Whey permeate as a substrate for the production of freeze-dried Lactiplantibacillus plantarum to be used as a malolactic starter culture

World J Microbiol Biotechnol. 2021 Jun 14;37(7):115. doi: 10.1007/s11274-021-03088-1.

Abstract

The aim of this work was to obtain freeze-dried biomass of the native Patagonian Lactiplantibacillus plantarum strain UNQLp 11 from a whey permeate (WP)-based medium and compare it with the growth in commercial MRS broth medium. Survival and activity of the freeze-dried Lb. plantarum strain were investigated after inoculation in wine as a starter culture for malolactic fermentation (MLF). The effect of storage and rehydration condition of the dried bacteria and the nutrient supplementation of wine were also studied. The freeze-dried cultures from WP and those grown in MRS showed similar survival results. Rehydration in MRS broth for 24 h and the addition of a rehydration medium to wine as nutrient supplementation improved the survival under wine harsh conditions and guaranteed the success of MLF. Storage at 4 °C under vacuum was the best option, maintaining high cell viability for at least 56 days, with malic acid consumption higher than 90% after 7 days of inoculation in a wine-like medium. These results represent a significant advance for sustainable production of dried malolactic starter cultures in an environmentally friendly process, which is low cost and easy to apply in winemaking under harsh physicochemical conditions.

Keywords: Freeze-drying; Lactiplantibacillus plantarum; Malolactic fermentation; Whey permeate; Wine.

MeSH terms

  • Bacteriological Techniques
  • Biomass
  • Culture Media / chemistry*
  • Fermentation
  • Food Microbiology
  • Freeze Drying
  • Lactobacillus plantarum / chemistry
  • Lactobacillus plantarum / growth & development*
  • Lactobacillus plantarum / isolation & purification
  • Malates / chemistry*
  • Microbial Viability
  • Whey / chemistry*
  • Wine / microbiology*

Substances

  • Culture Media
  • Malates
  • malic acid