Abstract

SCHMIDT-DURAN, Alexander  and  CHACON-CERDAS, Randall. Optimization of the growth conditions of the endophytic bacteria Klebsiella oxytoca in flask culture and in a bioreactor. Tecnología en Marcha [online]. 2021, vol.34, n.4, pp.92-104. ISSN 0379-3982.  http://dx.doi.org/10.18845/tm.v34i4.5385.

Endophytic bacteria are characterized for living within plant cells and tissue without causing any harm to the plants. Klebsiella oxytoca is an endophyte that promotes plant growth and also has a bio-controlling effect; therefore, the objective of the current study is to determine the optimal growth conditions, in flask culture as well as in a bioreactor, for this bacteria collected from previous studies performed on fig plants (Ficus carica). To achieve this, biomass growth of K. oxytoca flask cultured in nutritive broth was assessed under different agitation and temperature conditions, and it was determined that 200 rpm and 30 °C produced the highest biomass yield. On the other hand, using a broth culture in a 3.7 L bioreactor, it was established that 500 rpm presents higher KL a values and a shorter fermentation time than when using an agitation speed of 750 rpm. Additionally, under an agitation speed of 500 rpm, the use of culture media based on agro-industrial residues can provide an alternate source of energy for this microorganism. Finally, the treatment using culture broth at 500 rpm was modeled using a logistic model and Pirt's equation, resulting in both cases, on a coefficient of determination higher than 0.95.

Keywords : Klebsiella oxytoca; flask culture; bioreactor; agro-industrial residues; logistic model.

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