title: PCR-DGGE analysis of bacterial community dynamics in kava beverages during refrigeration.
abstract: OBJECTIVE
  Kava beverages are highly perishable even under refrigerated conditions. This study aimed to investigate the bacterial community dynamics in kava beverages during refrigeration.
  
  
  RESULTS
  Four freshly made kava beverages were obtained from kava bars and stored at 4°C. On days 0, 3 and 6, the aerobic plate count (APC), lactic acid bacteria (LAB) count and yeast and mould count (YMC) of the samples were determined. Meanwhile, bacterial DNA was extracted from each sample and subjected to the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Moreover, species-specific PCR assays were employed to identify predominant Pseudomonas spp. involved in kava spoilage. Over the storage period, the APC, LAB count and YMC of the four kava beverages all increased, whereas their pH values decreased. The DGGE profile revealed diverse bacterial populations in the samples. LAB, such as Weissella soli, Lactobacillus spp. and Lactococcus lactis, were found in the kava beverages. Species-specific PCR assays detected Pseudomonas putida and Pseudomonas fluorescens in the samples; Ps. fluorescens became dominant during refrigeration.
  
  
  CONCLUSIONS
  LAB and Pseudomonas may play a significant role in the spoilage of kava beverages.
  
  
  CONCLUSIONS
  This study provides important information that may be used to extend the shelf life of kava beverages.
authors.affiliation: Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Honolulu, Hawaii, HI, USA.
authors.forename: J
authors.initials: J
authors.lastname: Dong
authors.forename: P
authors.initials: P
authors.lastname: Kandukuru
authors.forename: A S
authors.initials: AS
authors.lastname: Huang
authors.forename: Y
authors.initials: Y
authors.lastname: Li
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D001628:Beverages / Q000382:microbiology; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis / Q000379:methods; D005516:Food Microbiology / Q000379:methods*; D020901:Kava / Q000382:microbiology*; D007778:Lactobacillus / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods; D012034:Refrigeration; D058836:Weissella / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial