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Ecology and Evolution Sep 2022Biological rhythms mediate important within-host processes such as metabolism, immunity, and behavior which are often linked to combating disease exposure. For many...
Biological rhythms mediate important within-host processes such as metabolism, immunity, and behavior which are often linked to combating disease exposure. For many hosts, exposure to pathogens occurs while feeding. However, the link between feeding rhythms and infection risk is unclear because feeding behavior is tightly coupled with immune and metabolic processes which may decrease susceptibility to infection. Here, we use the host-pathogen system to determine how rhythms in feeding rate and immune function mediate infection risk. The host is known to have a nocturnal circadian rhythm in feeding rate, yet we found that they do not exhibit a circadian rhythm in phenoloxidase activity. We found that the time of day when individuals are exposed to pathogens affects the probability of infection with higher infection prevalence at night, indicating that infection risk is driven by a host's circadian rhythm in feeding behavior. These results suggest that the natural circadian rhythm of the host should be considered when addressing epidemiological dynamics.
PubMed: 36177139
DOI: 10.1002/ece3.9264 -
Applied and Environmental Microbiology Nov 2022With industrial agriculture increasingly challenging our ecological limits, alternative food production routes such as microbial protein (MP) production are receiving...
With industrial agriculture increasingly challenging our ecological limits, alternative food production routes such as microbial protein (MP) production are receiving renewed interest. Among the multiple substrates so far evaluated for MP production, renewable bioethanol (EtOH) is still underexplored. Therefore, the present study investigated the cultivation of five microorganisms (2 bacteria, 3 yeasts) under carbon (C), nitrogen (N), and dual C-N-limiting conditions (molar C/N ratios of 5, 60, and 20, respectively) to evaluate the production (specific growth rate, protein and biomass yield, production cost) as well as the nutritional characteristics (protein and carbohydrate content, amino acid [AA] profile) of MP production from bioethanol. Under C-limiting conditions, all the selected microorganisms showed a favorable AA profile for human nutrition (average AA score of 1.5 or higher), with a negative correlation between protein content and growth rate. Maximal biomass yields were achieved under conditions where no extracellular acetate was produced. Cyberlindnera saturnus and Wickerhamomyces anomalus displayed remarkably high biomass yields (0.40 to 0.82 g cell dry weight [CDW]/g EtOH), which was reflected in the lowest estimated biomass production costs when cultivated with a C/N ratio of 20. Finally, when the production cost was evaluated on a protein basis, Corynebacterium glutamicum grown under C-limiting conditions showed the most promising economic outlook. The global protein demand is rapidly increasing at rates that cannot be sustained, with projections showing 78% increased global protein needs by 2050 (361 compared to 202 million ton/year in 2017). In the absence of dedicated mitigation strategies, the environmental effects of our current food production system (relying on agriculture) are expected to surpass the planetary boundaries-the safe operating space for humanity-by 2050. Here, we illustrate the potential of bioethanol-renewable ethanol produced from side streams-as a main resource for the production of microbial protein, a radically different food production strategy in comparison to traditional agriculture, with the potential to be more sustainable. This study unravels the kinetic, productive, and nutritional potential for microbial protein production from bioethanol using the bacteria Methylorubrum extorquens and Corynebacterium glutamicum and the yeasts Cyberlindnera saturnus, and Metschnikowia pulcherrima, setting the scene for microbial protein production from renewable ethanol.
Topics: Humans; Nitrogen; Carbon; Biomass; Ethanol; Yeasts; Fermentation; Biofuels
PubMed: 36286523
DOI: 10.1128/aem.01188-22 -
World Journal of Microbiology &... Nov 2022Yeast mannoproteins are proposed as a paraprobiotics with antimicrobial and prebiotic properties. They can be used as biopreservatives in food and in diseases therapies....
Yeast mannoproteins are proposed as a paraprobiotics with antimicrobial and prebiotic properties. They can be used as biopreservatives in food and in diseases therapies. The knowledge about the specificity and/or capability of their influence on the growth of different microorganism is limited. The study determined the effect of mannoprotein preparations of Saccharomyces cerevisiae (S. cerevisiae) ATCC 7090 and nonconventional yeast origin [Metschnikowia reukaufii (M. reukaufii) WLP 4650 and Wickerhamomyces anomalus (W. anomalus) CCY 38-1-13] on the growth of selected bacteria of the genera: Lactobacilllus, Limosilatobacillus, Limosilatobacillus, Bifidobacterium, Staphylococcus, Enterococcus, Pseudomonas, Escherichia, Proteus and Salmonella. The degree of stimulation or growth inhibition of tested bacteria depended on the type and dose of the mannoprotein and the bacterial strain. The addition of the tested preparations in the entire range of applied concentrations had a positive effect especially on the growth of Lactobacillus arabinosus ATCC 8014 and Bifidobacterium animalis subsp. lactis B12. Mannoproteins isolated from S. cerevisiae limited the growth of the Escherichia coli (E. coli) ATCC 25922, Pseudomonas aureoginosa (P. aureoginosa) ATCC 27853, Proteus mirabilis ATCC 35659 and Salmonella Enteritidis ATCC 13076 to the greatest extent, while preparations of M. reukaufii and W. anomalus origin most effectively limited the growth of Staphylococcus aureus strains, E. coli and P. aureoginosa. The growth of Enterococcus faecalis was stimulated by the presence of all studied preparations in most of the concentrations used. Further research will determine how the purification process of studied mannoproteins or oligosaccharide fractions, its structure and composition influence on the growth of selected bacteria and what is the mechanism of its activity.
Topics: Saccharomyces cerevisiae; Escherichia coli; Phylogeny; Anti-Infective Agents; Anti-Bacterial Agents; Bacteria; Microbial Sensitivity Tests
PubMed: 36319710
DOI: 10.1007/s11274-022-03448-5 -
Ecology and Evolution Feb 2023Organisms are increasingly facing multiple stressors, which can simultaneously interact to cause unpredictable impacts compared with a single stressor alone. Recent...
Organisms are increasingly facing multiple stressors, which can simultaneously interact to cause unpredictable impacts compared with a single stressor alone. Recent evidence suggests that phenotypic plasticity can allow for rapid responses to altered environments, including biotic and abiotic stressors, both within a generation and across generations (transgenerational plasticity). Parents can potentially "prime" their offspring to better cope with similar stressors or, alternatively, might produce offspring that are less fit because of energetic constraints. At present, it remains unclear exactly how biotic and abiotic stressors jointly mediate the responses of transgenerational plasticity and whether this plasticity is adaptive. Here, we test the effects of biotic and abiotic environmental changes on within- and transgenerational plasticity using a - zooplankton-fungal parasite system. By exposing parents and their offspring consecutively to the single and combined effects of elevated temperature and parasite infection, we showed that transgenerational plasticity induced by temperature and parasite stress influenced host fecundity and lifespan; offsprings of mothers who were exposed to one of the stressors were better able to tolerate elevated temperature, compared with the offspring of mothers who were exposed to neither or both stressors. Yet, the negative effects caused by parasite infection were much stronger, and this greater reduction in host fitness was not mitigated by transgenerational plasticity. We also showed that elevated temperature led to a lower average immune response, and that the relationship between immune response and lifetime fecundity reversed under elevated temperature: the daughters of exposed mothers showed decreased fecundity with increased hemocyte production at ambient temperature but the opposite relationship at elevated temperature. Together, our results highlight the need to address questions at the interface of multiple stressors and transgenerational plasticity and the importance of considering multiple fitness-associated traits when evaluating the adaptive value of transgenerational plasticity under changing environments.
PubMed: 36760704
DOI: 10.1002/ece3.9767 -
ELife Oct 2022Priority effects, where arrival order and initial relative abundance modulate local species interactions, can exert taxonomic, functional, and evolutionary influences on...
Priority effects, where arrival order and initial relative abundance modulate local species interactions, can exert taxonomic, functional, and evolutionary influences on ecological communities by driving them to alternative states. It remains unclear if these wide-ranging consequences of priority effects can be explained systematically by a common underlying factor. Here, we identify such a factor in an empirical system. In a series of field and laboratory studies, we focus on how pH affects nectar-colonizing microbes and their interactions with plants and pollinators. In a field survey, we found that nectar microbial communities in a hummingbird-pollinated shrub, (formerly ) , exhibited abundance patterns indicative of alternative stable states that emerge through domination by either bacteria or yeasts within individual flowers. In addition, nectar pH varied among flowers in a manner that is consistent with the existence of these alternative stable states. In laboratory experiments, , the bacterium most commonly found in nectar, exerted a strongly negative priority effect against , the most common nectar-specialist yeast, by reducing nectar pH. This priority effect likely explains the mutually exclusive pattern of dominance found in the field survey. Furthermore, experimental evolution simulating hummingbird-assisted dispersal between flowers revealed that could evolve rapidly to improve resistance against the priority effect if constantly exposed to -induced pH reduction. Finally, in a field experiment, we found that low nectar pH could reduce nectar consumption by hummingbirds, suggesting functional consequences of the pH-driven priority effect for plant reproduction. Taken together, these results show that it is possible to identify an overarching factor that governs the eco-evolutionary dynamics of priority effects across multiple levels of biological organization.
Topics: Animals; Plant Nectar; Pollination; Flowers; Birds; Plants; Yeasts; Bacteria
PubMed: 36300797
DOI: 10.7554/eLife.79647 -
Folia Microbiologica Apr 2024Patients with burn injury and inhalation injury are highly susceptible to infectious complications, including opportunistic pathogens, due to the loss of skin cover and...
Patients with burn injury and inhalation injury are highly susceptible to infectious complications, including opportunistic pathogens, due to the loss of skin cover and mucosal damage of respiratory tract as well as the disruption of homeostasis. This case report, a 34-year-old man suffered critical burns, provides the first literature description of triple-impact immunoparalysis (critical burns, inhalation injury, and SARS-CoV-2 infection), leading to a lethal multifocal infection caused by several fungi including very rare environmental representatives Metschnikowia pulcherrima and Wickerhamomyces anomalus. The co-infection by these common environmental yeasts in a human is unique and has not yet been described in the literature. Importantly, our patient developed refractory septic shock and died despite targeted antifungal therapy including the most potent current antifungal agent-isavuconazole. It can be assumed that besides immunoparalysis, effectiveness of therapy by isavuconazole was impaired by the large distribution volume in this case. As this is a common situation in intensive care patients, routine monitoring of plasmatic concentration of isavuconazole can be helpful in personalization of the treatment and dose optimization. Whatmore, many fungal species often remain underdiagnosed during infectious complications, which could be prevented by implementation of new methods, such as next-generation sequencing, into clinical practice.
PubMed: 38647991
DOI: 10.1007/s12223-024-01165-0 -
Foods (Basel, Switzerland) Oct 2023Three strains marketed as bioprotection yeasts were studied to compare their antimicrobial effect on a mixture of two yeast strains in synthetic must at 12 °C,...
Three strains marketed as bioprotection yeasts were studied to compare their antimicrobial effect on a mixture of two yeast strains in synthetic must at 12 °C, mimicking pre-fermentative maceration by combining different approaches. The growth of the different strains was monitored, their nitrogen and oxygen requirements were characterised, and their metabolomic footprint in single and co-cultures studied. Only the strain and one strains colonised the must and induced the rapid decline of . The efficiency of these two strains followed different inhibition kinetics. Furthermore, the initial ratio between and was an important factor to ensure optimal bioprotection. Nutrient consumption kinetics showed that apiculate yeasts competed with strains for nutrient accessibility. However, this competition did not explain the observed bioprotective effect, because of the considerable nitrogen content remaining on the single and co-cultures. The antagonistic effect of on probably implied another form of amensalism. For the first time, metabolomic analyses of the interaction in a bioprotection context were performed after the pre-fermentative maceration step. A specific footprint of the interaction was observed, showing the strong impact of the interaction on the metabolic modulation of the yeasts, especially on the nitrogen and vitamin pathways.
PubMed: 37959046
DOI: 10.3390/foods12213927 -
Food Microbiology Oct 2023Considering the growing interest in non-Saccharomyces wine yeasts, and notably in the context of mixed fermentations with S. cerevisiae, understanding their nutritional...
Considering the growing interest in non-Saccharomyces wine yeasts, and notably in the context of mixed fermentations with S. cerevisiae, understanding their nutritional behaviors is essential to ensure better management of these fermentations. The vitaminic consumption of three non-Saccharomyces yeasts (Starmerella bacillaris, Metschnikowia pulcherrima and Torulaspora delbrueckii) was investigated during their growth in wine-like conditions, providing initial evidence that they consume different vitamers. The vitamin consumption profiles during their growth highlighted releases of certain vitamers by the yeasts before re-assimilation, strongly suggesting the existence of synthesis pathways. Not only did the essential character of vitamin B1, in particular, appear to be a trait common to these yeasts, since all its vitamers are consumed, this investigation also provided evidence of the existence of species-dependent preferences for their vitaminic sources. These different behaviors were quite striking in certain vitamers, as was observed in nicotinamide: while it was consumed by T. delbrueckii, it was left untouched by S. bacillaris and produced by M. pulcherrima during growth. Furthermore, this offers grounds for further investigation into these yeasts' requirements, and provides the first tool for managing vitamin resources during mixed fermentations with S. cerevisiae, and for preventing nutritive deficiencies from occurring.
PubMed: 37567637
DOI: 10.1016/j.fm.2023.104332 -
Food Research International (Ottawa,... Aug 2023In this study we investigated the yeast population present on partially dehydrated Nebbiolo grapes destined for 'Sforzato di Valtellina', with the aim to select...
In this study we investigated the yeast population present on partially dehydrated Nebbiolo grapes destined for 'Sforzato di Valtellina', with the aim to select indigenous starters suitable for the production of this wine. Yeasts were enumerated, isolated, and identified by molecular methods (5.8S-ITS-RFLP and D1/D2 domain sequencing). A genetic, physiological (ethanol and sulphur dioxide tolerance, potentially useful enzymatic activities, hydrogen sulphide production, adhesive properties, and killer activity) and oenological (laboratory pure micro-fermentations) characterization was also carried out. Based on relevant physiological features, seven non-Saccharomyces strains were chosen for laboratory-scale fermentations, either in pure or in mixed-culture (simultaneous and sequential inoculum) with a commercial Saccharomyces cerevisiae strain. Finally, the best couples and inoculation strategy were further tested in mixed fermentations in winery. In both laboratory and winery, microbiological and chemical analyses were conducted during fermentation. The most abundant species on grapes were Hanseniaspora uvarum (27.4 % of the isolates), followed by Metschnikowia spp. (21.0 %) and Starmerella bacillaris (12.9 %). Technological characterization highlighted several inter- and intra-species differences. The best oenological aptitude was highlighted for species Starm. bacillaris, Metschnikowia spp., Pichia kluyveri and Zygosaccharomyces bailli. The best fermentation performances in laboratory-scale fermentations were found for Starm. bacillaris and P. kluyveri, due to their ability to reduce ethanol (-0.34 % v/v) and enhance glycerol production (+0.46 g/L). This behavior was further confirmed in winery. Results of this study contribute to the knowledge of yeast communities associated with a specific environment, like those of Valtellina wine region.
Topics: Saccharomyces cerevisiae; Vitis; Wine; Fermentation; Yeast, Dried; Metschnikowia
PubMed: 37316074
DOI: 10.1016/j.foodres.2023.113005 -
Scientific Reports Jan 2021Drosophila suzukii flies cause economic losses to fruit crops globally. Previous work shows various Drosophila species are attracted to volatile metabolites produced by...
Drosophila suzukii flies cause economic losses to fruit crops globally. Previous work shows various Drosophila species are attracted to volatile metabolites produced by individual fruit associated yeast isolates, but fruits naturally harbour a rich diversity of yeast species. Here, we report the relative attractiveness of D. suzukii to yeasts presented individually or in combinations using laboratory preference tests and field trapping data. Laboratory trials revealed four of 12 single yeast isolates were attractive to D. suzukii, of which Metschnikowia pulcherrima and Hanseniaspora uvarum were also attractive in field trials. Four out of 10 yeast combinations involving Candida zemplinina, Pichia pijperi, M. pulcherrima and H. uvarum were attractive in the laboratory. Whilst a combination of M. pulcherrima + H. uvarum trapped the greatest number of D. suzukii in the field, the efficacy of the M. pulcherrima + H. uvarum combination to trap D. suzukii was not significantly greater than traps primed with volatiles from only H. uvarum. While volatiles from isolates of M. pulcherrima and H. uvarum show promise as baits for D. suzukii, further research is needed to ascertain how and why flies are attracted to certain baits to optimise control efficacy.
Topics: Animals; Drosophila; Fruit; Hanseniaspora; Insect Control; Laboratories; Metschnikowia
PubMed: 33441642
DOI: 10.1038/s41598-020-79691-3