Cloning of the rice seed α-globulin-encoding gene: sequence similarity of the 5'-flanking region to those of the genes encoding wheat high-molecular-weight glutenin and barley D hordein

ABSTRACT Fructosyltransferase (FTF) enzymes produce fructose polymers (fructans) from sucrose. Here, we report the isolation and characterization of an FTF-encoding gene from Lactobacillus reuteri strain 121. A C-terminally truncated version of the ftf gene was successfully expressed in Escherichia coli. When incubated with sucrose, the purified recombinant FTF enzyme produced large amounts of fructo-oligosaccharides (FOS) with β-(2→1)-linked fructosyl units, plus a high-molecular-weight fructan polymer (>107) with β-(2→1) linkages (an inulin). FOS, but not inulin, was found in supernatants of L. reuteri strain 121 cultures grown on medium containing sucrose. Bacterial inulin production has been reported for only Streptococcus mutans strains. FOS production has been reported for a few bacterial strains. This paper reports the first-time isolation and molecular characterization of (i) a Lactobacillus ftf gene, (ii) an inulosucrase associated with a generally regarded as safe bacterium, (iii) an FTF enzyme synthesizing both a high molecular weight inulin and FOS, and (iv) an FTF protein containing a cell wall-anchoring LPXTG motif. The biological relevance and potential health benefits of an inulosucrase associated with an L. reuteri strain remain to be established.

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PCR analysis of genes encoding allelic variants of high-molecular-weight glutenin subunits at the Glu-D1 locus

Theoretical and Applied Genetics ◽

10.1007/bf00225894 ◽

1994 ◽

Vol 88 (2) ◽

pp. 175-180 ◽

Cited By ~ 46

Author(s):

R. D'Ovidio ◽

E. Porceddu ◽

D. Lafiandra

Keyword(s):

Molecular Weight ◽

High Molecular Weight ◽

Pcr Analysis ◽

Glutenin Subunits ◽

Allelic Variants ◽

Genes Encoding

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Reclassification of Lactobacillus amylophilus LMG 11400 and NRRL B-4435 as Lactobacillus amylotrophicus sp. nov.

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijs.0.64463-0 ◽

2006 ◽

Vol 56 (11) ◽

pp. 2523-2527 ◽

Cited By ~ 20

Author(s):

Sabri M. Naser ◽

Marc Vancanneyt ◽

Cindy Snauwaert ◽

Gino Vrancken ◽

Bart Hoste ◽

...

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Type Strain ◽

Gene Sequence ◽

Sequence Similarity ◽

Alpha Subunit ◽

Cell Protein ◽

Rrna Gene ◽

Gene Sequences ◽

Genes Encoding

The taxonomic position of six Lactobacillus amylophilus strains isolated from swine waste-corn fermentations was reinvestigated. All strains were included in a multilocus sequence analysis (MLSA) study for species identification of Lactobacillus using the genes encoding the phenylalanyl-tRNA synthase alpha subunit (pheS) and RNA polymerase alpha subunit (rpoA). Partial pheS and rpoA gene sequences showed that strains LMG 11400 and NRRL B-4435 represent a separate lineage that is distantly related to the type strain of L. amylophilus, LMG 6900T, and to three other strains of the species. The MLSA data showed that the two strains LMG 11400 and NRRL B-4435 constituted a distinct cluster, sharing 100 % pheS and rpoA gene sequence similarity. The other reference strains clustered together with the type strain of L. amylophilus, LMG 6900T, and were clearly differentiated from strains LMG 11400 and NRRL B-4435 (80 and 89 % pheS and rpoA gene sequence similarity, respectively). The 16S rRNA gene sequences of the latter two strains are 100 % identical, with the nearest phylogenetic neighbour L. amylophilus LMG 6900T showing only 97.2 % 16S rRNA gene sequence similarity. Further polyphasic taxonomic study based on whole-cell protein fingerprinting, DNA–DNA hybridization and biochemical features demonstrated that the two strains represent a single, novel Lactobacillus species, for which the name Lactobacillus amylotrophicus sp. nov. is proposed. The type strain is LMG 11400T (=NRRL B-4436T=DSM 20534T).

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