Thesis (Ph.D.) - Cairo University - Faculty of Agriculture - Department of Microbiology

The water hyacinth (eichhornia crassipes "martius" sloms-laubach) is a lignocellulosic biomass that could be utilized for reducing sugar production and thus further for bioethanol production. The chemical profile of the macrophyte showed the respective percentages of 24.0, 20.0 and 16.8 % for crude protein, crude fiber and ash. The biomass is rich in N (3.8 %) having a C/N ratio of ca. 9.0. The nutritive potential indicated the presence of Ca, Mg, K, and P as 14.9, 4.6, 11.3 and 5.2 %, respectively. Box BehnKen Design was used to evaluate the effect of treatment conditions (NaOH concentration, time and temperature) on bioethanol production. The combined interaction between pretreatment and enzyme mixture (celluclast 1.5 L and novozyme 188), afford the most promising glucose production of 184.0 mg g-1 DM. The highest bioethanol yield of 4.1 g l-1 was produced by Saccharomyces cerevisiae thermosacc and 0.10 M NaOH at 111 {u00B0}C for 120 min. The antimicrobial potential of ethanol and chloroform extracts of the weed biomass indicated that staphylococcus aureus ATCC 25923 was the most susceptible with inhibition zone diameters (IZDs) of 11.8-21.5 mm. The fungal candidates Macrophomina phaseolina and Rhizocotonia solani, also severely injured due to the weed extracts, respective IZDs f 16.0 and 9.5 mm were measured

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