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The gene cluster involved in the choline-glycine betaine conversion pathway was cloned from chromosomal DNA of the Gram-positive moderate halophile Halobacillus dabanensis D-8T. Nucleotide sequence analysis revealed four genes, designated gbsT, gbsI, gbsA, and gbsB, which are clustered in a 5.1-kb fragment. After heterologous expression of gbsAB in the Escherichia coli mutant strain PD141, the transformed cells were able to grow in a selective M63 medium containing 0.7 M NaCl and 1 mM choline, in contrast to the mutant strain. Glycine betaine biosynthesis was restored and its accumulation was confirmed by using 13C nuclear magnetic resonance spectroscopy. [ABSTRACT FROM AUTHOR]

Fungal communities in decaying sapwood and heartwood of K. evelyniana were demonstrated through construction of four 18 S rRNA gene libraries. The 210 sequenced clones were clustered into 11 subgroups, belonging to Basidiomycota (71.9%) and to Ascomycota (22.4%) and unclassified (1 subgroup; 5.7%). The heartwood displayed higher species richness than the sapwood. Basidiomycota were dominant in either the heartwood or the sapwood. Phylogenetically diverse Homobasidiomycetes were detected in the heartwood, contrary to the sapwood, where Heterobasidiomycetes were detected. Clones close to Spongipellis unicolor dominated in the heartwood (21 of 99 clones), while those close to Hydnochaete olivacea dominated in the sapwood (41 of 111 clones). The common species between the two parts were those related to S. unicolor, Calocera cornea, Debaryomyces hansenii, Davidiella tassiana, and Nomuraea rileyi and those from Chaetothyriomycetes. [ABSTRACT FROM AUTHOR]

By using Southern blot hybridization and inverse polymerase chain reaction, a 5.5-kb DNA fragment was obtained from the genomic DNA of Halobacillus trueperi DSM10404T. Sequence analysis revealed that it contained a potential operon with high levels of sequence similarity to the opuA operon encoding glycine betaine transporter from Bacillus subtilis, which is a member of the ATP-binding cassette (ABC) substrate binding the protein-dependent transporter superfamily. The potential operon, designated as qatA (quaternary amine transporter), consists of three structural genes, which are predicted to encode an ATP-binding protein (QatAA), a membrane-associated protein (QatAB), and an extracellular substrate-binding protein (QatAC). Moreover, the putative promoter region of the operon was found with close homology to the σA-dependent promoter of B. subtilis. Reverse transcription (RT)–PCR analysis revealed that qatAA, qatAB, and qatAC genes were transcribed in cells of H. trueperi. Cells of Escherichia coli mutant MKH13 harboring qatA on pAY41 were able to grow on selective M9 salt medium containing glycine betaine and accumulated glycine betaine in the cytoplasm, showing that qatAA, qatAB, and qatAC genes together encode a functional glycine betaine transporter. [ABSTRACT FROM AUTHOR]

By using Southern blot hybridization and inverse polymerase chain reaction, a 5.5-kb DNA fragment was obtained from the genomic DNA of Halobacillus trueperi DSM10404T. Sequence analysis revealed that it contained a potential operon with high levels of sequence similarity to the opuA operon encoding glycine betaine transporter from Bacillus subtilis, which is a member of the ATP-binding cassette (ABC) substrate binding the protein-dependent transporter superfamily. The potential operon, designated as qatA (quaternary amine transporter), consists of three structural genes, which are predicted to encode an ATP-binding protein (QatAA), a membrane-associated protein (QatAB), and an extracellular substrate-binding protein (QatAC). Moreover, the putative promoter region of the operon was found with close homology to the σA-dependent promoter of B. subtilis. Reverse transcription (RT)–PCR analysis revealed that qatAA, qatAB, and qatAC genes were transcribed in cells of H. trueperi. Cells of Escherichia coli mutant MKH13 harboring qatA on pAY41 were able to grow on selective M9 salt medium containing glycine betaine and accumulated glycine betaine in the cytoplasm, showing that qatAA, qatAB, and qatAC genes together encode a functional glycine betaine transporter. [ABSTRACT FROM AUTHOR]

A correction to the article that was published in the previous issue of the journal "Current Microbiology," incorrectly listing the GenBank assigned accession numbers, is presented.

The gene cluster involved in the choline-glycine betaine conversion pathway was cloned from chromosomal DNA of the Gram-positive moderate halophile Halobacillus dabanensis D-8T. Nucleotide sequence analysis revealed four genes, designated gbsT, gbsI, gbsA, and gbsB, which are clustered in a 5.1-kb fragment. After heterologous expression of gbsAB in the Escherichia coli mutant strain PD141, the transformed cells were able to grow in a selective M63 medium containing 0.7 M NaCl and 1 mM choline, in contrast to the mutant strain. Glycine betaine biosynthesis was restored and its accumulation was confirmed by using 13C nuclear magnetic resonance spectroscopy. [ABSTRACT FROM AUTHOR]

A correction to the article that was published in the previous issue of the journal "Current Microbiology," incorrectly listing the GenBank assigned accession numbers, is presented.