Redirection of Fusarium fujikuroi metabolism for the production of gibberellic acid and other metabolites
Resumen
Fusarium fujikuroi is an ascomycete characterized by the synthesis of a great variety of secondary metabolites. Among the most studied compounds are plant growth regulators such as gibberellic acid (GA3). This phytohormone is of commercial importance due to its activity in the stimulation of germination, fruiting and flowering, so that its demand in the agricultural market exceeds $1.20 billion dollars. However, there is a notable lack of information on the regulatory circuitry of the GA3 metabolic pathway, limiting the optimization of the production process on a large scale. Therefore, in the present research we propose to study and redirect the metabolism of F. fujikuroi IMI 58289 for the production of GA3 and other metabolites of interest; determining the profile of majority metabolites, establishing a genetic transformation strategy and comparing the productions by the native and parental strain at reactor level. The results obtained in the first stage of the project showed that the EM C:N 25 (10X) medium provided the best growth of the fungus (36 g/L), while the EM C:N 50 (10X) medium generated a maximum production of GA3 (5.72 g/L). The above is of relevance because, according to the amount of substrate provided, only ˜42% of the carbon source was utilized, giving rise to the search for other products. The synthesis of 5 organic acids (succinic, malic, citric, maleic and lactic) was determined, finding an outstanding production of lactic acid (101.09 g/L) in the EM C:N 50 (10X) medium, which establishes it as the major metabolite. Based on the above, the basis for obtaining mutant strains of F. fujikuroi that provide certainty of redirection to the superior biosynthesis of GA3 was generated, expecting an increase in the yields of the same and improvement in the profitability of the process with potential scaling up to industrial level.