Plant biotransformation as a guide on the search for endophytic microorganisms with particular biocatalytic activity

PAULA RODRIGUEZ BONNECARRERE; CYNTHIA ALEJANDRA MAGALLANES NOGUERA; DAVID GONZALES; MARCELA KURINA SANZ; SONIA RODRIGUEZ GIORDANO

Congreso; BIOTRANS; 2013

Endophytic microorganisms constitute a very interesting source of secondary metabolites, and thus a potential source of novel enzymes and novel biocatalytic activities. However, they have been scarcely explored as biocatalysts. The use of plant fragments as biocatalysts has been extensively studied since its first report in 2001. In our previous work, we have demonstrated that endophytic microorganism play an important role in reductions with vegetablesS. Following this work, we wondered weather the presence of a particular biocatalytic activity in a given vegetable could be used as indicative of endophytic microorganisms presenting the same activity. Herein we present our results with Raphanus sativus biocatalytic systems and their endophytic strains. R. sativus hairy roots have been shown to yield the anti-Prelog alcohols from a serie of prochiral ketones with excellent ee 6. Raphanus sativus was studied in three different sytems: hairy roots, seedlings and commercial edible root. Biotransformations of a-ethyl acetoacetate and acetophenone were carried on with all these systems, under different conditions, including the inclusion of bacteria and fungal inhibitors. All experiments were analyzed for the presence of endophytic microorganisms, which were isolated and screened for anti-Prelog reductase activity. Several strains were isolated that yielded similar biotransformation results with the plant material they carne from. Particularly interesting is a Bacillus megaterium strain with anti-Prelog activity isolated from R. sativus seedlings. lt is concluded that the activity registered with plant tissues can be a useful guide in the search of endophytic microorganisms with similar biocatalytic activity.