Vol. 5, Issue 1, Part A (2023)

The search for a suitable organism for bioethanol production is still ongoing. Zymomonas mobilis is a bacterium belonging to the genus Zymomonas and is notable for its bioethanol-producing capabilities, which surpass yeast in some aspects. In the present research work Zymomonas mobilis isolates were obtained from fresh palm sap and characterized using conventional biochemical tests as well as molecular techniques through the PCR detection of the alcohol dehydrogenase gene (the primer sequences used targeted 16SrRNA and 23SrRNA genes). The results of the biochemical characterization of presumptive isolates of Zymomonas mobilis showed that out of ten (10) isolates only four (4) isolates (40%) which include ZM2, ZM3, ZM4, and ZM5 matched with the characteristics of Zymomonas mobilis according to available standard techniques. For the molecular characterization of the presumptive Zymomonas mobilis isolates, genomic DNA was isolated from Zymomonas mobilis (ATCC 29191), ZM2, ZM3, ZM4 and ZM5. Two different primers were used; a fragment of 900 bp was amplified using 16SrRNA(Z16p3) and 23SrRNA (Z23p5) gene primers that were specific for Zymomonas mobilis and another fragment of 1200bp was amplified using ADH 1 gene (ZADH IF and ZADH IR primers) that were specific for Zymomonas mobilis for each of the isolates. The results of the amplification with the specific primer pairs coincided with the studies carried out by other authors. The two confirmed Zymomonas mobilis isolates were also screened for ethanol production using rich media and they showed relatively high ethanol yields (24-60g/l for ZM2 and 30-80g/l for ZM3). The results of this research work revealed that the two Zymomonas mobilis isolates obtained in this research have good potential as candidates for industrial bioethanol production.