Effect of some nutritional and environmental parameters on the production of diacetyl and on starch consumption by Pediococcus pentosaceus and Lactobacillus acidophilus in submerged cultures.
Three series of 5-day submerged cultures with Pediococcus pentosaceus MITJ-10 and Lactobacillus acidophilus Hansen 1748 were carried out in starch-based media, and the effect of cultural factors on the changes of starch, diacetyl and amylase activity determined. In axenic cultures, Ped. pentosaceus MITJ-10 produced more diacetyl (63.27 mg l(-1)) by adding glucose, yeast extract and CaCO3 (P < 0.01), at 28 degrees C (P < 0.05); but more starch was consumed (18.4 g l(-1)) in the absence of glucose (P < 0.01). Lact. acidophilus Hansen 1748 consumed more starch (26.56 g l(-1)) at 28 degrees C, with CaCO3, glucose (P < 0.01) and yeast extract (P < 0.05); however, the amylolytic activity (10077U l(-1)) was favoured at 35 degrees C (P < 0.01). Little starch was consumed in mixed cultures due to the low pH; nevertheless, diacetyl content rose to 135.76 mg l(-1) at 32 degrees C (P < 0.01). Therefore, both studied strains might be useful to produce aromatic extensors from starchy substrates. These natural aromatic extensors are of interest to the food industry.
Escamilla
M L
ML
Depto. Biotecnología, University of Autónoma Metropolitana-Iztapalapa, Mexico City, México. mleh@xanum.uam.mx
Valdés
S E
SE
Soriano
J
J
Tomasini
A
A
D000681:Amylases / Q000378:metabolism; D001431:Bacteriological Techniques; D002119:Calcium Carbonate / Q000494:pharmacology; D002849:Chromatography, Gas; D003470:Culture Media; D003931:Diacetyl / Q000378:metabolism*; D007779:Lactobacillus acidophilus / Q000254:growth & development* / Q000378:metabolism; D010376:Pediococcus / Q000254:growth & development* / Q000378:metabolism; D013213:Starch / Q000378:metabolism*; D013696:Temperature
D003470:Culture Media; D013213:Starch; D000681:Amylases; D002119:Calcium Carbonate; D003931:Diacetyl