title: Lactic acid bacteria production from whey.
abstract: The main purpose of this work was to isolate and characterize lactic acid bacteria (LAB) strains to be used for biomass production using a whey-based medium supplemented with an ammonium salt and with very low levels of yeast extract (0.25 g/L). Five strains of LAB were isolated from naturally soured milk after enrichment in whey-based medium. One bacterial isolate, designated MNM2, exhibited a remarkable capability to utilize whey lactose and give a high biomass yield on lactose. This strain was identified as Lactobacillus casei by its 16S rDNA sequence. A kinetic study of cell growth, lactose consumption, and titratable acidity production of this bacterial strain was performed in a bioreactor. The biomass yield on lactose, the percentage of lactose consumption, and the maximum increase in cell mass obtained in the bioreactor were 0.165 g of biomass/g of lactose, 100%, and 2.0 g/L, respectively, which were 1.44, 1.11, and 2.35 times higher than those found in flask cultures. The results suggest that it is possible to produce LAB biomass from a whey-based medium supplemented with minimal amounts of yeast extract.
authors.affiliation: Departamento de Ingenieria Bioquimica, Escuela Nacional de Ciencias Biologicas, del I.P.N. Carpio y Plan de Ayala, Centro Operativo Naranjo, Apdo. Postal C.O.N.-256, Jaime Torres Bodet No. 142, Col. Santa Maria la Rivera, CP 06401, Mexico, DF Mexico.
authors.forename: María Elena
authors.initials: ME
authors.lastname: Mondragón-Parada
authors.forename: Minerva
authors.initials: M
authors.lastname: Nájera-Martínez
authors.forename: Cleotilde
authors.initials: C
authors.lastname: Juárez-Ramírez
authors.forename: Juvencio
authors.initials: J
authors.lastname: Galíndez-Mayer
authors.forename: Nora
authors.initials: N
authors.lastname: Ruiz-Ordaz
authors.forename: Eliseo
authors.initials: E
authors.lastname: Cristiani-Urbina
mesh_terms: D000818:Animals; D019149:Bioreactors / Q000382:microbiology*; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation; D019344:Lactic Acid / Q000378:metabolism*; D007780:Lacticaseibacillus casei / Q000166:cytology / Q000302:isolation & purification* / Q000502:physiology*; D007785:Lactose / Q000378:metabolism*; D008892:Milk / Q000382:microbiology*
chemical_list: D019344:Lactic Acid; D007785:Lactose