Faculty of Applied Sciences
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Item Improving the survival of probiotic in simulated conditions and azoxymethane-induced colon tumour bearing mice using modified citrus pectin-alginate microencapsulation(PKP Publishing Services Network, 2016) Odun-Ayo, Frederick Oluwasheyi; Mellem, John Jason; Reddy, LaliniBackground: For a probiotic to be viable it needs to be preserved at a recommended minimum level of 6–7 log10cfu/g in the product being consumed, as suggested by the International Dairy Federation. Different biopolymer matrices have been used for encapsulation of probiotic; however, loss of viability is still a challenge. Materials and Methods: Modified citrus pectin-alginate microbeads containing Lactobacillus acidophilus ATCC 4356 was developed. Efficiency of the microbeads was evaluated in simulated conditions of the gastrointestinal tract and in Balb/c mice induced with colon tumor. Genomic identification of faecal lactobacilli samples from treated mice was also performed. Results: The Modified citrus pectin-alginate probiotic microbeads significantly enhanced the viability of Lactobacillus acidophilus ATCC 4356 compared to the control (p< 0.05) both in vitro and in vivo. Exposure of the modified citrus pectin-alginate microbeads to 3 hours of simulated gastric juice resulted in 82.7% survival of L. acidophilus ATCC 4356. Also, the number of faecal lactobacilli in the modified citrus pectin-alginate probiotic treated mice increased by 10.2% after 28 days. Conclusion: Modified citrus pectin-alginate is a novel effective means of oral delivery of bacterial cells and bioactive compounds. Modified citrus pectin-alginate can be used in probiotic therapy which may improve the prevention of colon cancer.Item Phytoremediation of heavy metals using Amaranthus dubius(2008) Mellem, John JasonPhytoremediation is an emerging technology where specially selected and engineered metal-accumulating plants are used for bioremediation. Amaranthus dubius (marog or wild spinach) is a popular nutritious leafy vegetable crop which is widespread especially in the continents of Africa, Asia and South America. Their rapid growth and great biomass makes them some of the highest yielding leafy crops which may be beneficial for phytoremediation. This study was undertaken to evaluate the potential of A. dubius for the phytoremediation of Chromium (Cr), Mercury (Hg), Arsenic (As), Lead (Pb), Copper (Cu) and Nickel (Ni). Locally gathered soil and plants of A. dubius were investigated for the metals from a regularly cultivated area, a landfill site and a sewage site. Metals were extracted from the samples using microwave-digestion and analyzed using Inductively Coupled Plasma – Mass Spectroscopy (ICP-MS). Further experiments were conducted with plants from locally collected seeds of A. dubius, in a tunnel house under controlled conditions. The mode of phytoremediation, the effect of the metals on the plants, the ability of the plant to extract metals from soil (Bioconcentration Factor - BCF), and the ability of the plants to move the metals to the aerial parts of the plants (Translocation Factor - TF) were evaluated for the different metals. Finally, A. dubius was micro-propagated in a tissue culture system with and without exposure to the metal, and the effect was studied by electron microscopy.