IIBYT   23944
INSTITUTO DE INVESTIGACIONES BIOLOGICAS Y TECNOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Fermentative production of Lactic acid by genetically transformed Lactobacillus casei and Lactobacillus plantarum
Autor/es:
FADIYA OV; PERILLO MA
Reunión:
Congreso; Primeras Jornadas Virtuales de la Sociedad Argentina de Biofísica; 2020
Institución organizadora:
Sociedad Argentina de Biofisica
Resumen:
The production of lactic acid (LA) is one ofthe most studied processes due to its wide applications in the food, cosmeticand pharmaceutical industries. Lactobacilluscasei and Lactobacillus plantarumare gram-positive bacteria that produce LA as the major metabolic end-product ofcarbohydrate fermentation.This study aimed to obtain the maximumefficiency of the production of LA by microbial fermentation of lactose using Lactobacillus casei and Lactobacillus plantarum wild-type (wt) and transformed before (tr) and after the induction(triptg) to overexpress β-Galactosidase (β-Gal), evaluating the influence of the physicochemical propertiesaffecting bacterial metabolism.Wild-type L.caseiand L.plantarum were transformed (throughelectroporation) by inserting a DNA plasmid containing a β-Gal coding gen. Isopropyl β-D-1thiogalactopyranoside(IPTG) was the inducer of β-Gal-gene expression. The fermentation was performed in lactose brothincubated at 37°C for 24hr, under continuous agitation, at different temperatureand pH. LA acid concentration, residual lactose and glucose were measuredspectophotometrically to evaluate lactose hydrolysis. The colony-forming units(CFU) were counted by dilution method in MRS agar plates.L.casei (wt) (19g/L) exhibited higher LA productioncapacity in comparison with L.casei(tr) (13g/L). The induction of β -Galincreased the LA produced in L.casei(triptg) (16g/L) while improved production of LA was observed in L.plantarum (triptg) 18g/L in comparisonto  L.plantarum(wt) (8g/L) and L.plantarum (tr)(16g/L).Next studies willbe directed to decipher the effect of dimension (2D, 3D, fractal D), macromolecularcrowding and fragmentation level of the environment on the long-rangeinteractions of bacteria with each other, measured through the efficiency of LAproduction. We expect that the use of the tools of soft-matter biophysics inbiology will reveal cues on the collective biochemical behavior of these bacteria.