Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 2 de 2
Filter
Add more filters










Database
Language
Publication year range
1.
J Microbiol Methods ; 52(3): 325-32, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12531501

ABSTRACT

Gas chromatography-mass spectrometry/solid phase microextraction (GC-MS/SPME) was applied to identify microbial volatile organic compounds (MVOCs) in water-damaged, mold-infested building materials (gypsum board papers (n=2), mineral wool, and masonite) and in cultivated molds (Aspergillus penicillioides, Stachybotrys chartarum, and Chaetomium globosum). Three SPME fibers (65-microm PDMS-DVB, 75-microm Carboxen-PDMS, and 70-microm Carbowax-stableflex) designed for automated injection were used of which the latter showed best performance. A number of previously reported MVOCs were detected both in the building materials and the cultivated molds. In addition, methyl benzoate was identified both in the S. chartarum and A. penicillioides cultures and in the building materials. SPME combined with GC-MS may be a useful method for the determination of MVOCs emitted from mold-infested building materials.


Subject(s)
Air Pollution, Indoor/analysis , Fungi/chemistry , Gas Chromatography-Mass Spectrometry/methods , Housing , Aspergillus/chemistry , Aspergillus/growth & development , Aspergillus/isolation & purification , Benzoates/analysis , Chaetomium/chemistry , Chaetomium/growth & development , Chaetomium/isolation & purification , Hot Temperature , Organic Chemicals/isolation & purification , Stachybotrys/chemistry , Stachybotrys/growth & development , Stachybotrys/isolation & purification , Time Factors , Volatilization
2.
Microbiology (Reading) ; 143 ( Pt 3): 855-865, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9084169

ABSTRACT

Maltose metabolism in Lactococcus lactis involves the conversion of beta-glucose 1-phosphate to glucose 6-phosphate, a reaction which is reversibly catalysed by a maltose-inducible and glucose-repressible beta-phosphoglucomutase (beta-PGM). The gene encoding beta-PGM (pgmB) was cloned from a genomic library of L. lactis using antibodies. The nucleotide sequence of a 5695 bp fragment was determined and six ORFs, including the pgmB gene, were found. The gene expressed a polypeptide with a calculated molecular mass of 24210 Da, which is in agreement with the molecular mass of the purified beta-PGM (25 kDa). A short sequence at the N-terminus was found to be similar to known metal-binding domains. The expression of beta-PGM in L lactis was found to be induced also by trehalose and sucrose, and repressed by lactose in the growth medium. This indicates that beta-PGM does not serve solely to degrade maltose, but that it is also involved in the metabolism of other carbohydrates. The specific activity of beta-PGM during fermentation was dependent on the maltose concentration in the medium. The maximum specific activity of beta-PGM increased by a factor of 4.6, and the specific growth rate by a factor of 7, when the maltose concentration was raised from 0.8 to 11.0 g l-1. Furthermore, a higher amount of lactate produced relative to formate, acetate and ethanol was observed when the initial maltose concentration in the medium was increased. The specific activity of alpha-PGM responded similarly to beta-PGM, but the magnitude of the response was lower. Preferential sugar utilization and alpha- and beta-PGM suppression was observed when L. lactis was grown on the substrate combinations glucose and maltose, or lactose and maltose; maltose was the least-preferred sugar. In contrast, galactose and maltose were utilized concurrently and both PGM activities were high throughout the fermentation.


Subject(s)
Genes, Bacterial , Lactococcus lactis/genetics , Phosphoglucomutase/genetics , Amino Acid Sequence , Base Sequence , Cloning, Molecular , Gene Expression Regulation, Bacterial , Gene Expression Regulation, Enzymologic , Lactococcus lactis/enzymology , Molecular Sequence Data , Sequence Alignment
SELECTION OF CITATIONS
SEARCH DETAIL
...