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Molecules (Basel, Switzerland) Jan 2021Sparkling wine made by the traditional method (Méthode Traditionelle) develops a distinct and desirable flavour and aroma profile attributed to proteolytic processes...
Sparkling wine made by the traditional method (Méthode Traditionelle) develops a distinct and desirable flavour and aroma profile attributed to proteolytic processes during prolonged ageing on lees. Microwave, ultrasound and addition of β-glucanase enzymes were applied to accelerate the disruption of , and added to the tirage solution for secondary fermentation in traditional sparkling winemaking. Scanning electron microscopy and flow cytometry analyses were used to observe and describe yeast whole-cell anatomy, and cell integrity and structure via propidium iodide (PI) permeability after 6-, 12- and 18-months post-tirage. Treatments applied produced features on lees that were distinct from that of the untreated control yeast. Whilst control yeast displayed budding cells (growth features) with smooth, cavitated and flat external cell appearances; microwave treated yeast cells exhibited modifications like 'doughnut' shapes immediately after treatment (time 0). Similar 'doughnut'-shaped and 'pitted/porous' cell features were observed on progressively older lees from the control. Flow cytometry was used to discriminate yeast populations; features consistent with cell disruption were observed in the microwave, ultrasound and enzyme treatments, as evidenced by up to 4-fold increase in PI signal in the microwave treatment. Forward and side scatter signals reflected changes in size and structure of yeast cells, in all treatments applied. When flow cytometry was interpreted alongside the scanning electron microscopy images, bimodal populations of yeast cells with low and high PI intensities were revealed and distinctive 'doughnut'-shaped cell features observed in association with the microwave treatment only at tirage, that were not observed until 12 months wine ageing in older lees from the control. This work offers both a rapid approach to visualise alterations to yeast cell surfaces and a better understanding of the mechanisms of yeast lysis. Microwave, ultrasound or β-glucanase enzymes are tools that could potentially initiate the release of yeast cell compounds into wine. Further investigation into the impact of such treatments on the flavour and aroma profiles of the wines through sensory evaluation is warranted.
Topics: Autolysis; Saccharomyces cerevisiae; Wine
PubMed: 33450966
DOI: 10.3390/molecules26020387 -
International Journal of Biological... Mar 2016The fig's ficin is a cysteine endoproteolytic enzyme, which plays fundamental roles in many plant physiological processes, and has many applications in different...
The fig's ficin is a cysteine endoproteolytic enzyme, which plays fundamental roles in many plant physiological processes, and has many applications in different industries such as pharmaceutical and food. In this work, we report the inhibition and activation of autolysis and structural changes associated with reaction of ficin with iodoacetamide and tetrathionate using high-performance liquid chromatography (HPLC), ultra filtration membrane, and dynamic light scattering (DLS) methods. The ficin structural changes were also determined using UV-absorption, circular dichroism (CD), fluorescence spectroscopy, and differential scanning calorimetry (DSC) techniques. These techniques demonstrated that iodoacetamide completely inhibited ficin autolysis, which was irreversible. However, tetrathionate partially and reversibility inhibited its autolysis. The ficin structural changes with two synthetic inhibitors were associated with secondary structural changes related to decreased alpha-helix and increased beta sheet and random coil conformations, contributing to its aggregation.
Topics: Calorimetry, Differential Scanning; Chromatography, High Pressure Liquid; Circular Dichroism; Enzyme Inhibitors; Ficain; Ficus; Hydrolysis; Latex; Protein Aggregates; Spectrum Analysis; Structure-Activity Relationship
PubMed: 26718871
DOI: 10.1016/j.ijbiomac.2015.12.009 -
RSC Advances Jan 2022Nanostructures exhibit a bactericidal effect owing to physical interaction with the bacterial cell envelope. Here, we aimed to identify the mechanism underlying the...
Nanostructures exhibit a bactericidal effect owing to physical interaction with the bacterial cell envelope. Here, we aimed to identify the mechanism underlying the bactericidal effect of nanostructures based on bacterial autolysis, in contrast to previous reports focusing on structural characteristics. The time profiles of active cell ratios of the strains (WT, Δ, Δ, Δ70), incubation time of the wild-type (WT) strains, and autolysis inhibition of WT strains were evaluated with respect to the bactericidal effect of the applied nanostructures. Addition of Mg, an autolysis inhibitor, was not found to cause significant cell damage. The incubation phase was significantly associated with envelope damage. The lytic transglycosylase-lacking strain of Slt70 (Δ70) also showed only minimal envelope damage. Our results indicate that nanostructures may act by triggering bacterial autolysis.
PubMed: 35425160
DOI: 10.1039/d1ra07623j -
Bio-protocol Jan 2022Recombinant protein expression is extensively used in biological research. Despite this, current protein expression and extraction methods are not readily scalable or...
Recombinant protein expression is extensively used in biological research. Despite this, current protein expression and extraction methods are not readily scalable or amenable for high-throughput applications. Optimization of protein expression conditions using traditional methods, reliant on growth-associated induction, is non-trivial. Similarly, protein extraction methods are predominantly restricted to chemical methods, and mechanical methods reliant on expensive specialized equipment more tuned for large-scale applications. In this article, we outline detailed protocols for the use of an engineered autolysis/autohydrolysis strain, in two-stage fermentations in shake-flasks. This two-stage fermentation protocol does not require optimization of expression conditions and results in high protein titers. Cell lysis in an engineered strain is tightly controlled and only triggered post-culture by addition of a 0.1% detergent solution. Upon cell lysis, a nuclease digests contaminating host oligonucleotides, which facilitates sample handling. This method has been validated for use at different scales, from microtiter plates to instrumented bioreactors. Graphic abstract: Reprinted with permission from Menacho-Melgar (2020a). Copyright 2020 John Wiley and Sons.
PubMed: 35127987
DOI: 10.21769/BioProtoc.4297 -
Frontiers in Microbiology 2017Lactic acid bacteria (LAB) are important organisms in food production. Indeed, LAB autolysis is very critical in dairy processing. For example, it influences the...
Lactic acid bacteria (LAB) are important organisms in food production. Indeed, LAB autolysis is very critical in dairy processing. For example, it influences the development of cheese flavor by releasing intracellular enzymes, and controls cell growth in yogurts and probiotic products. Two component systems (TCS) constitute essential environmental sensors and effectors of signal transduction in most bacteria. In the present work, mutants of one TCS (LBUL_RS00115/LBUL_RS00110) were generated to assess the relationship between TCS and cell autolysis. The mutants displayed decreased autolysis in comparison with wild type; meanwhile, complementation reversed this effect. The interaction between LBUL_RS00115 and LBUL_RS00110 was confirmed by yeast two-hybrid analysis. These observations suggested that the TCS (LBUL_RS00115/LBUL_RS00110) was involved in autolysis in subsp. .
PubMed: 28769917
DOI: 10.3389/fmicb.2017.01367 -
Foods (Basel, Switzerland) May 2021This study evaluated the food safety and proximate composition of shrimp head (SH). Potentially toxic elements in SH were below European Union legislation limits. SH had...
This study evaluated the food safety and proximate composition of shrimp head (SH). Potentially toxic elements in SH were below European Union legislation limits. SH had a high content of tasting amino acids (sweet and umami amino acids was 57%) and a high content of functional amino acids (essential amino acids was 37%). Moreover, the changes of flavor and key umami molecules in SH were studied by sensory evaluation, electronic tongue, electronic nose, automated amino acid analyzer, and high performance liquid chromatography (HPLC). The results showed that the significant difference of flavor in SH happened during autolysis. SH with autolysis had the best umami taste at 6 h, which may result from the synergistic work of free amino acids and nucleotide related compounds. Additionally, the performance of endogenous proteases in SH was investigated to efficiently analyze autolysis. The optimum pH and temperature of endogenous proteases in SH were 7.5 and 50 °C, respectively. The autolysis of SH depends on two endogenous proteases (~50 kDa and ~75 kDa). These results suggest that the formation of flavor in SH during autolysis can be controlled, which could provide guidance for SH recycle. SH could consider as one of the food materials for producing condiments.
PubMed: 34066655
DOI: 10.3390/foods10051020 -
Molecules (Basel, Switzerland) Mar 2022Autolysis is a common physiological process in eukaryotic cells that is often prevented or applied, especially in yeast expression systems. In this study, an...
Autolysis is a common physiological process in eukaryotic cells that is often prevented or applied, especially in yeast expression systems. In this study, an antimicrobial peptide from chicken (AMP) was recombinantly expressed in the expression system, which induced a series of cellular autolysis phenotypes after methanol treatment, such as the aggregated, lysed, irregular, and enlarged cell morphology, while the cells expressing a recombinant aflatoxin-detoxifizyme (ADTZ) were not autolyzed. A comparative transcriptomic analysis showed that the transcriptomic profiles of cells derived from the autolysis and non-autolysis groups were well discriminated, suggesting that the mechanisms of autolysis were at the transcriptional level. A further differential expression gene (DEG) analysis showed that the DEGs from the two groups were involved mainly in autophagy, the MAPK signaling pathway, transcriptional factors, the central carbon metabolism, anti-stress functions, and so on. In the autolysis group, the cell activity was significantly reduced with the MAPK signaling pathway, the central carbon metabolism was down-regulated, and components of the cytoplasm-to-vacuole targeting (CVT) and mitophagy pathways were up-regulated, suggesting that the autophagy involved in the trafficking of intracellular molecules in the vacuole and mitochondrion contributed to autolysis, which was regulated by transcriptional factors and signal pathways at the transcriptional level. This study provides a theoretical basis for genetic modifications to prevent or utilize cell autolysis in the recombinant protein expression system.
Topics: Animals; Anti-Bacterial Agents; Chickens; Peptides; Pichia; Recombinant Proteins; Saccharomycetales; Transcriptome
PubMed: 35335392
DOI: 10.3390/molecules27062029 -
Iranian Journal of Biotechnology Jul 2022Autolysate products from yeast origin are very interesting for food, feed, cosmetic, pharmaceutical, and fermentation industries. The lysis process greatly influences...
BACKGROUND
Autolysate products from yeast origin are very interesting for food, feed, cosmetic, pharmaceutical, and fermentation industries. The lysis process greatly influences the quality and efficiency of the final autolysates.
OBJECTIVES
Here, we have compared four lysis methods based on autolysis, plasmolysis (with ethanol 1.5% (v/v) and coconut fatty acids 1% (w/w)) and hydrolysis (with alkaline protease 0.4 % (v/w)) on degrading the baker's yeast .
MATERIALS AND METHODS
The efficiency of processes was evaluated according to the recovered solid and protein contents, release of intracellular materials, cell viability, microscopy imaging, degree of hydrolysis and electrophoresis studies.
RESULTS
Results showed that the increased recovered solids and proteins, as well as a higher degree of hydrolysis (DH) were obtained for the enzymatic hydrolyzed cells using alkaline protease. SDS-PAGE analysis also confirmed the results. Further, functionality of the final products by agglutination test showed that the hydrolyzed cells could effectively bind pathogenic bacteria compared to the other cell lysates.
CONCLUSIONS
In conclusion, this work provides adequate evidence for efficiency of alkaline protease for producing the nutritional cell lysates from baker's used in food, feed, cosmetic, and pharmaceutical applications. Moreover, this was the first report on using coconut fatty acids and alkaline protease in lysis of baker's yeast.
PubMed: 36381284
DOI: 10.30498/ijb.2022.282895.3036 -
Journal of Food Science and Technology Aug 2022This was the first study evaluating the impact of cold pre-fermentative maceration using refrigeration on the nutraceutical quality and color of red sparkling wines...
UNLABELLED
This was the first study evaluating the impact of cold pre-fermentative maceration using refrigeration on the nutraceutical quality and color of red sparkling wines elaborated with the cultivar Syrah, and the evolution of these variables with different autolysis times. The sparkling wines were elaborated using the traditional method with different maceration times (NM, 24 and 72 h) and aging on lees (3 and 18 months of autolysis). In the sequence, it was conducted the characterization of the phenolic compound profile by HPLC-DAD ( = 21), the antioxidant capacity (ABTS, DPPH, and FRAP assays), and the color (CIELab and CIEL*C*h systems). The total phenolic content (TPC) and antioxidant capacity (AOX) were higher with longer maceration (M72) and autolysis (18 months) times, reaching 453.54 mg L of TPC, and AOX above 2.11 mmol TEAC L by the three in vitro assays conducted. -resveratrol, kaempferol-3--glucoside, quercetin-3-β-d-glucoside, isorhamnetin-3--glucoside, and petunidin-3--glucoside showed a good correlation ( > 0.8; < 0.05) with the antioxidant capacity and were found in higher concentrations in the sparkling wines elaborated with maceration. In addition, maceration promoted a more intense red (a*) and saturated (C*) color. Thus, the results indicated that cold pre-fermentative maceration and autolysis positively influenced the bioactive potential and the color of the red sparkling wines. This practice should be better explored through the elaboration of this product.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13197-022-05531-z.
PubMed: 35789585
DOI: 10.1007/s13197-022-05531-z -
Sheng Wu Gong Cheng Xue Bao = Chinese... Aug 2023Yeast autolysis affects the flavor and quality of beer. The regulation of yeast autolysis is a need for industrial beer production. Previous studies on brewer's yeast...
Yeast autolysis affects the flavor and quality of beer. The regulation of yeast autolysis is a need for industrial beer production. Previous studies on brewer's yeast autolysis showed that the citric acid cycle-related genes had a great influence on yeast autolysis. To explore the contribution of isocitrate dehydrogenase genes in autolysis, the and genes were destroyed or overexpressed in typical lager yeast Pilsner. The destruction of gene improved the anti-autolytic ability of yeast, and the anti-autolytic index after 96 h autolysis was 8.40, 1.5 times higher than that of the original strain. The destruction of gene increased the supply of nicotinamide adenine dinucleotide phosphate (NADPH) and the NADPH/NADP ratio was 1.94. After fermentation, intracellular ATP level was 1.8 times higher than that of the original strain, while reactive oxygen species (ROS) was reduced by 10%. The destruction of gene resulted in rapid autolysis and a decrease in the supply of NADPH. Anti-autolytic index after 96 h autolysis was 4.03 and the NADPH/NADP ratio was 0.89. After fermentation, intracellular ATP level was reduced by 8% compared with original strain, ROS was 1.3 times higher than that of the original strain. The results may help understand the regulation mechanism of citric acid cycle-related genes on yeast autolysis and provide a basis for the selection of excellent yeast with controllable anti-autolytic performance.
Topics: Humans; Isocitrate Dehydrogenase; NADP; Reactive Oxygen Species; Autolysis; Adenosine Triphosphate
PubMed: 37622372
DOI: 10.13345/j.cjb.220790