Increased Varietal Aroma Diversity of Marselan Wine by Mixed Fermentation with Indigenous Non-Saccharomyces Yeasts

The common use of commercial yeasts usually leads to dull wine with similar aromas and tastes. Therefore, screening for novel indigenous yeasts to practice is a promising method. In this research, aroma discrepancies among six wine groups fermentated with indigenous yeasts were analyzed. Three Saccharomyces yeasts (FS36, HL12, YT28) and three matched non-Saccharomyces yeasts (FS31, HL9, YT2) were selected from typical Chinese vineyards. The basic oenological parameters, aroma compounds, and sensory evaluation were analyzed. The results showed that each indigenous Saccharomyces yeast had excellent fermentation capacity, and mixed-strain fermentation groups produced more glycerol, contributing to sweeter and rounder taste. The results from GC-MS, principal components analysis (PCA), and sensory evaluation highlighted that the HL mixed group kept the most content of Marselan varietal flavors such as calamenene and β-damascone hereby ameliorated the whole aroma quality. Our study also implied that the indigenous yeast from the same region as the grape variety seems more conducive to preserve the natural variety characteristics of grapes.

Comparative Genomics Reveals a Convergent Signature on the Vitamin D Receptor (VDR) in Herbivorous Mammals

Background: Dietary adaptation is one of hot topics in adaptive evolution of mammals. Herbivorous mammals generally digest structural carbohydrates (such as cellulose and hemicellulose) via intestinal microbial fermentation. However, the mechanism by which the host supports the intestinal fermentation capacity is still not well understood. To address this question, we conducted convergent amino acid scanning to identify candidate genes involving intestinal fermentation across mammalian phylogeny. Results: Among 4886 one-to-one orthologous genes, we found that 122 genes showed a significant increase of convergent signature in two foregut-fermenting families (Cercopithecidae: Rhinopithecus roxellana, Bovidae: Bos taurus and Ovis aries ) and particularly, in the vitamin D receptor (VDR), a convergent cysteine to serine substitution at amino acid 410 (VDR C410S) occurred in 14 mammalian families with intestinal fermentation capacity. As a critical role of VDR in the regulation of intestinal microbes and adaptive immunity, we employed phylogenetically independent contrast analysis to test whether the evolution of the VDR gene influenced intestinal fermentation and found this convergent amino acid substitution (VDR C410S) possess significant positively correlations with the intestinal fermentation capacity and the dietary components (plant parts except for fruits, seeds and nectar) consumed by 107 mammalian species, which indicated VDR have a positive impact on the herbivorous adaptation of intestinal fermentation. Conclusions: Our results suggest that nuclear receptor gene VDR involved in intestinal adaptive immune show rapid adaptive fixation of convergent amino acid substitutions (C410S) among herbivorous mammals with convergent methodology.

Using Nutritional Strategies to Shape the Gastro-Intestinal Tracts of Suckling and Weaned Piglets

This is a comprehensive review on the use of nutritional strategies to shape the functioning of the gastro-intestinal tract in suckling and weaned piglets. The progressive development of a piglet’s gut and the associated microbiota and immune system offers a unique window of opportunity for supporting gut health through dietary modulation. This is particularly relevant for large litters, for which sow colostrum and milk are insufficient. The authors have therefore proposed the use of supplemental milk and creep feed with a dual purpose. In addition to providing nutrients to piglets, supplemental milk can also serve as a gut modulator in early life by incorporating functional ingredients with potential long-term benefits. To prepare piglets for weaning, it is important to stimulate the intake of solid feed before weaning, in addition to stimulating the number of piglets eating. The use of functional ingredients in creep feed and a transition diet around the time of weaning helps to habituate piglets to solid feed in general, while also preparing the gut for the digestion and fermentation of specific ingredients. In the first days after weaning (i.e., the acute phase), it is important to maintain high levels of feed intake and focus on nutritional strategies that support good gastric (barrier) function and that avoid overloading the impaired digestion and fermentation capacity of the piglets. In the subsequent maturation phase, the ratio of lysine to energy can be increased gradually in order to stimulate piglet growth. This is because the digestive and fermentation capacity of the piglets is more mature at this stage, thus allowing the inclusion of more fermentable fibres. Taken together, the nutritional strategies addressed in this review provide a structured approach to preparing piglets for success during weaning and the period that follows. The implementation of this approach and the insights to be developed through future research can help to achieve some of the most important goals in pig production: reducing piglet mortality, morbidity and antimicrobial use.

Ingestion of xylooligosaccharides during the suckling period improve the feed efficiency and hindgut fermentation capacity of piglets after weaning

Fiber ingestion during the suckling period is helpful to gut development and probiotics colonization. Xylooligosaccharides (Xos) and xylan (Xyl) were selected to investigate the effects of different polymerization degree fiber...

Moderate Pulsed Electric Field Enhances Fermentation Capacity and Induces Stress Responses in Saccharomyces cerevisiae

Saccharomyces cerevisiae has always gained a huge amount of attention due to its extensive and enormous application value. Various methods are used to optimize the fermentation characteristics of S. cerevisiae. In this work, we investigated the fermentation capacity and stress responses on a physiological level of S. cerevisiae which affected by moderate pulsed electric field (PEF, 1 to 3 kV·cm-1). The fermentation capacity was illustrated by glucose consumption and metabolites yield (ethanol and glycerol). The expressions of ten glycolysis-associated genes were studied to elucidate the fermentative processes. The results showed that fermentation capacity of S. cerevisiae was promoted by moderate PEF treatments, with higher glucose consumption and ethanol yield. Yeast cells also gained a faster growth rate under constant PEF stimulation. Analysis of gene expression involved in glycolytic pathway showed that moderate PEF treatments induced a higher glycolytic flux, especially in terms of synthesis of ethanol. It would be a promising technique for PEF to enhance fermentation capacity and growth of S. cerevisiae. © 2021 Friends Science Publishers

Potential of Lactic Acid Bacteria Isolated From Different Forages as Silage Inoculants for Improving Fermentation Quality and Aerobic Stability

We aimed at isolating lactic acid bacteria (LAB) from different plant materials to study their crossed-fermentation capacity in silos and to find strains able to confer enhanced aerobic stability to silage. A total of 129 LAB isolates were obtained from lucerne (alfalfa), maize, sorghum, ryegrass, rice, barley, canola, Gatton panic, Melilotus albus, soy, white clover, wheat, sunflower, oat, and moha. Four Lactiplantibacillus plantarum subsp. plantarum strains (isolated from oat, lucerne, sorghum, or maize) were selected for their growth capacity. Identity (16S sequencing) and diversity (RAPD-PCR) were confirmed. Fermentative capacity (inoculated at 104, 105, 106, 107 CFU/g) was studied in maize silage and their cross-fermentation capacity was assessed in oat, lucerne, sorghum, and maize. Heterofermentative strains with the highest acetic acid production capacity conferred higher aerobic stability to maize silages. Regardless the source of isolation, L. plantarum strains, inoculated at a rate of 106 CFU/g, were effective to produce silage from different plant materials. From more than 100 isolates obtained, the application of a succession of experiments allowed us to narrow down the number of potential candidates of silage inoculants to two strains. Based on the studies made, L. plantarum LpM15 and Limosilactobacillus fermentum LfM1 showed potential to be used as inoculants, however further studies are needed to determine their performance when inoculated together. The former because it positively influenced different quality parameters in oat, lucerne, sorghum, and maize silage, and the latter because of its capacity to confer enhanced aerobic stability to maize silage. The rest of the strains constitute a valuable collection of autochthonous strains that will be further studied in the future for new applications in animal or human foods.

Heat Stress Increases In Vitro Hindgut Fermentation of Distinct Substrates in Iberian Pigs

Heat stress reduces the feed intake and growth of pigs. We hypothesized that heat stress affects the intestinal fermentation capacity of pigs. Sixteen Iberian pigs (44 ± 1.0 kg) were randomly assigned to one of two treatments (eight pigs/treatment) for 4 weeks—heat stress (HS; 30 °C) ad libitum or thermoneutral (TN; 20 °C) pair feeding. Frozen rectum contents were used as inocula for 24 h in vitro incubations in which a mixture of starches, citrus pectin, inulin from chicory, and cellulose were the substrates. Cellulose was poorly degraded, whereas pectin and the mixture of starches were the most fermentable substrates according to total short-chain fatty acid (SCFA) production. The mixture of starches and inulin produced the greatest amount of gas. For all substrates, heat stress enhanced gas production (8%, p = 0.001), total SCFA production (16%, p = 0.001), and the production of acetate and propionate (12% and 42%, respectively; p = 0.001). The increased isoacid production (33%, p = 0.001) and ammonia concentration (12%, p = 0.001) may indicate protein fermentation under heat stress. In conclusion, the in vitro intestinal fermentation capacity of pigs under heat stress was increased compared to thermoneutral conditions, which may indicate an adaptive response to heat stress.

The composition of sacarine substrates for ethanol production and the fermentative capacity Saccharomyces cerevisiae Pedra-2

The production of ethanol in Brazil is based on sugarcane juice, however other biomasses can be used for this process, such as sweet sorghum. However, some nutrients can interfere with fermentation, such as the presence of metals, carbon and nitrogen sources, which can affect the fermentation capacity of yeasts. Thus, this study aims to analyze the presence of fundamental nutrients present in saccharine substrates, as well as their assimilation and conversion of ethanol by the yeast Pedra-2. Samples of sugarcane and sorghum juice were obtained, in which analysis of the presence of metals was carried out using acid digestion and the levels determined by atomic flame absorption spectroscopy. The amino acid analysis was performed on the saccharine substrates at a concentration of 22 ºBrix, before and after fermentation, and analyzed by high-performance liquid chromatography and the concentration of ethanol by gas chromatography. The sorghum broth showed higher amounts of available amino acid metals. The yeast Pedra-2 showed better fermentative performance in the sorghum broth. We can conclude that the sorghum broth represents an important substrate to be used to increase the sustainability and production of ethanol in Brazil.

The impact of food additives, artificial sweeteners and domestic hygiene products on the human gut microbiome and its fibre fermentation capacity

Purpose This study investigated the effect of food additives, artificial sweeteners and domestic hygiene products on the gut microbiome and fibre fermentation capacity. Methods Faecal samples from 13 healthy volunteers were fermented in batch cultures with food additives (maltodextrin, carboxymethyl cellulose, polysorbate-80, carrageenan-kappa, cinnamaldehyde, sodium benzoate, sodium sulphite, titanium dioxide), sweeteners (aspartame-based sweetener, sucralose, stevia) and domestic hygiene products (toothpaste and dishwashing detergent). Short-chain fatty acid production was measured with gas chromatography. Microbiome composition was characterised with 16S rRNA sequencing and quantitative polymerase chain reaction (qPCR). Results Acetic acid increased in the presence of maltodextrin and the aspartame-based sweetener and decreased with dishwashing detergent or sodium sulphite. Propionic acid increased with maltodextrin, aspartame-based sweetener, sodium sulphite and polysorbate-80 and butyrate decreased dramatically with cinnamaldehyde and dishwashing detergent. Branched-chain fatty acids decreased with maltodextrin, aspartame-based sweetener, cinnamaldehyde, sodium benzoate and dishwashing detergent. Microbiome Shannon α-diversity increased with stevia and decreased with dishwashing detergent and cinnamaldehyde. Sucralose, cinnamaldehyde, titanium dioxide, polysorbate-80 and dishwashing detergent shifted microbiome community structure; the effects were most profound with dishwashing detergent (R2 = 43.9%, p = 0.008) followed by cinnamaldehyde (R2 = 12.8%, p = 0.016). Addition of dishwashing detergent and cinnamaldehyde increased the abundance of operational taxonomic unit (OTUs) belonging to Escherichia/Shigella and Klebsiella and decreased members of Firmicutes, including OTUs of Faecalibacterium and Subdoligranulum. Addition of sucralose and carrageenan-kappa also increased the abundance of Escherichia/Shigella and sucralose, sodium sulphite and polysorbate-80 did likewise to Bilophila. Polysorbate-80 decreased the abundance of OTUs of Faecalibacterium and Subdoligranulum. Similar effects were observed with the concentration of major bacterial groups using qPCR. In addition, maltodextrin, aspartame-based sweetener and sodium benzoate promoted the growth of Bifidobacterium whereas sodium sulphite, carrageenan-kappa, polysorbate-80 and dishwashing detergent had an inhibitory effect. Conclusions This study improves understanding of how additives might affect the gut microbiota composition and its fibre metabolic activity with many possible implications for human health.

In vitro approach to evaluate the fermentation pattern of inulin-rich food in obese individuals

Alterations of the gut microbiome have been associated with obesity and metabolic disorders. The gut microbiota can be influenced by the intake of dietary fibres with prebiotic properties, such as inulin-type fructans. The present study tested the hypothesis that obese individuals subjected for 12 weeks to an inulin-enriched v. inulin-poor diet have differential faecal fermentation patterns. The fermentation of cellulose and inulin hydrolysates of six different inulin-rich and inulin-poor vegetables of both groups was analysed in vitro on faecal inocula. The results showed that the microbiota from obese patients who received a fructan-rich diet for 3 weeks produces more gas and total SCFA compared with the microbiota taken from the same individuals before the treatment. Obese individuals fed with a low-fructan diet produce less gas and less SCFA compared with the treated group. The present study highlighted profound changes in microbiota fermentation capacity obtained by prebiotic intervention in obese individuals, which favours the production of specific bioactive metabolites.