Prevalence of Lentilacobacillus hilgardii over Lactiplantibacillus plantarum in Low-Temperature Spontaneous Malolactic Fermentation of a Patagonian Pinot Noir

The spontaneous malolactic fermentation (MLF) in a centenary winery from Patagonia, Argentina, is conducted by predominantly mesophilic Oenococcus oeni and Lactiplantibacillus plantarum. In this region, MLF takes place from 14 to 4 °C, leading to heat cellars incurring in higher costs and non-sustainable practices. Previously, psychrotrophic strains of O. oeni had been obtained from a Patagonian wine. The goal of this work was to identify the Lactobacillaceae microbiota related to low-temperature MLF and assess their contribution. Nine sychrotrophicc Lentilactibacillus hilgardii strains were identified by sequencing the 16S rRNA gene, and the strains typified by RAPD-PCR. All strains consumed L-malic acid at 4 and 10 °C in sterile wine. The selected UNQLh1.1 strain revealed implantation capacity and L-malic acid consumption at 4 and 10 °C in the presence of the native microbial consortium. Furthermore, the histidine decarboxylase (hdc) gene was not detected in any of the Len. hilgardii strains. The prevalence of Len. hilgardii under low-temperature conditions represents a novelty compared to previous findings of LAB diversity in the MLF of Patagonian wines. The native Patagonian psychrotrophic Len. hilgardii strains are a new player in fermentations conducted at low temperatures with the potential to be used as a sustainable MLF starter.Fil: Manera, Camila. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; ArgentinaFil: Rivas, Gabriel Alejandro. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Flores, Naiquen Elizabeth. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; ArgentinaFil: Brizuela, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; ArgentinaFil: Caballero, Adriana Carmen. Universidad Nacional del Comahue; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Semorile, Liliana Carmen. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; ArgentinaFil: Valdes la Hens, Danay. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Microbiología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Mass Ratio of Single-line Spectroscopic Binaries with Visual Orbits Using Bayesian Inference and Suitable Priors

We present orbital elements for 22 single-line binaries, nine of them studied for the first time, determined from a joint spectroscopic and astrometric solution. The astrometry is based on interferometric measurements obtained with the HRCam Speckle camera on the SOAR 4.1 m telescope at Cerro Pachon, Chile, supplemented with historical data. The spectroscopic observations were secured using Echelle spectrographs (FEROS, FIDEOS, and HARPS) at La Silla, Chile. A comparison of our orbital elements and systemic velocities with previous studies, including Gaia radial velocities, shows the robustness of our estimations. By adopting suitable priors of the trigonometric parallax and spectral type of the primary component, and using a Bayesian inference methodology developed by our group, we were able to estimate mass ratios for these binaries. Combining the present results with a previous study of other single-line binaries from our team, we present a pseudo mass-to-luminosity relationship based on 23 systems (46 stars) in the mass range 0.6 ≤ M _⊙ ≤ 2.5. We find a reasonable correspondence with a fiducial mass-to-luminosity relationship. We conclude that our methodology does allow us to derive tentative mass ratios for these types of binaries