• H. T. BALOGUN-ABIOLA Department of Biological Sciences, Crescent University, Abeokuta, Nigeria
  • S. O. KAREEM Department of Microbiology, Federal University of Agriculture, Abeokuta, Nigeria
  • R. B. AFOLABI Department of Microbiology, Federal University of Agriculture, Abeokuta, Nigeria
  • O. A. AKINLOYE Department of Biochemistry, Federal University of Agriculture, Abeokuta, Nigeria
Keywords: A. niger PJ-02, ethydium bromide, orange peel (OP), mutant, methanol, pawpaw peel


This present study was concerned with the biosynthesis of citric acid (CA) with mutant strain of Aspergillus niger using pawpaw and orange peel as substrates by solid state fermentation process. The A. niger strain isolated from spoilt orange was identified, screened for CA production on Czapek-Dox Agar and subjected to mutation by ethidium bromide. The effect of carbon sources, nitrogen sources and substrates were also determined.  Among the mutant strains, A. niger PJ-02 A120 was found to be the best mutant that produced citric acid (65.00±0.58f) after 48 hours in Vogel’s medium. The effects of carbon sources (sucrose and glucose) on CA production from each substrate (orange and pawpaw peel) using mutant A. niger PJ-02 was determined and sucrose, the best carbon source was combined with two the nitrogen sources (groundnut cake and soyabeans) to determine the most suitable supplement for CA production. Groundnut cake enhances the production of citric acid while soyabeans was inhibitory. Citric acid was further produced in pawpaw peel and orange peel medium containing sucrose (5 %) groundnut cake (2 %), methanol (1.5 %) and the mutant strain. The orange peel substrates yielded 112.07g/kg of CA while 107.17g/kg was recorded for pawpaw peel when fermented for 5 days at 30°C. The Production of citric acid with mutant Aspergillus niger proved better with orange peel than pawpaw peel when optimized with alcohol.





Abam, T. K. S. 1997. Genesis of canal bank overhangs in the Niger Delta and analysis of mechanisms of failure. Geomorphology, 18, 151–164.

Allen, J. R. L. 1970. Sediments of the modern Niger Delta. In: Morgan, J. P. (ed.) Deltaic Sedimentation: Modern and Ancient, Soc. Econ. Paleontol. And Mineral. Spec. Publ. 15, p. 138 – 151.

Anejionu, O., Blackburn, A., Whyatt, D. 2012. Improved remote survey of Gas flaring in the Niger Delta region of Nigeria with landsat imagery. In D.Whyatt, & B. Rowlingson (Eds.), Proceedings of the GIS Research UK 20th Annual Conference. Lancaster: Lancaster University.

Anejionu, O., Blackburn, A., & Whyatt, D. 2013. Remote mapping of gas flares in the Niger Delta with MODIS imagery. Earsel Special Research Forum dedicated to Remote Sensing for Developing Countries. Matera, Italy, 5 June.

Baird, J. July 26, 2010. Oil's shame in Africa. Newsweek 27.

Bishop, M. P., Shroder Jr., J. F., 2004. In: Bishop, Shroder (Eds.), GIScience and Mountain Geomorphology: Overview, Feedbacks, and Research Directions, p. 1–31.

Bishop, M. P., James, L. A., Shroder Jr., J. F., & Walsh, S. J. 2012. Geospatial technologies and digital geomorphological mapping: Concepts, issues and research. Geomorphology, 137, 5–26.

Bishop, M. P., Shroder Jr., J. F., & Colby, J. D. 2003. Remote sensing and geomorphometry for studying relief production in high mountains. Geomorphology 55, 345–361.

Connallon, C. B., Schaetzl, R. J. 2017. Geomorphology of the Chippewa River delta of Glacial Lake Saginaw, central Lower Michigan, USA. Geomorphology, 290 (1): 128–141.

Fabiyi, O.O., Yesuf, G. U. 2013: Dynamics and Characterization of Coastal Flooding in Nigeria: Implication for Local Community Management Strategies, Ife Research Publications in Geography 12 (1&2) 45-61

Faniran, A., Sada, P.O., Areola, O 1976. River and Mining, its Organisation and Building Industry in the Lagos Areas. Quart.journal Admin. (University of Ife), 10 (4), 423-435.

Gallant, J. C., Wilson, J. P. 2000. Primary topographic attributes. In Wilson, J.P., Gallant, J.C. (Eds.), Terrain Analysis, Principles and Applications. New York: John Wiley & Sons, pp. 51–85.

Gelumbauskaitė, L. Z. 2010. Palaeo–Nemunas delta history during the Holocene time. Baltica, 23 (2): 109–116.

Gessler, P., Pike, R., MacMillan, R. A., Hengl, T., Reuter, H. I. 2009. In: Hengl, Reuter (Eds.), The Future of Geomorphometry, p. 637–651.

Goudie, A. S. 2005. The drainage of Africa since the Cretaceous. Geomorphology, 67, 437–456.

Hengl, T., & Reuter, H. I. (eds) 2009. Geomorphometry: Concepts, Software, Applications. Developments in Soil Science, vol. 33, Elsevier, 772 pp.

Hofierka, J., Mitasova, H., & Neteler, M. 2009. In: Hengl, Reuter (Eds.), Geomorphometry in GRASS GIS, pp. 387–410.

Isola, I., Bini, M., Ribolini, A., Zanchetta, G. & D’Agata, A. L. 2017. Geomorphology of the Ceyhan River lower plain (Adana Region, Turkey). Journal of Maps, 13 (2): 133–141.

Jordan, G., Meijninger, B. M. L., van Hinsbergen, D. J. J. Meulenkamp, J. E., van Dijk, P. M. 2005. Extraction of morphotectonic features from DEMs: Development and applications for study areas in Hungary and NW Greece. International Journal of Applied Earth Observation and Geoinformation, 7, 163–182.

Khadri, S. F. R., Thakare, S., Armal, P. (2015). Geomorphological study of Amravati Tehsil, District Amravati, Maharashtra using remote sensing and GIS techniques. International Journal on Recent and Innovation Trends in Computing and Communication, 3 (2): 125 – 129.

Kuenzer, C., van Beijma, S., Gessner, U., Dech, S. 2014. Land surface dynamics and environmental challenges of the Niger Delta, Africa: Remote sensing-based analyses spanning three decades (1986–2013). Applied Geography, 53, 354–368.

Lecours, V., Dolan, M. F. J., Micallef, A., Lucieer, V. L. 2016. A review of marine geomorphometry, the quantitative study of the seafloor. Hydrol. Earth Syst. Sci., 20, 3207–3244.

Marston, B. E., Jenny, B. 2015. Improving the representation of major landforms in analytical relief shading. International Journal of Geographical Information Science, 29 (7), 1144–1165.

Minár, J., Evans, I. S., Krcho J. 2013. Geomorphometry: Quantitative land-surface analysis. In: Schroder JF (Ed.) Treatise on Geomorphology. Academic Press: San Diego, p. 22-34.

Odunuga, S., Oyebande, L. 2007. Change detection and hydrological implication in the Lower Ogun flood plain, SW Nigeria. In Owe, M and Neale, C. (eds). Remote Sensing for Environmental Monitoring and Change Detection. IAHS Publ. 316, IAHS Press, Wallingford Pp 91-99.

Odunuga, S., Ajijola, A., Aiyede, P., Delima, T. & Akpan A. (2013) Geomorphic mapping and human activities along the Nigeria southwestern coastline In Gordon Young & Gerardo M. E. Perillo (eds). Deltas:Landforms, Ecosystems and Human Activities. IAHS Publ. 358, ISBN 0144-7815, IAHS Press, Wallingford p. 116-123

Odunuga, S., Omojola, A., Oyebande, L. 2011. Urban land use dynamics of system 6c watershed, Lagos, Nigeria, Lagos Jour. of Geo-Information. Sci., Volume 1 (1) Pp 7-18.

Palmtag, J., Cable, S., Christiansen, H. H. Hugelius, G., Kuhry, P. (2017). Improved landscape partitioning and estimates of deep storage of soil organic carbon in the Zackenberg area (NE Greenland) using a geomorphological landform approach. The Cryosphere Discuss., https://doi.org/10.5194/tc-2017-255.

Reijers, T. A. J. (2011). Stratigraphy and sedimentology of the Niger Delta. Geologos, 17(3): 133–162.

Ruszkiczay-Rudiger, Z., Fodor, L., Hovath, E., Telbisz, T., 2009. Discrimination of fluvial, eolian and neotectonic features in a low hilly landscape: a DEM-based morphotectonic analysis in the Central Pannonian Basin, Hungary. Geomorphology, 104, 203–217.

Schillaci, C., Braun, A., Kropáček, J. 2015. Section 2.4.2: Terrain analysis and landform recognition. In Cook, S. J., Clarke, L. E. & Nield, J. M. (Eds.) Geomorphological Techniques, (Online Edition). British Society for Geomorphology; London, UK. ISSN: 2047-0371.
Sexton, W. J., Murday, M. 1994. The morphology and sediment character of the coastline of Nigeria-the Niger delta. Journal of Coastal Research, 10 (4): 959-977.

Short, K. C., Staeuble, A. J. 2004. Outline of geology of Niger delta. AAPG Bulletin, 51(5): 761–799.

Shroder, J. F. 2013. Ground, aerial, and satellite photography for Geomorphology and geomorphic change. In: Shroder, J. and Bishop, M.P. (Ed.) Remote Sensing and GIScience in Geomorphology, San Diego: Academic Press, Vol 3 Pp 25–42.

Sivakumar V. 2015. Geological, geomorphological and lineament mapping through remote sensing and GIS techniques, in parts of Madurai, Ramanathapuram and Tiruchirappalli districts of Tamil Nadu. International Journal of Geomatics and Geosciences, 6 (3): 1669 – 1675.

Temovski, M., Milevski, I. 2015. DEM based geomorphometric analyses of karst surface in the Republic of Macedonia. In Jasiewicz, J., Zwoliński, Z., Mitasova, H., & Hengl, T. (Ed). Geomorphometry for Geosciences. Bogucki Wydawnictwo Naukowe, Poznań p. 65–68.

Tucker, G. E., Hancock, G. R. 2010. Modeling landscape evolution. Earth Surface Processes and Landforms, 35, 28–50.

Ventura, S. J., Irvin, B. J. 2000. Automated landform classification methods for soil-landscape studies. In Wilson, J.P., Gallant, J.C. (Eds.), Terrain Analysis, Principles and Applications. New York: John Wiley & Sons, pp 245–294.

Wright, J. B., Hastings, D. A., Jones, W. B., Williams, H. R. 1985. Geology and mineral resources of West Africa. London: George Allen & Unwin. 187 p.

Yan, X., Su, X. G. 2009. Linear Regression Analysis: Theory and Computing. Published by World Scientific Publishing Co. Pte. Ltd. 348 p.
Zhang, Y., Zhang, Z., He, H., Chen Y., Jiang S., Ren H. 2017. Processes of small-scale tidal flat accretion and salt marsh changes on the plain coast of Jiangsu Province, China. Acta Oceanol. Sin. 36 (4): 80–86. DOI: 10.1007/s13131-017-0971-9.