| Title: | Investigating the biochemical and fermentation attributes of Lachancea species and strains: Deciphering the potential contribution to wine chemical composition |
| Author(s): | Porter TJ; Divol B; Setati ME; |
| Address: | "Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, Stellenbosch 7600, South Africa. Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, Stellenbosch 7600, South Africa. Electronic address: setati@sun.ac.za" |
| DOI: | 10.1016/j.ijfoodmicro.2018.10.025 |
| ISSN/ISBN: | 1879-3460 (Electronic) 0168-1605 (Linking) |
| Abstract: | "Yeasts of various genera are increasingly used alongside Saccharomyces cerevisiae to drive wine fermentations owing to their positive contribution to the organoleptic profile of the resulting wines. One such yeast species is Lachancea thermotolerans. Other species of the genus Lachancea, namely, L. fermentati and L. lanzarotensis have also been isolated from the fermentation environment, but have not received the same degree of attention as L. thermotolerans. The aim of this study was to investigate the oenological potential of these three Lachancea species, regarding their expression of oenologically relevant enzymes, their fermentation attributes and the expression and location of beta-glucosidase during fermentation of synthetic and real grape must (Muscat of Alexandria). In the current study we evaluated three species viz. L. thermotolerans (14 strains), L. fermentati (1 strain) and L. lanzarotensis (2 strains). Our data show that all the species and strains produced beta-glucosidase but with different substrate specificities. Moreover, L. theromotolerans and L. fermentati also produced beta-xylosidase. H(2)S production, SO(2) and ethanol tolerance was variable between species and strains, with the L. lanzarotensis and L. fermentati displaying considerably high H(2)S production while L. thermotolerans and L. fermentati displayed higher ethanol tolerance. Furthermore, L. fermentati showed higher SO(2) tolerance and could proliferate at 20?ª+mg/L total SO(2). Interestingly, an increase in beta-glucosidase activity during fermentation did not result in a significant increase in monoterpene concentrations. However, mixed-fermentations with L. fermentati and L. thermotolerans Concerto enhanced geraniol levels. The data show that this activity was mostly cell-associated and constitutively expressed. Sequential fermentations with the Lachancea spp. and S. cerevisiae resulted in wines with significantly altered chemical compositions compared to that obtained from S. cerevisiae inoculated alone. Wines produced from L. thermotolerans and L. lanzarotensis mixed culture fermentations exhibited similar volatile compound composition. Conversely, L. fermentati produced chemically distinct wines consistently associated with high isobutanol and isobutyric acid, and higher monoterpenes. In particular, linalool and geraniol had potential to make perceivable aroma contribution (OAV?ª+>/=?ª+1)" |
| Keywords: | Acyclic Monoterpenes Coculture Techniques Esters/analysis *Fermentation Food Handling Food Microbiology Hydrogen Sulfide/metabolism Monoterpenes/analysis Polygalacturonase/metabolism Principal Component Analysis Saccharomyces cerevisiae/metabolism Sacchar; |
| Notes: | "MedlinePorter, Tristan Jade Divol, Benoit Setati, Mathabatha Evodia eng Netherlands 2018/11/10 Int J Food Microbiol. 2019 Feb 2; 290:273-287. doi: 10.1016/j.ijfoodmicro.2018.10.025. Epub 2018 Nov 2" |
