scholarly journals Toward application of biocontrol to inhibit wine spoilage yeasts: The use of statistical designs for screening and optimisation

OENO One ◽  
2021 ◽  
Vol 55 (2) ◽  
pp. 75-96
Author(s):  
Benjamin Kuchen ◽  
Fabio Vazquez ◽  
Yolanda Paola Maturano ◽  
Gustavo J. E. Scaglia ◽  
Licia María Pera ◽  
...  
Keyword(s):  
Killer Toxin ◽  
Statistical Design ◽  
Wine Industry ◽  
Economic Losses ◽  
Negative Effects ◽  
Spoilage Yeast ◽  
Spoilage Yeasts ◽  
Physicochemical Factors ◽  
Statistical Designs ◽  
Yeast Interactions

Spoilage yeasts generate considerable economic losses in the wine industry, and although sulphur dioxide (SO2) is traditionally used for control, its use has become controversial because of its negative effects on health. Biocontrol has emerged as a partial alternative to SO2, and most research has focused on the selection of biocontrol yeasts and/or the mechanisms involved, while little research has been directed to the environmental conditions that make biocontrol effective for application. When there are two or more interacting yeasts, the physicochemical factors that affect their antagonism are many and therefore the application of biocontrol is complex. To reduce SO2, the present study aimed to elucidate biocontrol mechanisms of two yeast interactions and to establish optimal physicochemical conditions for biocontrol of the spoilage yeast during grape must fermentation. Through the use of statistical design, it was possible to find relevant physicochemical factors and optimise them. Wickerhamomyces anomalus “BWa156” developed an active supernatant against ZygoSaccharomyces rouxii “BZr6” while supernatant from Metschnikowia pulcherrima “BMp29” was ineffective. In mixed must fermentations, the first interaction (BWa156 vs. BZr6) showed fewer physicochemical factors impacting biocontrol compared to the second interaction (BMp29 vs. BZr6). However, the fewer factors of the first interaction had a stronger effect on the decline in the spoilage population. Validations showed that the optimal conditions for biocontrol with the first interaction could be predicted. Analysis of the results with BWa156 vs. BZr6 and BMp29 vs. BZr6 suggests that the first interaction is a competition that includes a killer toxin, while the second interaction involves competition for iron resources. Response surface methodology (RSM) allowed a reduction in the number of experiments and permitted to find the optimal biocontrol conditions (SO2: 0 mg mL-1; pH: 3.7; Reducing sugars: 23 °Brix) for the interaction between BWa156 and BZr6.

Kluyveromyces phaffii killer toxin active against wine spoilage yeasts: purification and characterization

Microbiology ◽  
2004 ◽  
Vol 150 (8) ◽  
pp. 2535-2541 ◽  
Author(s):  
Francesca Comitini ◽  
Natalia Di Pietro ◽  
Laura Zacchi ◽  
Ilaria Mannazzu ◽  
Maurizio Ciani
Keyword(s):  
Biochemical Characterization ◽  
Competitive Inhibition ◽  
Killer Toxin ◽  
Receptor Site ◽  
Wine Industry ◽  
Cell Wall Polysaccharides ◽  
Killer Activity ◽  
Spoilage Yeast ◽  
Spoilage Yeasts ◽  
Potential Applications

The killer toxin secreted by Kluyveromyces phaffii (KpKt) is active against spoilage yeast under winemaking conditions and thus has potential applications in the biocontrol of undesired micro-organisms in the wine industry. Biochemical characterization and N-terminal sequencing of the purified toxin show that KpKt is a glycosylated protein with a molecular mass of 33 kDa. Moreover, it shows 93 % and 80 % identity to a β-1,3-glucanase of Saccharomyces cerevisiae and a β-1,3-glucan transferase of Candida albicans, respectively, and it is active on laminarin and glucan, thus showing a β-glucanase activity. Competitive inhibition of killer activity by cell-wall polysaccharides suggests that glucan (β-1,3 and β-1,6 branched glucans) represents the first receptor site of the toxin on the envelope of the sensitive target. Flow cytometry analysis of the sensitive target after treatment with KpKt and K1 toxin of S. cerevisiae, known to cause loss of cell viability via formation of pores in the cell membrane, suggests a different mode of action for KpKt.

scholarly journals PMKT2, a new killer toxin from Pichia membranifaciens, and its promising biotechnological properties for control of the spoilage yeast Brettanomyces bruxellensis

Microbiology ◽  
2009 ◽  
Vol 155 (2) ◽  
pp. 624-634 ◽  
Author(s):  
A. Santos ◽  
M. San Mauro ◽  
E. Bravo ◽  
D. Marquina
Keyword(s):  
Biochemical Characterization ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Killer Toxin ◽  
Small Scale ◽  
Brettanomyces Bruxellensis ◽  
Killer Activity ◽  
Pichia Membranifaciens ◽  
Spoilage Yeast ◽  
Spoilage Yeasts

Pichia membranifaciens CYC 1086 secretes a killer toxin (PMKT2) that is inhibitory to a variety of spoilage yeasts and fungi of agronomical interest. The killer toxin in the culture supernatant was concentrated by ultrafiltration and purified to homogeneity by two successive steps, including native electrophoresis and HPLC gel filtration. Biochemical characterization of the toxin showed it to be a protein with an apparent molecular mass of 30 kDa and an isoelectric point of 3.7. At pH 4.5, optimal killer activity was observed at temperatures up to 20 °C. Above approximately this pH, activity decreased sharply and was barely noticeable at pH 6. The toxin concentrations present in the supernatant during optimal production conditions exerted a fungicidal effect on a variety of fungal and yeast strains. The results obtained suggest that PMKT2 has different physico-chemical properties from PMKT as well as different potential uses in the biocontrol of spoilage yeasts. PMKT2 was able to inhibit Brettanomyces bruxellensis while Saccharomyces cerevisiae was fully resistant, indicating that PMKT2 could be used in wine fermentations to avoid the development of the spoilage yeast without deleterious effects on the fermentative strain. In small-scale fermentations, PMKT2, as well as P. membranifaciens CYC 1086, was able to inhibit B. bruxellensis, verifying the biocontrol activity of PMKT2 in simulated winemaking conditions.

scholarly journals Selection of Native Non-Saccharomyces Yeasts with Biocontrol Activity against Spoilage Yeasts in Order to Produce Healthy Regional Wines

Fermentation ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 60 ◽  
Author(s):  
Benjamín Kuchen ◽  
Yolanda Paola Maturano ◽  
María Victoria Mestre ◽  
Mariana Combina ◽  
María Eugenia Toro ◽  
...  
Keyword(s):  
Fermentation Medium ◽  
Wine Industry ◽  
Economic Losses ◽  
Negative Contribution ◽  
Brettanomyces Bruxellensis ◽  
Spoilage Yeasts ◽  
Biocontrol Activity ◽  
Off Flavors ◽  
Saccharomyces Yeasts ◽  
Selection Of

Two major spoilage yeasts in the wine industry, Brettanomyces bruxellensis and Zygosaccharomyces rouxii, produce off-flavors and gas, causing considerable economic losses. Traditionally, SO2 has been used in winemaking to prevent spoilage, but strict regulations are in place regarding its use due to its toxic and allergenic effects. To reduce its usage researchers have been searching for alternative techniques. One alternative is biocontrol, which can be used either independently or in a complementary way to chemical control (SO2). The present study analyzed 122 native non-Saccharomyces yeasts for their biocontrol activity and their ability to be employed under fermentation conditions, as well as certain enological traits. After the native non-Saccharomyces yeasts were assayed for their biocontrol activity, 10 biocontroller yeasts were selected and assayed for their ability to prevail in the fermentation medium, as well as with respect to their corresponding positive/negative contribution to the wine. Two yeasts that satisfy these characteristics were Wickerhamomyces anomalus BWa156 and Metschnikowia pulcherrima BMp29, which were selected for further research in application to mixed fermentations.

scholarly journals Study on the Inhibitory Activity of a Synthetic Defensin Derived from Barley Endosperm against Common Food Spoilage Yeast

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 165
Author(s):  
Laila N. Shwaiki ◽  
Aylin W. Sahin ◽  
Elke K. Arendt
Keyword(s):  
Apple Juice ◽  
Digestive Enzyme ◽  
Inhibitory Effect ◽  
Food Preservation ◽  
Food Spoilage ◽  
Inhibitory Effects ◽  
Barley Endosperm ◽  
Spoilage Yeast ◽  
Spoilage Yeasts ◽  
Spoilage Microorganisms

In the food industry, food spoilage is a real issue that can lead to a significant amount of waste. Although current preservation techniques are being applied to reduce the occurrence of spoilage microorganisms, the problem persists. Food spoilage yeast are part of this dilemma, with common spoilers such as Zygosaccharomyces, Kluyveromyces, Debaryomyces and Saccharomyces frequently encountered. Antimicrobial peptides derived from plants have risen in popularity due to their ability to reduce spoilage. This study examines the potential application of a synthetic defensin peptide derived from barley endosperm. Its inhibitory effect against common spoilage yeasts, its mechanisms of action (membrane permeabilisation and overproduction of reactive oxygen species), and its stability in different conditions were characterised. The safety of the peptide was evaluated through a haemolysis and cytotoxicity assay, and no adverse effects were found. Both assays were performed to understand the effect of the peptide if it were to be consumed. Its ability to be degraded by a digestive enzyme was also examined for its safety. Finally, the peptide was successfully applied to different beverages and maintained the same inhibitory effects in apple juice as was observed in the antiyeast assays, providing further support for its application in food preservation.

scholarly journals Assessing Genetic Diversity among Brettanomyces Yeasts by DNA Fingerprinting and Whole-Genome Sequencing

2014 ◽  
Vol 80 (14) ◽  
pp. 4398-4413 ◽  
Author(s):  
Sam Crauwels ◽  
Bo Zhu ◽  
Jan Steensels ◽  
Pieter Busschaert ◽  
Gorik De Samblanx ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Dna Fingerprinting ◽  
Wine Industry ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Content Type ◽  
Carbon And Nitrogen ◽  
Spoilage Yeasts ◽  
Off Flavors ◽  
Carbon And Nitrogen Metabolism

ABSTRACTBrettanomycesyeasts, with the speciesBrettanomyces(Dekkera)bruxellensisbeing the most important one, are generally reported to be spoilage yeasts in the beer and wine industry due to the production of phenolic off flavors. However,B. bruxellensisis also known to be a beneficial contributor in certain fermentation processes, such as the production of certain specialty beers. Nevertheless, despite its economic importance,Brettanomycesyeasts remain poorly understood at the genetic and genomic levels. In this study, the genetic relationship between more than 50Brettanomycesstrains from all presently known species and from several sources was studied using a combination of DNA fingerprinting techniques. This revealed an intriguing correlation between theB. bruxellensisfingerprints and the respective isolation source. To further explore this relationship, we sequenced a (beneficial) beer isolate ofB. bruxellensis(VIB X9085; ST05.12/22) and compared its genome sequence with the genome sequences of two wine spoilage strains (AWRI 1499 and CBS 2499). ST05.12/22 was found to be substantially different from both wine strains, especially at the level of single nucleotide polymorphisms (SNPs). In addition, there were major differences in the genome structures between the strains investigated, including the presence of large duplications and deletions. Gene content analysis revealed the presence of 20 genes which were present in both wine strains but absent in the beer strain, including many genes involved in carbon and nitrogen metabolism, and vice versa, no genes that were missing in both AWRI 1499 and CBS 2499 were found in ST05.12/22. Together, this study provides tools to discriminateBrettanomycesstrains and provides a first glimpse at the genetic diversity and genome plasticity ofB. bruxellensis.

scholarly journals Biochemical Changes in Orange Fruit Due to Plant – Penicillium italicum – Antagonism Interactions

2015 ◽  
Vol 43 (2) ◽  
pp. 413-419
Author(s):  
Rahil GHASEMI ◽  
Hasan Reza ETEBARIAN ◽  
Navazallah SAHEBANI ◽  
Heshmatolah AMINIAN
Keyword(s):  
Initial Result ◽  
Biochemical Changes ◽  
Economic Losses ◽  
Total Phenolic ◽  
Conidial Suspension ◽  
Penicillium Italicum ◽  
Orange Fruit ◽  
Pichia Kluyveri ◽  
Yeast Interactions ◽  
And Control

One of the most important orange fruit diseases is blue mold which cause by Penicillium italicum that is responsible for important economic losses. This study investigated biochemical changes in exo-mesocarp layers of orange fruits related to host- pathogen- yeast interactions. Initial result showed that among eight strains isolated, the most effective antagonist were belonged to two species of Pichia kluyveri (M45) and Rhodotorula mucilaginosa (M61). These isolates were selected for biochemical evaluation. In order to assessment of biochemical changes, the orange fruits were inoculated with 40 µl of yeast cell suspension and after 24 h, the wounds were inoculated with 20 µl of conidial suspension of P. italicum. The analysis of variance showed that all of the measured biochemical characterises were significant in both layers by treatments (yeast isolates; pathogen; yeast isolates + pathogen and control) (P ≤ 0.01), including POD, CAT and β-1, 3-glucanase activities and total phenolic compounds. Also result showed that when the yeast isolates (M45 or M54) were inoculated into wounds with the pathogen, it stimulated the orange to increase produce of total phenol and enzymes activity (POD, CAT and β-1, 3-glucanase) and these changes were related to incubation time. The result showed that understanding biochemical mechanism derived from plant-pathogen-antagonist interactions is essential for investigating the dynamics of infectious processes.

scholarly journals The Management Response to Wind Disturbances in European Forests

2021 ◽  
Author(s):  
Paula Sanginés de Cárcer ◽  
Piotr S. Mederski ◽  
Natascia Magagnotti ◽  
Raffaele Spinelli ◽  
Benjamin Engler ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Economic Losses ◽  
Future Research ◽  
Forest Site ◽  
Negative Effects ◽  
Salvage Logging ◽  
Forest Ownership ◽  
Forest Ecosystem Services ◽  
Disturbance Management ◽  
Timber Market

Abstract Purpose of the Review The review synthesises the current knowledge of post-windstorm management in selected European countries in order to identify knowledge gaps and guide future research. Recent Findings Despite the differences in forest ownership and national regulations, management experiences in Europe converge at (1) the need for mechanization of post-windthrow management to ensure operator safety, (2) the importance to promote operator training and optimise the coordination between all the actors involved in disturbance management and (3) the need to implement measures to consolidate the timber market while restoring forest ecosystem services and maintain biodiversity. Summary Windstorms are natural disturbances that drive forest dynamics but also result in socio-economic losses. As the frequency and magnitude of wind disturbances will likely increase in the future, improved disturbance management is needed. We here highlight the best practices and remaining challenges regarding the strategic, operational, economic and environmental dimensions of post-windthrow management in Europe. Our literature review underlined that post-disturbance management needs to be tailored to each individual situation, taking into account the type of forest, site conditions, available resources and respective legislations. The perspectives on windthrown timber differ throughout Europe, ranging from leaving trees on site to storing them in sophisticated wet storage facilities. Salvage logging is considered important in forests susceptible to bark beetle outbreaks, while no salvage logging is recommended in forests protecting against natural hazards. Remaining research gaps include questions of balancing between the positive and negative effects of salvage logging and integrating climate change considerations more explicitly in post-windthrow management.

scholarly journals On certain issues related to chronic exposure to occupational noise and impacts exerted by it on workers’ bodies (literature review)

2021 ◽  
pp. 186-196
Author(s):  
V.F. Spirin ◽  
◽  
A.M. Starshov ◽  
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Chronic Exposure ◽  
Life Quality ◽  
Research Literature ◽  
Sensorineural Hearing ◽  
Economic Losses ◽  
Physical Factors ◽  
Negative Effects ◽  
Work Related

Chronic exposure to noise becomes especially significant when it occurs at workplaces since it results not only in deteriorated life quality of workers but also in disorders in their occupational activities. Occupational sensorineural hearing loss (SHL) holds the 1st rank place among occupational diseases caused by exposure to industrial physical factors. As any other work-related disease, sensorineural hearing loss makes it more difficult to preserve labor resources in the country and leads to significant economic losses. Given that, it is extremely vital to develop procedures for early diagnostics, to determine all possible risks that cause hearing loss directly or indirectly, and to create efficient prevention activities aimed at preserving health of workers exposed to noise at their workplaces. We reviewed literature data published over the last 5–7 years and analyzed more than 100 scientific works on the matter. Our review covers data from 61 sources that are the most relevant regarding tasks we aimed to solve in this research. Literature analysis allowed us to conclude that hearing loss caused by chronic exposure to noise at a workplace was a rather significant problem outlined by occupational medicine experts all over the world. It was shown that noise factor, apart from its direct impacts on the acoustic apparatus, produced apparent negative effects on many organs and systems causing various functional disorders in them which could directly or indirectly exacerbate hearing loss in workers.

Statistical Optimization of HVAF Sprayed Cr3C2-NiCr Coatings for Minimizing Decarburization

2000 ◽  
Author(s):  
S.J. Matthews ◽  
M.M. Hyland
Keyword(s):  
Factorial Design ◽  
Statistical Design ◽  
Process Variable ◽  
Traverse Speed ◽  
Deposition Efficiency ◽  
Spray Parameters ◽  
Statistical Design Of Experiments ◽  
Spray Coatings ◽  
Wide Range ◽  
Statistical Designs

Abstract High-velocity air fuel (HVAF) spraying was selected for spray trials of a Cr3C2-NiCr powder. To determine the effect of spray parameters on coating characteristics, particularly porosity and phase degradation, a statistical design of experiments was implemented. A wide range of statistical designs have been applied to the optimization of thermal spray coatings with a great deal of success. In this instance, a lack of prior knowledge and the need to assess many process-variable interactions efficiently led to the selection of a two-level full factorial design. High and low settings for each variable, including spray distance, traverse speed, and powder feedrate, were chosen based on the ranges typically used to spray similar materials. The resulting coatings were assessed for microhardness, porosity, residual stress, deposition efficiency, and phase transformation, after which several follow-up runs were conducted to explore trends brought to light by the initial factorial design.

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