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Table olives are the most important fermented vegetable in the Mediterranean countries. In a continuous effort to improve the quality of this food, this work applies an experimental design with four variables to study the use of 1-methylcyclopropene (1-MCP, 2.85 µL/L) in combination with a light heat shock (65 °C, 5 min) and dimethyl dicarbonate (DMDC, 83 mg/L), during the processing of Spanish style and natural table olives. Fruits processed in the Spanish style exhibited higher moisture levels, luminance, and combined acidity. On the contrary, natural olives contained more sugars, had a firmer texture, and displayed a greener colour. Our results show that applying 1-MCP, heat shock, and DMDC can positively impact the processing of Spanish style and natural table olives and influence their physicochemical characteristics. Adding DMDC to the initial brine caused colour degradation but lowered the pH. Using 1-MCP with a light heat shock improved the sugar content and luminance of olives and increased the titratable acidity in the brine. Applying 1-MCP to the Spanish style enhanced the luminosity (brightness) and, when combined with DMDC, led to the lowest pH levels. Further research at an industrial scale is necessary to validate these results and study their influence on microorganisms. These treatments could have applications in developing new table olive processing methods that allow for more predictable products.

The objective of this study is to assess the inhibitory effects of an aqueous extract from olive oil mill waste (alperujo) on the growth of a lactic acid bacteria (LAB) cocktail consisting of various strains of Lactiplantibacillus pentosus and Lactiplantibacillus plantarum species. For this purpose, response surface methodology was employed using two independent variables (pH levels 3.5-5.55; hydroxytyrosol concentration ranging from 0.93-2990 ppm). The response variable was the average inhibition per treatment on the LAB cocktail (expressed as a percentage). The developed model identified significant terms, including the linear effect of hydroxytyrosol and pH, their interaction, and the quadratic effect of pH. Maximum inhibition of the LAB cocktail was observed at progressively higher concentrations of hydroxytyrosol and lower pH values. Therefore, complete inhibition of LAB in the synthetic culture medium could only be achieved for concentrations of 2984 ppm hydroxytyrosol at a pH of 3.95. These findings suggest that extracts derived from "alperujo" could be utilized as a natural preservative in acidified foods with a bitter flavor and antioxidant requirements.

Lactiplantibacillus pentosus (Lbp. pentosus) is a species of lactic acid bacteria with a great relevance during the table olive fermentation process, with ability to form non-pathogenic biofilms on olive epidermis. The objective of this work is to deepen into the genetic mechanisms of adaptation of Lpb. pentosus LPG1 during Spanish-style green table olive fermentations, as well as to obtain a better understanding of the mechanisms of adherence of this species to the fruit surface. For this purpose, we have carried out a transcriptomic analysis of the differential gene expression of this bacterium during 60 days of fermentation in both brine and biofilms ecosystems. In brines, it was noticed that a total of 235 genes from Lpb. pentosus LPG1 were differentially expressed during course of fermentation and grouped into 9 clusters according to time-course analysis. Transport and metabolism of carbohydrates and amino acids, energy production, lactic acid and exopolysaccharide synthesis genes increased their expression in the planktonic cells during course of fermentation. On the other hand, expression of genes associated to stress response, bacteriocin synthesis and membrane protein decreased. A total of 127 genes showed significant differential expression between Lpb. pentosus LPG1 planktonic (brine) and sessile (biofilms) cells at the end of fermentation process (60 days). Among the 64 upregulated genes in biofilms, we found genes involved in adhesion (strA), exopolysaccharide production (ywqD, ywqE, and wbnH), cell shape and elongation (MreB), and well as prophage excision. Deeping into the genetic bases of beneficial biofilm formation by Lpb. pentosus strains with probiotic potential will help to turn this fermented vegetable into a carrier of beneficial microorganisms to the final consumers.

This work uses Compositional Data Analysis (CoDA) to examine the typical human faecal bacterial diversity in 39 healthy volunteers from the Andalusian region (Spain). Stool samples were subjected to high-throughput sequencing of the V3 and V4 regions of the 16S ribosomal RNA gene using Illumina MiSeq. The numbers of sequences per sample and their genus-level assignment were carried out using the Phyloseq R package. The alpha diversity indices of the faecal bacterial population were not influenced by the volunteer’s sex (male or female), age (19–46 years), and weight (48.6–99.0 kg). To study the relationship between these variables and the faecal bacterial population, the ALDEx2 and coda4microbiome CoDA packages were used. Applying ALDEx2, a trend suggesting a connection between sex and the genera Senegalimassilia and Negatibacillus (slightly more abundant in females) and Desulfovibrio (more abundant in males) was found. Moreover, age was tentatively associated with Streptococcus, Tizzerella, and Ruminococaceae_UCG-003, while weight was linked to Senegalimassilia. The exploratory tool of the coda4microbiome package revealed numerous bacterial log-ratios strongly related to sex and, to a lesser extent, age and weight. Moreover, the cross-sectional analysis identified bacterial signature balances able to assign sex to samples regardless of controlling for volunteers’ age or weight. Desulfovibrio, Faecalitalea, and Romboutsia were relevant in the numerator, while Coprococcus, Streptococcus, and Negatibacillus were prominent in the denominator; the greater presence of these could characterise the female sex. Predictions for age included Caproiciproducens, Coprobacter, and Ruminoclostridium in the numerator and Odoribacter, Ezakiella, and Tyzzerella in the denominator. The predictions depend on the relationship between both groups, but the abundance of the first group and scarcity of the second could be related to older individuals. However, the association of the faecal

The search for vegetable-origin probiotic microorganisms is a recent area of interest. This study conducted a phase I clinical trial to assess the effects of oral administration of Lactiplantibacillus pentosus LPG1, a natural strain with probiotic potential isolated from table olive fermentations, on the gut microbiota. The trial was a randomised, placebo-controlled, single-blind study involving 39 healthy volunteers. Group A (n = 20) ingested one capsule/day of L. pentosus LPG1 containing 1 × 1010 UFC/capsule, while Group B (n = 19) received one capsule/day containing only dextrose (placebo). The capsules were taken during breakfast for 30 consecutive days. Human stool samples were collected from all volunteers at the beginning (baseline) and at the end of the study (post-intervention) and were subjected to 16S rRNA metataxonomic analysis using Illumina MiSeq. Sequencing data at the genus level were statistically analysed using traditional methods and compositional data analysis (CoDA). After treatment, the alpha diversity in Group B (placebo) decreased according to an increase in the Berger and Parker dominance index (p-value < 0.05); moreover, dominance D increased and Simpson 1-D index decreased (p-value < 0.10). The Lactobacillus genus in the faeces was included in the CoDA signature balances (selbal and coda4microbiome) and played a notable role in distinguishing samples from baseline and post-intervention in Group A (LPG1). Additionally, ingesting L. pentosus LPG1 modified the gut microbiota post-intervention, increasing the presence of Parabacteroides and Agathobacter, but reducing Prevotella. These findings suggest that L. pentosus LPG1 is a potentially beneficial gut microbiota modulator in healthy persons.

In recent years, there has been a growing interest in obtaining probiotic bacteria from plant origins. This is the case of Lactiplantibacillus pentosus LPG1, a lactic acid bacterial strain isolated from table olive biofilms with proven multifunctional features. In this work, we have sequenced and closed the complete genome of L. pentosus LPG1 using both Illumina and PacBio technologies. Our intention is to carry out a comprehensive bioinformatics analysis and whole-genome annotation for a further complete evaluation of the safety and functionality of this microorganism. The chromosomic genome had a size of 3,619,252 bp, with a GC (Guanine-Citosine) content of 46.34%. L. pentosus LPG1 also had two plasmids, designated as pl1LPG1 and pl2LPG1, with lengths of 72,578 and 8713 bp (base pair), respectively. Genome annotation revealed that the sequenced genome consisted of 3345 coding genes and 89 non-coding sequences (73 tRNA and 16 rRNA genes). Taxonomy was confirmed by Average Nucleotide Identity analysis, which grouped L. pentosus LPG1 with other sequenced L. pentosus genomes. Moreover, the pan-genome analysis showed that L. pentosus LPG1 was closely related to the L. pentosus strains IG8, IG9, IG11, and IG12, all of which were isolated from table olive biofilms. Resistome analysis reported the absence of antibiotic resistance genes, whilst PathogenFinder tool classified the strain as a non-human pathogen. Finally, in silico analysis of L. pentosus LPG1 showed that many of its previously reported technological and probiotic phenotypes corresponded with the presence of functional genes. In light of these results, we can conclude that L. pentosus LPG1 is a safe microorganism and a potential human probiotic with a plant origin and application as a starter culture for vegetable fermentations.

To turn table olives into appropriate carriers of beneficial bacteria and yeasts to consumers, it is essential to have reliable methods for analysing microorganisms in biofilms. This work validates the application of a non-destructive procedure to study the lactic acid bacteria and yeasts distribution in fruits during Spanish-style green table olive fermentations. Laboratory-scale fermentations were inoculated simultaneously with three Lactiplantibacillus pentosus strains (LPG1, 119, and 13B4) and two yeasts (Wickerhamomyces anomalus Y12 and Saccharomyces cerevisiae Y30), all of them natives of table olive fermentations. Data showed that L. pentosus LPG1 and yeasts W. anomalus Y12 were quite prone to colonise olive biofilms, but only the Lactiplantibacillus strain also can penetrate the epidermis of the fruit and colonise the flesh. Applying a non-destructive treatment consisting in shelling the fruits with glass beads led to obtaining similar lactic acid bacteria and yeast recovery than the classical stomacher destructive method. However, the glass bead procedure improved the quality of the metagenomics analysis (especially when using 16 S rRNA gene-based sequencing). Results show the great utility of procedures that do not destroy the fruit for studying fermented vegetable biofilms.

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This work evaluates the effect of 1-methylcyclopropene (1-MCP) on postharvest and fermentation of Manzanilla cultivar, processed as Spanish-style or directly brined table olives. During postharvest handling, 1-MCP (2.85 µL/L) reduced the number of colour-turning olives by 18.42% over the untreated fruits. In Spanish-style and directly brined fermentation, the 1-MCP treatment led to lower pH levels, higher titratable acidities, improved firmness and colour olives than untreated fruits. A panel of expert testers also gave higher scores, and overall acceptability to the 1-MCP treated fruits, especially in the case of Spanish-style fermented olives. Metagenomic analysis of olive biofilms at the end of the fermentation process (176 days) revealed that Lactiplantibacillus was the most abundant bacterial genus in both Spanish-style and directly brined olives (>72%). However, fungal biodiversity was higher than bacterial in all treatments. Saccharomyces was the predominant yeast genus associated with directly brined olives (>97%), whilst Wickerhamomyces (>37%) and Zygoascus (>18%) were with Spanish-style fermentations. The 1-MCP treatment doubled the presence of Wickerhamomyces in Spanish-style fruits (74%) whilst reducing the presence of Zygoascus and allowing the growth of Enterobacter (15%) in directly brined olives. Thus, the postharvesting treatment of table olives with 1-MCP could help reduce the maturation progress of olives and improve the organoleptic and quality characteristics of the products without affecting the microbiological evolution of the fermentations.

In this work, metataxonomic-compositional data analysis was applied to study the influence of inoculation, type of ecosystem (brine or fruit), and time of fermentation (0, 24, and 83 days) on the bacterial composition dynamic during industrial Manzanilla Spanish-style green table olive fermentations. Differences in the physicochemical and microbiological characteristics between inoculated and spontaneous fermentations were scarce, except for the high lactic acid bacteria population (>10 million CFU/g) in the inoculated olive biofilms. The metataxonomic analysis showed eight relevant taxa (Lactiplantibacillus, Vibrio, Halolactibacillus, Aerococcus, Catenococcus, Salinivibrio, Alkalibacterium, and Marinilactibacillus) and absence of pathogens, but the microbiota composition markedly changed throughout fermentation. At the process onset, the main genera were Vibrio, Halolactibacillus, Marinilactibacillus, and Alkalibacterium, while Lactiplantibacillus was almost absent. Regardless of inoculation, Lactiplantibacillus became the predominant genus as the fermentation progressed, albeit Vibrio, Marinilactibacillus, Alkalibacterium, and Halolactibacillus also persisted until the end of the process (but did not cause spoilage). Ferrimonas genus was detected for the first time in table olives, being found in 71% of the samples. Besides, there was more bacterial biodiversity in the brine ecosystem than olive biofilms. Overall, inoculation led to more homogenous and equilibrated bacterial populations at the end of the process. This study expands the knowledge on the bacterial population changes occurring during industrial table olive fermentation, the differences between populations in brines and biofilms, and the beneficial effects of inoculation for using table olives as a carrier of beneficial microorganisms.

The study of the table olive biofilms is usually achieved using a stomacher which causes the physical rupture of pitted olives in an osmotic media but does not differentiate between those on the surface and inside the fruits. Besides, the high amount of eukaryotic DNA released from the vegetable cells makes the further molecular study of the detached microbiota complex. This work applies Response Surface Methodology, based on a D-optimal experimental design and glass beads, to recover lactic acid bacteria (LAB) and yeasts from the biofilm of fermented olives without crushing the flesh. The RSM showed that the best simultaneous results were obtained by shelling the olives, at 8 °C, with glass beads (6 mm diameter) in a 0.16 (w/w) bead/olive ratio for 15 min at 330–400 rpm. Its application recovered lower LAB (possibly because of excluding those in the flesh), but similar yeast counts to the stomacher. The metataxonomic analysis of total DNA from biofilms showed that the glass bead-based protocol reduced the chloroplast sequences and improved the genera assignation for bacteria (16S) and yeast (ITS). The new non-destructive procedure enhances biofilm studies and may allow validating table olives as a carrier of probiotic microorganisms.

Aloreña de Málaga is a table olive especially characterised by its natural freshness and short shelf-life. In this work, we applied a metataxonomic approach to unravel the microbial diversity of bacterial and fungi populations through the shelf-life of traditionally packed Aloreña de Málaga. A significant increase in lactic acid bacteria and mesophilic aerobic populations was observed during shelf-life, reaching the maximum population levels (4–5 log10 CFU) at the end of the study (260 days). On the contrary, a rapid reduction in yeast and mould populations was reported. The use of a metataxonomic analysis based on the amplification of 16S (bacteria) and internal transcribed spacer (ITS) region (fungi) regions revealed a low diversity for both microbial groups. Lactiplantibacillus (65.05 ± 8.65% in brine vs. 58.70 ± 15.70% in fruit), Pediococcus (28.17 ± 7.36% in brine vs. 27.20 ± 15.95% in fruit), and Celerinatantimonas (4.64 ± 1.08% in brine vs. 11.82 ± 18.17% in fruit) were the main genera found among bacteria, and an increase in Lactiplantibacillus and a reduction in Celerinatantimonas populations during the shelf-life were observed. On the other hand, Citeromyces was the dominant fungi genus (54.11 ± 2.00% in brine vs. 50.91 ± 16.14% in fruit), followed by Candida (8.80 ± 2.57% in brine vs. 12.32 ± 8.61% in fruit) and Penicillium (6.48 ± 1.87% vs. 8.48 ± 4.43% in fruit). No food-borne pathogen genera were detected in any of the samples analysed, indicating the high level of food safety found in this ready-to-eat fermented vegetable. Data obtained in this work will help in the design of new strategies for the control of microbial populations during the shelf-life of Aloreña de Málaga.

Debido ao aumento do número de robots de muxido en Galicia nos últimos anos, no seguinte estudo analizáronse en 18 explotacións de Galicia como cambiaron os principais parámetros reprodutivos (intervalos dende o parto á inseminación fecundante e entre partos e número de inseminacións por xestación) e produtivos (produción, porcentaxe de graxa e proteína e reconto de células somáticas) obtidos a partir de datos do control leiteiro dun ano antes da instalación do robot de muxido e do segundo ano despois da instalación do mesmo. Tamén se realizou unha enquisa para coñecer a situación de antes e despois da instalación do robot así como as opinións dos propietarios das explotacións sobre o robot de muxido. Para a análise realizáronse tres ANOVA nas que se compararon os parámetros produtivos antes e despois da instalación do robot e tamén en función do modelo de robot e os parámetros reprodutivos en función de si instalara tamén detector de celos ou non. Os resultados indican que hai un incremento significativo (p< 0,01) na produción de leite (Kgs) dun 12,5% sen prexuízos para a calidade do leite nin para os parámetros reprodutivos, de feito hai unha tendencia á redución do intervalo entre partos e do intervalo entre parto e inseminación fecundante que se comprobou que non había relación coa presencia ou non de detectores de celo. Nos resultados da análise na que se compararon os parámetros en función do modelo (Lely A3 e Lely A4) non se observaron diferenzas significativas na produción en función ao modelo do robot pero si que se observaron diferencias significativas (p< 0,05) na puntuación lineal de células somáticas. Por último, as enquisas realizadas aos xerentes das explotacións indican que o principal inconveniente é a adaptación ao robot e a principal vantaxe a diminución da man de obra., Debido a un aumento del número de robots de ordeño en Galicia en los últimos años, en el siguiente estudio se analizaron en 18 explotaciones de Galicia como cambiaron los principales parámetros reproductivos (intervalos desde el parto hasta la inseminación fecundante y entre partos y número de inseminaciones por gestación) y productivos (producción; porcentaje de grasa y proteína y recuento de células somáticas) a partir de datos del control lechero de un año antes de la instalación del robot de ordeño y del segundo año despues de la instalación del mismo. También se realizó una encuesta para la conocer la situación antes y despúes la instalación do robot así como las opiniones de los propietarios de las explotaciones sobre el robot de ordeño. Para el análisis de los datos se realizaron tres ANOVA en las que se compararon los parámetros productivos y reproductivos antes y despúes de la instalación del robot y también en función del modelo de robot y los parámetros reproductivos en función de si se instalara también detector de celos. Los resultados indican que hay un incremento significativo (p<0,01) en la produción de leche (Kgs) de un 12,5 % sin prejuizios para la calidad de la leche ni para los parámetros reproductivos, de hecho hay una tendencia a la redución del intervalo entre partos y del intervalo entre parto e inseminación fecundante que se comprobó que no había relación con la presencia o no de detectores de celo. En los resultados del análisis que comparó los parámetros en función del modelo (Lely A3 y Lely A4) no se observaron diferencias significativas en la produción ni en la reprodución pero si que se observaron diferencias significativas (p< 0,05) en la puntuación lineal de células somáticas. Por último, los resultados de las encuestas muestran que el principal inconveniente es la adpación al robot y la principal ventaja la disminución de la mano de obra., Nowadays, thanks of the development of the Automatic Milking System in Galicia, the following study analyzes in 18 Galician farms how the reproductive parameters have changed (calf-fecundation insemination interval, between calfs and iseminations number) and also the productive ones (production; fat and protein percentage and somatic cells recount) from the milking control data since one year previous to it’s instalation and the second year after. A survey was also conducted to know the situation before and after the installation of the robot as well as the opinions of the owners of the farms on the milking robot. For the analysis of the data, three ANOVA were performed where the productive and reproductive parameters were compared before and after the robot installation and also depending on the robot model and the reproductive parameters depending on heat detector was installed or not. The results indicates that there is a milk production increment (kgs) significant (p<0,01) in 12,5%, without any prejudges about it’s quality and reproduction, in fact there is a tendency to reduction of the interval between calfs and the interval between calf and fecundation insemination that was found to be unrelated to the presence or absence of heat detectors. In the results of the analysis that compared the parameters according to the model (Lely A3 and Lely A4), no significant differences were observed in the production or in the reproduction but there were significant differences (p <0.05) in the linear somatic cell score. Finally, the results of the surveys made to the managers of the farms show that the main inconvenient is the adaptation to the robot and the main advantage is the decrease in the manpower.