Search

The bioprospection of indigenous microorganism strains with biotechnological potential represents a prominent trend. Metschnikowia yeasts exhibit diverse capabilities, such as ethanol reduction in winemaking, biocontrol potential, and lipid production. In this work, local Metschnikowia strains were isolated from different fruits by their ability to produce pulcherrimic acid, a molecule that has been linked to biocontrol activity and that binds iron giving colored colonies. Five strains were selected, each from one of five distinct sources. All of them were identified as M. pulcherrima. All five were able inhibit other yeasts and one M. pulcherrima, called M7, inhibited the growth of Aspergillus nidulans. The selected strains accumulated lipid bodies in stationary phase. Certain non-conventional yeasts like Hanseniaspora vineae are very sensitive to biomass drying, but cell extracts from M. pulcherrima added to the growth media as a source of antioxidant lipids increased their tolerance to drying. All strains isolated showed good stress tolerance (particularly to heat) and have nutrient requirements similar to a commercial M. pulcherrima strain. In addition, the M7 strain had a good growth in sugarcane and beet molasses and behaved like Saccharomyces cerevisiae in a growth medium derived from agricultural waste, a persimmon hydrolysate. Therefore, the isolation of local strains of Metschnikowia able to grow in a variety of substrates is a good source of biocontrol agents. [ABSTRACT FROM AUTHOR]

This work focuses on the establishment of analytical and sensory differences between young wines obtained from the same grape must fermented using different strategies. The main purpose is to provide winemakers with objective criteria to help them to choose the best fermentation method to obtain the desired wine characteristics. The effects of four strategies were tested: a spontaneous fermentation with wild yeasts (WYs) and the addition of starter cultures of Lachancea thermotolerans (LT), Metschnikowia pulcherrima (MP), and a Saccharomyces cerevisiae strain that is an overproducer of glutathione (SC) in different batches of the same must of the Pedro Ximénez white grape. The analytical results obtained show as the LT wine has the highest glutathione content, while the lowest ethanol concentrations. The use of chemometric tools applied to the volatile compounds allowed to differentiate the four wines by a principal component analysis (PCA) and the identification of 27 key compounds. The four wines did not show statistical differences in their smell or taste attributes and only the LT wine was visually differentiated from the rest. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine the fecal excretion of N (TN and NH4 +-N) in dairy cows receiving the feed supplement Biolife® (Eurovix S.p.A., Italy) containing active dry yeast Saccharomyces cerevisiae. Two groups of 14 Holstein cows (B – experimental; C – control) at tie-stalled breeding participated in the experiment. Group B received the feed supplement through the total mixed ration (TMR). Fresh feces samples from both groups were collected on d 7, 14, 21, 28, 35 from the start of supplementation. Mean values of fecal pH and excreted DM did not differ between groups. The concentration of NH4 +-N in the fecal samples of group B was reduced by 28.05%, average for the entire studied period (P<0.05). In the period d 21-35, this reduction was 35% (P=0.095). Excreted TN, averaged over the entire period, was reduced by 16.18% in group B, but the difference was not statistically significant. The reduction of TN content in feces from group B was more pronounced in the period d 21-35, when the reduction was 31.99% compared to group C (P=0.084). A period of at least 14 days is required for adaptation to the supplement and for an occur effect on N excretion. [ABSTRACT FROM AUTHOR]

Simple Summary: Subacute ruminal acidosis (SARA) is a most prevalent metabolic disorder of ruminants which poses a great threat to the health and wellbeing of animals. The purpose of this research was to induce SARA in in vitro conditions and to determine the potential of active dry yeast (ADT) and thiamine synergistically in mitigating the adverse effects of SARA. Both the supplements ADY and thiamine synergistically enhanced the ruminal pH, decreased the abundance of negative rumen bacteria and increased the abundance of useful rumen bacteria and protozoa. It was concluded that the combined use of ADY and thiamine as a supplement could mitigate SARA. SARA not only damages the health of the animals but also has detrimental effects on the economic conditions of the farmers. Therefore, this research could be beneficial for society. Ruminal acidosis is a type of metabolic disorder of high-yielding ruminants which is associated with the consumption of a high-grain diet. It not only harms the productive efficiency, health and wellbeing of the animals but also has detrimental effects on the economy of the farmers. Various strategies have been adapted to control ruminal acidosis. However, none of them have produced the desired results. This research was carried out to investigate the potential of active dry yeast (ADY) and thiamine in a synergistic mode to mitigate in vitro-induced ruminal acidosis. The purpose of this study was to determine how active dry yeast alone and in combination with thiamine affected the ruminal pH, lactate, volatile fatty acids, lipopolysaccharides (LPS) and microbial community in in vitro-induced ruminal acidosis. The experiment comprises three treatment groups, (1) SARA/control, (2) ADY and (3) ADYT (ADY + thiamine). In vitro batch fermentation was conducted for 24 h. The results indicated that ruminal induced successfully and both additives improved the final pH (p < 0.01) and decreased the LPS and lactate (p < 0.01) level as compared to the SARA group. However, the ADYT group decreased the level of lactate below 0.5 mmol/L. Concomitant to fermentation indicators, both the treatment groups decreased (p < 0.05) the abundance of lactate-producing bacteria while enhancing (p < 0.01) the abundance of lactate-utilizing bacteria. However, ADYT also increased (p < 0.05) the abundance of protozoa compared to the SARA and ADY group. Therefore, it can be concluded that ADY and thiamine in synergistic mode could be a better strategy in combating the adverse effects of subacute ruminal acidosis. [ABSTRACT FROM AUTHOR]

In agriculture, the use of environmentally friendly materials both in place of and alongside chemical ones is continuously increasing. Two field experiments were conducted during the 2019 and 2020 seasons to investigate the effects of foliar application of three doses (5.0, 7.5, and 10 g L-1) of active dry yeast were sprayed on maize (Zea mays L. Cv. Tuano) at two intervals, the first 54 days after planting (DAP), and the second 15 days later. Plants were grown for silage purposes under alkaline soil conditions at the Experimental and Research Station of the Field Crops Dep., Van Yuzuncu Yıl University-(VYYU), Turkey. Measurements were taken three times at the vegetative stage 64, 74, and 84-DAP, and one times at the dough stage 117-123 DAP. Morphologically, the results showed that the foliar application of different doses of yeast increased the plant height (cm), stem, leaves, and cobs weight per plant and total plant weight (g), number of cobs plant-1 (piece), and green and dry herbage yield (ton da-1) at 117- 123 DAP during the two seasons. In contrast, there was no significant increase in plant height (cm), chlorophyll as SPAD (The Soil Plant Analysis Development) value, and the number of leaves per plant at 64 DAP. Chemically, the spraying of the yeast improved the P, K, Ca, Mg, Fe, Cu, Se, and Zn concentrations at 117- 123 DAP as well as chlorophyll content at 74 and 84 DAP compared to the control. From this study, it could be concluded that the highest values of the studied parameters were recorded when active dry yeast was used at a dose of 10 g L-1 on maize under high pH soil. [ABSTRACT FROM AUTHOR]

The experiment was carried out in the lath house of Horticulture and Landscape Gardening Department, College of Agriculture, University of Anbar, Iraq, during the 2020 growing season, on three-year-old nagami kumquat saplings to study the effect of foliar spraying with KT-30 at four concentrations (0 and 2, 4 and 8 mg.L-1), active dry yeast at three levels (0, 0.4 and 0.8%) and their interactions in some vegetative growth traits and chemical content. The results indicated that the two study factors showed a significant effect in all of the studied characteristics especially the foliar application treatment of KT-30 at a concentration of 8 mg.L-1 and the spraying with dry yeast at a level of 0.8% where achieved a significant superiority in the number and length of secondary shoots increment, leaves number increment, leaves area, percentage of nitrogen, phosphorus, potassium in leaves and their total chlorophyll content compared to the control treatment which achieved the lowest values. Bilateral interference treatments had a significant effect on all of the studied traits especially K3XY2 treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The use of pied de cuve, spontaneous fermentation or active dry yeast to start alcoholic fermentation give different wines. • Metabolomics study discriminated the three modalities based on their chemical profiles and revealed exclusive metabolites for each modality. • Sensorial analysis of Chardonnay wine showed a more qualitative sensory outcome for Active Dry Yeast and Spontaneous Fermentation compared to Pied de Cuve. • Contrary to common speculation, autochthonous yeast fermentations do not lead to greater complexity and uniqueness in comparison to other strategies. While most producers in recent decades have relied on commercial yeasts (ADY) as their primary choice given their reliability and reproducibility, the fear of standardising the taste and properties of wine has led to the employment of alternative strategies that involve autochthonous yeasts such as pied de cuve (PdC) and spontaneous fermentation (SF). However, the impact of different fermentation strategies on wine has been a subject of debate and speculation. Consequently, this study describes, for the first time, the differences between the three kinds of fermentation at the metabolomic, chemical, and sensory levels in two wines: Chardonnay and Pinot Noir. The results showed how the yeast chosen significantly impacted the molecular composition of the wines, as revealed by metabolomic analysis that identified biomarkers with varying chemical compositions according to the fermentation modality. Notably, higher numbers of lipid markers were found for SF and PdC than ADY, which contained more peptides. Key molecules from the metabolic amino acid pathway, which are addressed in this article, showed evidence of such variations. In addition, the analysis of volatile aromatic compounds revealed an increase in groups of compounds specific to each fermentation. The sensorial analysis of Chardonnay wine showed a more qualitative sensory outcome (Higher fruit intensity) for ADY and SF compared to PdC. Our finding challenges the common speculation among wine producers that autochthonous yeast fermentations may offer greater complexity and uniqueness in comparison to commercial yeast fermentations. [ABSTRACT FROM AUTHOR]

Yeast cryotolerance brings some advantages for wine fermentations, including the improved aromatic complexity of white wines. Naturally cold-tolerant strains are generally less adept at wine fermentation but fermentative fitness can potentially be improved through hybridization. Here we studied the potential of using hybrids involving Saccharomyces eubayanus and a S. cerevisiae wine strain for low-temperature winemaking. Through screening the performance in response to variable concentrations of sugar, nitrogen and temperature, we isolated one hybrid strain that exhibited the superior performance. This hybrid strain was propagated and dried in pilot scale and tested for the fermentation of Macabeu and Sauvignon blanc grape musts. We obtained highly viable active dry yeast, which was able to efficiently ferment the grape musts with superior production of aroma active volatiles, in particular, 2-phenylethanol. The genome sequences of the hybrid strains revealed variable chromosome inheritance among hybrids, particularly within the S. cerevisiae subgenome.With the present paper, we expand the knowledge on the potentialities of using S. eubayanus hybrids in industrial fermentation at beverages other than lager beer. [ABSTRACT FROM AUTHOR]

The preparation of yeast starter culture ( Pied de Cuve) for producing sparkling wine with the traditional method is a key factor for manufacturing a good Prise de mousse. In this paper, the evolution of total yeast population, its viability during Pied de Cuve preparation, and the pressure profile during the 2nd fermentation in 2 different base wines made from Bombino bianco and Chardonnay grapes were investigated using 4 different commercial active dried yeasts. The study proves that despite the initial differences observed throughout the acclimatization phase, all the tested strains showed similar results on either the total population (from 8.2 × 107 cells/mL to 1.3 × 108 cells/mL) or cellular viability (from 70% to 84%). Independently from the base wine tested, the kinetic of sugar consumption was faster during the gradual acclimatization to the alcoholic medium (phase II) and slower during the preparation of starter culture in active growth phase (phase III). During both of these phases Saccharomyces cerevisiae bayanus Vitilevure DV10® (Station œnotechnique de Champagne) proved to have a higher sugar consumption rate than the other strains. During the Prise de mousse, S. cerevisiae bayanus Lalvin EC-1118® (Lallemand) reached the maximum pressure increase within time in both base wines. [ABSTRACT FROM AUTHOR]

This investigation was carried out during three seasons i.e. 2010, 2011 and 2012 on Flame Seedless grapevines grown in sandy soil in El-Karnak vineyard for table grapes production, Luxor governorate, Egypt. Ten combined treatments of GA3 , urea and active dry yeast spraying at various stage of berry development were evaluated. The experimental vines were arranged in a complete randomized design with three replications per treatment, two vines each. From the results of this investigation it could be concluded that spraying with GA3 seven times, once at pre-bloom (5 ppm), thrice at full-bloom (2.5, 5 and 7.5 ppm) and other thrice when the berry at (6 mm) pea stage (30, 30 and 20 ppm). As well as, combined spraying GA3 four times once at pre-bloom and thrice at full-bloom plus 0.4% active dry yeast when the berry at pea stage to obtain heavy and less compact cluster and hasten the ripening with fairly good Flame Seedless berries quality. In addition, it could be used urea and yeast instead of GA3 in grape production to overcome the adverse GA3 effects especially for colored cultivars. [ABSTRACT FROM AUTHOR]

The storage of microorganisms in liquid form is the main drawback of commercializing epiphytic coffee yeasts. This work aimed to evaluate the fermentative performance of microencapsulated yeasts by spray drying in a coffee peel and pulp media (CPM). The yeasts, Saccharomyces cerevisiae CCMA 0543, Torulaspora delbrueckii CCMA 0684, and Meyerozyma caribbica CCMA 1738, were microencapsulated using maltodextrin DE10 (MD), high maltose (MA), and whey powder (WP) as wall materials. A Central Composite Rotational Design (CCRD) was used to investigate the effect of operating parameters on the microcapsules' cell viability, drying yield, and water activity. Yeasts reached cell viability and drying yields above 90 and 50 %, respectively. WP maintained the cell viability of the three yeasts over 90 days of storage at room temperature (25 °C) and was selected as a wall material for the three yeasts. M. caribbica showed to be more sensitive to spray drying and less resistant to storage. Some differences were found in the fermentation of the CPM medium, but the microencapsulated yeasts maintained their biotechnological characteristics. Therefore, the microencapsulation of epiphytic coffee yeasts by spray drying was promising to be used in the coffee fermentation process. • The yeasts reached cell viability and drying yields above 90 and 50 %, respectively. • M. caribbica showed to be more sensitive to the spray drying process and storage. • Whey powder maintained the yeasts cell viability over 90 days of storage at 25 °C. • Microencapsulated yeasts maintained their biotechnological characteristics. [ABSTRACT FROM AUTHOR]

Abstract: “Propagation” or “conditioning” of active dry yeast (ADY) for the production of fuel ethanol is thought to reduce lag times in fermentation and reduce overall fermentation times. The objectives of this study were to determine the optimal time that ADY should be conditioned prior to fermentation and to determine how well yeast and bacterial contaminants present in ADY are propagated. A new term, metabolic acclimatization (MAcc), was introduced to describe events occurring during conditioning. It was observed that MAcc is not necessary prior to alcoholic fermentation. Lag times were reduced but overall fermentation times were unaffected. In fact, fermentation rates were slower than control conditions where ADY was directly inoculated into fermentors. In addition, if MAcc systems were to be used, it is recommended that only batch MAcc systems be practiced. Continuous MAcc (continuous yeast propagation) leads to increased bacterial numbers and organic acid levels, which become stressful to yeast. [Copyright &y& Elsevier]

Yeast products (live yeast, yeast cell wall, yeast culture) have been added to the diet of beef cattle under conditions that characterize stress, such as receiving period, high-concentrate finishing diet, periods of elevated ambient temperature, with variable responses in animal performance, health and physiological parameters. Therefore, we conducted a meta-analysis to examine the yeast product's effects on performance parameters, health, and physiological responses of beef cattle. Studies that met the selection criteria included 27 articles. Twenty-seven studies with up to 119 treatments means were included in the data set. The magnitude of the effect (effect size) was assessed using weighted mean differences (WMD) for continuous results, between the yeast products addition and control treatments. The binary results (health parameters) were examined using risk ratio (RR). Heterogeneity was explored by meta-regression and subgroup analysis. The addition of yeast products increased (P ≤ 0.04) animal performance with increase in dry matter intake (DMI; WMD = 0.083 kg/d), average daily gain (ADG; WMD = 0.036 kg/d), final body weight (WMD = 3.75 kg), and feed efficiency (WMD = 2.08 g/kg). In the current study, most of the responses had low heterogeneity (I 2 < 25%), which means low inconsistency in the effect size estimates and independent response from the possible sources of heterogeneity included. Yeast products increased (P ≤ 0.02) the digestibility of dry matter (WMD = 11.84 g/kg), organic matter, (WMD = 15.88 g/kg), crude protein (WMD = 26.99 g/kg), neutral detergent fiber (WMD = 36.84 g/kg) and, increased the average ruminal pH (WMD = 0.088), enabling a reduction in the risk ratio of severely abscessed occurrence (RR = 0.41). In blood parameters, yeast products decreased glucose (P < 0.01; WMD = −5.47 mg/dL) and increased (P ≤ 0.04) urea (WMD = 1.59 mg/dL) and non-esterified fatty acid (WMD = 0.006 mM) concentrations. The acute-phases protein concentrations (Amyloid A, WMD = 3.79 μg/mL and lipopolysaccharide-binding protein WMD = 11.01 μg/mL) were also increased (P = 0.01) when the yeast product was fed. On the other hand, the risk ratio of occurrence of morbidity and mortality were similar (P ≥ 0.49; RR = 0.94 and 0.77 respectively). This meta-analysis indicated that yeast products increased animal performance, and the benefits can be attributed to better rumen health and increases in nutrient digestibility. • By meta-analysis, effects of different yeast products (YPs) for beef cattle were studied. • Conditions characterized as stress for beef cattle were considered. • Yeast products increased ADG, intake and final body weight, promoting rumen health, and greater digestibility. • Low heterogeneity indicates consistency in estimates of weighted mean differences (WMD). • Presence of antibiotics in diets can mitigate the effects of YPs on OM digestibility. [ABSTRACT FROM AUTHOR]

Plant secondary metabolites (PSM) and yeast supplemented in growing cattle have been reported as improving dry matter digestibility (DMD) and reducing enteric methane emissions. This study aimed to evaluate the effect of combined supplementation with condensed tannin (CT; Schinopsis balansae) extract and active dry yeast (ADY; Saccharomyces cerevisiae) on fermentation dynamics, utilizing in vitro gas production (IVGP) technique. A 2 × 2 Latin square design was used to study fermentation patterns of four dietary treatments (CON-no CT and no ADY, ADY alone, CT alone or combined CT + ADY). Animals received daily CT at 1% DM and 10 g of ADY, respectively. On d 0, 7, 14, 21, 28, and 35 rumen inoculum was collected from 23 fistulated steers (284.3 ± 4.1 kg) four hours post-feeding. Samples were incubated under anaerobic conditions at 39oC for 48 h with 200 mg of a grower diet (14.8% CP, 40.6% NDF, 88.5% DM). Gas parameters were analyzed using a mixed linear statistical model. There was a day effect for total gas production (TGP; P < 0.001), non-fiber carbohydrate degradation (P = 0.031) and fractional degradation assuming an asymptote model (P = 0.015). Both asymptote and non-fiber fractional degradation rate estimates had an interaction between Day × TRT (P = 0.001 and 0.0104, respectively). Data were analyzed using polynomial contrasts showed a difference in non-fiber fractional rate of fermentation for CON × CT and CT × ADY (P = 0.052 and 0.054, respectively). This was also true if an asymptote model was assumed (P = 0.0 34 and 0.034, respectively). We concluded that combined supplementation of CT and ADY exhibited similar IVGP trends over time, this may be because animals only received a grower diet at 1.5% shrunk BW. Future studies should investigate the impact of combined supplementation on varying levels of concentrate diets. [ABSTRACT FROM AUTHOR]