Conference Book of Abstracts - Taita Taveta University College

Development and Assessment of Technologies for Exploration of Genomic and MetaboliteDiversity of extremophiles from Kenyan Soda LakesFrancis J. Mulaa, Biochemistry Department, Faculty of Medicine, University of Nairobimulaafj@uonbi.ac.keThe study highlights, technologies aimed at the mining of enzymes and metabolic pathways fromextremophilic organisms and metagenomes from microbial communities from peculiar sodalakes environments and consequent funneling the new enzymatic reactions and processestowards new biotechnological applications are. The technologies are build up on the scientificand technological application of the state-of-the-art technologies for archiving, molecularactivity screening, enzyme engineering and directed evolution and establishing newbiotechnological processes including biocatalysis and pathway engineering for the synthesis offine chemicals. The central approach of the biocatalysis and metabolic engineering is based onthe “Activity First” principle, allowing to directly access metabolic reactions of biotechnologicalrelevance. This approach contrasts with the massive sequencing and consequent“genome/metagenome gazing” approach which can only reveal those genes encoding theenzymes of already known protein families. Designed and/or directed evolution methods areemployed to improve the performance and specificity of the enzymes. A comprehensivebioinformatic approach throughout the whole tree of cellular life is used to suggest newcandidates homologous to the discovered new proteins, from other organisms to be cloned andassayed.Amongst other highlights include: Molecular methods to identify and quantify bacteria witheconomic potential directly in any given soil sample and to assess their state of activity. Wecombine quantitative PCR and DNA-chip technology to retrieve specific gene sequences andassess their amounts in soil samples. 16S rRNA sequences serve to identify species.The studies also show the development of a versatile fermentation platform, using the oleaginousyeastYarrowialipolytica, for the conversion of lipid feedstocks into diverse added-valueproducts. Relevant enzymatic properties for the production of compounds of interest are derivedfrom marine hydrocarbonoclastic bacteria. Research directed at elucidating the lipid metabolismof the yeast, together with available genomic data make it possible to intercept its lipidmetabolism for biotechnological purposes.Genomic and phenotypic analyses are performed to characterize the new species and to allowreliable identification. The geographical dissemination of extremophiles strains can be monitoredby 16S rRNA directly extracted from soil samples. The presence of soda lakes bacteria will beunveiled by cloning and sequencing of PCR-amplified 16S rDNA. Their species richness andabundance in microbial communities of different environmental soils will be spatially monitoredby 16S rDNA analysis. We show how extremophile strains recalcitrant to cultivation can beenriched by cell sorting methods. The show how specialised high-throughput screening for novel