Scale-up from shake flasks to pilot-scale production of the plant growth-promoting bacterium Azospirillum brasilense for preparing a liquid inoculant formulation.
Azospirillum brasilense has industrial significance as a growth promoter in plants of commercial interest. However, there is no report in the literature disclosing a liquid product produced in pilot-scale bioreactors and is able to be stored at room temperature for more than 2 years. The aim of this work was to scale up a process from a shake flask to a 10-L lab-scale and 1,000-L pilot-scale bioreactor for the production of plant growth-promoting bacterium A. brasilense for a liquid inoculant formulation. Furthermore, this work aimed to determine the shelf life of the liquid formulation stored at room temperature and to increase maize crops yield in greenhouses. Under a constant oxygen mass transfer coefficient (K L a), a fermentation process was successfully scaled up from shake flasks to 10- and 1,000-L bioreactors. A concentration ranging from 3.5 to 7.5 × 10(8) CFU/mL was obtained in shake flasks and bioreactors, and after 2 years stored at room temperature, the liquid formulation showed one order of magnitude decrease. Applications of the cultured bacteria in maize yields resulted in increases of up to 95 % in corncobs and 70 % in aboveground biomass.
Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, AP. 70228, Mexico, D.F., 04510, Mexico, maurotru@biomedicas.unam.mx.
Mauricio A
MA
Trujillo-Roldán
Norma A
NA
Valdez-Cruz
César F
CF
Gonzalez-Monterrubio
Eduardo V
EV
Acevedo-Sánchez
Carlos
C
Martínez-Salinas
Ramsés I
RI
García-Cabrera
Ramsés A
RA
Gamboa-Suasnavart
Luz D
LD
Marín-Palacio
Jesús
J
Villegas
Abel
A
Blancas-Cabrera
D015806:Azospirillum brasilense / Q000254:growth & development*; D058491:Bacterial Load; D015169:Colony Count, Microbial; D007218:Industrial Microbiology / Q000379:methods*; D011309:Preservation, Biological / Q000379:methods; D013997:Time Factors; D003313:Zea mays / Q000254:growth & development / Q000382:microbiology