Novel Maltogenic Amylase CoMA from Corallococcus sp. Strain EGB Catalyzes the Conversion of Maltooligosaccharides and Soluble Starch to Maltose

Abstract

The gene encoding the novel amylolytic enzyme designated CoMA was cloned from sp. strain EGB. The deduced amino acid sequence contained a predicted lipoprotein signal peptide (residues 1 to 18) and a conserved glycoside hydrolase family 13 (GH13) module. The amino acid sequence of CoMA exhibits low sequence identity (10 to 19%) with cyclodextrin-hydrolyzing enzymes (GH13_20) and is assigned to GH13_36. The most outstanding feature of CoMA is its ability to catalyze the conversion of maltooligosaccharides (≥G3) and soluble starch to maltose as the sole hydrolysate. Moreover, it can hydrolyze γ-cyclodextrin and starch to maltose and hydrolyze pullulan exclusively to panose with relative activities of 0.2, 1, and 0.14, respectively. CoMA showed both hydrolysis and transglycosylation activities toward α-1,4-glycosidic bonds but not to α-1,6-linkages. Moreover, glucosyl transfer was postulated to be the major transglycosidation reaction for producing a high level of maltose without the attendant production of glucose. These results indicated that CoMA possesses some unusual properties that distinguish it from maltogenic amylases and typical α-amylases. Its physicochemical properties suggested that it has potential for commercial development. The α-amylase from sp. EGB, which was classified to the GH13_36 subfamily, can catalyze the conversion of maltooligosaccharides (≥G3) and soluble starch to maltose as the sole hydrolysate. An action mechanism for producing a high level of maltose without the attendant production of glucose has been proposed. Moreover, it also can hydrolyze γ-cyclodextrin and pullulan. Its biochemical characterization suggested that CoMA may be involved the accumulation of maltose in media.

A GH13 glycoside phosphorylase with unknown substrate specificity from Corallococcus coralloides

“…Bacteriolytic myxobacteria can utilize several polysaccharides and maltotriose as carbon source, but mono-or disaccharides do not stimulate growth [45]. Several new glycoside hydrolases from Corallococcus species, including some from family GH13, have already been characterised in the past few years [46][47][48][49][50][51]. Those GH13 hydrolases indeed process maltooligosaccharides, but the GH13 phosphorylase discussed in this work did not appear to show such activity.…”

Unravelling the diversity of glycoside hydrolase family 13 α-amylases from Lactobacillus plantarum WCFS1

“…A mesophilic behaviour was observed in Corallococcus sp. α-amylase, as almost all activity remained after the enzyme was incubated 60 min at temperatures higher than 40 °C; however, a dramatic loss of enzymatic stability occurred at temperatures higher than 50 °C after 30 min of incubation [16]. Thermostable α-amylases were described in Arthrobacter agilis [17] and Alicyclobacillus [14], as they were highly active after prolonged incubations at 60 °C.…”

“…Both L. plantarum WCFS1 α-amylases were inhibited by Cu 2+ ions, which also inhibited the activity of L. plantarum S21 [12], and Corallococcus sp. [16] α-amylases.…”

“…A higher catalytic efficiency on soluble starch was observed on the maltogenic amylase from Corallococcus sp. (16.91 (ml/mg) min −1 ) [16]. Among polysaccharides, the Lp_0179 catalytic efficiency was higher in amylose than in amylopectin, 1.44 and 0.45 (ml/mg) min −1 , respectively [7].…”

Synergistic Degradation of Pyrethroids by the Quorum Sensing-Regulated Carboxylesterase of Bacillus subtilis BSF01

“…The expression of ComA protein was carried out as reported with slight modification ( Zhou et al, 2018 ). Briefly, the E. coli BL21 (DE3) harboring the pET-SUMO- comA plasmid were cultured in 1 mL of LB broth with Kan (100 μg L –1 ) at 200 rpm and 37°C overnight.…”