Optimizing Cucumis sativus seedling vigor: the role of pistachio wood vinegar and date palm compost in nutrient mobilization.

BACKGROUND: The goal of this research is to enhance the quality of cucumber seedlings grown in greenhouses by experimenting with various soilless culture mediums (CMs) and the application of pistachio wood vinegar (WV). The experimental setup was designed as a factorial experiment within a randomized complete block design (RCBD), in greenhouse conditions featuring three replications to assess the effects of different culture media (CMs) and concentrations of pistachio wood vinegar (WV) on cucumber seedling growth. Cucumber seeds were planted in three CMs: coco peat-peat moss, coco peat-vermicompost, and date palm compost-vermicompost mixed in a 75:25 volume-to-volume ratio. These were then treated with pistachio WV at concentrations of 0, 0.5, and 1%, applied four times during irrigation following the emergence of the third leaf. RESULTS: The study revealed that treating seedlings with 0.5% WV in the date palm compost-vermicompost CM significantly enhanced various growth parameters. Specifically, it resulted in a 90% increase in shoot fresh mass, a 59% increase in shoot dry mass, an 11% increase in root fresh mass, a 36% increase in root dry mass, a 65% increase in shoot length, a 62% increase in leaf area, a 25% increase in stem diameter, a 41% increase in relative water content (RWC), and a 6% improvement in membrane stability index (MSI), all in comparison to untreated seedlings grown in coco peat-peat moss CM. Furthermore, chlorophyll a, b, total chlorophyll, and carotenoid levels were 2.3, 2.7, 2.6, and 2.7 times higher, respectively, in seedlings treated with 0.5% WV and grown in the date palm compost-vermicompost CM, compared to those treated with the same concentration of WV but grown in coco peat-peat moss CM. Additionally, the Fv/Fm ratio saw a 52% increase. When plant nutrition was enhanced with the date palm compost-vermicompost CM and 1% WV, auxin content rose by 130% compared to seedlings grown in coco peat-peat moss CM and treated with 0.5% WV. CONCLUSIONS: The study demonstrates that using 0.5% WV in conjunction with date palm compost-vermicompost CM significantly betters the quality of cucumber seedlings, outperforming other treatment combinations.

The role of ion homeostasis in adaptation and tolerance to acetic acid stress in yeasts.

Maintenance of asymmetric ion concentrations across cellular membranes is crucial for proper yeast cellular function. Disruptions of these ionic gradients can significantly impact membrane electrochemical potential and the balance of other ions, particularly under stressful conditions such as exposure to acetic acid. This weak acid, ubiquitous to both yeast metabolism and industrial processes, is a major inhibitor of yeast cell growth in industrial settings and a key determinant of host colonization by pathogenic yeast. Acetic acid toxicity depends on medium composition, especially on the pH (H+ concentration), but also on other ions' concentrations. Regulation of ion fluxes is essential for effective yeast response and adaptation to acetic acid stress. However, the intricate interplay among ion balancing systems and stress response mechanisms still presents significant knowledge gaps. This review offers a comprehensive overview of the mechanisms governing ion homeostasis, including H+, K+, Zn2+, Fe2+/3+, and acetate, in the context of acetic acid toxicity, adaptation, and tolerance. While focus is given on Saccharomyces cerevisiae due to its extensive physiological characterization, insights are also provided for biotechnologically and clinically relevant yeast species whenever available.

Co-culturing Propionibacterium freudenreichii and Bifidobacterium animalis subsp. lactis improves short-chain fatty acids and vitamin B12 contents in soy whey.

The lack of vitamin B12 in unprocessed plant-based foods can lead to health problems in strict vegetarians and vegans. The main aim of this study was to investigate the potential synergy of co-culturing Bifidobacterium animalis subsp. lactis and Propionibacterium freudenreichii in improving production of vitamin B12 and short-chain fatty acids in soy whey. Different strategies including mono-, sequential and simultaneous cultures were adopted. Growth, short-chain fatty acids and vitamin B12 were assessed throughout the fermentation while free amino acids, volatiles, and isoflavones were determined on the final day. P. freudenreichii monoculture grew well in soy whey, whereas B. lactis monoculture entered the death phase by day 4. Principal component analysis demonstrates that metabolic changes in both sequential cultures did not show drastic differences to those of P. freudenreichii monoculture. However, simultaneous culturing significantly improved vitamin B12, acetic acid and propionic acid contents (1.3 times, 5 times, 2.5 times, compared to the next highest treatment [sequential cultures]) in fermented soy whey relative to other culturing modes. Hence, co-culturing of P. freudenreichii and B. lactis would provide an alternative method to improve vitamin B12, acetic acid and propionic acid contents in fermented foods.

Enhancing citric acid tolerance of Acetobacter tropicalis using chemical and physical mutagenesis and adaptive evolution to improve the quality of lemon fruit vinegar.

The high concentration of citric acid in lemons limits the production of lemon fruit vinegar because it inhibits the metabolism of acetic acid bacteria and reduces the utilization of raw materials. This study aimed to enhance the citric acid tolerance of Acetobacter tropicalis by using complex mutagenesis and adaptive laboratory evolution (ALE) and improving the quality of lemon fruit vinegar. After mutagenesis and ALE, A. tropicalis JY-135 grew well under 40 g/L citric acid, and it showed high physiological activity and excellent fermentation performance under high concentrations of citric acid. The survival rate and ATP content of JY-135 were 15.27 and 9.30 times higher than that of the original strain J-2736. In the fermentation of lemon fruit vinegar, the acid production and the number of aroma-active compounds were 1.61-fold and 2.17-fold than J-2736. In addition, we found that citric acid tolerance of JY-135 is related to the respiratory electron-transport chain and the tricarboxylic acid (TCA) cycle. This work is of great significance for the production of high-quality lemon fruit vinegar and the enrichment of seed resources of acetic acid bacteria.

Inhibition of iron oxidation in Acidithiobacillus ferrooxidans by low-molecular-weight organic acids: Evaluation of performance and elucidation of mechanisms.

The catalytic role of Acidithiobacillus ferrooxidans (A. ferrooxidans) in iron biooxidation is pivotal in the formation of Acid Mine Drainage (AMD), which poses a significant threat to the environment. To control AMD generation, treatments with low-molecular-weight organic acids are being studied, yet their exact mechanisms are unclear. In this study, AMD materials, organic acids, and molecular methods were employed to gain a deeper understanding of the inhibitory effects of low-molecular-weight organic acids on the biooxidation of iron by A. ferrooxidans. The inhibition experiments of A. ferrooxidans on the oxidation of Fe2+ showed that to attain a 90 % inhibition efficacy within 72 h, the minimum concentrations required for formic acid, acetic acid, propionic acid, and lactic acid are 0.5, 6, 4, and 10 mmol/L, respectively. Bacterial imaging illustrated the detrimental effects of these organic acids on the cell envelope structure. This includes severe damage to the outer membrane, particularly from formic and acetic acids, which also caused cell wall damage. Coupled with alterations in the types and quantities of protein, carbohydrate, and nucleic acid content in extracellular polymeric substances (EPS), indicate the mechanisms underlying these inhibitory treatments. Transcriptomic analysis revealed interference of these organic acids with crucial metabolic pathways, particularly those related to energy metabolism. These findings establish a comprehensive theoretical basis for understanding the inhibition of A. ferrooxidans' biooxidation by low-molecular-weight organic acids, offering a novel opportunity to effectively mitigate the generation of AMD at its source.

Targeted 1-H-NMR wine analyses revealed specific metabolomic signatures of yeast populations belonging to the Saccharomyces genus.

This study aimed to explore the non-volatile metabolomic variability of a large panel of strains (44) belonging to the Saccharomyces cerevisiae and Saccharomyces uvarum species in the context of the wine alcoholic fermentation. For the S. cerevisiae strains flor, fruit and wine strains isolated from different anthropic niches were compared. This phenotypic survey was achieved with a special focus on acidity management by using natural grape juices showing opposite level of acidity. A 1H NMR based metabolomics approach was developed for quantifying fifteen wine metabolites that showed important quantitative variability within the strains. Thanks to the robustness of the assay and the low amount of sample required, this tool is relevant for the analysis of the metabolomic profile of numerous wines. The S. cerevisiae and S. uvarum species displayed significant differences for malic, succinic, and pyruvic acids, as well as for glycerol and 2,3-butanediol production. As expected, S. uvarum showed weaker fermentation fitness but interesting acidifying properties. The three groups of S. cerevisiae strains showed different metabolic profiles mostly related to their production and consumption of organic acids. More specifically, flor yeast consumed more malic acid and produced more acetic acid than the other S. cerevisiae strains which was never reported before. These features might be linked to the ability of flor yeasts to shift their metabolism during wine oxidation.

Mind your marker: the effect of common auxotrophic markers on complex traits in yeast.

Yeast cells are extensively used as a key model organism owing to their highly conserved genome, metabolic pathways, and cell biology processes. To assist in genetic engineering and analysis, laboratory yeast strains typically harbor auxotrophic selection markers. When uncompensated, auxotrophic markers cause significant phenotypic bias compared to prototrophic strains and have different combinatorial influences on the metabolic network. Here, we used BY4741, a laboratory strain commonly used as a "wild type" strain in yeast studies, to generate a set of revertant strains, containing all possible combinations of four common auxotrophic markers (leu2∆, ura3∆, his3∆1, met15∆). We examined the effect of the auxotrophic combinations on complex phenotypes such as resistance to rapamycin, acetic acid, and ethanol. Among the markers, we found that leucine auxotrophy most significantly affected the phenotype. We analyzed the phenotypic bias caused by auxotrophy at the genomic level using a prototrophic version of a genome-wide deletion library and a decreased mRNA perturbation (DAmP) library. Prototrophy was found to suppress rapamycin sensitivity in many mutants previously annotated for the phenotype, raising a possible need for reevaluation of the findings in a native metabolic context. These results reveal a significant phenotypic bias caused by common auxotrophic markers and support the use of prototrophic wild-type strains in yeast research.

PECTIN ACETYLESTERASE12 regulates shoot branching via acetic acid and auxin accumulation in alfalfa shoots.

Shoot branching is an important biological trait affecting alfalfa (Medicago sativa L.) production, but its development is complicated and the mechanism is not fully clear. In the present study, pectin acetylesterase 12 (MsPAE12) and NAM/ATAF/CUC-domain transcription factor gene (MsNAC73) were isolated from alfalfa. MsPAE12 was highly expressed in shoot apexes, and MsNAC73 was found to be a key transcriptional repressor of MsPAE12 by directly binding to salicylic acid (SA) and jasmonic acid (JA) elements in the MsPAE12 promoter. The biological functions of MsPAE12 and MsNAC73 were studied through overexpression (OE) and down-expression (RNAi) of the 2 genes in alfalfa. The numbers of shoot branches increased in MsPAE12-OE lines but decreased in MsPAE12-RNAi and MsNAC73-OE plants, which was negatively related to their indole-3-acetic acid (IAA) accumulation in shoot apexes. Furthermore, the contents of acetic acid (AA) in shoot apexes decreased in MsPAE12-OE plants but increased in MsPAE12-RNAi and MsNAC73-OE plants. The changes of AA contents were positively related to the expression of TRYPTOPHAN AMINOTRANSFERASE 1 (MsTAA1), TRYPTOPHAN AMINOTRANSFERASE-RELATED 2 (MsTAR2), and YUCCA flavin monooxygenase (MsYUCC4) and the contents of tryptophan (Trp), indole-3-pyruvic acid (IPA), and IAA in shoot apexes of MsPAE12-OE, MsPAE12-RNAi, and MsNAC73-OE plants. Exogenous application of AA to wild type (WT) and MsPAE12-OE plants increased Trp, IPA, and IAA contents and decreased branch number. Exogenous IAA suppressed shoot branching in MsPAE12-OE plants, but exogenous IAA inhibitors increased shoot branching in MsPAE12-RNAi plants. These results indicate that the MsNAC73-MsPAE12 module regulates auxin-modulated shoot branching via affecting AA accumulation in shoot apexes of alfalfa.

Dynamic changes of microbiota and metabolite of traditional Hainan dregs vinegar during fermentation based on metagenomics and metabolomics.

Hainan dregs vinegar (HNDV) is a traditional fermented food in China that is renowned for its unique flavor. HNDV is one of the most popular vinegars in Southeast Asia. However, research on the microorganisms and characteristic metabolites specific to HNDV is lacking. This study investigated the changes in microbial succession, volatile flavor compounds and characteristic non-volatile flavor compounds during HNDV fermentation based on metagenomics and metabolomics. The predominant microbial genera were Lactococcus, Limosilactobacillus, Lactiplantibacillus, and Saccharomyces. Unlike traditional vinegar, l-lactic acid was identified as the primary organic acid in HNDV. Noteworthy flavor compounds specific to HNDV included 3-methylthiopropanol and dl-phenylalanine. Significant associations were observed between six predominant microorganisms and six characteristic volatile flavor compounds, as well as seven characteristic non-volatile flavor compounds. The present results contribute to the development of starter cultures and the enhancement of HNDV quality.

Melanoidin-like carbohydrate-containing macromolecules from Shanxi aged vinegar exert immunoenhancing effects on macrophage RAW264.7 cells.

Bioactive macromolecule mining is important for the functional chemome analysis of traditional Chinese vinegar. In this study, we isolated and characterized carbohydrate-containing macromolecules from Shanxi aged vinegar (CCMSAV) and evaluated their immunomodulatory activity. The isolation process involved ethanol precipitation, deproteinization, decolorization, and DEAE-650 M column chromatography, resulting in the acquisition of four sub-fractions. All sub-fractions exhibited a molecular weight range of 6.92 to 16.71 kDa and were composed of 10 types of monosaccharides. Comparative analysis of these sub-fractions with two melanoidins exhibited similarities in elemental composition, spectral signature, and pyrolytic characteristics. Immunological assays confirmed the significantly enhanced cell viability, phagocytic activity, and secretion of nitric oxide, tumor necrosis factor (TNF)-α and interleukin (IL)-6 in RAW264.7 cells by all four sub-fractions. Further investigation of the immunomodulatory mechanism revealed that SAV-RP70-X, the most potent purified sub-fraction, enhanced aerobic glycolysis in macrophages and activated Toll-like receptor 2 (TLR2), TLR4, mannose receptor (MR), scavenger receptor (SR), and the dendritic cell-associated C-type lectin-1 receptor (Dectin-1). Furthermore, the activation of macrophages was associated with the MyD88/PI3K/Akt/NF-κB signaling pathway. Methylation analysis revealed that 1,4-Xylp was the most abundant glycosidic linkage in SAV-RP70-X.

Role of calcium signaling in cadmium stress mitigation by indol-3-acetic acid and gibberellin in chickpea seedlings.

Given the adverse impacts of heavy metals on plant development and physiological processes, the present research investigated the protective role of indole-3-acetic acid (IAA) and gibberellic acid (GA3) against cadmium (Cd)-induced injury in chickpea seedlings. Therefore, seeds germinated for 6 days in a medium containing 200 µM Cd alone or combined with 10 µM GA3 or 10 µM IAA. Both GA3 and IAA mitigated Cd-imposed growth delays in roots and shoots (80% and 50% increase in root and shoot length, respectively). This beneficial effect was accompanied by a significant reduction in Cd2+ accumulation in both roots (74% for IAA and 38% for GA3) and shoots (68% and 35%, respectively). Furthermore, these phytohormones restored the cellular redox state by reducing the activity of NADPH oxidase and downregulating the transcription level of RbohF and RbohD genes. Likewise, hydrogen peroxide contents were reduced by GA3 and IAA supply. Additionally, GA3 and IAA countered the Cd-induced reduction in total phenols, flavonoids, and reducing sugars in both roots and shoots. The exogenous effectors enhanced the activities of catalase, ascorbate peroxidase, and thioredoxin, as well as the corresponding gene expressions. Interestingly, adding GA3 and IAA to the Cd-contaminated germination media corrected the level of calcium (Ca2+) ion within seedling tissues. This effect coincided with the upregulation of key genes associated with stress sensing and signal transduction, including auxin-binding protein (ABP19a), mitogen-activated protein kinase (MAPK2), calcium-dependent protein kinase (CDPK1), and calmodulin (CaM). Overall, the current results suggest that GA3 and IAA sustain the Ca2+ signaling pathway, resulting in metal phytotoxicity relief. Amendment of agricultural soils contaminated with heavy metals with GA3 or IAA could represent an effective practice to improve crop yield.

Recent advances in applying omic technologies for studying acetic acid bacteria in industrial vinegar production: A comprehensive review.

Vinegar and related bioproducts containing acetic acid as the main component are among the most appreciated fermented foodstuffs in numerous European and Asian countries because of their exceptional organoleptic and bio-healthy properties. Regarding the acetification process and obtaining of final products, there is still a lack of knowledge on fundamental aspects, especially those related to the study of biodiversity and metabolism of the present microbiota. In this context, omic technologies currently allow for the massive analysis of macromolecules and metabolites for the identification and characterization of these microorganisms working in their natural media without the need for isolation. This review approaches comprehensive research on the application of omic tools for the identification of vinegar microbiota, mainly acetic acid bacteria, with subsequent emphasis on the study of the microbial diversity, behavior, and key molecular strategies used by the predominant groups throughout acetification. The current omics tools are enabling both the finding of new vinegar microbiota members and exploring underlying strategies during the elaboration process. The species Komagataeibacter europaeus may be a model organism for present and future research in this industry; moreover, the development of integrated meta-omic analysis may facilitate the achievement of numerous of the proposed milestones. This work might provide useful guidance for the vinegar industry establishing the first steps towards the improvement of the acetification conditions and the development of new products with sensory and bio-healthy profiles adapted to the agri-food market.

Labetalol Ameliorates Experimental Colitis in Rat Possibly Through its Effect on Proinflammatory Mediators and Oxidative Stress.

BACKGROUND: Members of beta blockers drugs possess significant antioxidant activities. The current research is to assess the effect of the labetalol on acetic acid (AA-induced) colitis in rat model. METHODS: Forty adult Wistar rats were separated into 4 groups, including the negative control group, AA group, AA + sulfasalazine (100 mg/kg/day) group, and AA + labetalol (300 mg/kg/day) group. Colitis was induced in rats by the interrectal installation of 2 mL of 4% (v/v) AA. Sulfasalazine and labetalol were administered orally for 7 days after 2 hours of induction. The following parameters were measured: disease activity index (DAI), histopa-thological changes and colon tissue homogenate concentrations of proinflammatory mediators IL-1ß, adhesion molecules ICAM-1, and oxidative stress marker myeloperoxidase (MPO). RESULTS: The treatment with labetalol significantly reduced DAI and histopathological changes induced by AA. Also, labetalol markedly decreased the concentrations of IL-1ß, ICAM-1, and MPO in colonic tissue that were increased by AA. The effects of labetalol were significantly lower than that produced by sulfasalazine as standard drug. CONCLUSIONS: Labetalol exerts ameliorative effects on disease activity and histopathological features of AA-induced colitis in rats possibly through antioxidant effects and inhibition of inflammatory mediators.

Investigating luxS gene expression in lactobacilli along lab-scale cocoa fermentations.

Previous metagenomic analyses have suggested that lactobacilli present potential for Quorum Sensing (QS) in cocoa fermentation, and in the present research, laboratory scale fermentations were carried out to monitor the expression of luxS, a universal marker of QS. For that, 96 h-fermentations were studied, as follows: F0 (non inoculated control), F1 (inoculated with yeasts, lactic acid bacteria, and acetic acid bacteria), F2 (inoculated with yeasts and acetic acid bacteria), F3 (inoculated with yeasts only). The parameters evaluated were: plate counting, quantification of key enzymes and analysis of volatile organic compounds associated with key sensory descriptors, using headspace gas chromatography-mass spectrometry (GC-MS). Furthermore, QS was estimated by the quantification of the expression of luxS genes by Reverse Transcriptase Real-Time PCR. The results demonstrated that microbial succession occurred in pilot scale fermentations, but no statistical differences for microbial enumeration and α-diversity index were observed among experiments and control. Moreover, it was not possible to make conclusive correlations of enzymatic profile and fermenting microbiota, likely due to the intrinsic activity of plant hydrolases. Regarding to the expression of luxS genes, in Lactiplantibacillus plantarum they were active along the fermentation, but for Limosilactobacillus fermentum, luxS was expressed only at early and middle phases. Correlation analysis of luxS expression and production of volatile metabolites evidenced a possible negative association of Lp. Plantarum with fermentation quality. In conclusion, these data corroborate former shotgun metagenomic analysis by demonstrating the expression of luxS by lactobacilli in pilot scale cocoa fermentation and evidence Lp. Plantarum is the main lactic acid bacteria related to its expression.

Deeply analyzing dynamic fermentation of highland barley vinegar: Main physicochemical factors, key flavors, and dominate microorganisms.

Highland barley vinegar, as a solid-state fermentation-type vinegar emerged recently, is well-known in Qinghai-Tibet plateau area of China. This work aimed to explore the main physicochemical factors, key flavor volatile compounds, and dominate microorganisms of highland barley vinegar during fermentation. The results showed that the decrease trend of reducing sugar, pH and the increase trend of amino acid nitrogen were associated with the metabolism of dominate bacteria, especially Lactobacillus and Acetobacter. Totally, 35 volatile compounds mainly including 20 esters, 10 alcohols, 2 aldehydes, 1 ketone and 2 pyrazines and 7 organic acids were identified. Especially, isoamyl acetate, acetyl methyl carbinol, ethyl caprylate, 1,2-propanediol, 3-methyl-1-butanol and ethyl isovalerate with high odor activity values were confirmed as key aroma compounds. Meanwhile, the relative average abundance of bacteria at genus level decreased significantly as fermentation time goes on. Among these microbes, Lactobacillus were the dominate bacteria at alcohol fermentation stage, Lactobacillus and Acetobacter were dominate at acetic acid fermentation stage. Furthermore, the correlations between dominate bacteria and the key volatile compounds were revealed, which highlighted Lactobacillus and Acetobacter were significantly correlated with key volatile compounds (|r| > 0.5, P < 0.01). The fundings of this study provide insights into the flavor and assist to improve the production quality of highland barley vinegar.

Exploring diversity and functional traits of lactic acid bacteria in traditional vinegar fermentation: A review.

Vinegar has been used for centuries as a food preservative, flavor enhancer, and medicinal agent. While commonly known for its sour taste and acidic properties due to acetic acid bacteria metabolism, vinegar is also home to a diverse community of lactic acid bacteria (LAB). The main genera found during natural fermentation include Lactobacillus, Lacticaseibacillus, Lentilactobacillus, Limosilactbacillus, Leuconostoc, and Pedicoccus. Many of the reported LAB species fulfill the probiotic criteria set by the World Health Organization (WHO). However, it is crucial to acknowledge that LAB viability undergoes a significant reduction during vinegar fermentation. While containing LAB, none of the analyzed vinegar met the minimum viable amount required for probiotic labeling. To fully unlock the potential of vinegar as a probiotic, investigations should be focused on enhancing LAB viability during vinegar fermentation, identifying strains with probiotic properties, and establishing appropriate dosage and consumption guidelines to ensure functional benefits. Currently, vinegar exhibits substantial potential as a postbiotic product, attributed to the high incidence and growth of LAB in the initial stages of the fermentation process. This review aims to identify critical gaps and address the essential requirements for establishing vinegar as a viable probiotic product. It comprehensively examines various relevant aspects, including vinegar processing, total and LAB diversity, LAB metabolism, the potential health benefits linked to vinegar consumption, and the identification of potential probiotic species.

New biomarkers underlying acetic acid tolerance in the probiotic yeast Saccharomyces cerevisiae var. boulardii.

Evolutionary engineering experiments, in combination with omics technologies, revealed genetic markers underpinning the molecular mechanisms behind acetic acid stress tolerance in the probiotic yeast Saccharomyces cerevisiae var. boulardii. Here, compared to the ancestral Ent strain, evolved yeast strains could quickly adapt to high acetic acid levels (7 g/L) and displayed a shorter lag phase of growth. Bioinformatic-aided whole-genome sequencing identified genetic changes associated with enhanced strain robustness to acetic acid: a duplicated sequence in the essential endocytotic PAN1 gene, mutations in a cell wall mannoprotein (dan4Thr192del), a lipid and fatty acid transcription factor (oaf1Ser57Pro) and a thiamine biosynthetic enzyme (thi13Thr332Ala). Induction of PAN1 and its associated endocytic complex SLA1 and END3 genes was observed following acetic acid treatment in the evolved-resistant strain when compared to the ancestral strain. Genome-wide transcriptomic analysis of the evolved Ent acid-resistant strain (Ent ev16) also revealed a dramatic rewiring of gene expression among genes associated with cellular transport, metabolism, oxidative stress response, biosynthesis/organization of the cell wall, and cell membrane. Some evolved strains also displayed better growth at high acetic acid concentrations and exhibited adaptive metabolic profiles with altered levels of secreted ethanol (4.0-6.4% decrease), glycerol (31.4-78.5% increase), and acetic acid (53.0-60.3% increase) when compared to the ancestral strain. Overall, duplication/mutations and transcriptional alterations are key mechanisms driving improved acetic acid tolerance in probiotic strains. We successfully used adaptive evolutionary engineering to rapidly and effectively elucidate the molecular mechanisms behind important industrial traits to obtain robust probiotic yeast strains for myriad biotechnological applications. KEY POINTS: •Acetic acid adaptation of evolutionary engineered robust probiotic yeast S. boulardii •Enterol ev16 with altered genetic and transcriptomic profiles survives in up to 7 g/L acetic acid •Improved acetic acid tolerance of S. boulardii ev16 with mutated PAN1, DAN4, OAF1, and THI13 genes.

Comparison of plant biostimulating properties of Chlorella sorokiniana biomass produced in batch and semi-continuous systems supplemented with pig manure or acetate.

Microalgae-derived biostimulants provide an eco-friendly biotechnology for improving crop productivity. The strategy of circular economy includes reducing biomass production costs of new and robust microalgae strains grown in nutrient-rich wastewater and mixotrophic culture where media is enriched with organic carbon. In this study, Chlorella sorokiniana was grown in 100 l bioreactors under sub-optimal conditions in a greenhouse. A combination of batch and semi-continuous cultivation was used to investigate the growth, plant hormone and biostimulating effect of biomass grown in diluted pig manure and in nutrient medium supplemented with Na-acetate. C. sorokiniana tolerated the low light (sum of PAR 0.99 ± 0.18 mol/photons/(m2/day)) and temperature (3.7-23.7° C) conditions to maintain a positive growth rate and daily biomass productivity (up to 149 mg/l/day and 69 mg/l/day dry matter production in pig manure and Na-acetate supplemented cultures respectively). The protein and lipid content was significantly higher in the biomass generated in batch culture and dilute pig manure (1.4x higher protein and 2x higher lipid) compared to the Na-acetate enriched culture. Auxins indole-3-acetic acid (IAA) and 2-oxindole-3-acetic acid (oxIAA) and salicylic acid (SA) were present in the biomass with significantly higher auxin content in the biomass generated using pig manure (> 350 pmol/g DW IAA and > 84 pmol/g DW oxIAA) compared to cultures enriched with Na-acetate and batch cultures (< 200 pmol/g DW IAA and < 27 pmol/g DW oxIAA). No abscisic acid and jasmonates were detected. All samples had plant biostimulating activity measured in the mungbean rooting bioassay with the Na-acetate supplemented biomass eliciting higher rooting activity (equivalent to 1-2 mg/l IBA) compared to the pig manure (equivalent to 0.5-1 mg/l IBA) and batch culture (equivalent to water control) generated biomass. Thus C. sorokiniana MACC-728 is a robust new strain for biotechnology, tolerating low light and temperature conditions. The strain can adapt to alternative nutrient (pig manure) and carbon (acetate) sources with the generated biomass having a high auxin concentration and plant biostimulating activity detected with the mungbean rooting bioassay.

Differential consumption of malic acid and fructose in apple musts by Pichia kudriavzevii strains.

AIMS: To assess the capability of Pichia kudriavzevii strains isolated from wine, cider, and natural environments in North Patagonia to produce ciders with reduced malic acid levels. METHODS AND RESULTS: Fermentation kinetics and malic acid consumption were assessed in synthetic media and in regional acidic apple musts. All P. kudriavzevii strains degraded malic acid and grew in synthetic media with malic acid as the sole carbon source. Among these strains, those isolated from cider exhibited higher fermentative capacity, mainly due to increased fructose utilization; however, a low capacity to consume sucrose present in the must was also observed for all strains. The NPCC1651 cider strain stood out for its malic acid consumption ability in high-malic acid Granny Smith apple must. Additionally, this strain produced high levels of glycerol as well as acceptable levels of acetic acid. On the other hand, Saccharomyces cerevisiae ÑIF8 reference strain isolated from Patagonian wine completely consumed reducing sugars and sucrose and showed an important capacity for malic acid consumption in apple must fermentations. CONCLUSIONS: Pichia kudriavzevii NPCC1651 strain isolated from cider evidenced interesting features for the consumption of malic acid and fructose in ciders.

Tiron ameliorates acetic acid-induced colitis in rats: Role of TGF-ß/EGFR/PI3K/NF-κB signaling pathway.

BACKGROUND: Ulcerative colitis (UC), an ongoing inflammatory disorder of the colon, is marked by persistent mucosal surface irritation extending from the rectum to the near-proximal colon. Tiron is a synthetic analogue of vitamin E which is known to have antioxidant and anti-inflammatory effects in various animal models, so the goal of this study was to find out whether Tiron had any preventive impacts on UC inflicted by acetic acid (A.A) exposure in rats. METHOD: Tiron (235 and 470 mg/kg) was administered intra-peritoneally for 2 weeks, and A.A (2 ml, 3 % v/v) was injected intra-rectally to cause colitis. Colon tissues and blood samples were then collected for measurement of various inflammatory and oxidative stress biomarkers. RESULTS: Tiron administration significantly diminished lactate dehydrogenase (LDH), C-reactive protein (CRP), colon weight, and the weight/length ratio of the colon as compared to A.A-injected rats. Additionally, Tiron attenuated oxidative stress biomarkers. Tiron also enforced the levels of Glucagon-like peptide-1 (GLP-1) and trefoil factor-3 (TFF-3), while it greatly lowered the expression of nuclear factor kappa B (NF-κB), interleukin-6 (IL-6), interferon-γ (IFN-γ), and transforming growth factor-1(TGF-ß1), phosphorylated epidermal growth factor receptor (P-EGFR), phosphatidylinositol-3-kinase (PI3K) and protein kinase B (AKT) expression in colonic cellular structures. Furthermore, colonichistopathologic damages, revealed by hematoxylin and eosin (H&E) and Alcian Blue stain, were significantly decreased upon Tiron administration. CONCLUSION: Tiron prevented A.A-induced colitis in rats via modulating inflammatory pathway TGF-ß1/P-EGFR/PI3K/AKT/NF-κB, alongside managing the oxidant/antioxidant equilibrium, and boosting the reliability of the intestinal barrier.