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Philosophical Transactions of the Royal... Mar 2023One major concern related to climate change is that elevated temperatures will drive increases in parasite outbreaks. Increasing temperature is known to alter host...
One major concern related to climate change is that elevated temperatures will drive increases in parasite outbreaks. Increasing temperature is known to alter host traits and host-parasite interactions, but we know relatively little about how these are connected mechanistically-that is, about how warmer temperatures impact the relationship between epidemiologically relevant host traits and infection outcomes. Here, we used a zooplankton-fungus () disease system to experimentally investigate how temperature impacted physical barriers to infection and cellular immune responses. We found that reared at warmer temperatures had more robust physical barriers to infection but decreased cellular immune responses during the initial infection process. Infected hosts at warmer temperatures also suffered greater reductions in fecundity and lifespan. Furthermore, the relationship between a key trait-gut epithelium thickness, a physical barrier-and the likelihood of terminal infection reversed at warmer temperatures. Together, our results highlight the complex ways that temperatures can modulate host-parasite interactions and show that different defense components can have qualitatively different responses to warmer temperatures, highlighting the importance of considering key host traits when predicting disease dynamics in a warmer world. This article is part of the theme issue 'Infectious disease ecology and evolution in a changing world'.
Topics: Animals; Daphnia; Temperature; Parasites; Host-Pathogen Interactions; Host-Parasite Interactions
PubMed: 36744571
DOI: 10.1098/rstb.2022.0009 -
Philosophical Transactions of the Royal... Mar 2023The accumulation of micro- and nanoplastic particles in freshwater bodies has given rise to much concern regarding their potential adverse effects on aquatic biota....
The accumulation of micro- and nanoplastic particles in freshwater bodies has given rise to much concern regarding their potential adverse effects on aquatic biota. Beyond their known effects on single species, recent experimental evidence suggests that host-parasite interactions can also be affected by environmental concentrations of micro- and nanoplastics. However, investigating the effects of contaminants in simplified infection settings (i.e. one host, one parasite) may understate their ecological relevance, considering that co-infections are common in nature. We exposed the cladoceran to a fungal parasite of the haemolymph () and a gut microsporidium (), either in single or co-infection. In addition, were raised individually in culture media containing 0, 5 or 50 mg l of polystyrene nanoplastic beads (100 nm). Only few infections were successful at the higher nanoplastic concentration, due to increased mortality of the host. While no significant effect of the low concentration was detected on the microsporidium, the proportion of hosts infected by the fungal parasite increased dramatically, leading to more frequent co-infections under nanoplastic exposure. These results indicate that nanoplastics can affect the performance of distinct pathogens in diverging ways, with the potential to favour parasite coexistence in a common zooplanktonic host. This article is part of the theme issue 'Infectious disease ecology and evolution in a changing world'.
Topics: Animals; Polystyrenes; Microplastics; Daphnia; Coinfection; Host-Parasite Interactions
PubMed: 36744559
DOI: 10.1098/rstb.2022.0013 -
Foods (Basel, Switzerland) Dec 2022This study aimed to investigate in vitro the probiotic potential of three yeasts strains (BB06, OBT05, and MT07) isolated from agro-food natural sources. Screening was...
This study aimed to investigate in vitro the probiotic potential of three yeasts strains (BB06, OBT05, and MT07) isolated from agro-food natural sources. Screening was performed, including several functional, technological, and safety aspects of the yeast strains, in comparison to a reference Saccharomyces boulardii, to identify the ones with suitable probiotic attributes in aquaculture. The yeast strains were identified by 5.8S rDNA-ITS region sequencing as Metschnikowia pulcherrima OBT05, Saccharomyces cerevisiae BB06, and Torulaspora delbrueckii MT07. All yeast strains were tolerant to different temperatures, sodium chloride concentrations, and wide pH ranges. S. cerevisiae BB06 showed a strong and broad antagonistic activity. Moreover, the S. cerevisiae strain exhibited a high auto-aggregation ability (92.08 ± 1.49%) and good surface hydrophobicity to hexane as a solvent (53.43%). All of the yeast strains have excellent antioxidant properties (>55%). The high survival rate in the gastrointestinal tract (GIT) can promote yeast isolates as probiotics. All yeast strains presented a resistance pattern to the antibacterial antibiotics. Non-hemolytic activity was detected. Furthermore, freeze-drying with cryoprotective agents maintained a high survival rate of yeast strains, in the range of 74.95−97.85%. According to the results obtained, the S. cerevisiae BB06 strain was found to have valuable probiotic traits.
PubMed: 36613340
DOI: 10.3390/foods12010124 -
Ecology and Evolution Dec 2022Host immune traits arise from both genetic and environmental sources of variation. When immune traits have a strong genetic basis, the presence and severity of disease...
Host immune traits arise from both genetic and environmental sources of variation. When immune traits have a strong genetic basis, the presence and severity of disease in a population may influence the distribution of those traits. Our study addressed how two immune-related traits (gut penetrability and the hemocyte response) are shaped by genetic and environmental sources of variation, and how the presence of a virulent disease altered the relative frequency of these traits in natural populations. hosts were sampled from five Indiana lakes between June and December 2017 before and during epidemics of their fungal pathogen, . Collected were experimentally exposed to and assayed for their gut penetrability, hemocyte response, and multi-locus genotype. Mixed-effects models were constructed to partition variance in immune traits between genetic and environmental sources. We then isolated the genetic sources to produce genotype-specific estimates of immune traits for each multi-locus genotype. Finally, we assessed the relative frequency and dynamics of genotypes during epidemics and asked whether genotypes with more robust immune responses increased in frequency during epidemics. Although genotype was an important source of variation for both gut penetrability and the hemocyte response, environmental factors (e.g., resource availability, prevalence, and co-infection) still explained a large portion of observed variation, suggesting a high degree of flexibility in immune traits. Additionally, no significant associations were detected between a genotype's immune traits and its frequency in a population. Our study highlights the power of variance partitioning in understanding the factors driving variation in traits and motivates further research on immunological flexibility and the ecological drivers of immune variation.
PubMed: 36545366
DOI: 10.1002/ece3.9640 -
Plants (Basel, Switzerland) Dec 2022The present study aims to investigate the effectiveness of bioformulations based on endophytic fungi to control apple scab and Valsa canker disease in two orchards in...
The present study aims to investigate the effectiveness of bioformulations based on endophytic fungi to control apple scab and Valsa canker disease in two orchards in the Aurès region (Algeria). In both orchards, the results showed that the treatment of senescent apple leaves by invert emulsions containing and harmed the ascogenesis of winter forms of by reducing the number of ascospore-ejecting asci, the number of morphologically mature asci, and a considerable increase in the immature asci number. This antifungal activity was more essential in soil-incorporated leaves, showing the importance of the combination of treatments with cultural practices to efficiently control the apple scab disease. Furthermore, the disease incidence decreased by 52.63% and 50.68% in R'haouat and Bouhmama orchards, respectively. Moreover, the treatment of cankers with a biogel containing the endophytic yeast sp. led to wound healing varying from 43.52% and 87.97% after 120 days but remained more considerable than conventional treatment with Folicur (tebuconazol). The current results open real opportunities concerning the implementation of eco-friendly and potent apple protection systems.
PubMed: 36501444
DOI: 10.3390/plants11233405 -
Foods (Basel, Switzerland) Nov 2022On the one hand, the species Lachancea thermotolerans is known for its high genetic diversity, allowing for the existence of strains that produce high concentrations of...
On the one hand, the species Lachancea thermotolerans is known for its high genetic diversity, allowing for the existence of strains that produce high concentrations of lactic acid. In contrast, the species Metschnikowia pulcherrima is renowned for its high enzymatic activity capable of producing aromatic esters during fermentation. By enhancing acidity and boosting the concentration of aromatic compounds, both species are currently used to enhance the organoleptic profile of wines. In this regard, ternary fermentations with M. pulcherrima and L. thermotolerans were carried out and the wines produced were further analysed with GC-FID, FTIR, and UV-Vis spectrophotometry. The outcomes showed that the species M. pulcherrima favored an increase in ethyl lactate (between 37 and 41 mg/L) along with an increased concentration of 2-phenylethyl alcohol (between 30 and 35 mg/L), whereas the species L. thermotolerans was able to produce 1 g/L of lactic acid in ternary fermentations. Additionally, pH levels were slightly lower in these fermentations and the color of the white wines produced showed less chemical oxidation as hue values were lower than the control. Finally, the ternary fermentations of L. thermotolerans and M. pulcherrima had higher overall rating in the tasting. In conclusion, ternary fermentations involving these two non-Saccharomyces species are suggested as a substitute for spontaneous fermentations in the production of wines from neutral varieties to express freshness more vividly. This biotechnology may be further favored by the possibility of applying emerging technologies for the removal of microorganisms in grapes and musts.
PubMed: 36429326
DOI: 10.3390/foods11223734 -
Foods (Basel, Switzerland) Nov 2022The use of wild yeasts, isolated from different environments, is becoming the most interesting option for the production of new beers. The objective of this study is to...
The use of wild yeasts, isolated from different environments, is becoming the most interesting option for the production of new beers. The objective of this study is to evaluate the potential of seven non-conventional yeast strains from five different species (, , , , and ) isolated from Madrid agriculture to produce type ale beer. Wild yeast strains were evaluated at laboratory and pilot plant scales under different fermentation conditions (pure, aerated, and sequential culture). Strain SafAle S-04 was used as a reference. Throughout the fermentation of beer, volatile compounds were determined by GC and residual sugars by HPLC, among other parameters. The yeast strains used for the fermentation in pure culture conditions were unable to ferment maltose and maltotriose (0.73-1.18% / of ethanol). The results of the study under aerated conditions showed varying levels of higher alcohol and ester concentrations. It should be noted that the strain CLI 1057 () fermented maltose in the presence of oxygen (Kluyver effect). This strain also showed a high production of 4-vinyl guaiacol, making it suitable for producing beers with a phenolic profile. Finally, three strains (, and ) were evaluated in sequential culture together with commercial strain and found to improve the organoleptic characteristics of the brewed beer. These approaches offer the opportunity to add new product characteristics to the beers.
PubMed: 36429309
DOI: 10.3390/foods11223717 -
Mycobiology 2022Oomycete pathogens that belong to the genus cause devastating diseases in solanaceous crops such as pepper, potato, and tobacco, resulting in crop production losses...
Oomycete pathogens that belong to the genus cause devastating diseases in solanaceous crops such as pepper, potato, and tobacco, resulting in crop production losses worldwide. Although the application of fungicides efficiently controls these diseases, it has been shown to trigger negative side effects such as environmental pollution, phytotoxicity, and fungicide resistance in plant pathogens. Therefore, biological control of -induced diseases was proposed as an environmentally sound alternative to conventional chemical control. In this review, progress on biological control of the soilborne oomycete plant pathogens, , and , infecting pepper, potato, and tobacco is described. Bacterial (e.g., and ) and fungal (e.g., and arbuscular mycorrhizal fungi) agents, and yeasts (e.g., , , and ) have been reported as successful biocontrol agents of pathogens. These microorganisms antagonize spp. antimicrobial compounds with inhibitory activities against mycelial growth, sporulation, and zoospore germination. They also trigger plant immunity-inducing systemic resistance several pathways, resulting in enhanced defense responses in their hosts. Along with plant protection, some of the microorganisms promote plant growth, thereby enhancing their beneficial relations with host plants. Although the beneficial effects of the biocontrol microorganisms are acceptable, single applications of antagonistic microorganisms tend to lack consistent efficacy compared with chemical analogues. Therefore, strategies to improve the biocontrol performance of these prominent antagonists are also discussed in this review.
PubMed: 36404903
DOI: 10.1080/12298093.2022.2136333 -
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 -
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