Project Number
WW 10-06
Project title
Investigation of the occurrence and growth of lactic acid bacteria in wine and factors affecting the induction of malolactic fermentation
Project leader
Du Plessis, H W
Team members
Jolly, N P
Bergstedt, J
Project description
The factors influencing malolactic fermentation (MLF) were investigated in this project. Chardonnay and MLF problems associated with this cultivar, were one of the main focus points of this project. Yeast, bacteria and cultivar interaction studies confirmed that the progress of malolactic fermentation was slower in Chardonnay than in Sauvignon blanc wine. It was shown that certain commercial cultures were more sensitive to Chardonnay than others and that this had an effect on malolactic fermentation. Lactic acid bacteria and cultivar interaction tests showed that the cultivar has an impact, but that the most important factor to consider in the occurrence of malolactic fermentation was the yeast and lactic acid bacteria interaction.
Investigations on Chardonnay from different regions showed that there were differences between the regions. There were also differences amongst cellars from the same region. The Chardonnay factor appears to be cultivar associated, but is strongly affected by cellar practices. It was found that D 47, like VIN 13, has an inhibitory and negative effect on malolactic fermentation. The degree of inhibition varied for the different malolactic fermentation cultures. The lactic acid bacteria culture Viniflora CH 35 was the least affected by yeast and cultivar combination.
The investigation into a nutrient deficiency in Chardonnay did not point out any specific deficiency. Only Bactiv aid (nutrient source for lactic acid bacteria) had an effect on the progress of malolactic fermentation. It was again demonstrated that VIN 7 supported malolactic fermentation and that VIN 13 did not. Further investigation of the influence of Bactiv aid on the progress of malolactic fermentation was performed. Bactiv aid had a positive effect on the progress of malolactic fermentation. Further trials are needed to determine the extent of Bactiv aid’s ability to facilitate malolactic fermentation.
Poster(s)
Loubser, P A. 1997. Interactions between lactic acid bacteria and South African wine yeast. Poster presented at the 18th International Specialized Symposium on Yeasts. 24-29 August, Bled, Slovenia.
Loubser, P A. 1997. Interactions between lactic acid bacteria and South African wine yeast. Poster presented at the 22nd National Congress of the South African Society for Enology and Viticulture. 12-13 November, Cape Town, South Africa.
Loubser, P A. 1998. Temperature affects malolactic fermentation. Poster presented at the 23rd National Congress of the South African Society for Enology and Viticulture. 12-13 November, Cape Town, South Africa.
Du Plessis, H W and Jolly, N P. 2002. Malolactic fermentation in Chardonnay. Poster presented at the 26th National Congress of the South African Society for Enology and Viticulture. 13-15 November, Cape Town, South Africa.
Article
Dicks, L M T, Loubser, P A, Augustyn, O P H. 1995. Identification of Leuconostocoenos from South African fortified wines by numerial analysis of total soluble cell protein patterns and DNA-DNA hybridizations, Journal of Applied Bacteriology, v. 79 (1) (p. 43-48)
Loubser, P A. 1997. Die werkverrigting van appelmelksuurkulture in Suid-Afrikaanse wyne, Wynboer, Mnth May (p. T10-T11)
Loubser, P A. 1999. Die interaksie tussen appelmelksuurbakteriee, wyndruifkultivars en Suid-Afrikaanse wyngiste, Wynboer, Mnth May (p. T2-4)
Loubser, P A. 1999. Optimum temperatuur – ‘n besliste voorvereiste vir suksesvolle appel-melksuurgisting, Wynboer, Mnth May (p. T10-11)
Paper
Loubser, P A, Dicks, L M T. Lonvaud-Funel, A (ed). 1995. Identification of Leuconostoc oenos from South African fortified wines, IN: Proceedings of the 5th Symposium International d’Oenologie: Oenology 95. (p. 332-336) 15-17 June 1995, Paris, Londres,