Contamination of immobilized yeast bioreactors

Jukka Kronlöf, Auli Haikara

Research output: Contribution to journalArticleScientificpeer-review

13 Citations (Scopus)

Abstract

Microbiological contamination of immobilized yeast bioreactors for lagering of beer was studied. Four common brewery contaminants and two contaminants isolated from the continuous processing system were tested for their ability to survive and grow in the packed bed DEAE‐cellulose bioreactors. Bacterial contaminants were washed out within less than six weeks without causing any alterations in the flavour composition of the beer. The initial contamination levels were 104–106 cells ml−1. Gram positive lactic acid bacteria, Lactobacillus brevis and Pediococcus damnosus, were more persistent than a Gram negative wort bacterium, Enterobacter agglomerans.

The wild yeasts Saccharomyces cerevisiae (ex. diastaticus) and Candida krusei were the most persistent contaminants and the only ones able to grow in the reactors. Another wild yeast, Rhodotorula rubra, did not survive in competition with brewer's yeast and was washed out within a few weeks. C. krusei and R. rubra were previously isolated from a spontaneously contaminated system. None of the contaminants caused formation of phenolic or other off‐flavour compounds in detectable levels.

Original languageEnglish
Pages (from-to)375 - 380
Number of pages6
JournalJournal of the Institute of Brewing
Volume97
Issue number5
DOIs
Publication statusPublished - 1991
MoE publication typeA1 Journal article-refereed

Fingerprint

Bioreactors
bioreactors
Rhodotorula rubra
Candida krusei
Yeasts
yeasts
beers
Saccharomyces cerevisiae
Pediococcus damnosus
Lactobacillus brevis
Pediococcus
Rhodotorula
continuous systems
brewers yeast
Pantoea agglomerans
wort (brewing)
Enterobacter
brewing industry
bacterial contamination
Gram-positive bacteria

Cite this

Kronlöf, Jukka ; Haikara, Auli. / Contamination of immobilized yeast bioreactors. In: Journal of the Institute of Brewing. 1991 ; Vol. 97, No. 5. pp. 375 - 380.
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abstract = "Microbiological contamination of immobilized yeast bioreactors for lagering of beer was studied. Four common brewery contaminants and two contaminants isolated from the continuous processing system were tested for their ability to survive and grow in the packed bed DEAE‐cellulose bioreactors. Bacterial contaminants were washed out within less than six weeks without causing any alterations in the flavour composition of the beer. The initial contamination levels were 104–106 cells ml−1. Gram positive lactic acid bacteria, Lactobacillus brevis and Pediococcus damnosus, were more persistent than a Gram negative wort bacterium, Enterobacter agglomerans. The wild yeasts Saccharomyces cerevisiae (ex. diastaticus) and Candida krusei were the most persistent contaminants and the only ones able to grow in the reactors. Another wild yeast, Rhodotorula rubra, did not survive in competition with brewer's yeast and was washed out within a few weeks. C. krusei and R. rubra were previously isolated from a spontaneously contaminated system. None of the contaminants caused formation of phenolic or other off‐flavour compounds in detectable levels.",
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Contamination of immobilized yeast bioreactors. / Kronlöf, Jukka; Haikara, Auli.

In: Journal of the Institute of Brewing, Vol. 97, No. 5, 1991, p. 375 - 380.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Contamination of immobilized yeast bioreactors

AU - Kronlöf, Jukka

AU - Haikara, Auli

N1 - Project code: BIO8010

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AB - Microbiological contamination of immobilized yeast bioreactors for lagering of beer was studied. Four common brewery contaminants and two contaminants isolated from the continuous processing system were tested for their ability to survive and grow in the packed bed DEAE‐cellulose bioreactors. Bacterial contaminants were washed out within less than six weeks without causing any alterations in the flavour composition of the beer. The initial contamination levels were 104–106 cells ml−1. Gram positive lactic acid bacteria, Lactobacillus brevis and Pediococcus damnosus, were more persistent than a Gram negative wort bacterium, Enterobacter agglomerans. The wild yeasts Saccharomyces cerevisiae (ex. diastaticus) and Candida krusei were the most persistent contaminants and the only ones able to grow in the reactors. Another wild yeast, Rhodotorula rubra, did not survive in competition with brewer's yeast and was washed out within a few weeks. C. krusei and R. rubra were previously isolated from a spontaneously contaminated system. None of the contaminants caused formation of phenolic or other off‐flavour compounds in detectable levels.

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