title: Present knowledge of the bacterial microflora in the extreme environment of sugar thick juice.
abstract: The diversity of the bacterial population in sugar thick juice, an intermediate product in the production of beet sugar, which exhibits an extreme, osmophilic environment with a water activity value (a(w)) less than 0.86, was assessed with both culture-dependent and -independent 16S ribosomal RNA (rRNA) gene-based analyses. In comparison with previous studies, the number of different thick juice bacterial species increased from 29 to 72. Remarkably, a limited, gram-positive, culturable flora, encompassing species of Bacillus, Staphylococcus and mainly Tetragenococcus dominated thick juice during storage, while a more heterogeneous and unculturable fraction of Acinetobacter, Sporolactobacillus and Thermus species could be detected in freshly produced thick juice. Notably, almost all bacteria detected in the thick juice were also detected in the air, emphasising the importance of further investigation and assessment of strategies to reduce (air) contamination during processing and storage. The discovery of the contamination source may be used for the development of management strategies for thick juice degradation resulting from microbial activity.
authors.affiliation: Laboratory of Food Microbiology and Leuven Food Science and Nutrition Research Centre, Department of Microbial and Molecular Systems, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, 3001 Leuven, Belgium.
authors.forename: Annelies
authors.initials: A
authors.lastname: Justé
authors.forename: Bart
authors.initials: B
authors.lastname: Lievens
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Frans
authors.forename: Michael
authors.initials: M
authors.lastname: Klingeberg
authors.forename: Chris W
authors.initials: CW
authors.lastname: Michiels
authors.forename: Kris A
authors.initials: KA
authors.lastname: Willems
mesh_terms: D000391:Air Microbiology; D001419:Bacteria / Q000254:growth & development / Q000302:isolation & purification*; D027461:Beta vulgaris / Q000737:chemistry; D015169:Colony Count, Microbial / Q000379:methods; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005506:Food Contamination / Q000032:analysis*; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D015723:Gene Library; D007218:Industrial Microbiology / Q000379:methods*; D009994:Osmolar Concentration; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013045:Species Specificity; D013395:Sucrose / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D013395:Sucrose