Taxonomic structure and stability of the bacterial community in belgian sourdough ecosystems as assessed by culture and population fingerprinting.

A total of 39 traditional sourdoughs were sampled at 11 bakeries located throughout Belgium which were visited twice with a 1-year interval. The taxonomic structure and stability of the bacterial communities occurring in these traditional sourdoughs were assessed using both culture-dependent and culture-independent methods. A total of 1,194 potential lactic acid bacterium (LAB) isolates were tentatively grouped and identified by repetitive element sequence-based PCR, followed by sequence-based identification using 16S rRNA and pheS genes from a selection of genotypically unique LAB isolates.

Influence of turning and environmental contamination on the dynamics of populations of lactic acid and acetic acid bacteria involved in spontaneous cocoa bean heap fermentation in Ghana.

The influence of turning and environmental contamination on six spontaneous cocoa bean heap fermentations performed in Ghana was studied through a multiphasic approach, encompassing both microbiological (culture-dependent and culture-independent techniques) and metabolite target analyses. A sensory analysis of chocolate made from the fermented, dried beans was performed as well. Only four clusters were found among the isolates of acetic acid bacteria (AAB) identified: Acetobacter pasteurianus, Acetobacter ghanensis, Acetobacter senegalensis, and a potential new Acetobacter lovaniensis-like species.

Influence of geographical origin and flour type on diversity of lactic acid bacteria in traditional Belgian sourdoughs.

A culture-based approach was used to investigate the diversity of lactic acid bacteria (LAB) in Belgian traditional sourdoughs and to assess the influence of flour type, bakery environment, geographical origin, and technological characteristics on the taxonomic composition of these LAB communities. For this purpose, a total of 714 LAB from 21 sourdoughs sampled at 11 artisan bakeries throughout Belgium were subjected to a polyphasic identification approach. The microbial composition of the traditional sourdoughs was characterized by bacteriological culture in combination with genotypic identification methods, including repetitive element sequence-based PCR fingerprinting and phenylalanyl-tRNA synthase (pheS) gene sequence analysis.

Lactobacillus crustorum sp. nov., isolated from two traditional Belgian wheat sourdoughs.

A polyphasic taxonomic study of the lactic acid bacteria (LAB) population in three traditional Belgian sourdoughs, sampled between 2002 and 2004, revealed a group of isolates that could not be assigned to any recognized LAB species. Initially, sourdough isolates were screened by means of (GTG)(5)-PCR fingerprinting. Four isolates displaying unique (GTG)(5)-PCR patterns were further investigated by means of phenylalanyl-tRNA synthase (pheS) gene sequence analysis and represented a bifurcated branch that could not be allocated to any LAB species present in the in-house pheS database.

Population dynamics and metabolite target analysis of lactic acid bacteria during laboratory fermentations of wheat and spelt sourdoughs.

Four laboratory sourdough fermentations, initiated with wheat or spelt flour and without the addition of a starter culture, were prepared over a period of 10 days with daily back-slopping. Samples taken at all refreshment steps were used for determination of the present microbiota. Furthermore, an extensive metabolite target analysis of more than 100 different compounds was performed through a combination of various chromatographic methods including liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry.

Lactobacillus namurensis sp. nov., isolated from a traditional Belgian sourdough.

A biodiversity study on lactic acid bacteria (LAB) occurring in traditional Belgian sourdoughs resulted in the isolation of two Lactobacillus isolates, LMG 23583T and LMG 23584, that could not be assigned to any recognized LAB species. The two isolates were initially investigated by means of phenylalanyl-tRNA synthase (pheS) gene sequence analysis and were found to occupy a separate position relative to recognized Lactobacillus species present in the pheS database. Subsequently, their phylogenetic affiliation was determined by 16S rRNA gene sequence analysis, indicating that the two isolates belong to the Lactobacillus buchneri species group with Lactobacillus zymae, Lactobacillus acidifarinae and Lactobacillus spicheri as closest relatives.

Reclassification of Streptomyces nigrifaciens as a later synonym of Streptomyces flavovirens; Streptomyces citreofluorescens, Streptomyces chrysomallus subsp. chrysomallus and Streptomyces fluorescens as later synonyms of Streptomyces anulatus; Streptomyces chibaensis as a later synonym of Streptomyces corchorusii; Streptomyces flaviscleroticus as a later synonym of Streptomyces minutiscleroticus; and Streptomyces lipmanii, Streptomyces griseus subsp. alpha, Streptomyces griseus subsp. cretosus and Streptomyces willmorei as later synonyms of Streptomyces microflavus.

A DNA-DNA hybridization survey was performed on 13 Streptomyces species and two subspecies, dispersed over five genotypically defined clusters as delineated by Lanoot et al. [Syst Appl Microbiol 27 (2004), 84-92]. Within each of the latter clusters, strains shared DNA-DNA relatedness values above 70 %.