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Ogunbanwo's Research

My research focused in the area of food microbiology with emphasis on taxonomy of microorganisms of food origin, starter cultures selection, biopreservation, probiotic cultures and microbial genetics.

 

The taxonomy aspect of my research is aimed at identifying microorganisms using phenotypic, biochemical and molecular tools to characterize Microorganisms from different Africa fermented foods. This was to contribute in the use of starter cultures of known identities for fermented foods production (Publications 23, 24, 27, 28). Selection of starter cultures with good physiological (or excellent) and functional attributes for use in specific foods was carried out. Work done in this area indicated that Lactobacillus species in combination with Saccharomyces cerevisae can be used as starter culture to improve the nutritional content, physical properties, obtained consistency in product, reduced fermentation time, enhance sensory attributes and extend the shelf life of some fermented food resulting in transforming traditional art of fermented foods in sub-Saharan Africa to science.

 

Consumers nowadays, demand food products with fewer synthetic additives with increased safety, quality and shelf life. Biopreservation investigation in recent times carefully assessed antimicrobial compounds such as lactic acid, diacetly, hydrogen peroxide and bacteriocin produced by Lactic acid bacteria (LAB) on safety and shelf life of some foods. Thus, possible potential of use as antimicrobial retardation of food spoilage and prevented infestation of pathogens Microorganisms in foods was provided. Antifungal attributes of LAB was confirmed by research to have the potential of being effective as food-grade biopreserva­tives in combating the problem of aflatoxin contami­nation.

 

                        Probiotic cultures investigation significantly reduced clinical signs of colibacillosis and improved the growth rate of the studied birds. This indicated that bacteriocin from appropriate LAB strains could be employed for the treatment of respiratory E. coli infection. Lactic acid bacteria such as L. fermentum used as feed additive at 109cfu/ml was found to be highly beneficial for growth performance and improved resistance of fish to P. aeruginosa a fish culture pathogen in Nile tilapia (Oreochromis niloticus).

 

                        Chromosomal DNA and extra chromosomal plasmid linkage of drug resistance and functional importance of Lactobacillus species isolated from ogi was investigated. Curing experiment carried out showed that some of the isolates lost their resistance to ampicillin, cotrimoxazole and streptomycin. Evidence was provided on the transfer of ampicillin resistance plasmid from L. reuteri to L. delbrueckii at frequency of 25% which indicated danger of transfer of resistance genes among probiotic microorganisms. Grouping of LAB through amplified ribosomal DNA restriction analysis (ARDRA) and sequencing of 16S rDNA was established.

 

(a)               Research completed:  

(1)         Drug resistance and bacteriocin production in Lactobacillus species isolated from ogi.

(2)         Probiotic and Biopreservation properties of Lactic acid bacteria isolated from some  

      traditional fermented foods in Nigeria.                                                                            

(3)         Influence of Lactic acid bacteria on fungal growth and aflatoxin production in ogi.

(4)         Selection of starter cultures for the production of ugba.

(5)         Production of cassava-wheat bread using Lactic acid bacteria and Yeast cultures.

(6)         Growth of Bacillus species isolated from condiments under different regimens.

(7)         Bio-detoxication of aflatoxin in artificially contaminated maize.

(8)         Antagonistic activity of Lactic acid bacteria isolated from salad vegetables.

(9)         Evaluation of probiotics for growth enhancement and immunomodulation of Nile tilapia and

      African catfish.

 

(b)                 Research in progress:

 

(1)          A quantitative and qualitative comparison of extracellular polysaccharide (EPS) yields by

Lactic acid bacteria isolated from milk and fermented milk products in South-West Nigeria. This study started in 2010. The current research assesses mutant strains of LAB with enhanced capacity for economic production of exopolysaccharides. Application of the EPS+ mutant   strains in the production of some fermented milk products (cheese and yogurt), the haematological and immunomodulating potential of LAB EPS in-vivo using Albino Rats is currently on.

 

(2)          Synergistic effect of Lactic Acid Bacteria (LAB) and yeast as starter cultures for the production of fermented infant weaning food.

 

(3)          Diversity and molecular characterization of Vibrio species from seafoods in Lagos state. The research aims at isolation and molecular characterization of vibrios from the various seafoods. Effect of season on the prevalence and distribution of Vibrio species from seafoods will be carried out. The work will elucidate the antibiotic susceptibility profiles, Minimum inhibitory concentration and Minimum bacterial concentration of the isolated Vibrio species. The use of an already identified Lactobacillus species as a probiotics on the identified clinical Vibrio species will equally be carried out. This study started 2011.

 

(4)          Stress responses of Yeasts and Lactic acid bacteria isolated from some selected African fermented foods:  Exposure of LAB and yeasts to multiple environmental stresses (low and high temperature, low pH, high osmotic pressure, nutrient starvation and oxidation) can cause loss or reduction of bacterial viability, reproducibility, as well as organoleptic and fermentative qualities, leading to inconsistencies in the production of fermented foods especially from one producer to the other. It is essential to know not only which conditions are favourable or detrimental for the life of LAB and yeasts but also which mechanisms permit their survival and metabolic activities. The research aims at determine the physiological and proteomic responses of identified LAB and yeasts to stress conditions.

 

(c)     Dissertations and Thesis:

 (1)    Bacterial flora of three soil types in L.A.S.U. B.Sc. project of Lagos State University

          July,1992; 85p.

 

             (2)    Drug resistance and bacteriocin production in Lactobacillus species isolated from Ogi  

                     fermented cereal gruel. M.Sc. project, University of Ibadan, Ibadan, September 1997; 102p.

 

(3)     Probiotic and Biopreservation Properties of Lactic acid bacterial Isolated from some traditional  

  fermented foods in Nigeria. Ph.D. Thesis, University of Ibadan, Ibadan, July, 2003; 229p.