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1.
Sci Rep ; 14(1): 15456, 2024 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965317

RESUMO

Medicinal plant microbiomes undergo selection due to secondary metabolite presence. Resident endophytic/epiphytic microorganisms directly influence plant's bioactive compound synthesis. Hypothesizing low microbial diversity in Serjania erecta leaves, we assessed leaf colonization by epiphytic and endophytic fungi. Given its traditional medicinal importance, we estimated diversity in the endophytic fungal microbiome. Analyses included scanning electron microscopy (SEM), isolation of cultivable species, and metagenomics. Epiphytic fungi interacted with S. erecta leaf tissues, horizontally transmitted via stomata/trichome bases, expressing traits for nematode trapping. Cultivable endophytic fungi, known for phytopathogenic habits, didn't induce dysbiosis symptoms. This study confirms low leaf microbiome diversity in S. erecta, with a tendency towards more fungal species, likely due to antibacterial secondary metabolite selection. The classification of Halicephalobus sp. sequence corroborated the presence of nematode eggs on the epidermal surface of S. erecta by SEM. In addition, we confirmed the presence of methanogenic archaea and a considerable number of methanotrophs of the genus Methylobacterium. The metagenomic study of endophytic fungi highlighted plant growth-promoting yeasts, mainly Malassezia, Leucosporidium, Meyerozyma, and Hannaella. Studying endophytic fungi and S. erecta microbiomes can elucidate their impact on beneficial bioactive compound production, on the other hand, it is possible that the bioactive compounds produced by this plant can recruit specific microorganisms, impacting the biological system.


Assuntos
Fungos , Microbiota , Nematoides , Folhas de Planta , Folhas de Planta/microbiologia , Folhas de Planta/parasitologia , Animais , Nematoides/microbiologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Endófitos/genética , Endófitos/isolamento & purificação , Leveduras/classificação , Leveduras/isolamento & purificação , Leveduras/genética , Metagenômica/métodos , Biodiversidade
2.
Int J Mol Sci ; 25(13)2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-39000255

RESUMO

4'-dihydrochalcones are secondary metabolites isolated from many medicinal plants and from the resin known as 'dragon's blood'. Due to their biological potential, our research objective was to determine the possibilities of using biocatalysis processes carried out in deep eutectic solvents (DESs) to obtain 4'-dihydrochalcones as a model compound. The processes were carried out in a culture of the yeast Yarrowia lipolytica KCh 71 and also in cultures of strains of the genera Rhodotorula and Debaryomyces. Based on the experiments carried out, an optimum process temperature of 35 °C was chosen, and the most suitable DES contained glycerol as a hydrogen bond donor (HBD). For a medium with 30% water content (DES 11), the conversion observed after 24 h exceeded 70%, while increasing the amount of water to 50% resulted in a similar level of conversion after just 1 h. A fivefold increase in the amount of added substrate resulted in a reduction in conversion, which reached 30.3%. Of the other yeast strains tested, Rhodotorula marina KCh 77 and Rhodotorula rubra KCh 4 also proved to be good biocatalysts for the bioreduction process. For these strains, the conversion reached 95.4% and 95.1%, respectively. These findings highlight the potential of yeast as a biocatalyst for the selective reduction of α,ß-unsaturated ketones and the possibility of using a DESs as a reaction medium in this process.


Assuntos
Chalconas , Solventes Eutéticos Profundos , Oxirredução , Rhodotorula , Rhodotorula/metabolismo , Chalconas/metabolismo , Chalconas/química , Solventes Eutéticos Profundos/metabolismo , Solventes Eutéticos Profundos/química , Yarrowia/metabolismo , Leveduras/metabolismo , Temperatura , Biocatálise
3.
Int J Mol Sci ; 25(13)2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-39000260

RESUMO

Extracellular vesicles (EVs) constitute a sophisticated molecular exchange mechanism highly regarded for their potential as a next-generation platform for compound delivery. However, identifying sustainable and biologically safe sources of EVs remains a challenge. This work explores the emergence of novel sources of plant and bacterial-based EVs, such as those obtained from food industry by-products, known as BP-EVs, and their potential to be used as safer and biocompatible nanocarriers, addressing some of the current challenges of the field. These novel sources exhibit remarkable oral bioavailability and biodistribution, with minimal cytotoxicity and a selective targeting capacity toward the central nervous system, liver, and skeletal tissues. Additionally, we review the ease of editing these recently uncovered nanocarrier-oriented vesicles using common EV editing methods, examining the cargo-loading processes applicable to these sources, which involve both passive and active functionalization methods. While the primary focus of these novel sources of endogenous EVs is on molecule delivery to the central nervous system and skeletal tissue based on their systemic target preference, their use, as reviewed here, extends beyond these key applications within the biotechnological and biomedical fields.


Assuntos
Bactérias , Sistemas de Liberação de Medicamentos , Vesículas Extracelulares , Plantas , Vesículas Extracelulares/metabolismo , Bactérias/metabolismo , Humanos , Plantas/metabolismo , Animais , Sistemas de Liberação de Medicamentos/métodos , Leveduras/metabolismo , Portadores de Fármacos/química
5.
Food Microbiol ; 123: 104571, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39038885

RESUMO

The pieddecuve (PdC) technique involves using a portion of grape must to undergo spontaneous fermentation, which is then used to inoculate a larger volume of must. This allows for promoting autochthonous yeasts present in the must, which can respect the typicality of the resulting wine. However, the real impact of this practice on the yeast population has not been properly evaluated. In this study, we examined the effects of sulphur dioxide (SO2), temperature, ethanol supplementation, and time on the dynamics and selection of yeasts during spontaneous fermentation to be used as PdC. The experimentation was conducted in a synthetic medium and sterile must using a multi-species yeast consortium and in un-inoculated natural grape must. Saccharomyces cerevisiae dominated both the PdC and fermentations inoculated with commercial wine yeast, displaying similar population growth regardless of the tested conditions. However, using 40 mg/L of SO2 and 1% (v/v) ethanol during spontaneous fermentation of Muscat of Alexandria must allowed the non-Saccharomyces to be dominant during the first stages, regardless of the temperature tested. These findings suggest that it is possible to apply the studied parameters to modulate the yeast population during spontaneous fermentation while confirming the effectiveness of the PdC methodology in controlling alcoholic fermentation.


Assuntos
Etanol , Fermentação , Saccharomyces cerevisiae , Dióxido de Enxofre , Vitis , Vinho , Leveduras , Vitis/microbiologia , Vinho/microbiologia , Vinho/análise , Etanol/metabolismo , Dióxido de Enxofre/farmacologia , Dióxido de Enxofre/metabolismo , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Leveduras/metabolismo , Temperatura , Estresse Fisiológico
6.
Food Microbiol ; 123: 104583, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39038889

RESUMO

Gray mold, caused by Botrytis cinerea, is a prevalent postharvest disease of apple that limits their shelf life, resulting in significant economic losses. The use of antagonistic microorganisms has been shown to be an effective approach for managing postharvest diseases of fruit. In the present study, an endophytic yeast strain PGY-2 was isolated from apples and evaluated for its biocontrol efficacy against gray mold and its mechanisms of action. Results indicated that strain PGY-2, identified as Bullera alba, reduced the occurrence of gray mold on apples and significantly inhibited lesion development in pathogen-inoculated wounds. Gray mold control increased with the use of increasing concentrations of PGY-2, with the best disease control observed at 108 cells/mL. Notably, Bullera alba PGY-2 did not inhibit the growth of Botrytis cinerea in vitro indicating that the yeast antagonist did not produce antimicrobial compounds. The rapid colonization and stable population of PGY-2 in apple wounds at 4 °C and 25 °C confirmed its ability to compete with pathogens for nutrients and space. PGY-2 also had a strong ability to form a biofilm and enhanced the activity of multiple defense-related enzymes (POD, PPO, APX, SOD, PAL) in host tissues. Our study is the first time to report the use of Bullera alba PGY-2 as a biocontrol agent for postharvest diseases of apple and provide evidence that Bullera alba PGY-2 represents an endophytic antagonistic yeast with promising biocontrol potential and alternative to the use of synthetic, chemical fungicides for the control of postharvest gray mold in apples.


Assuntos
Antibiose , Botrytis , Endófitos , Frutas , Malus , Doenças das Plantas , Malus/microbiologia , Botrytis/crescimento & desenvolvimento , Botrytis/fisiologia , Botrytis/efeitos dos fármacos , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Endófitos/fisiologia , Endófitos/isolamento & purificação , Frutas/microbiologia , Leveduras/fisiologia , Leveduras/isolamento & purificação , Biofilmes/crescimento & desenvolvimento
7.
Food Microbiol ; 123: 104589, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39038894

RESUMO

To further explore strain potential and develop an aromatic kiwifruit wine fermentation technique, the feasibility of simultaneous inoculation by non-Saccharomyces yeast and lactic acid bacteria was investigated. Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, and Limosilactobacillus fermentum, which have robust ß-glucosidase activity as well as good acid and ethanol tolerance, were inoculated for simultaneous fermentation with Zygosaccharomyces rouxii and Meyerozyma guilliermondii, respectively. Subsequently, the chemical compositions and sensory characteristics of the wines were comprehensively evaluated. The results showed that the majority of the simultaneous protocols effectively improved the quality of kiwifruit wines, increasing the content of polyphenols and volatile compounds, thereby enhancing sensory acceptability compared to the fermentation protocols inoculated with non-Saccharomyces yeast individually. Particularly, the collaboration between Lacp. plantarum and Z. rouxii significantly increased the diversity and content of esters, alcohols, and ketones, intensifying floral and seeded fruit odors, and achieving the highest overall acceptability. This study highlights the potential significance of simultaneous inoculation in kiwifruit wine production.


Assuntos
Actinidia , Fermentação , Frutas , Odorantes , Paladar , Compostos Orgânicos Voláteis , Vinho , Actinidia/microbiologia , Vinho/microbiologia , Vinho/análise , Frutas/microbiologia , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/análise , Odorantes/análise , Humanos , Polifenóis/metabolismo , Polifenóis/análise , Lactobacillales/metabolismo , Leveduras/metabolismo , Zygosaccharomyces/metabolismo , Zygosaccharomyces/crescimento & desenvolvimento
8.
J Appl Microbiol ; 135(7)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38991988

RESUMO

AIM: In this study, we investigated culturable yeast community, present in grape must sampled from vineyards with apiaries on the borders, and in honey bees collected in these apiaries. METHODS AND RESULTS: To this aim, yeasts isolated from spontaneously fermented grapes randomly collected in two vineyards (P1 and P2) with apiaries on the borders (A1 and A2) were compared to those isolated from spontaneously fermented grapes collected from a vineyard without apiary (P4). At the same time, yeast community was analyzed on bees collected in each apiary placed in the vineyards, in comparison to yeasts isolated from an apiary (A3) located far from the vineyards. The analysis was performed for two consecutive years (2021 and 2022). The isolated yeasts were identified by restriction analysis of amplified ITS region, followed by sequencing of ITS fragment.Our research showed that the presence of apiaries seems to increase yeast counts of grape must, in particular of Saccharomyces cerevisiae; furthermore, the permanence of apiaries in the vineyards allowed the recovering of these yeasts also from bees. CONCLUSIONS: Our findings seem to corroborate the role of bees as vectors and reservoirs of oenologically relevant yeasts, such as a source of non-conventional yeasts with potential biotechnological applications.


Assuntos
Fazendas , Vitis , Leveduras , Animais , Abelhas/microbiologia , Vitis/microbiologia , Leveduras/isolamento & purificação , Leveduras/classificação , Leveduras/genética , Saccharomyces cerevisiae/isolamento & purificação , Vinho/microbiologia , Fermentação
9.
Appl Microbiol Biotechnol ; 108(1): 420, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39017989

RESUMO

Fruit wine is one of the oldest fermented beverages made from non-grape fruits. Owing to the differences in fruit varieties, growing regions, climates, and harvesting seasons, the nutritional compositions of fruits (sugars, organic acids, etc.) are different. Therefore, the fermentation process and microorganisms involved are varied for a particular fruit selected for wine production, resulting in differences in volatile compound formation, which ultimately determine the quality of fruit wine. This article reviews the effects of various factors involved in fruit wine making, especially the particular modifications differing from the grape winemaking process and the selected strains suitable for the specific fruit wine fermentation, on the formation of volatile compounds, flavor and aroma profiles, and quality characteristics of the wine thus produced. KEY POINTS: • The volatile profile and fruit wine quality are affected by enological parameters. • The composition and content of nutrients in fruit must impact volatile profiles. • Yeast and LAB are the key determining factors of the volatile profiles of fruit wines.


Assuntos
Fermentação , Frutas , Vitis , Compostos Orgânicos Voláteis , Vinho , Vinho/análise , Vinho/microbiologia , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/metabolismo , Frutas/química , Frutas/microbiologia , Vitis/química , Vitis/microbiologia , Odorantes/análise , Leveduras/metabolismo , Paladar
10.
Appl Microbiol Biotechnol ; 108(1): 426, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39046596

RESUMO

Horses stay in different types of stables; especially during the cold season, they stay inside for most of the day. A stable is also a place where many people spend quite a lot of time either as employees who care for and train horses or as equine enthusiasts. Keeping horses in stables causes their constant exposure to high concentrations of particulate matter (PM) and molds in the air inside these facilities. The study was conducted in Udórz Stud Farm located in the southern region of Poland. It was carried out in two different types of stables: three runners and two box stables. The study continued for 2 years; samples were collected in each season of the year. The following devices were used: a six-stage Andersen-Graseby cascade impactor, the DustTrak™ II Aerosol Monitor 8530. The obtained results allowed for the conclusion that horses kept in box stables are exposed to lower concentrations of molds and yeasts than those kept in runners. Molds dominated in the stable air during humid periods-spring and autumn-while yeasts were more prominent during summer and winter. It was observed that cleaning stables reduces the morphotic elements of fungi in the air, even though it results in a higher level of particulate matter in the stable air. It should be noted that microclimate conditions were optimal for horses practically throughout the whole year. KEY POINTS: • In stables, there is a high level of air intoxication, both by yeast and by mold fungi • The concentrations of fungi in the air depend on the season and the stable cleaning procedure • The PM concentrations depend on the type of stable.


Assuntos
Aerossóis , Microbiologia do Ar , Fungos , Material Particulado , Estações do Ano , Cavalos , Polônia , Animais , Material Particulado/análise , Fungos/isolamento & purificação , Fungos/classificação , Poluição do Ar em Ambientes Fechados/análise , Abrigo para Animais , Leveduras/isolamento & purificação , Leveduras/classificação , Monitoramento Ambiental
11.
Food Res Int ; 190: 114558, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38945562

RESUMO

Fermented beverages, including wine, can accumulate high concentrations of biogenic amines (BAs), which can pose potential health risks. BAs are produced by various yeasts and lactic acid bacteria (LAB) during winemaking. LAB are the main contributors to the formation of histamine and tyramine, the most toxic and food safety relevant biogenic amines. Numerous factors, ranging from agricultural and oenological practices to sanitation conditions, can contribute to the formation of BAs in wines. Moreover, organic and biodynamic wines impose limitations on the use of common food additives employed to control the proliferation of native and spoilage microorganisms during vinification and storage. To mitigate histamine production, commercial starter cultures incapable of synthesising histamine have been effectively utilised to reduce wine histamine content. Alternative fermentative microorganisms are currently under investigation to enhance the safety, quality, and typicity of wines, including indigenous LAB, non-Saccharomyces yeasts, and BAs degrading strains. Furthermore, exploration of extracts from BAs-degrading microorganisms and their purified enzymes has been undertaken to reduce BAs levels in wines. This review highlights microbial contributors to BAs in wines, factors affecting their growth and BA production, and alternative microorganisms that can degrade or avoid BAs. The aim is to lessen reliance on additives, providing consumers with safer wine choices.


Assuntos
Aminas Biogênicas , Fermentação , Vinho , Leveduras , Vinho/análise , Vinho/microbiologia , Aminas Biogênicas/análise , Leveduras/metabolismo , Microbiologia de Alimentos , Histamina/análise , Histamina/metabolismo , Tiramina/análise , Lactobacillales/metabolismo
12.
Food Res Int ; 190: 114596, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38945612

RESUMO

Yeast extracts (YEs) are used in foods because of their flavour properties and ability to reduce bitterness. The adenosine 5'-monophosphate (AMP) found in YEs is known to decrease the bitterness of some compounds. This study aimed to investigate the ability of YEs to inhibit bitter taste receptors (TAS2Rs) using in vitro cell-based assays. A screen of TAS2Rs activated by AMP and YEs revealed that AMP and the AMP-rich YE activated more TAS2Rs. The inhibitory effect of the AMP-rich YE on seven TAS2Rs activated by bitter agonists was studied. YE reduced TAS2R activation, increased the EC50 value and decreased the maximum amplitude, demonstrating competitive and non-competitive inhibitions. Amongst the nineteen TAS2Rs tested, seven showed 40 % or greater inhibition after treatment of AMP-rich YE. Our data provide a better understanding of the TAS2R inhibition mechanism of AMP-rich YEs and promote their use as a strategy to reduce bitterness in foods and medicines.


Assuntos
Receptores Acoplados a Proteínas G , Paladar , Receptores Acoplados a Proteínas G/metabolismo , Humanos , Monofosfato de Adenosina/metabolismo , Monofosfato de Adenosina/farmacologia , Células HEK293 , Leveduras/metabolismo
13.
Sci Rep ; 14(1): 14726, 2024 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-38926524

RESUMO

Zoonotic yeast species have been implicated in disease development in both humans and cats. This study analyzed the yeast mycobiota present in feline facial hair and human nails and explored potential interspecies associations. A total of 118 biological specimens were examined, including 59 feline facial hair and 59 human nail samples. DNA extraction and DNA sequencing were performed to identify the specific yeast species. The most predominant yeast species in humans and cats were selected for antifungal susceptibility testing (itraconazole, ketoconazole, miconazole, and terbinafine). The findings unveiled diverse yeast species in cats and humans. Malassezia pachydermatis (45.8%) and Malassezia furfur (30.5%) were the most common yeast species in cats and humans, respectively. However, no significant correlation was detected between the yeast species identified in cats and their owners residing in the same household (p > 0.05). Miconazole exhibited the highest minimum inhibitory concentrations (MICs) against Malassezia pachydermatis and Malassezia furfur in both cat and human isolates, whereas terbinafine showed the lowest MICs against most Malassezia pachydermatis and Malassezia furfur in both cat and human isolates. Diverse yeast species in cat facial hair and human nails suggest possible cross-contamination among humans, pets, and environments.


Assuntos
Antifúngicos , Testes de Sensibilidade Microbiana , Unhas , Gatos , Humanos , Antifúngicos/farmacologia , Animais , Unhas/microbiologia , Malassezia/efeitos dos fármacos , Malassezia/genética , Malassezia/isolamento & purificação , Cabelo/microbiologia , Leveduras/efeitos dos fármacos , Leveduras/isolamento & purificação , Leveduras/genética , Terbinafina/farmacologia , Miconazol/farmacologia , Masculino , Pelo Animal/microbiologia , Feminino
14.
Sci Rep ; 14(1): 14233, 2024 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902520

RESUMO

Converting waste into high-value products promotes sustainability by reducing waste and creating new revenue streams. This study investigates the potential of diverse yeasts for microbial oil production by utilizing short-chain fatty acids (SCFAs) that can be produced from organic waste and focuses on identifying strains with the best SCFA utilisation, tolerance and lipid production. A collection of 1434 yeast strains was cultivated with SCFAs as the sole carbon source. Eleven strains emerged as candidates with promising growth rates and high lipid accumulation. Subsequent fermentation experiments in liquid SCFA-rich media, which focused on optimizing lipid accumulation by adjusting the carbon to nitrogen (C/N) ratio, showed an increase in lipid content at a C/N ratio of 200:1, but with a concurrent reduction in biomass. Two strains were characterized by their superior ability to produce lipids compared to the reference strain Yarrowia lipolytica CECT124: Y. lipolytica EXF-17398 and Pichia manshurica EXF-7849. Characterization of these two strains indicated that they exhibit a biotechnologically relevant balance between maximizing lipid yield and maintaining growth at high SCFA concentrations. These results emphasize the potential of using SCFAs as a sustainable feedstock for oleochemical production, offering a dual benefit of waste valorisation and microbial oil production.


Assuntos
Ácidos Graxos Voláteis , Fermentação , Ácidos Graxos Voláteis/metabolismo , Leveduras/metabolismo , Leveduras/crescimento & desenvolvimento , Yarrowia/metabolismo , Yarrowia/crescimento & desenvolvimento , Ensaios de Triagem em Larga Escala/métodos , Biomassa , Biocombustíveis/microbiologia , Ácidos Carboxílicos/metabolismo , Pichia/metabolismo , Pichia/crescimento & desenvolvimento
15.
J Environ Manage ; 362: 121351, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38838535

RESUMO

In this study, the growth of yeast and yeast-like fungi in the liquid digestate from vegetable wastes was investigated in order to remove nutrients and organic pollutants, and for their application as co-culture members with green microalgae. The studied yeast strains were characterized for their assimilative and enzymatic profiles as well as temperature requirements. In the first experimental stage, the growth dynamics of each strain were determined, allowing to select the best yeasts for further studies. In the subsequent stage, the ability of selectants to remove organic pollutants was assessed. Different cultivation media containing respectively 1:3, 1:1, 3:1 vol ratio of liquid digestate and the basal minimal medium were used. Among all tested yeast strains, Rhodotorula mucilaginosa DSM 70825 showed the most promising results, demonstrating the highest potential for removing organic substrates and nutrients. Depending on the medium, this strain achieved 50-80% sCOD, 45-60% tVFAs, 21-45% TN, 33-52% PO43- reduction rates. Similar results were obtained for the strain Candida sp. OR687571. The high nutrient and organics removal efficiency by these yeasts could likely be linked to their ability to assimilate xylose (being the main source of carbon in the liquid digestate). In culture media containing liquid digestate, both yeast strains achieved good viability and proliferation potential. In the liquid digestate medium, R. mucilaginosa and Candida sp. showed vitality at the level of 51.5% and 45.0%, respectively. These strains seem to be a good starting material for developing effective digestate treatment strategies involving monocultures and/or consortia with other yeasts or green microalgae.


Assuntos
Técnicas de Cocultura , Microalgas , Leveduras , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Leveduras/metabolismo , Leveduras/crescimento & desenvolvimento , Rhodotorula/metabolismo , Rhodotorula/crescimento & desenvolvimento , Nutrientes/metabolismo , Biodegradação Ambiental , Candida/crescimento & desenvolvimento , Candida/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-38936832

RESUMO

d-Xylose is a metabolizable carbon source for several non-Saccharomyces species, but not for native strains of S. cerevisiae. For the potential application of xylose-assimilating yeasts in biotechnological processes, a deeper understanding of pentose catabolism is needed. This work aimed to investigate the traits behind xylose utilization in diverse yeast species. The performance of 9 selected xylose-metabolizing yeast strains was evaluated and compared across 3 oxygenation conditions. Oxygenation diversely impacted growth, xylose consumption, and product accumulation. Xylose utilization by ethanol-producing species such as Spathaspora passalidarum and Scheffersomyces stipitis was less affected by oxygen restriction compared with other xylitol-accumulating species such as Meyerozyma guilliermondii, Naganishia liquefaciens, and Yamadazyma sp., for which increased aeration stimulated xylose assimilation considerably. Spathaspora passalidarum exhibited superior conversion of xylose to ethanol and showed the fastest growth and xylose consumption in all 3 conditions. By performing assays under identical conditions for all selected yeasts, we minimize bias in comparisons, providing valuable insight into xylose metabolism and facilitating the development of robust bioprocesses. ONE-SENTENCE SUMMARY: This work aims to expand the knowledge of xylose utilization in different yeast species, with a focus on how oxygenation impacts xylose assimilation.


Assuntos
Etanol , Fermentação , Oxigênio , Xilose , Xilose/metabolismo , Etanol/metabolismo , Oxigênio/metabolismo , Leveduras/metabolismo , Leveduras/crescimento & desenvolvimento , Cinética , Saccharomycetales/metabolismo , Saccharomycetales/crescimento & desenvolvimento , Aerobiose
18.
Vitae (Medellín) ; 31(1): 1-11, 2024-05-03. Ilustraciones
Artigo em Inglês | LILACS, COLNAL | ID: biblio-1553606

RESUMO

Background: Mild Colombian coffees are recognized worldwide for their high-quality coffee cup. However, there have been some failures in post-harvest practices, such as coffee grain fermentation. These failures could occasionally lead to defects and inconsistencies in quality products and economic losses for coffee farmers. In Colombia, one of the fermentation methods most used by coffee growers is wet fermentation, conducted by submerging the de-pulped coffee beans for enough time in water tanks to remove the mucilage. Objectives: We evaluated the effect of the water (g)/de-pulped coffee (g) ratio (I: 0/25, II: 10/25, III: 20/25) and final fermentation time (24, 48, and 72 hours) on the total number of microbial groups. We also identified microorganisms of interest as starter cultures. Methods: We used a completely randomized experimental design with two factors; the effect of the water (g)/de-pulped coffee (g) ratio (I: 0/25, II: 10/25, III: 20/25) and final fermentation time (24, 48, and 72 hours), for 9 treatments with two replicates. During the coffee fermentation (1,950 g), the pH and °Brix were monitored. Total counts of different microbial groups (mesophiles, coliforms, lactic-acid bacteria, acetic-acid bacteria, and yeasts) were performed. Various isolates of microorganisms of interest as starter cultures (lactic-acid bacteria and yeasts) were identified using molecular sequencing techniques. Results: 21 lactic-acid bacteria (LAB) isolates and 22 yeasts were obtained from the different mini-batch fermentation systems. The most abundant lactic-acid bacteria species found were Lactiplantibacillus plantarum (46%) and Levilactobacillus brevis (31%). Pichia kluivery (39%) and Torulaspora delbrueckii (22%) were the most abundant yeast species. Conclusion The studied factors did not have effect over the microorganism's development. The identified bacterial and yeasts species have potential as starter cultures for better-quality coffees and in fermentation-related applications.


Antecedentes: Los cafés suaves lavados colombianos son reconocidos a nivel mundial por su buena puntuación sensorial; sin embargo, se han detectado fallas en las prácticas de postcosecha, como lo es la fermentación de los granos de café. Dichas fallas pueden causar defectos y carecer de consistencia en la calidad del producto, ocasionando pérdidas económicas para los caficultores. En Colombia, uno de los métodos más usados por los caficultores es la fermentación húmeda, la cual consiste en sumergir los granos de café despulpado en tanques con agua por un período de tiempo que permita la remoción del mucílago. Objetivos: La presente investigación evaluó la incidencia que tienen la proporción agua/granos despulpados de café (I: 0/25, II: 10/25, III: 20/25) y el tiempo final de fermentación (24, 48 y 72 horas) en el recuento final de grupos microbianos. Por otra parte, se identificaron taxonómicamente microorganismos de interés para su uso como cultivos iniciadores. Métodos: Mini-lotes consistieron en café despulpado (1950 g) puesto en recipientes de plástico abiertos y sumergidos en agua. Se aplicó un diseño experimental completamente aleatorizado de dos factores (proporción agua/ granos de café despulpado y tiempo) a tres niveles, para un total de nueve tratamientos con dos replicas. Durante las fermentaciones de café (1,950 g), el pH y los grados ºBrix, fueron monitoreados. Se realizaron los recuentos totales de los diferentes grupos microbianos: mesófilos, coliformes, bacterias ácido-lácticas, bacterias ácido-acéticas y levaduras. Se identificaron molecularmente diferentes aislados con potencial para ser usados como cultivos iniciadores (bacterias ácido-lácticas y levaduras). Resultados: Los resultados obtenidos mostraron que no hubo diferencia estádisticamente significativa entre los tratamientos aplicados y el recuento final de microorganismos. Un total de 21 aislados de bacterias ácido-lácticas (BAL) y 22 levaduras lograron obtenerse a partir de los diferentes sistemas de fermentación en mini-lote. Las especies de bacterias ácido-lácticas con mayor porcentaje acorde a su identificación taxonómica, corresponden a Lactiplantibacillus plantarum (46%), Levilactobacillus brevis (31%). Las especies de levaduras con mayor porcentaje acorde a su identificación taxonómica corresponden a Pichia kluivery (39%) y Torulaspora delbrueckii (22%). Conclusión Los factores estudiados no afectaron el crecimiento de ninguno de los grupos microbianos presentes en la fermentacion del café. Las especies de microorganismos identificados tienen potencial para se usados como cultivos starter o en aplicaciones dentro de las ciencias de fermentación.


Assuntos
Humanos , Fermentação , Leveduras , Técnicas Microbiológicas , Coffea , Lactobacillales
19.
Environ Microbiol Rep ; 16(3): e13213, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38738810

RESUMO

Since a significant proportion of plant matter is consumed by herbivores, a necessary adaptation for many phyllosphere microbes could be to survive through the guts of herbivores. While many studies explore the gut microbiome of herbivores by surveying the microbiome in their frass, few studies compare the phyllosphere microbiome to the gut microbiome of herbivores. High-throughput metabarcode sequencing was used to track the fungal community from milkweed (Asclepias spp.) leaves to monarch caterpillar frass. The most commonly identified fungal taxa that dominated the caterpillar frass after the consumption of leaves were yeasts, mostly belonging to the Basidiomycota phylum. While most fungal communities underwent significant bottlenecks and some yeast taxa increased in relative abundance, a consistent directional change in community structure was not identified from leaf to caterpillar frass. These results suggest that some phyllosphere fungi, especially diverse yeasts, can survive herbivory, but whether herbivory is a key stage of their life cycle remains uncertain. For exploring phyllosphere fungi and the potential coprophilous lifestyles of endophytic and epiphytic fungi, methods that target yeast and Basidiomycota fungi are recommended.


Assuntos
Asclepias , Fungos , Herbivoria , Folhas de Planta , Animais , Folhas de Planta/microbiologia , Asclepias/microbiologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/fisiologia , Leveduras/classificação , Leveduras/isolamento & purificação , Leveduras/genética , Micobioma , Basidiomycota/classificação , Basidiomycota/genética , Basidiomycota/fisiologia , Basidiomycota/isolamento & purificação , Microbioma Gastrointestinal , Larva/microbiologia , Mariposas/microbiologia
20.
FEMS Microbiol Ecol ; 100(7)2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38777744

RESUMO

Microbial communities are vital to our lives, yet their ecological functioning and dynamics remain poorly understood. This understanding is crucial for assessing threats to these systems and leveraging their biotechnological applications. Given that temporal dynamics are linked to community functioning, this study investigated the drivers of community succession in the wine yeast community. We experimentally generated population dynamics data and used it to create an interpretable model with a gradient boosted regression tree approach. The model was trained on temporal data of viable species populations in various combinations, including pairs, triplets, and quadruplets, and was evaluated for predictive accuracy and input feature importance. Key findings revealed that the inoculation dosage of non-Saccharomyces species significantly influences their performance in mixed cultures, while Saccharomyces cerevisiae consistently dominates regardless of initial abundance. Additionally, we observed multispecies interactions where the dynamics of Wickerhamomyces anomalus were influenced by Torulaspora delbrueckii in pairwise cultures, but this interaction was altered by the inclusion of S. cerevisiae. This study provides insights into yeast community succession and offers valuable machine learning-based analysis techniques applicable to other microbial communities, opening new avenues for harnessing microbial communities.


Assuntos
Saccharomyces cerevisiae , Vinho , Vinho/microbiologia , Saccharomyces cerevisiae/genética , Leveduras/genética , Microbiota , Análise de Regressão
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