Professor I. C. Ononogbu Biochemistry Department

Current Research:

(a) Effects of local diets on lipid and lipoprotein metabolism

(b) :Lipid and lipoprotein standardization

(c) Epidemiological study of lipid and lipoprotein disorders in various parts of

Nigeria.

(d) Changes associated with lipids and lipoprotein during infection and

Disease conditions

(e) Tropical oils

(f) Renewable Energy Sources

(g) Monitoring and Evaluation

(h) Culture and Tradition

(i) Traditional Institution



 Dr. V. N. Ogugua Biochemistry Department

Special Research Areas:

Medical Biochemistry – Biochemistry of Free Radicals and Membrane

Biochemistry.

Professor J. C. Ogbonna Microbiology Department

Research and Teaching Objectives



Research activities

As the gap between the developed and developing countries continue to widen, there is a need for the developing countries to explore areas where they can favourably compete with the developed countries. Many developing countries such as Nigeria have abundant renewable biomass resources that can be efficiently processed or converted to various useful metabolites. Furthermore, Nigeria has good solar radiation and temperature that can support photosynthetic cell culture throughout the year. Photosynthetic cell cultivation can be used to convert the abundant and clean solar energy into many useful metabolites. This technology has been extensively explored in developed countries but in the whole of Africa, there is almost no industry that is engaged in commercial photosynthetic cell cultivation. This is due to lack of appropriate technology that can be sustained in the region.

Many fermentation and cell cultivation processes can be done without the need for very high-level technologies. Thus many bio-industries based on fermentation or cell cultivation can be sustained in developing countries. I have been working on development of cell cultivation technologies suitable for use in developing countries. Most of my research works are centered on process development for efficient utilization of biomass resources and solar light energy. They can be discussed under the following headings.



(i) Development of technologies for efficient biomass utilization

Nigeria has abundant biomass resources that are not fully exploited. Development of processes for their efficient utilization and processing of the agricultural products will definitely help in the country’s economic development. Efficient processing of agricultural products will create the demand and thus boast the agricultural sector.

I did some work on the physiological basis of crop improvement (1,2) and I have been working on development of fermentation technology for production of alcoholic beverages from various fruits (4,5). I have also developed a method for efficient conversion of cassava into ethanol and L-lactic acid (44, 46). The use of local raw materials as both Nitrogen and carbon sources in bio-industries is also being investigated (40, 48, 50, 51). As a means of improving the efficiency of converting biomass resources into various useful metabolites, I have been working on development of efficient immobilized cell systems (3, 7), and have developed and patented a system for production of micro-gel beads for improved mass transfer characteristics (6, 8, 9). The instrument is now commercially produced by Marubishi Bioengineering Company, Japan. Since most of the currently used carriers for cell immobilization are very expensive synthetic materials and often not biodegradable, I did some screening of many natural fibrous materials for suitable microbial cell immobilization carrier. It was found that loofa (Luffa cylindrica) sponge is very suitable for immobilization of aerobic and anaerobic microorganisms, and have successfully developed a method for scaling up bioreactors with loofa sponge as immobilization carrier (17, 22, 25, 37). We have now developed methods for immobilization of various filamentous cells. Furthermore, in order to use loofa sponge as an immobilization carrier in systems containing/producing cellulase enzymes, a method of protecting the loofa from cellulase by acetylation has been developed (53). The cost of sterilization is definitely a problem when fermentation process is to be operated in a developing country. Thus, I did some work on development of fermentation processes under un-sterile conditions (15, 16) and how to increase the biomass concentration for reduced cost of downstream processing (10 –14).

I believe that development of bio-industries is pivotal to Economic development of Nigeria and will thus continue to work on development of various practical systems for efficient conversion of the abundant biomass resources in Nigeria.



(ii) Development of technologies for efficient solar light utilization

Solar light energy is one of the most abundant natural resources in the globe. The total amount of solar energy reaching the earth surface is several times higher than the total energy consumed in the world today. Most of this solar light is concentrated within the tropics where the temperature is also favourable for outdoor cultivation of photosynthetic cells throughout the year. I have been working on development of systems for efficient biological fixation of solar energy through photosynthetic cell cultivation. Many photosynthetic cells contain more than 60% protein and a lot of vitamins and minerals. Thus, they are excellent sources of many nutrients that are lacking in the diet of many Africans. Most of these cells are currently produced in many developed countries as health food, animal feed and for extraction of many fine chemicals and pharmaceutical products. The climatic conditions in most African countries are favourable for photosynthetic cell cultivation. Thus, I have been working on development of appropriate photobioreactors and systems for efficient cultivation of photosynthetic cells within the tropics.

I developed a photosynthetic cell growth index and proposed a concept of “light supply coefficient” as an index for evaluation of light conditions inside photobioreactors (18 – 20). This index was found to be very good for photobioreactor design and scale up. Using this index, an internally illuminated photobioreactor was deigned and constructed, and a method of its scale up was proposed (21, 27). This scale-up method has been validated by scaling up a photobioreactor while maintaining the light supply coefficient the same.

Night biomass loss is a major problem when only solar light is used for photosynthetic cell cultivation. I have investigated night biomass loss and changes in the biochemical composition of cells under day/night cycles (23) and designed a system where the solar night energy is supplemented by artificial light. The illumination system switches automatically from solar light to artificial light whenever the solar radiation decreases below a set value (32). For cells with heterotrophic metabolism I have developed a cyclic photoautotrophic/heterotrophic cultivation method by which the cells are cultivated photoautotrophically during the day and a specified amount of organic carbon source is added at night for heterotrophic culture. This system has been tested with Chlorella and Euglena cells (28). Furthermore, an integrated system of solar light, artificial light, and organic carbon source has also been developed for efficient cell cultivation in localities without steady weather and electricity supply (39). As a means of improving the productivity of photosynthetic cell culture, I have developed a sequential heterotrophic/photoautotrophic cultivation of photosynthetic cells. In this method, the cells are cultivated hetrotrophically to high cell concentration and then subjected to photoautotrophic condition for accumulation of desired intracellular metabolites (26, 29, 31). Another method of utilizing both the photoautotrophic and heterotrophic metabolic activities in photosynthetic cells is to simultaneously supply both light and organic carbon source to the culture (mixotrophic culture). In this system, it is very important to regulate the two metabolic activities (41, 42).

In terms of application of photosynthetic cell cultivation, I have investigated biological carbon dioxide fixation by various strains of photosynthetic cells, production of many useful metabolites such as α-tocopherol by Euglena gracilis (31), and astaxanthin by Haematococcus pluvialis (38). I am also working on the use of photosynthetic cells for environmental bioremediation and have developed a system for simultaneous removal of organic acids, nitrogen and phosphorus from wastewater by photosynthetic microorganisms (34). With the accumulated basic knowledge on photobioreactor design and optimization, I have constructed a simple, cheap and efficient tubular photobioreactor that will be optimized under tropical condition (43, 45, 47, 49). Here the emphasis is on how to reduce the construction and maintenance costs, how to simplify the technology so that it can be operated and maintained in developing countries, how to improve the mass transfer coefficient and provide low-cost cooling systems during the very hot period. I believe that this type of technology is required in Nigeria and one of my major research ambitions is to establish photosynthetic cell cultivation industries for production of various useful materials in Nigeria.



Teaching

One of the main functions of University is to educate and train students and I believe that Universities should emphasize teaching and training of the students. It is the responsibility of the lecturers to ensure that the majority of the students understand his classes. Thus, I devote a lot of time for preparation of the teaching materials. I adjust the pace of the lecture depending on the rate of understanding by the students. My personal teaching philosophy is to get students involved as much as possible and not to maintain a rigid methodology, rather to adjust the method and pace, depending on the type of students in the class. In University of Tsukuba, students are asked to evaluate each course at the end of each term and my classes are among the most highly rated classes in the University. As shown above, I have taught a lot of courses and have good basic knowledge and practical experience to develop and teach any course in Biotechnology and related fields, including use of computer for analysis of fermentation and bioprocess data, and Statistical analysis of research data in Biological Sciences.