Testicular Damage in Wistar Rats: Protective Effects of Hibiscus sabdariffa L. Anthocyanins, International Journal of Biochemistry Research & Review Vol. Pages: 1-8

  4. Orororo, O. C., Asagba, S. O., Tonukari, N. J., Okandeji, O. J., & Mbanugo, J. J. (2018) Comparative Assessment of the Antioxidant Properties of Hibiscus sabdarrifa L Anthocyanins and its Aqueous Extract in Cadmium exposed Rats, Research Journal of Pharmaceutical, Biological and Chemical Sciences Vol.9 Pages: 836 - 843

  5. Orororo, O. C., Asagba, S. O., Tonukari, N. J., Okandeji, O. J., & Mbanugo, J. J. (2018) Hibiscus Sabdarrifa L. Anthocyanins-Induced Changes in Reproductive Hormones of Cadmium-Exposed Rats, International Journal of Scientific and Research Publications Vol.8 Pages: 308 - 311

  6. Avwioroko, O. J., Anigboro, A. A., Unachukwu, N. N., & Tonukari, N. J. (2018) Isolation, identification and in silico analysis of alpha-amylase gene of Aspergillus niger strain CSA35 obtained from cassava undergoing spoilage, Biochemistry and biophysics reports Vol.14 Pages: 35-42

  7. Orororo, O. C., Asagba, S. O., Tonukari, N. J., Okandeji, O. J., & Mbanugo, J. J. (2018) Effects of Hibiscus Sabdarrifa L. anthocyanins on cadmium-induced oxidative stress in Wistar rats, Journal of Applied Sciences and Environmental Management Vol.22 Pages: 465-470

  8. Apiamu, A., Asagba, S. O., & Tonukari, N. J. (2018) Reporting the toxicological profile of methanolic leaf extract of Anthocleista vogelii Planch on Wistar rats, Journal of Applied Sciences and Environmental Management Vol.22 Pages: 887-894

  9. Anigboro, A. A., Avwioroko, O. J., & Tonukari, N. J. (2018) Brillantasia patula aqueous Leaf Extract Averts Hyperglycermia, Lipid Peroxidation, and Alterations in Hematological Parameters in Alloxan-Induced Diabetic Rats, International Journal of Biomedical Science and Engineering Vol.6 Pages: 43

  10. Aganbi, E., Onyeukwu, B. O., Avwioroko, J. O., & Tonukari, J. N. (2017) Effect of fermentation on sensory, nutritional and antioxidant properties of mixtures of aqueous extracts of Hibiscus sabdariffa (Zobo) and Raphia hookeri (Raffia) wine, Nig. J. Sci. Environ Vol.15 Pages: 66-74

  11. Orororo, O. C., Tonukari, N. J., Avwioroko, O. J., & Ezedom, T. (2017) Effect of Supplementation of Animal Feed with Dried Cassava (Manihot esculenta) Peels, and Stems of Vernonia amydalina and Pennisetum purpereum on Some Biochemical Parameters in Pigs, NISEB Journal Vol.14 Pages: 177-183

  12. Tonukari, N.J., Oliseneku, E.E., Avwioroko, O.J., Aganbi, E., Orororo, O.C. and Anigboro, A.A. (2016) A novel pig feed formulation containing Aspergillus niger CSA35 pretreated-cassava peels and its effect on growth and selected biochemical parameters of pigs, African Journal of Biotechnology Vol.15 Pages: 776-785

  13. Avwioroko, O.J., Anigboro, A.A. and Tonukari, N.J. (2016) Biotechnological application of cassava-degrading fungal (CDF) amylase in broiler feed formulation, Br. Biotechnol. J Vol.10 Pages: 1-12

  14. N. J. Tonukari, O. J. Avwioroko, and A. A. Anigboro (2015) Effect of preservation on the chlorophyll content, phytochemicals, and antioxidant capacity of two different varieties of pumpkin (Telfairia occidentalis) leaves, Nigerian Journal of Technological Research Vol.10 Pages: 9-16

  15. N. J. Tonukari, T. Ezedom, C.C. Enuma, S. O. Sakpa, O. J. Avwioroko, L. Eraga, and E. Odiyoma (2015) White Gold: Cassava as an Industrial Base, American Journal of Plant Sciences Vol.6 Pages: 972-979

  16. N. J. Tonukari, O. J. Avwioroko, T. Ezedom, and A. A. Anigboro (2015) Effect of preservation on two different varieties of Vernonia amygdalina Del. (bitter) leaves, Food and Nutrition Sciences Vol.6 Pages: 633-642

  17. O. J. Avwioroko, N. J. Tonukari, and S. O. Asagba (2015) Biochemical characterization of crude a-amylase of Aspergillus spp. associated with the spoilage of cassava (Manihot esculenta) tubers and processed products in Nigeria, Advances in Biochemistry Vol.3 Pages: 15-23

  18. Anigboro A.A., Onakurhefe P., Tonukari N.J., Avwioroko O.J. and Egbeme E. (2014) Quantitative determination of some phytochemicals (phenol, flavonoid, saponin and alkaloid) in twenty-two Nigerian medicinal plants, Nigerian Journal of Science and Environment Vol.13 Pages: 86 - 93

  19. N. J. Tonukari, O. J. Avwioroko, T. Ezedom, U. Edema, L. Eraga and A. A. Anigboro (2014) Growth of Raphia farinifera and Elaeis guineensis Wine Yeast on Cassava (Manihot esculenta) and Poultry Manure Media, Nigerian Society for Experimental Biology Journal Vol.14 Pages: 118 - 123

  20. O. J. Avwioroko and N. J. Tonukari (2014) Isolation and molecular identification of Aspergillus species associated with the spoilage of cassava in Nigeria, Nigerian Journal of Science and Environment Vol.13 Pages: 55 – 68

  21. S. Ighosotu and N. J. Tonukari (2013) The effects of Cassia alata L.aqueous leaf extract on the germination of Corchorus olitorius, Journal of Agricultural Biotechnology and Sustainable Development
    Vol.5 Pages: 1-5

  22. N. J. Tonukari, O. J. Avwioroko, G. Seitonkumoh, C. C. Enuma, S. O. Sakpa, L. Eraga, T. Ezedom, Ufuoma Edema, E. Odiyoma, and A. A. Anigboro (2013) Nutritional compositions and antioxidant properties of typical Urhobo Nigerian soups, Nigerian Journal of Technological Research Vol.8 Pages: 1-9

  23. Jeroh E. and Tonukari N.J. (2011) The pH level and alkaline phosphatase activity in crude oil contaminated soil bioremediated with poultry manure and sawdust, Proceedings of the Delta State University Faculty of Science Maiden Conference
    Vol.2011 Pages: 339 - 343

  24. Jeroh E., Tonukari N.J. and Anigboro A (2011) Glucose level and amylase activity in crude oil contaminated soil bioremediated with poultry manure and sawdust, Asian Journal of Biological Science Vol. Pages: 1-6

  25. Tonukari, N. J. (2010) Theileria parva apical membrane antigen-1 (AMA-1) shares conserved sequences with apicomplexan homologs, International Journal of Biotechnology and Molecular Biology Research Vol.1 Pages: 36-41

  26. Tonukari, N. J. (2010) Theileria parva genome and CTL candidate vaccine antigens: An overview, International Journal of Genetics and Molecular Biology Vol.2 Pages: 72-77

  27. Osumah, L.I. and Tonukari, N. J. (2010) Production of yeast using acid-hydrolyzed cassava and poultry manure extract, African Journal of Biochemistry Research Vol.4 Pages: 119-125

  28. Ighosotu, S. and Tonukari, N. J. (2010) The influence of dietary intake on the serum lipid profile, body mass index and risk of cardiovascular diseases in adults on the Niger Delta region, International Journal of Nutrition and Metabolism Vol.2 Pages: 40-44

  29. Tonukari, N. J. and Osumah, L.I. (2010) Application of acid-hydrolyzed cassava (Manihot esculenta) and cowpea (Vigna unguiculata) for the production of yeast (Saccharomyces cerevisiae), African Journal of Biochemistry Research Vol.4 Pages: 88-94

  30. Tonukari, N. J. and Kangethe, R.T. (2009) Cloning and expression of Theileria parva T-complex 1 protein zeta subunit ortholog, Journal of Cell and Animal Biology Vol.3 Pages: 183-187

  31. Tonukari, N. J. (2009) Acid phosphatase activity and pH of cassava farms in different location of Delta State, Nigeria, Nigerian Journal of Science and Environment
    Vol.8 Pages: 52-55

  32. Tonukari, N. J. and Kangethe, R.T. (2009) Isolation of Theileria parva ring-infected erythrocyte surface antigen (RESA) homolog. , Journal of Cell and Animal Biology Vol.3 Pages: 179-182

  33. Anigboro, A. A. and Tonukari, N. J. (2008) Effect of crude oil on invertase and amylase activities in cassava leaf extract and germinating cowpea seedlings, Asian Journal of Biological Science Vol.1 Pages: 56-60

  34. Fatland-Bloom, B., Rai, G., Rayapati, P. J. and Tonukari, N. J. (2008) Compositions and methods for manipulating carbon flux in cells., United States Patent 20060246560. Vol. Pages:

  35. Mwangi, D.M., Graham, S.P., Pelle,R, Honda,Y, Tonukari, N.J., Yamage,I.M., Glew, E.J., Villiers,E.P., de., Shah,T., Bishop,R., Abuya, E., Awino,E., Gachanja,J., Luyai,A.E., Mbwika,F., Muthiani,A.M., Ndegwa, D.M., Njahira, M., Nyanju, J.K., Onono, F.O., Osaso,J., Saya,R.M., Wildmann,C., Fraser, C.M., Maudlin., Gardner,M.J., Morzaria, S.P., Loosmore, S., Gilbert, S.C., Audonnet,J-C., Bruggen,P. van der., Nene,V., Tracha, E.L.N. (2006) Exploiting host immunity and parasite genomics to develop a robust sub unit vaccine against East Coast fever in cattle-mdash; Where are we? Rege, J.E.O. (ed); Nyamu, A.M. (ed); Sendalo,D. (ed). Tanzania Society for Animal Production, Dar es Salam; All Africa Society For animal Production, Nairobi (Kenya). The role of biotechnology in animal agriculture to address poverty in Africa: opportunities and challenges., Proceedings of the 4th all Africa conference on animal agriculture and the 31st annual meeting of the Tanzania Society for Animal Production.
    Vol. Pages: 187 – 191

  36. Graham, S., Pelle, R., Honda, Y., Mwangi, D., Tonukari, N. J., Yamage, M., Glew, E., de Villiers E., Shah, T., Bishop, R., Abuya, E., Awino, E., Gachaja, J., Luyai, A., Mbwika, F., Muthiani, A., Ndegwa, D., Njahira, M., Nyanjui, J., Onono, F., Osaso, J., Saya, R., Wildmann, C., Fraser, C., Maudlin, I., Gardner, M., Morzaria, S., Loosmore, S., Gilbert, S., Audonnet, J., van der Bruggen, P., Nene, V. and Taracha, E. (2006) Theileria parva candidate vaccine antigens recognized by immune bovine cytotoxic T lymphocytes., Proceedings of the National Academy of Science Vol.103 Pages: 3286-3291

  37. Tonukari, N.J. (2005) Properties of Snf1 protein kinases – a minireview, Nigerian Journal of Biochemistry and Molecular Biology
    Vol.20 Pages: 57-60

  38. Taracha, E., Glew, J., Graham, S., Mwangi, D., Honda, Y., Pelle, R., Tonukari, N. J. and Yamage M. (2005) East Coast Fever vaccine based on CTL-specific schizont antigens., World Intellectual Property Organization, Geneva PCT/US2004/030831. Vol. Pages:

  39. Tonukari, N.J., Scott-Craig, J.S. and Walton, J.D. (2003) Isolation of the carbon catabolite repressor (CREA) gene from the plant-pathogenic fungus Cochliobolus carbonum. , DNA Sequence Vol.14 Pages: 103-107

  40. Tonukari, N.J. (2003) Enzymes and fungal virulence, Journal of Applied Science and Environmental Management Vol.7 Pages: 5-8

  41. Tonukari, N.J., Scott-Craig, J.S. and Walton, J.D. (2002) Influence of carbon source on the expression of Cochliobolus carbonum xylan-degreding enzyme genes, African Journal of Biotechnology Vol.1 Pages: 64-66

  42. Baidyaroy, D., Brosch, G., Ahn, J.H., Gracessle, S., Wegener, S., Tonukari, N.J., Caballero, O., Loidl, P., Walton, J.D. (2001) A gene related to yeast HOS2 histone deacetylase affects extracellular depolymerase expression and virulence in a plat pathogenic fungus, Plant Cell Vol.13 Pages: 1609 – 1624

  43. Mignouna, H., Asiedu, R., Dixon, A., Tonukari, J., Ng, N., Thottappilly, G and Ellis, T. (1998) Application of Molecular Markers in XA98484I4 Germplasm enhancement of cassava (Manihot esculenta L. Crantz) and yams (Dioscorea spp.) at IITA. Use of novel DNA fingerprinting techniques for the detection and characterization of genetic variation in vegetatively propagated crops, 85. , IAEA
    Vol. Pages:

  44. Tonukari, N.J., Thottapilly, G., Ng, N. Q. and Mignouna, H.D. (1997) Genetic polymorphism of cassava within the Republic of Benin detected with RAPD markers., African Crop Science Journal Vol. 5 Pages: 219-228

  45. Petrilli, P. and Tonukari, N. J. (1997) PFDB: A protein families database for Macintosh computers. The effectiveness of its organization in searching for protein similarity, Journal of Protein Chemistry Vol.16 Pages: 713-720

  46. Schaal, B., Olson, P., Prinzie, T., Carvalho, L.J.C.B., Tonukari, N. J. and Hayworth, D.A. (1994) hylogenetic analysis of the genus Manihot based on molecular markers., Proceedings of the second International Scientific meeting of the Cassava Biotechnology Network
    Vol. Pages: 62-70

  47. Osowole, O.A., Tonukari, N.J. and Uwaifo, A. O. (1992) Isolation and partial Characterization of pigeon pea protease inhibitor: its effect on the genotoxic action of aflatoxin B1., Biochem. Pharmacol. Vol.43 Pages: 1880-1882

  48. Tonukari, N.J., Scott-Craig, J.S. and Walton, J.D. ( 2000) Cochliobolus carbonum SNF1 gene is required for cell wall degrading enzyme expression and virulence on maize. , Plant Cell Vol.12 Pages: 237-248