Homeopathic drugs complementary, antidotal and inimical to Nux vomica produce stronger anti-alcoholic effect on toads than Nux.

Background In homeopathy some drugs are known to act as complementary, antidotal or inimical to a particular drug. Practitioners can follow this rule when they apply one drug following another. Potentized Nux vomica can reduce acute hypnotic effect of alcohol on toads. Sulphur and Sepia are reported to be complementary to Nux-vom, while Coffea cruda and Zincum met are antidotal and inimical to Nux, respectively .The four drugs have been tested on the toad model to find out their actual therapeutic relationship with Nux vom. Objective To verify the complementary effect of Sulphur and Sepia, antidotal effect of Coffea and inimical effect of Zincum in relation to Nux vom in the toad model. Methods Five batches of toads, each comprising 20 individuals, were treated by partial immersion in a drug diluted with distilled water 1:500 for 20 min. The control consisted of 90% ethanol diluted with distilled water 1:500. The drugs were Nux vom 200 CH, Sulphur 200 CH, Sepia 200 CH, Coffea 200 CH and Zincum 200 CH. Toads of each batch were separately exposed to 260mM ethanol solution and tested every 10 min to see if they had lost their righting reflex (RR). For this, each toad was laid on its dorsal surface. If it failed to turn on its ventrum in a cut-off time of 60 sec it was considered to have lost it’s RR. Four more batches of toads were pretreated with Nux vom 200 CH and subsequently treated separately by Sulphur 200 CH, Sepia 200 CH, Coffea 200 CH and Zincum 200 CH. All the toads were then exposed to 260 mM ethanol solution to record their tolerance to ethanol anesthesia in terms of time to lose RR. Results Toads treated with the five drugs took significantly longer time (P

Isolation of thermo-tolerant and ethanol-tolerant yeast from local fermented foods and their potential as bioethanol producers

Bioethanol is a liquid chemical produced from sugar-, starch-or lignocellulosic-based biomass through fermentation by ethanol-producing microbes. Ethanol-producing yeast generally has limited tolerance to ethanol and has limitation to high temperatures above 40°C. High-temperature tolerant yeast is required because it potentially reduces the risk of contamination and it also reduces the cost of the cooling process. This study aims to determine ethanol-producing yeasts that have tolerance to ethanol and high temperatures from local fermented food products. This study uses a descriptive method conducted in three stages. Isolation and selection of yeast were performed from 18 local fermented foods in Indonesia. Temperature and ethanol tolerance of selected yeast were performed by using a spot test method. The ethanol content was tested using Gas Chromatography (GC). The results exhibited that isolate F08b had the highest tolerance to ethanol and temperature. The isolate was able to grow up to a temperature of 50°C and a concentration of 18% ethanol. Meanwhile, isolate F10 was able to produce the highest ethanol concentration at 3.37% (v/v) in 48th-hour fermentation.

High Diversity of β-Glucosidase-Producing Bacteria and Their Genes Associated with Scleractinian Corals

β-Glucosidase is a microbial cellulose multienzyme that plays an important role in the regulation of the entire cellulose hydrolysis process, which is the rate-limiting step in bacterial carbon cycling in marine environments. Despite its importance in coral reefs, the diversity of β-glucosidase-producing bacteria, their genes, and enzymatic characteristics are poorly understood. In this study, 87 β-glucosidase-producing cultivable bacteria were screened from 6 genera of corals. The isolates were assigned to 21 genera, distributed among three groups: Proteobacteria, Firmicutes, and Actinobacteria. In addition, metagenomics was used to explore the genetic diversity of bacterial β-glucosidase enzymes associated with scleractinian corals, which revealed that these enzymes mainly belong to the glycosidase hydrolase family 3 (GH3). Finally, a novel recombinant β-glucosidase, referred to as Mg9373, encompassing 670 amino acids and a molecular mass of 75.2 kDa, was classified as a member of the GH3 family and successfully expressed and characterized. Mg9373 exhibited excellent tolerance to ethanol, NaCl, and glucose. Collectively, these results suggest that the diversity of β-glucosidase-producing bacteria and genes associated with scleractinian corals is high and novel, indicating great potential for applications in the food industry and agriculture.

Adaptive evolution of Saccharomyces cerevisiae and its application in co-culture with Saccharomyces kudriavzevii in the production of fermented Myrciaria jaboticaba

The objective of this work was to apply the adaptive evolution technique using the Saccharomyces cerevisiae T73 strain to increase its tolerance to ethanol and to evaluate its behavior in co-culture with Saccharomyces kudriavzevii CR85 in the production of fermented Myrciaria jaboticaba. Fermentations were carried out at 25 °C for 186 hours under agitation of 150 rpm, according to a central. The consumption of sugar, ethanol, glycerol and acetic acid formed during the fermentation process was evaluated. The results showed that there is an improvement in ethanol tolerance in S. cerevisiae T73 when submitted to the evolution process. Its use for the production of fermentation of Myrciaria jaboticaba in co-culture shows that the highest yield was observed when 0.0372 g.L-1 and 0.0648 g.L-1 of S. cerevisiae T73 PE (that underwent evolution) and CR85 respectively. These results differed statistically from the experiments using the original T73 strain. Regarding the production of ethanol in co-culture there is a significant increase when using the evolved T73 strain, showing possible changes in the primary metabolism of the ethanol production process, due to the changes promoted during the adaptive evolution of the T73 strain. The results show the potential of the new strain for the production of fermented with higher concentrations of sugars in the must.

The Important Contribution of Non-Saccharomyces Yeasts to the Aroma Complexity of Wine: A Review

Non-Saccharomyces yeast plays an important role in the initial stages of a wild ferment, as they are found in higher abundance in the vineyard than Saccharomyces cerevisiae. As such, there has been a focus in recent years to isolate these yeast species and characterize their effect on wine fermentation and subsequent aroma. This effect on wine aroma is often species and strain dependent, as the enzymatic profile of each yeast will determine which aroma compounds are formed as secondary metabolites. Semi-fermentative yeast, such as Hanseniaspora spp., Candida spp. and Metschnikowia pulcherrima, are commonly in high abundance in fresh grape must and have diverse enzymatic profiles, however they show a weak tolerance to ethanol, limiting their impact to the initial stages of fermentation. Fully fermentative non-Saccharomyces yeast, characterized by high ethanol tolerance, are often found at low abundance in fresh grape must, similar to Saccharomyces cerevisiae. Their ability to influence the aroma profile of wine remains high, however, due to their presence into the final stages of fermentation. Some fermentative yeasts also have unique oenological properties, such as Lanchancea thermotolerans and Schizosaccharomyces pombe, highlighting the potential of these yeast as inoculants for specific wine styles.

Adaptive Laboratory Evolution of Native Torulaspora delbrueckii YCPUC10 With Enhanced Ethanol Resistance and Evaluation in Co-inoculated Fermentation

Torulaspora delbrueckii is a yeast species typically present in the early stages of the fermentation process. T. delbrueckii positively modifies the aromatic properties of wines. However, its contribution to the final quality of the wine is restricted by its low tolerance to ethanol. T. delbrueckii is capable of fermenting and tolerating an ethanol concentration ranging from 7.4% (v/v) to slightly higher than 9% (v/v). For this reason, it cannot complete fermentation, when alcohol reach levels higher than 12% (v/v), limiting their use in the industry. The objective of this work was to obtain new variants of T. delbrueckii with improved resistance to ethanol through adaptive laboratory evolution. Variants capable of tolerating ethanol levels of 11.5% (v/v) were obtained. These presented improved kinetic parameters, and additionally showed an increase in resistance to SO2 in ethanol compared to the original strain. Co-inoculated fermentations were performed with the original strain (FTd/Sc) and with the evolved strain (FTdF/Sc), in addition to a control fermentation using only Saccharomyces cerevisiae EC1118 (FSc). The results obtained show that FTdF/Sc present higher levels of 2-Ethylhexanol, compared to FTd/Sc and FSc. Furthermore, FTdF/Sc presents higher levels of total alcohols, total aldehydes, total phenolic derivatives, and total sulfur compounds with significant differences with FSc. These results provide a T. delbrueckii YCPUC10-F yeast with higher resistance to ethanol, which can be present throughout the fermentation process and be used in co-inoculated fermentations. This would positively impact the performance of T. delbrueckii by allowing it to be present not only in the early stages of fermentation but to remain until the end of fermentation.

OENOLOGICAL CHARACTERIZATION OF SOME YEAST STRAINS ISOLATED FROM THE IASI VINEYARDROMANIA

This study investigated the oenological potential of indigenousSaccharomyces and non-Saccharomyces yeasts isolated from different stages of the natural must fermentation process. Screening of extracellular enzymatic activities was performed on agarized media in which the following substrates were added: arbutin, cellobiose, Tween 80, tributyrin, casein and citrus pectin, to highlight the activity of enzymes: ßglucosidase, esterase, lipase, protease and pectinase. Among the 30 Saccharomyces cerevisae strains tested, 37% showed very low β-glucosidase activity, 100% showed esterase activity, 40% lipase activity, 90% protease activity and 53% pectinase activity.The non-Saccharomyces strain tested showed β-glucosidase, esteraseand protease activity. Tolerance to ethanol was assessed in YPD medium with ethanol concentrations of 5, 10 and 15% (v/v) by yeast culture development index.At 15% ethanol, development of all tested strains were inhibited. In the case of SO2 tolerance, decrease in strains development was inversely correlated with the increase in potassium metabisulphite concentration, up to 200 mg/L. Only four Saccharomyces strains showed specific oenological characteristics and were selected to be tested in mixed and/or sequential cultures to obtain wines with improved sensory features.

Heat Shock Drives Genomic Instability and Phenotypic Variations in Yeast

High temperature causes ubiquitous environmental stress to microorganisms, but studies have not fully explained whether and to what extent heat shock would affect genome stability. Hence, this study explored heat-shock-induced genomic alterations in the yeast Saccharomyces cerevisiae . Using genetic screening systems and customized single nucleotide polymorphism (SNP) microarrays, we found that heat shock (52°C) for several minutes could heighten mitotic recombination by at least one order of magnitude. More than half of heat-shock-induced mitotic recombinations were likely to be initiated by DNA breaks in the S/G 2 phase of the cell cycle. Chromosomal aberration, mainly trisomy, was elevated hundreds of times in heat-shock-treated cells than in untreated cells. Distinct chromosomal instability patterns were also observed between heat-treated and carbendazim-treated yeast cells. Finally, we demonstrated that heat shock stimulates fast phenotypic evolutions (such as tolerance to ethanol, vanillin, fluconazole, and tunicamycin) in the yeast population. This study not only provided novel insights into the effect of temperature fluctuations on genomic integrity but also developed a simple protocol to generate an aneuploidy mutant of yeast.

Characterizing an engineered carotenoid-producing yeast as an anti-stress chassis for building cell factories

Background A microorganism engineered for non-native tasks may suffer stresses it never met before. Therefore, we examined whether a Kluyveromyces marxianus strain engineered with a carotenoid biosynthesis pathway can serve as an anti-stress chassis for building cell factories. Results Carotenoids, a family of antioxidants, are valuable natural products with high commercial potential. We showed that the free radical removal ability of carotenoids can confer the engineered host with a higher tolerance to ethanol, so that it can produce more bio-ethanol than the wild type. Moreover, we found that this engineered strain has improved tolerance to other toxic effects including furfurals, heavy metals such as arsenate (biomass contaminant) and isobutanol (end product). Furthermore, the enhanced ethanol tolerance of the host can be applied to bioconversion of a natural medicine that needs to use ethanol as the delivery solvent of hydrophobic precursors. The result suggested that the engineered yeast showed enhanced tolerance to ethanol-dissolved hydrophobic 10-deacetylbaccatin III, which is considered a sustainable precursor for paclitaxel (taxol) bioconversion. Conclusions The stress tolerances of the engineered yeast strain showed tolerance to several toxins, so it may serve as a chassis for cell factories to produce target products, and the co-production of carotenoids may make the biorefinary more cost-effective.

Overcoming factors limiting high-solids fermentation of lignocellulosic biomass to ethanol

Simultaneous saccharification and fermentation (SSF) of solid biomass can reduce the complexity and improve the economics of lignocellulosic ethanol production by consolidating process steps and reducing end-product inhibition of enzymes compared with separate hydrolysis and fermentation (SHF). However, a long-standing limitation of SSF has been too low ethanol yields at the high-solids loading of biomass needed during fermentation to realize sufficiently high ethanol titers favorable for more economical ethanol recovery. Here, we illustrate how competing factors that limit ethanol yields during high-solids fermentations are overcome by integrating newly developed cosolvent-enhanced lignocellulosic fractionation (CELF) pretreatment with SSF. First, fed-batch glucose fermentations by Saccharomyces cerevisiae D5A revealed that this strain, which has been favored for SSF, can produce ethanol at titers of up to 86 g⋅L−1. Then, optimizing SSF of CELF-pretreated corn stover achieved unprecedented ethanol titers of 79.2, 81.3, and 85.6 g⋅L−1 in batch shake flask, corresponding to ethanol yields of 90.5%, 86.1%, and 80.8% at solids loadings of 20.0 wt %, 21.5 wt %, and 23.0 wt %, respectively. Ethanol yields remained at over 90% despite reducing enzyme loading to only 10 mg protein⋅g glucan−1 [∼6.5 filter paper units (FPU)], revealing that the enduring factors limiting further ethanol production were reduced cell viability and glucose uptake by D5A and not loss of enzyme activity or mixing issues, thereby demonstrating an SSF-based process that was limited by a strain’s metabolic capabilities and tolerance to ethanol.