Isolation and characterization of Oenococcus oeni from Aglianico wines

Abstract

A technological characterization of Oenococcus oeni strains isolated from Aglianico wines was performed to select starter cultures for malolactic fermentation (MLF). One hundred and fifty six O. oeni isolates were extracted from Aglianico wines, and identified by using speciesspecific PCR. Malolactic activity (MLA), sulphur dioxide (SO 2 ) resistance, acetaldehyde metabolism and other technological characteristics were tested. Differences in the technologically relevant characteristics were observed. All O. oeni strains were able to grow at low temperature and none in presence of 14% of ethanol. About 80% of O. oeni degraded more than 80% of acetaldehyde, producing ethanol and acetic acid as final products. Among nine O. oeni chosen, four isolates were sensitive to 60 mg of SO 2 l -1 , while the other five had high resistance. Considering their technological characteristics, five O. oeni strains could be selected starter cultures for MLF in Aglianico.

The application of malolactic fermentation process to create good-quality grape wine produced in cool-climate countries: a review

“…Yeast S. cerevisiae is capable of producing SO 2 at varying amounts, depending on an applied strain. Most of them produce it at less than 30 mg/l wine; however, there are also strains that are capable of producing this compound at more than 100 mg/l wine [21,55]. Free sulfur dioxide at a concentration of 15 mg/l wine at pH below 3.5 considerably reduces the viability of cells and their capacity to proliferate.…”

“…Additionally, the content of molecular SO 2 at an amount of over 0.5 mg/l wine causes an inhibition of bacterial growth. In combination with other inhibitors, sulfur dioxide may at the same time limit the growth of bacteria and their ability for malic acid fermentation [24,55,56].…”

Assessment of the genetic polymorphism and physiological characterization of indigenous Oenococcus oeni strains isolated from Aglianico del Vulture red wine

“…Thirty-two O. oeni strains used in this study were previously isolated from Aglianico wines of two different wineries operating in the Vulture area of the Basilicata region (Southern Italy) and identified by molecular analysis and technological characterization (Sico et al 2008). All strains (23 of winery D and 9 of winery S) were maintained as freeze-dried stocks in reconstituted (11 % w/v) skim milk, containing 0.1 % (w/v) ascorbic acid in the culture collection of the Dipartimento di Scienze, Università degli Studi della Basilicata (Potenza, Italy), and routinely propagated in de Man, Rogosa, and Sharpe (MRS) broth supplemented with 20 % (v/v) tomato juice (MRS-TJ) and adjusted to pH 4.8 at 30°C under strict anaerobic conditions for 5-6 days before the analyses.…”

“…The few studies carried out on the microbial community of Aglianico wine underlined high intra-species heterogeneity in bacterial populations (Sico et al 2008).…”

“…Differentiation of several O. oeni strains isolated from Aglianico wine produced in different wineries has been reported (Lechiancole et al 2006;Sico et al 2008); however, information about the level and the meaning of the heterogeneity within a single O. oeni natural population has not yet been obtained.…”