title: Microbial communities and chemical changes during fermentation of sugary Brazilian kefir.
abstract: The microorganisms associated with sugary Brazilian kefir beverage were investigated using a combination of culture-dependent and -independent methods. A total of 289 bacteria and 129 yeasts were identified via phenotypic and genotypic methods. Lb. paracasei (23.8%) was the major bacterial isolate identified, followed by Acetobacter lovaniensis (16.31%), Lactobacillus parabuchneri (11.71%), Lactobacillus kefir (10.03%) and Lactococcus lactis (10.03%). Saccharomyces cerevisiae (54.26%) and Kluyveromyces lactis (20.15%) were the most common yeast species isolated. Scanning electron microscopy showed that the microbiota was dominated by lemon-shaped yeast cells growing in close association with Lactobacillus (long and curved). Some lactic acid bacteria detected by sequence analysis of DGGE (denaturing gradient gel electrophoresis) bands were not recovered at any time through fermentation by plating. Conversely, DGGE fingerprints did not reveal bands corresponding to some of the species isolated by culturing methods. The bacteria Acetobacter lovaniensis and the yeast Kazachstania aerobia are described for the first time in sugary kefir. During the 24 h of fermentation, the concentration of lactic acid ranged from 0.2 to 1.80 mg/ml, and that of acetic acid increased from 0.08 to 1.12 mg/ml. The production of ethanol was limited, reaching a final mean value of 1.24 mg/ml.
authors.affiliation: Biology Department, Federal University of Lavras (UFLA), 37.200-000, Lavras, MG, Brazil.
authors.forename: Karina Teixeira
authors.initials: KT
authors.lastname: Magalhães
authors.forename: G V
authors.initials: GV
authors.lastname: de M Pereira
authors.forename: Disney Ribeiro
authors.initials: DR
authors.lastname: Dias
authors.forename: Rosane Freitas
authors.initials: RF
authors.lastname: Schwan
references.citation: Food Microbiol. 2008 May;25(3):492-501
references.pmid: 18355674
references.citation: Int J Food Microbiol. 2007 Nov 30;120(1-2):146-51
references.pmid: 17888538
references.citation: Mol Ecol. 1997 May;6(5):475-82
references.pmid: 9161015
references.citation: FEMS Yeast Res. 2007 Sep;7(6):966-72
references.pmid: 17697080
references.citation: J Ind Microbiol Biotechnol. 2009 Apr;36(4):557-69
references.pmid: 19190949
references.citation: Antonie Van Leeuwenhoek. 2001 Jan;79(1):89-96
references.pmid: 11392489
references.citation: J Gen Appl Microbiol. 2000 Jun;46(3):147-165
references.pmid: 12483588
references.citation: J Biotechnol. 2003 Jan 9;100(1):43-53
references.pmid: 12413785
references.citation: Curr Microbiol. 2001 Mar;42(3):199-202
references.pmid: 11270655
references.citation: Int J Food Microbiol. 2006 Mar 15;107(2):112-23
references.pmid: 16297479
references.citation: J Dairy Res. 2001 Nov;68(4):639-52
references.pmid: 11928960
references.citation: J Ind Microbiol Biotechnol. 2002 Jan;28(1):1-6
references.pmid: 11938463
references.citation: Nucleic Acids Res. 1997 Dec 15;25(24):4876-82
references.pmid: 9396791
references.citation: Food Microbiol. 2009 Dec;26(8):770-5
references.pmid: 19835760
references.citation: J Clin Microbiol. 1999 Apr;37(4):920-4
references.pmid: 10074502
references.citation: FEMS Microbiol Rev. 2004 May;28(2):251-60
references.pmid: 15109787
references.citation: J Appl Bacteriol. 1990 Sep;69(3):311-20
references.pmid: 2246138
references.citation: Appl Environ Microbiol. 1997 Sep;63(9):3367-73
references.pmid: 9292986
references.citation: Int J Food Microbiol. 2006 May 25;109(1-2):79-87
references.pmid: 16499984
references.citation: FEMS Microbiol Ecol. 2006 Jul;57(1):106-15
references.pmid: 16819954
references.citation: Brief Bioinform. 2008 Jul;9(4):299-306
references.pmid: 18417537