title: Beta-glucose 1-phosphate-interconverting enzymes in maltose- and trehalose-fermenting lactic acid bacteria.
abstract: Maltose and trehalose catabolic pathways are linked through their common enzyme, beta-phosphoglucomutase, and metabolite, beta-glucose 1-phosphate, in Lactococcus lactis. Maltose is degraded by the concerted action of maltose phosphorylase and beta-phosphoglucomutase, whereas trehalose is assimilated by a novel pathway, including the recently discovered enzyme, trehalose 6-phosphate phosphorylase, and beta-phosphoglucomutase. In the present study, 40 strains of lactic acid bacteria were investigated for utilization of metabolic reactions involving beta-glucose 1-phosphate. All genera of the low G+C content lactic acid bacteria belonging to the clostridial subbranch of Gram-positive bacteria were represented in the study. The strains, which fermented maltose or trehalose, were investigated for beta-phosphoglucomutase, maltose phosphorylase and trehalose 6-phosphate phosphorylase activity, as indications of maltose and trehalose catabolic pathways involving beta-glucose 1-phosphate interconversions. Eighty per cent of all strains fermented maltose and, of these strains, 63% were shown to use a maltose phosphorylase/beta- phosphoglucomutase pathway. One-third of the strains fermenting trehalose were found to harbour trehalose 6-phosphate phosphorylase activity, and these were also shown to possess beta-phosphoglucomutase activity. Mainly L. lactis and Enterococcus faecalis strains were found to harbour the novel trehalose 6-phosphate phosphorylase/beta-phosphoglucomutase pathway. As lower beta-glucose 1-phosphate interconverting enzyme activities were observed in the majority of glucose-cultivated lactic acid bacteria, glucose was suggested to repress the synthesis of these enzymes in most strains. Thus, metabolic reactions involving the beta-anomer of glucose 1-phosphate are frequently found in both maltose- and trehalose-utilizing lactic acid bacteria.
authors.affiliation: Applied Microbiology, Center for Chemistry and Chemical Engineering, Lund Institute of Technology, Lund University, PO Box 124, SE-221 00 Lund, Sweden.
authors.forename: Ulrika
authors.initials: U
authors.lastname: Andersson
authors.forename: Peter
authors.initials: P
authors.lastname: Rådström
mesh_terms: D003470:Culture Media; D005947:Glucose; D005958:Glucosephosphates / Q000378:metabolism*; D005964:Glucosyltransferases / Q000378:metabolism; D013294:Lactococcus lactis / Q000201:enzymology* / Q000254:growth & development; D008320:Maltose / Q000378:metabolism*; D010733:Phosphoglucomutase / Q000378:metabolism; D014199:Trehalose / Q000378:metabolism*
chemical_list: D003470:Culture Media; D005958:Glucosephosphates; D008320:Maltose; D014199:Trehalose; C031590:glucose-1-phosphate; D005964:Glucosyltransferases; C442221:trehalose-6-phosphate phosphorylase; C021535:maltose phosphorylase; D010733:Phosphoglucomutase; D005947:Glucose