Beta-glucose 1-phosphate-interconverting enzymes in maltose- and trehalose-fermenting lactic acid bacteria.

• 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.

Subject headings

NATURVETENSKAP  -- Biologi -- Mikrobiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Microbiology (hsv//eng)

Keyword

Support

Phosphoglucomutase : metabolism

Maltose : metabolism

Lactococcus lactis : growth & development

Lactococcus lactis : enzymology

Glucosyltransferases : metabolism

Glucosephosphates : metabolism

Glucose

Culture Media

Comparative Study

Non-U.S. Gov't

Trehalose : metabolism

Publication and Content Type

art (subject category)

ref (subject category)