Diversity of the total bacterial community associated with Ghanaian and Brazilian cocoa bean fermentation samples as revealed by a 16 S rRNA gene clone library.
Cocoa bean fermentation is a spontaneous process involving a succession of microbial activities, starting with yeasts, followed by lactic acid bacteria and acetic acid bacteria. So far, all microbiological studies about cocoa bean fermentation were based on culture-dependent (isolation, cultivation, and identification), or, more recently, culture-independent (PCR-DGGE, or polymerase chain reaction denaturing gradient gel electrophoresis) methods. Using a metagenomic approach, total DNA was extracted from heap and box fermentations at different time points and from different locations (Ghana and Brazil, respectively) to generate a 16 S rDNA clone library that was sequenced. The sequencing data revealed a low bacterial diversity in the fermentation samples and were in accordance with the results obtained through culture-dependent and a second, culture-independent analysis (PCR-DGGE), suggesting that almost all bacteria involved in the fermentation process are cultivable. One exception was the identification by 16 S rDNA library sequencing of Gluconacetobacter species of acetic acid bacteria that were not detected by the two other approaches. The presence of Enterobacteriaceae related to Erwinia/Pantoea/Tatumella, as revealed by 16 S rDNA library sequencing, suggests an impact of these bacteria on fermentation.
Garcia-Armisen
Tamara
T
Department of Molecular and Cellular Interactions, Flanders Institute of Biotechnology, Vrije Universiteit Brussel, Brussels, Belgium.
Papalexandratou
Zoi
Z
Hendryckx
Hugo
H
Camu
Nicholas
N
Vrancken
Gino
G
De Vuyst
Luc
L
Cornelis
Pierre
P
D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D044822:Biodiversity; D001938:Brazil; D002099:Cacao / Q000382:microbiology*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D005285:Fermentation; D005638:Fruit / Q000382:microbiology; D015723:Gene Library; D005869:Ghana; D012336:RNA, Ribosomal, 16S / Q000235:genetics
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S