The Occurrence of Adenosine Diphosphate Glucose:Glycogen Transglucosylase in Bacteria

The enzymatic synthesis of glycogen in mammals occurs via a transglucosylation from uridine diphosphate glucose to a glycogen primer (Reaction 1) (l-4). UDP-glucose + a-(1,4)-glucan -+ a-(1,4)-glucosyl-glucan + UDPThere are many reports of glycogen accumulation in various species of bacteria (58).However, the enzymatic synthesis of glycogen in bacteria has received little attention.Madsen has reported the presence of a UDP-glucose:glycogen transferase in Agrobacterium tumefaciens (A6) (9).Recently the occurrence of an ADP-glucose : glycogen transglucosylase in cell-free extracts of Arthrobacter was reported (10).This enzyme was specific for the adenine sugar nucleotide; UDPglucose, TDP-glucose, GDP-glucose, CDP-glucose, and IDPglucose could not replace ADP-glucose as the glucosyl donor.Because of the specificity of the Arthrobacter glycogen transglucosylase, cell-free extracts of other bacteria were examined.Aerobacter aerogenes were grown on tryptone-glucose media (6); Agrobacterium tumefaciens were grown according to Madsen (11); Arthrobacter species NRRL B1973 were grown on glucosesynthetic media (12); Escherichia coli B were grown according to Holme and Palmistierna (5); Rhodospirillum rubrum