PROIMI   05436
PLANTA PILOTO DE PROCESOS INDUSTRIALES MICROBIOLOGICOS
Unidad Ejecutora - UE
artículos
Título:
Lactic acid bacteria isolated from apples are able to catabolise arginine
Autor/es:
MARIA J. SAVINO; SANCHEZ L. A,; SAGUIR, F.; MANCA DE NADRA, MARIA C.
Revista:
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
Editorial:
SPRINGER
Referencias:
Año: 2011
ISSN:
0959-3993
Resumen:
We investigated the potentiality of lactic acid bacteria (LAB) isolated
from two apples variety to utilize arginine at different initial pH
values. Apples surface contained average levels of bacteria ranging from
log 2.49 ± 0.53 to log 3.73 ± 0.48 cfu/ml for Red Delicious and Golden
Delicious varieties, respectively. Thirty-one strains able to develop in
presence of arginine at low pH were phenotypically and genotipically
identified as belonging to Lactobacillus, Pediococcus and Leuconostoc
genera. In general, they did not produce ammonia from arginine when
cultivated in basal medium with arginine (BMA) at pH 4.5 or 5.2. When
this metabolite was quantified only six strains belonging to Leuconostoc
dextranicum, Lactobacillus brevis and Lactobacillus plantarum species
formed higher ammonia amounts in BMA as compared to control. This was
correlated with arginine utilization and it was more pronounced at pH
4.5 than 5.2. Analysis of citrulline production confirmed the arginine
utilization in these bacteria by the arginine deiminase (ADI) pathway.
Maxima citrulline production was observed for Lactobacillus brevis M15
at the two pH values. In this strain ammonia was formed at higher rate
than citrulline, which was detected in concentration lower than 1 mM.
Thus, main LAB species found on apple surfaces with abilities to degrade
arginine by the ADI pathway under different conditions were reported
here at the first time. The results suggested that the ADI pathway in
apples LAB might not be mainly relevant for their survival in the acid
natural environmental, despite leading to the ammonia formation, which
may contribute to the increase in pH, coping the acid stress.