The impact of multiple abiotic stresses on ns-LTP2.8 gene transcript and ns-LTP2.8 protein accumulation in germinating barley (Hordeum vulgare L.) embryos

Abiotic stresses occur more often in combination than alone under regular field conditions limiting in more severe way crop production. Stress recognition in plants primarily occurs in the plasma membrane, modification of which is necessary to maintain homeostasis in response to it. It is known that lipid transport proteins (ns-LTPs) participate in modification of the lipidome of cell membranes. Representative of this group, ns-LTP2.8, may be involved in the reaction to abiotic stress of germinating barley plants by mediating the intracellular transport of hydrophobic particles, such as lipids, helping to maintain homeostasis. The ns-LTP2.8 protein was selected for analysis due to its ability to transport not only linear hydrophobic molecules but also compounds with a more complex spatial structure. Moreover, ns-LTP2.8 has been qualified as a member of pathogenesis-related proteins, which makes it particularly important in relation to its high allergenic potential. This paper demonstrates for the first time the influence of various abiotic stresses acting separately as well as in their combinations on the change in the ns-LTP2.8 transcript, ns-LTP2.8 protein and total soluble protein content in the embryonal axes of germinating spring barley genotypes with different ns-LTP2.8 allelic forms and stress tolerance. Tissue localization of ns-LTP2.8 transcript as well as ns-LTP2.8 protein were also examined. Although the impact of abiotic stresses on the regulation of gene transcription and translation processes remains not fully recognized, in this work we managed to demonstrate different impact on applied stresses on the fundamental cellular processes in very little studied tissue of the embryonal axis of barley.

Addition of Hop (Humulus Lupulus L.) Bitter Acids Yields Modification of Malt Protein Aggregate Profiles during Wort Boiling

Hop bitter acids are used in the brewing industry to give beer bitterness. However, much of this bitterness is lost during processing, specifically during the wort boiling step. One of the major causes might be the interaction with protein-protein complexes. Therefore, the aim of this study was to clarify the role of hop bitter acids in protein aggregate formation using a proteomic approach. The effect of hop addition on protein composition was analyzed by liquid chromatography-mass spectrometry/MS (LC-MS/MS), and further analyses were performed to characterize the wort before and after boiling. Addition of hop bitter acids yielded a change in wort protein profiles, and hop bitter acids were found to bind primarily to less abundant proteins which are not related to beer quality traits, such as foam or haze. Wort protein aggregate profiles were revealed, and findings from this study suggested the precipitation of particular proteins in the aggregates during boiling when hops were added.

Recent advances in research in the rumen bloat of ruminant animals fed high-concentrate diets

Rumen bloat is the most common digestive disorder in fattening ruminants, which is responsible for around 2-3 % of deaths in the ruminants industry and is therefore considered to be a serious threat to ruminant farming. The root cause of rumen bloat caused by feeding high concentrate dies would be attributed to the production of a large amount of stable foam during the fattening period. The exact mechanism of rumen foam formation has yet to be investigated. Proteins, polysaccharides and carboxylates derived from feed, and synthesized by microbes during the rumen fermentation may act as foaming agents or stabilizers in the formation progress of rumen foam. Supplementation of condensed tannins and other additives can be an effective way to prevent feedlot bloat induced by feeding high concentrate diets.

Application of Mass Spectrometry-Based Proteomics to Barley Research

Barley (Hordeum vulgare) is the fourth most cultivated crop in the world in terms of production volume, and it is also the most important raw material of the malting and brewing industries. Barley belongs to the grass (Poaceae) family and plays an important role in food security and food safety for both humans and livestock. With the global population set to reach 9.7 billion by 2050, but with less available and/or suitable land for agriculture, the use of biotechnology tools in breeding programs are of considerable importance in the quest to meet the growing food gap. Proteomics as a member of the "omics" technologies has become popular for the investigation of proteins in cereal crops and particularly barley and its related products such as malt and beer. This technology has been applied to study how proteins in barley respond to adverse environmental conditions including abiotic and/or biotic stresses, how they are impacted during food processing including malting and brewing, and the presence of proteins implicated in celiac disease. Moreover, proteomics can be used in the future to inform breeding programs that aim to enhance the nutritional value and broaden the application of this crop in new food and beverage products. Mass spectrometry analysis is a valuable tool that, along with genomics and transcriptomics, can inform plant breeding strategies that aim to produce superior barley varieties. In this review, recent studies employing both qualitative and quantitative mass spectrometry approaches are explored with a focus on their application in cultivation, manufacturing, processing, quality, and the safety of barley and its related products.

Antioxidant mechanism, antibacterial activity, and functional characterization of peptide fractions obtained from barred mackerel gelatin with a focus on application in carbonated beverages

The present study aimed to use fish by-products to generate gelatin peptides with potential applications in carbonated beverages. After ultrafiltration, the F < 3 kDa (fraction < 3 kDa) showed the highest peptide concentration (227.22 mg/g) as well as antibacterial (MIC of ≤ 0.5 mg/mL) and antioxidant activities, including hydroxyl and superoxide radical scavenging, ferrous chelation, and ferric reduction (with IC₅₀ values of 0.88, 1.04, 0.50 mg/mL, and 0.58, respectively). 2,2-diphenyl-1-picrylhydrazyl scavenging was the highest in the 3 < F < 10 kDa (IC₅₀ of 0.64 mg/mL). In vitro gastrointestinal digestion significantly decreased all biological activities. Solubility, water holding capacity, and emulsifying activity of the F < 3 kDa were the highest while foaming properties and overfoaming were reversibly related to the molecular weight. All abovementioned properties, in addition to in vitro cytotoxicity analysis in different cell lines and better flavor characteristics, indicated that the F < 3 kDa could be safely and properly used as an ingredient for the fortification of carbonated beverages.

Transcriptomic Analysis of Verbena bonariensis Leaves Under Low-Temperature Stress

Verbena bonariensis is a valuable plant for both ornament and flower border. As a major constraint, low temperature affects the growing development and survival of V. bonariensis. However, there are few systematic studies in terms of molecular mechanism on the tolerance of low temperature in V. bonariensis. In this study, Illumina sequencing technology was applied to analyze the cold resistance mechanism of plants. Six cDNA libraries were obtained from two samples of two groups, the cold-treated group and the control group. A total of 271,920 unigenes were produced from 406,641 assembled transcripts. Among these, 19,003 differentially expressed genes (DEGs) (corrected p-value <0.01, |log2(fold change) | >3) were obtained, including 9852 upregulated and 9151 downregulated genes. The antioxidant enzyme system, photosynthesis, plant hormone signal transduction, fatty acid metabolism, starch and sucrose metabolism pathway, and transcription factors were analyzed. Based on these results, series of candidate genes related to cold stress were screened out and discussed. The physiological indexes related to response mechanism of low temperature were tested. Eleven upregulated DEGs were validated by Quantitative Real-time PCR. In this study, we provided the transcriptome sequence resource of V. bonariensis and used these data to realize its molecular mechanism under cold stress. The results contributed to valuable clues for genetic studies and helped to screen candidate genes for cold-resistance breeding.

A Review on the Source of Lipids and Their Interactions during Beer Fermentation that Affect Beer Quality

The presence of lipids in wort and beer are important due to their influence on yeast metabolism and beer quality. Barley lipids have long been considered to have adverse effects on beer quality where some long-chain fatty acids are associated with high flavour potential. In addition, beer foam stability can be influenced by the concentration of lipids as well as other factors such as hop acids (e.g., iso-α-acids), proteins, polysaccharides and the presence of metal ions (e.g., nickel). Lipids can also influence yeast protease activity as well as the production of ethanol. This review provides an overview of the effect of climate change on the chemical composition of barley in relation to lipids and the influence of lipids in the process of this raw material in order to produce beer.

Process Proteomics of Beer Reveals a Dynamic Proteome with Extensive Modifications

Modern beer production is a complex industrial process. However, some of its biochemical details remain unclear. Using mass spectrometry proteomics, we have performed a global untargeted analysis of the proteins present across time during nanoscale beer production. Samples included sweet wort produced by a high temperature infusion mash, hopped wort, and bright beer. This analysis identified over 200 unique proteins from barley and yeast, emphasizing the complexity of the process and product. We then used data independent SWATH-MS to quantitatively compare the relative abundance of these proteins throughout the process. This identified large and significant changes in the proteome at each process step. These changes described enrichment of proteins by their biophysical properties, and identified the appearance of dominant yeast proteins during fermentation. Altered levels of malt modification also quantitatively changed the proteomes throughout the process. Detailed inspection of the proteomic data revealed that many proteins were modified by protease digestion, glycation, or oxidation during the processing steps. This work demonstrates the opportunities offered by modern mass spectrometry proteomics in understanding the ancient process of beer production.

Optimised purification and characterisation of lipid transfer protein 1 (LTP1) and its lipid-bound isoform LTP1b from barley malt

In beer brewing, brewers worldwide strive to obtain product consistency in terms of flavour, colour and foam. Important proteins contributing to beer foam are lipid transfer proteins (LTPs), in particular LTP1 and its lipid-bound isoform LTP1b, which are known to transport lipids in vivo and prevent lipids from destabilising the beer foam. LTP1 and LTP1b were successfully purified using only five purification steps with a high purified protein yield (160 mg LTP1 and LTP1b from 200 g barley). Circular dichroism of LTP1 and LTP1b confirmed that both proteins are highly tolerant to high temperatures (>90 °C) and are pH stable, particularly at a neutral to a more basic pH. Only LTP1 exhibited antiyeast and thermo-stable lytic activity, while LTP1b was inactive, indicating that the fatty acid moiety compromised the antimicrobial activity of LTP1. This lack in antiyeast activity and the positive foam properties of LTP1b would benefit beer fermentation and quality.

The impact of different ale brewer's yeast strains on the proteome of immature beer

Background

It is well known that brewer’s yeast affects the taste and aroma of beer. However, the influence of brewer’s yeast on the protein composition of beer is currently unknown. In this study, changes of the proteome of immature beer, i.e. beer that has not been matured after fermentation, by ale brewer’s yeast strains with different abilities to degrade fermentable sugars were investigated.

Results

Beers were fermented from standard hopped wort (13° Plato) using two ale brewer’s yeast (Saccharomyces cerevisiae) strains with different attenuation degrees. Both immature beers had the same alcohol and protein concentrations. Immature beer and unfermented wort proteins were analysed by 2-DE and compared in order to determine protein changes arising from fermentation. Distinct protein spots in the beer and wort proteomes were identified using Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and MS/MS and revealed common beer proteins, such as lipid transfer proteins (LTP1 and LTP2), protein Z and amylase-protease inhibitors. During fermentation, two protein spots, corresponding to LTP2, disappeared, while three protein spots were exclusively found in beer. These three proteins, all derived from yeast, were identified as cell wall associated proteins, that is Exg1 (an exo-β-1,3-glucanase), Bgl2 (an endo-β-1,2-glucanase), and Uth1 (a cell wall biogenesis protein).

Conclusion

Yeast strain dependent changes in the immature beer proteome were identified, i.e. Bgl2 was present in beer brewed with KVL011, while lacking in WLP001 beer.

Long distance movement of DIR1 and investigation of the role of DIR1-like during systemic acquired resistance in Arabidopsis

DIR1 is a lipid transfer protein (LTP) postulated to complex with and/or chaperone a signal(s) to distant leaves during Systemic Acquired Resistance (SAR) in Arabidopsis. DIR1 was detected in phloem sap-enriched petiole exudates collected from wild-type leaves induced for SAR, suggesting that DIR1 gains access to the phloem for movement from the induced leaf. Occasionally the defective in induced resistance1 (dir1-1) mutant displayed a partially SAR-competent phenotype and a DIR1-sized band in protein gel blots was detected in dir1-1 exudates suggesting that a highly similar protein, DIR1-like (At5g48490), may contribute to SAR. Recombinant protein studies demonstrated that DIR1 polyclonal antibodies recognize DIR1 and DIR1-like. Homology modeling of DIR1-like using the DIR1-phospholipid crystal structure as template, provides clues as to why the dir1-1 mutant is rarely SAR-competent. The contribution of DIR1 and DIR1-like during SAR was examined using an Agrobacterium-mediated transient expression-SAR assay and an estrogen-inducible DIR1-EGFP/dir1-1 line. We provide evidence that upon SAR induction, DIR1 moves down the leaf petiole to distant leaves. Our data also suggests that DIR1-like displays a reduced capacity to move to distant leaves during SAR and this may explain why dir1-1 is occasionally SAR-competent.

Characterization of lipids and lignans in brewer's spent grain and its enzymatically extracted fraction

Brewer's spent grain (BSG), the major side stream of brewing, consists of the husks and the residual parts of malts after the mashing process. BSG was enzymatically fractionated by a two-step treatment with carbohydrate- and protein-degrading enzymes, which solubilized 66% of BSG. BSG contained 11% lipids, which were mostly triglycerides, but also a notable amount of free fatty acids was present. Lipids were mostly solubilized due to the alkaline pH applied in the protease treatment. The main fatty acids were linoleic, palmitic, and oleic acids. Several lignans were identified in BSG, syringaresinol and secoisolariciresinol being the most abundant, many associated with the cell wall matrix and released by the alkaline-protease treatment.

Nonhost resistance of barley to different fungal pathogens is associated with largely distinct, quantitative transcriptional responses

Nonhost resistance protects plants against attack by the vast majority of potential pathogens, including phytopathogenic fungi. Despite its high biological importance, the molecular architecture of nonhost resistance has remained largely unexplored. Here, we describe the transcriptional responses of one particular genotype of barley (Hordeum vulgare subsp. vulgare 'Ingrid') to three different pairs of adapted (host) and nonadapted (nonhost) isolates of fungal pathogens, which belong to the genera Blumeria (powdery mildew), Puccinia (rust), and Magnaporthe (blast). Nonhost resistance against each of these pathogens was associated with changes in transcript abundance of distinct sets of nonhost-specific genes, although general (not nonhost-associated) transcriptional responses to the different pathogens overlapped considerably. The powdery mildew- and blast-induced differences in transcript abundance between host and nonhost interactions were significantly correlated with differences between a near-isogenic pair of barley lines that carry either the Mlo wild-type allele or the mutated mlo5 allele, which mediates basal resistance to powdery mildew. Moreover, during the interactions of barley with the different host or nonhost pathogens, similar patterns of overrepresented and underrepresented functional categories of genes were found. The results suggest that nonhost resistance and basal host defense of barley are functionally related and that nonhost resistance to different fungal pathogens is associated with more robust regulation of complex but largely nonoverlapping sets of pathogen-responsive genes involved in similar metabolic or signaling pathways.