Project Number
IWBT W 14-01
Project title
Investigating the impact of acid proteases on wine quality
Project leader
Divol, B
Institution
University of Stellenbosch. Faculty of AgriSciences. Institute for Wine Biotechnology
Team members
Divol, B
Theron, L W
Bely, M
Coulon, J
Project description
Acid proteases have the potential to degrade grape and or wine proteins thereby releasing assimilable nitrogen and impacting on the secondary metabolism of fermentative microbial species. Literature also provides evidence that some proteases can contribute to reducing the risk of protein haze in white wine. However, the global impact of the addition of proteases in wine has never been investigated thoroughly. A recent study conducted at the Institute of Wine Biotechnology has shown that Metschnikowia pulcherrima possesses at least one gene encoding such a protease. Purification and characterisation of this protease is currently on-going. The proposed study aims to fully characterise the following properties of this protease under winemaking conditions: (i) their ability to degrade wine proteins and eliminate or reduce haze formation, (ii) their impact on wine composition and other oenological parameters upon direct addition. Finally, the presence and impact of the protease will also be assessed following co-inoculation of a strong protease-producing non-Saccharomyces yeast (e.g. M. pulcherrima) with Saccharomyces cerevisiae. This study will be conducted within the framework of the Oenodoc PhD programme in partnership with Dr Marina Bely (Université Bordeaux Segalen, Bordeaux, France) to benefit from her expertise and that of her research institution in wine fermentations and chemical analyses. A partnership with Biolaffort will also be established for the funding of the experimental work that will be carried out in Bordeaux.
Presentation(s)
Theron, L W, Zietsman, J J and Divol, B. 2013. Utilisation of acid protease produced by non-Saccharomyces yeast to prevent haze and release assimilable nitrogen. Paper presented at the 35th South African Society for Enology and Viticulture Conference. 13-15 November, Somerset West, South Africa.
Theron, L W, Zietsman, J J and Divol, B. 2013. Optimising recombinant expression and purification of aspartic protease from Metschnikowia pulcherrima. Paper presented at the 35th South African Society for Enology and Viticulture Conference. 13-15 November, Somerset West, South Africa.
Theron, L W and Divol, B. 2014. Characterisation of an enological relevant protease isolated from Metschnikowia pulcherrima. Paper presented at the 36th South African Society for Enology and Viticulture Conference. 12-14 November, Somerset West, South Africa.
Theron, L, Bely, M and Divol, B 2015. Enzymatic characterization of an enological relevant protease isolated from Metschnikowia pulcherrima. Paper presented at Oeno 2015: 10th International Symposium of Enology at Bordeaux. 29 June – 1 July, Bordeaux, France.
Theron, L W, Belly, M, Divol, B. 2014. Characterization of aspartic proteases from non-Saccharomyces yeasts to assess their oenological potential. Paper presented at the 36th South African Society of Enology and Viticulture Conference. 12-14 November, Somerset West, South Africa.
Theron, L W, Bely, M, Divol, B 2016. Investigating an aspartic protease isolated from Metschnikowia pulcherrima and its potential application in wine. Paper presented at the 25th International ICFMH Conference – FoodMicro 2016. 19-22 July 2016, Dublin, Ireland.
Theron, L W, Bely, M, Divol, B 2016. Investigating the potential application of MpAPr1, an aspartic protease isolated from Metschnikowia pulcherrima IWBT Y1123, for wine making purposes. Paper presented at the 38th South African Society of Enology and Viticulture Conference. 23-25 August, Somerset West, South Africa.
Article
Theron, L W, Divol, B. 2014. Microbial aspartic proteases: current and potential applications in industry, Applied Microbiology and Biotechnology, Mnth Nov v. 98 (21) (p. 8853-68)
http://doi.org/10.1007/s00253-014-6035-6
Theron, L W, Bely, M, Divol, B. 2017. Characterization of the enzymatic properties of MpAPr1, an aspartic protease secreted by the wine yeast Metschnikowia pulcherrima, Journal of the Science of Food and Agriculture, Mnth February v. 97 (11) (p. 3584-3593)
DOI: 10.1002/jsfa.8217
Paper
Theron, L W, Bely, M, Divol, B. 2015. Enzymatic characterization of an oenological relevant protease isolated from Metschnikowia pulcherrima, IN: Proceedings of the 10th International Symposium of Oenology of Bordeaux. (p. 211-214) 29 June-1 July 2015,