Search Results (48)

The introduction of living mulches into an orchard can be considered an agroecological practice that can provide several ecosystem services related to integrated crop protection, also in relation to the impact on soil microbiome. In this study, the introduction in an organic apple orchard of two plant mixtures designed as multifunctional living mulches to reduce weed competition and increase shelter for beneficial arthropods was evaluated in relation to their impact on soil nutrient content and bacterial activity indices. One mixture was composed of Trifolium repens (20%) and Festuca ovina (80%), the second made of 40 different plant species including legumes, flowering species and grasses. Both living mulches increased N-nitrate levels in spring, and the two-component plant mixture was also able to improve P and K levels in soil at the same time, in comparison to the natural cover (control). The two mixtures induced an increase in bacterial activity in the beginning (40 plant species mix) or middle of the growing season (two-component plant mix), without major effects on bacterial biodiversity at the phyla level, showing a high share of Proteobacteria and Actinobacteriota among treatments. Nevertheless, both plant mixtures modified the phenotypic profile of the bacterial population, measured with the Biolog method, of different classes of C sources including carbohydrates, amino acids and carboxylic acid. The results are pointing to possible benefits of the practice on soil microbial activity, which will have to be confirmed by longer studies. Full article

Apples and pears are among the most popular and frequently consumed fruits worldwide. The polyphenol and dietary fibre components of these fruits are known to influence the gut microbiota and the subsequent human health outcomes. This study investigated the effects of New Zealand grown apples and pears with differing polyphenol contents on the structure and function of the human gut microbiota. Five apple and two pear cultivars underwent in vitro human digestion and microbial fermentation. Samples taken at 0 and 18 h were analysed for changes in pH, microbial composition, and organic acid production. The change in pH after faecal fermentation was influenced by the type of fruit (apple or pear), with lower pH being observed in the apples. Significant apple or pear cultivar effects were observed for the gut microbiome and organic acid production. The apple cultivar ‘Golden Hornet’ produced the least butyrate and the greatest microbial alpha diversity, while the pear ‘PremP009’ showed greater butyrate production with increases in a butyrogenic species (Acidaminococcus intestini). Further studies are needed to investigate the effect of cultivar and type of fruit on nutrient absorption and microbial fermentation and the impact of these on human health. Full article

Fermented apple juice (FAJ), a nutrient-dense beverage rich in vitamins, offers multiple health benefits, including improved digestion, enhanced fat metabolism, and sustained energy provision with reduced caloric intake. To advance the development of probiotic-enriched flavored and functional juices, this study establishes Lactiplantibacillus plantarum (L. plantarum) as a safe and effective starter culture for apple juice fermentation. The selected strain exhibited minimal biogenic amine synthesis, producing only 30.55 ± 1.2 mg/L of putrescine and 0.59 ± 0.55 mg/L of cadaverine, while histamine and tyramine were undetectable. Furthermore, the strain demonstrated no hemolytic activity and exhibited robust biofilm-forming capacity, reinforcing its suitability for fermentation applications. An electronic nose analysis revealed that L. plantarum significantly enriched the volatile compound profile of FAJ, leading to an improved flavor profile. The strain also displayed excellent growth adaptability in the apple juice matrix, further optimizing fermentation efficiency and sensory quality. Crucially, 16S rRNA sequencing demonstrated that FAJ specifically restructures the gut microbiota in obese individuals, significantly elevating the relative abundance of beneficial genera, including Enterococcus, Parabacteroides, and Bifidobacterium (p < 0.05). Concurrently, FAJ enhanced glycolytic activity, suggesting a potential role in metabolic regulation. Collectively, these findings confirm that L. plantarum-fermented FAJ combines favorable sensory properties and safety with promising anti-obesity effects mediated through gut microbiome modulation and metabolic pathway activation. This study provides a critical scientific foundation for designing next-generation functional fermented beverages with targeted health benefits. Full article

Background/Objectives: High-fat-diet (HFD) consumption drives chronic liver injury via gut dysbiosis and metabolic disturban. Apple cider vinegar, rich in polyphenols and organic acids, shows potential in metabolic regulation. This study aimed to investigate whether apple cider vinegar powder (ACVP) alleviates HFD-induced liver injury by modulating the gut–liver axis. Methods: For 12 weeks, C57BL/6 J mice received daily ACVP gavage while being fed a HFD. A series of biological assessments were conducted, including systemic metabolic evaluations (body weight, serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST), and lipid/glucose levels), hepatic steatosis (hematoxylin and eosin (H&E) staining), intestinal microbiome characterization (16S rRNA gene genomic analysis), and comprehensive metabolite profiling of cecal contents (non-targeted metabolomics). Pearson correlation networks integrated multi-omics data. Results: ACVP attenuated HFD-induced weight gain by 26.3%, hepatomegaly and dyslipidemia, as well as reduced hepatic lipid vacuoles and serum ALT (48%)/AST (21.5%). ACVP restored gut microbiota diversity, enriching Muribaculaceae. Cecal metabolomics identified 38 HFD-perturbed metabolites reversed by ACVP, including indolelactate, hyocholate, and taurocholic acid. the Kyoto encyclopedia of genes and genomes (KEGG) analysis revealed ACVP-mediated recovery of linoleic acid metabolism. Correlation networks linked Akkermansia to anti-inflammatory metabolites (e.g., trans-ferulic), while Desulfobacterota correlated with pro-inflammatory oxylipins (e.g., 12,13-dihydroxy-9Z-octadecenoic acid (DHOME)). Conclusions: ACVP mitigates HFD-induced liver injury by remodeling gut microbiota, restoring microbial metabolites, and enhancing gut–liver crosstalk. Full article

Kazakhstan’s rich biodiversity includes diverse apple populations, notably the wild apple tree (Malus sieversii) prized for traits like disease resistance and adaptability, potentially aiding breeding programs. Analyzing their microbiomes offers insights into bacterial diversity and how it influences apple tree development, making it a reliable method for understanding ecological interactions. In this research, 334 apple tree samples were collected from different mountain ranges in southeastern Kazakhstan. An analysis using nanopore-based 16S rRNA sequencing showed a distinct similarity in the microbiome compositions of samples from the Zhongar and Ile Alatau mountain ranges, with a predominance of Pseudomonadaceae, Enterobacteriaceae, and Microbacteriaceae. In contrast, samples from Ketmen ridge showed a higher prevalence of Enterobacteriaceae. Alongside the less represented Pseudomonadaceae family, in the Ketmen ridge region, bacteria of the Xanthomonadaceae, Alcaligenaceae, and Brucellaceae families were also present. Across all regions, beneficial plant-associated bacteria were identified, such as Pseudomonas veronii, Stenotrophomonas geniculata, and Kocuria rhizophila, potentially enhancing plant resilience. However, opportunistic phytopathogens were also detected, including Pseudomonas viridiflava and Serratia marcescens, particularly in the Ile Alatau region. These findings highlight the complex microbial interactions in M. sieversii, thus offering key insights into host—microbe relationships that can inform apple breeding and ecological preservation efforts. Full article

This study is the first investigation of tree–insect–bacteria interactions in southern Romania, documenting the distribution of 19 insect species across various fruit trees and their insect-associated bacterial diversity. Insect species were identified through DNA barcoding, while bacterial communities in Anthomyia, Botanophila, Drosophila, and Scaptomyza insects were analyzed via 16S rRNA gene sequencing. Insect diversity varied across apple, cherry, plum, peach, and quince trees, with most species showing tree-specific distribution, except for Drosophila melanogaster, which was found on all tree species. Its presence was primarily influenced by fruit development stages rather than temperature changes. Insect bacterial communities comprised 51 genera across four phyla, predominantly Pseudomonadota and Bacillota, that varied by tree species rather than insect species, suggesting the potential role of these flies as bacterial vectors. Several potential pathogenic bacterial genera were identified as biomarkers within insect microbiomes, suggesting their involvement in disease transmission, particularly affecting apple and cherry trees. This study also provides the first report of seven insect species in Romania, being the first microbiome characterization of four dipteran species associated with regional fruit trees. Full article

This study examines the effect of pre-extraction methods, namely, sonication, grinding, and lyophilization, and the use of peptide nucleic acid (PNA) blockers on the DNA recovery, diversity, and taxonomic resolution of bacterial and fungal communities in apple blossoms. Sonication was the most successful in recovering bacterial 16S and fungal ITS reads across all the collection points and plots. Lyophilization and grinding led to a significant reduction in fungal read counts, while PNA enhanced the recovery of bacterial 16S reads. Sonication improved the efficiency of DNA extraction and yielded greater diversity in the recovered microbial community. Sonicated samples showed greater sensitivity to temporal shifts in microbial community composition. Communities in sonicated samples contained a larger number of bacterial genera, such as Bacillus, Staphylococcus, and Erwinia, and fungal genera, including Didymellaceae and Cladosporium. In contrast, lyophilization and grinding led to a reduction in detected taxa. The indicator species analysis determined that 35 bacterial and 21 fungal genera were closely related to sonication, whereas no other pre-extraction method had any associated genera. Our findings suggest that sonication is the most appropriate pre-extraction method for analyzing blossom-associated microbiomes, and that the use of PNA blockers can improve the recovery of bacteria and minimize contamination by host DNA. Full article

Background: Self-organizing maps (SOMs) are a class of neural network algorithms able to visually describe a high-dimensional dataset onto a two-dimensional grid. SOMs were explored to classify soils based on an array of physical, chemical, and biological parameters. Methods: The SOM analysis was performed considering soil physical, chemical, and microbial data gathered from an array of apple orchards and strawberry plantations managed by organic or conventional methods and located in different European climatic zones. Results: The SOM analysis considering the “climatic zone” categorical variables was able to discriminate the samples from the three zones for both crops. The zones were associated with different soil textures and chemical characteristics, and for both crops, the Continental zone was associated with microbial parameters—including biodiversity indices derived from the NGS data analysis. However, the SOM analysis based on the “management method” categorical variables was not able to discriminate the soils between organic and integrated management. Conclusions: This study allowed for the discrimination of soils of medium- and long-term fruit crops based on their pedo-climatic characteristics and associating these characteristics to some indicators of the soil biome, pointing to the possibility of better understanding the interactions among diverse variables, which could support unraveling the intricate web of relationships that define soil quality. Full article

Côte d’Ivoire has the largest cashew tree cultivation area in the world, but the cashew apple produced is still underutilized despite its potential for industrial use. The present study aimed to isolate and identify acetic acid bacterial strains and assess their potential use for cashew apple-based vinegar production. Vinegar mother from fermented juice was used to isolate acetic acid bacteria on a standard glucose-based medium. Physiological and biochemical tests followed by 16S rRNA gene analysis and phylogeny were used for isolate characterization. Moreover, their acetic acid production capacity was assessed. As results, five strains of the Acetobacter genus were isolated. Phenotypic and phylogenetic analysis revealed that four of them, namely OYA2, OYA6, OYA9, and OYA10, belong to the A. tropicalis/A. senegalensis species complex with 99.7% or 100% similarity. The fifth strain, OYA7, being similar (99.7%) to A. syzygii. All the isolates were resistant to alcohol 15% (v/v) and grew well between pH 5.0 and 6.5. Their optimal growth temperatures varied between 27 °C and 37 °C, and only isolate OYA6 grew at a temperature of up to 40 °C. They produced vinegar with a yield (Y_p/s, g/g) varying from 0.82 to 0.92, and acetic acid contents (g/L) of 80.67, 70.26, 70.11, 68.70 and 67.22 were obtained with OYA6, OYA7, OYA2, OYA10, and OYA9, respectively. Thus, the isolate OYA6 appeared as the best candidate for vinegar production, owing to its superior yield and thermotolerance abilities that need to be further explored for industry use. Full article

The use of rain shelters is a promising agronomic practice to protect crops from rainfall, reducing the need for fungicides to control certain pathogens that take advantage of leaf wetness. However, the combined condition of absence of rain and reduced fungicide schedule can affect the fungal populations, possibly favoring biocontrol agents and/or other pathogens. In this study, the effects this practice on epiphytic and endophytic fungal communities associated with barks, leaves, flowers, and fruits of two apple cultivars (Fuji and Golden Delicious) were evaluated across two seasons. Apple plants were grown under two conditions in a commercial-like orchard: (1) covered by rain shelters with reduced fungicide schedule and (2) uncovered with standard integrated pest management (IPM) schedule. The use of rain shelters combined with reduced fungicide applications affects the overall fungal community structure and their abundance of specific taxa. Leaf epiphytes were the most impacted community, and fungal communities also differed between the two apple cultivars. The use of rain shelters helped reduce fungicide input in the orchard, but it increased the abundance of potential pathogens compared to the IPM in open field conditions, such as powdery mildew and apple scab. Understanding how the plant microbiome responds to new practices that help in reducing fungicides can help developing strategies that avoid the build-up of potentially new pathogens. Full article

Natural vinegar fermentation is a complex process influenced by the interplay between microbial communities and metabolites. This study examined the interplay between the microbiome and the metabolome over a three-month period, with samples collected every ten days. Using Illumina sequencing and chromatographic techniques (HPLC and GC-MS), we mapped microbial shifts and metabolite profiles. Early fermentation showed a diverse microbial presence, including genera such as Cronobacter, Luteibacter, and Saccharomyces. A stable microbial ecosystem established between days 15 and 70, characterized by the dominance of Leuconostoc, Gluconobacter, and Saccharomyces, which facilitated consistent substrate consumption and metabolite production, including various organic acids and ethanol. By day 70, Acetobacter prevalence increased significantly, correlating with a peak acetic acid production of 12.4 g/L. Correlation analyses revealed significant relationships between specific microbes and volatile organic compounds. This study highlights the crucial roles of these microbes in developing sensory profiles suited for industrial applications and proposes an optimal microbial consortium for enhancing vinegar quality. These data suggest that an optimal microbial consortium for vinegar fermentation should include Saccharomyces for efficient alcohol production, Leuconostoc for ester-mediated flavor complexity, and Acetobacter for robust acetic acid production. The presence of Komagataeibacter could further improve the sensory and functional qualities due to its role in producing bacterial cellulose. Full article

White haze, an emerging disorder caused by extensive fungal growth on the apple surface, results in a compromised fruit quality and decreased marketability. The use of biological control agents could be an interesting tool to reduce its development. This work aimed to test the efficacy of two Aureobasidium pullulans strains (AP2 and PL5) in controlling white haze on stored apples. An in vivo trial was conducted by inoculating fruits with white haze causal agents (Entyloma belangeri, Golubevia pallescens, Tilletiopsis washingtonensis) and treating them with the antagonistic yeasts. Three commercial biofungicides were also included in the trial. Both A. pullulans strains, along with the Metschnikowia fructicola-based product, reduced white haze incidence after 110 days of storage at 1 ± 1 °C and after 7 days of shelf life. Furthermore, the effect of A. pullulans application on the fruit fungal microbiome was assessed. A significant impact of apple matrix and treatment on the mycobiome composition was observed. Analyses showed a good colonization of A. pullulans on the treated apples, both epiphytically and endophytically. A decrease in white haze-related fungi abundance was observed in the treated fruits. Additionally, a reduction of Ramularia spp. and modifications in the abundance of other fungal genera were detected after storage and shelf life. Full article

Secondary metabolites, polyphenols, are widespread in the entire kingdom of plants. They contain one or more hydroxyl groups that have a variety of biological functions in the natural environment. These uses include polyphenols in food, beauty products, dietary supplements, and medicinal products and have grown rapidly during the past 20 years. Antimicrobial polyphenols are described together with their sources, classes, and subclasses. Polyphenols are found in different sources, such as dark chocolate, olive oil, red wine, almonds, cashews, walnuts, berries, green tea, apples, artichokes, mushrooms, etc. Examples of benefits are antiallergic, antioxidant, anticancer agents, anti-inflammatory, antihypertensive, and antimicrobe properties. From these sources, different classes of polyphenols are helpful for the growth of internal functional systems of the human body, providing healthy fats, vitamins, and minerals, lowering the risk of cardiovascular diseases, improving brain health, and rebooting our cellular microbiome health by mitochondrial uncoupling. Among the various health benefits of polyphenols (curcumin, naringenin, quercetin, catechin, etc.) primarily different antimicrobial activities are discussed along with possible future applications. For polyphenols and antimicrobial agents to be proven safe, adverse health impacts must be substantiated by reliable scientific research as well as in vitro and in vivo clinical data. Future research may be influenced by this evaluation. Full article

Patulin is a secondary metabolite primarily synthesized by the fungus Penicillium expansum, which is responsible for blue mold disease on apples. The latter are highly susceptible to fungal infection in the postharvest stages. Apples destined to produce compotes are processed throughout the year, which implies that long periods of storage are required under controlled atmospheres. P. expansum is capable of infecting apples throughout the whole process, and patulin can be detected in the end-product. In the present study, 455 apples (organically and conventionally grown), destined to produce compotes, of the variety “Golden Delicious” were sampled at multiple postharvest steps. The apple samples were analyzed for their patulin content and P. expansum was quantified using real-time PCR. The patulin results showed no significant differences between the two cultivation techniques; however, two critical control points were identified: the long-term storage and the deck storage of apples at ambient temperature before transport. Additionally, alterations in the epiphytic microbiota of both fungi and bacteria throughout various steps were investigated through the application of a metabarcoding approach. The alpha and beta diversity analysis highlighted the effect of long-term storage, causing an increase in the bacterial and fungal diversity on apples, and showed significant differences in the microbial communities during the different postharvest steps. The different network analyses demonstrated intra-species relationships. Multiple pairs of fungal and bacterial competitive relationships were observed. Positive interactions were also observed between P. expansum and multiple fungal and bacterial species. These network analyses provide a basis for further fungal and bacterial interaction analyses for fruit disease biocontrol. Full article

The impact of living mulches established with three officinal plants (Alchemilla vulgaris, Fragaria vesca and Mentha x piperita) on the soil bacterial microbiome and activity, the nematodes population, and the nutrient status of an organic apple orchard was assessed. The composition and diversity of the bacterial communities were differentially modified by living mulches. The activity of the bacterial microbiome associated with F. vesca was higher and utilized more C sources in comparison to other treatments. The combined analysis of the core bacterial microbiome and metabolic activity pointed to a potential effect of F. vesca on different levels of the soil’s trophic network. The living mulches did not affect the overall number of nematodes, but in some cases, they modified the structure of the population: F. vesca induced the highest share of bacteria feeders and the lowest number of herbivores and fungal feeders. The living mulches modified the availability of some nutrients and the pH. Multivariate analysis of the whole dataset showed several potential inter-dependencies between the assessed parameters that are worthy of further study. In conclusion, the introduction of multifunctional living mulches based on officinal plants induced changes to the soil’s genetic and functional biodiversity and chemical properties. These modifications could deliver ecosystem services particularly relevant to organic apple orchards. Full article