Glycerol metabolism of Lactobacillus rhamnosus ATCC 7469: cloning and expression of two glycerol kinase genes.
Lactobacillus rhamnosus ATCC 7469 was able to grow in glycerol as the sole source of energy in aerobic conditions, producing lactate, acetate, and diacetyl. A biphasic growth was observed in the presence of glucose. In this condition, glycerol consumption began after glucose was exhausted from the culture medium. Glycerol kinase activity was detected in L. rhamnosus ATCC 7469, a characteristic of microorganisms which catabolize glycerol in aerobic conditions. Genetic analysis revealed that this strain possesses two glycerol kinase genes: gykA and glpK, that encode for two different glycerol kinases GykA and GlpK, respectively. The glpK geneis associated in an operon with alpha-glycerophosphate oxidase (glpO) and glycerol facilitator (glpF) genes. Transcriptional analysis revealed that only glpK is expressed when L. rhamnosus was grown on glycerol.
Alvarez
María de Fátima
Mde F
Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco, Argentina. falvarez@cerela.org.ar
Medina
Roxana
R
Pasteris
Sergio E
SE
Strasser de Saad
Ana M
AM
Sesma
Fernando
F
D000085:Acetates / Q000378:metabolism; D000222:Adaptation, Physiological; D000332:Aerobiosis; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D003931:Diacetyl / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005947:Glucose / Q000032:analysis / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism*; D005991:Glycerol Kinase / Q000235:genetics* / Q000378:metabolism*; D005993:Glycerolphosphate Dehydrogenase / Q000235:genetics; D019344:Lactic Acid / Q000378:metabolism; D007778:Lactobacillus / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008969:Molecular Sequence Data; D009876:Operon; D011401:Promoter Regions, Genetic; D012329:RNA, Bacterial / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D000085:Acetates; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012333:RNA, Messenger; D019344:Lactic Acid; D005993:Glycerolphosphate Dehydrogenase; D005991:Glycerol Kinase; D005947:Glucose; D003931:Diacetyl; D005990:Glycerol