scholarly journals The Bacterial Microbiome of the Tomato Fruit Is Highly Dependent on the Cultivation Approach and Correlates With Flavor Chemistry

2021 ◽  
Vol 12 ◽  
Author(s):  
Carolina Escobar Rodríguez ◽  
Johannes Novak ◽  
Franziska Buchholz ◽  
Pia Uetz ◽  
Laura Bragagna ◽  
...  

The modes of interactions between plants and plant-associated microbiota are manifold, and secondary metabolites often play a central role in plant-microbe interactions. Abiotic and biotic (including both plant pathogens and endophytes) stress can affect the composition and concentration of secondary plant metabolites, and thus have an influence on chemical compounds that make up for the taste and aroma of fruit. While the role of microbiota in growth and health of plants is widely acknowledged, relatively little is known about the possible effect of microorganisms on the quality of fruit of plants they are colonizing. In this work, tomato (Solanum lycopersicum L.) plants of five different cultivars were grown in soil and in hydroponics to investigate the impact of the cultivation method on the flavor of fruit, and to assess whether variations in their chemical composition are attributable to shifts in bacterial microbiota. Ripe fruit were harvested and used for bacterial community analysis and for the analysis of tomato volatiles, sugars and acids, all contributing to flavor. Fruit grown in soil showed significantly higher sugar content, whereas tomatoes from plants under hydroponic conditions had significantly higher levels of organic acids. In contrast, aroma profiles of fruit were shaped by the tomato cultivars, rather than the cultivation method. In terms of bacterial communities, the cultivation method significantly defined the community composition in all cultivars, with the bacterial communities in hydroponic tomatoes being more variable that those in tomatoes grown in soil. Bacterial indicator species in soil-grown tomatoes correlated with higher concentrations of volatiles described to be perceived as “green” or “pungent.” A soil-grown specific reproducibly occurring ASV (amplicon sequence variants) classified as Bacillus detected solely in “Solarino” tomatoes, which were the sweetest among all cultivars, correlated with the amount of aroma-relevant volatiles as well as of fructose and glucose in the fruit. In contrast, indicator bacterial species in hydroponic-derived tomatoes correlated with aroma compounds with “sweet” and “floral” notes and showed negative correlations with glucose concentrations in fruit. Overall, our results point toward a microbiota-related accumulation of flavor and aroma compounds in tomato fruit, which is strongly dependent on the cultivation substrate and approach.

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 367 ◽  
Author(s):  
Julia A. H. Kaeswurm ◽  
Lisa Könighofer ◽  
Melanie Hogg ◽  
Andreas Scharinger ◽  
Maria Buchweitz

An inhibitory effect on α-amylase and α-glucosidase is postulated for polyphenols. Thus, ingestion of those secondary plant metabolites might reduce postprandial blood glucose level (hyperglycemia), which is a major risk factor for diabetes mellitus type II. In addition to a previous study investigating structure−effect relationships of different phenolic structures, the effect of anthocyanins is studied in detail here, by applying an α-amylase activity assay, on the basis of the conversion of 2-chloro-4-nitrophenyl-4-O-ß-galactopyranosyl maltoside (GalG2CNP) and detection of CNP release by UV/Vis spectroscopy and isothermal titration calorimetry (ITC). All anthocyanin-3-glucosides showed a mixed inhibition with a strong competitive proportion, Kic < 134 µM and Kiu < 270 µM; however, the impact of the B-ring substitution was not statistically significant. UV/Vis detection failed to examine the inhibitory effect of acylated cyanidins isolated from black carrot (Daucus carota ssp. Sativus var. Autrorubens Alef.). However, ITC measurements reveal a much stronger inhibitory effect compared to the cyanidin-3-glucoside. Our results support the hypothesis that anthocyanins are efficient α-amylase inhibitors and an additional acylation with a cinnamic acid boosts the observed effect. Therefore, an increased consumption of vegetables containing acylated anthocyanin derivatives might help to prevent hyperglycemia.


2016 ◽  
Vol 2 (6) ◽  
pp. e1600124 ◽  
Author(s):  
Alexandre Jousset ◽  
Nico Eisenhauer ◽  
Monika Merker ◽  
Nicolas Mouquet ◽  
Stefan Scheu

There is a growing awareness that biodiversity not only drives ecosystem services but also affects evolutionary dynamics. However, different theories predict contrasting outcomes on when do evolutionary processes occur within a context of competition. We tested whether functional diversity can explain diversification patterns. We tracked the survival and diversification of a focal bacterial species (Pseudomonas fluorescens) growing in bacterial communities of variable diversity and composition. We found that high functional diversity reduced the fitness of the focal species and, at the same time, fostered its diversification. This pattern was linked to resource competition: High diversity increased competition on a portion of the resources while leaving most underexploited. The evolved phenotypes of the focal species showed a better use of underexploited resources, albeit at a cost of lower overall growth rates. As a result, diversification alleviated the impact of competition on the fitness of the focal species. We conclude that biodiversity can stimulate evolutionary diversification, provided that sufficient alternative niches are available.


2019 ◽  
Vol 295 ◽  
pp. 412-422 ◽  
Author(s):  
Rebecca Klopsch ◽  
Susanne Baldermann ◽  
Franziska S. Hanschen ◽  
Alexander Voss ◽  
Sascha Rohn ◽  
...  

2019 ◽  
Vol 85 (15) ◽  
Author(s):  
D. P. R. Herlemann ◽  
S. Markert ◽  
C. Meeske ◽  
A. F. Andersson ◽  
I. de Bruijn ◽  
...  

ABSTRACTEnclosure experiments are frequently used to investigate the impact of changing environmental conditions on microbial assemblages. Yet, how the incubation itself challenges complex bacterial communities is thus far unknown. In this study, metaproteomic profiling, 16S rRNA gene analyses, and cell counts were combined to evaluate bacterial communities derived from marine, mesohaline, and oligohaline conditions after long-term batch incubations. Early in the experiment, the three bacterial communities were highly diverse and differed significantly in their compositions. Manipulation of the enclosures with terrigenous dissolved organic carbon resulted in notable differences compared to the control enclosures at this early phase of the experiment. However, after 55 days, bacterial communities in the manipulated and the control enclosures under marine and mesohaline conditions were all dominated by gammaproteobacteriumSpongiibacter. In the oligohaline enclosures, actinobacterial cluster I of the hgc group (hgc-I) remained abundant in the late phase of the incubation. Metaproteome analyses suggested that the ability to use outer membrane-based internal energy stores, in addition to the previously described grazing resistance, may enable the gammaproteobacteriumSpongiibacterto prevail in long-time incubations. Under oligohaline conditions, the utilization of external recalcitrant carbon appeared to be more important (hgc-I). Enclosure experiments with complex natural microbial communities are important tools to investigate the effects of manipulations. However, species-specific properties, such as individual carbon storage strategies, can cause manipulation-independent effects and need to be considered when interpreting results from enclosures.IMPORTANCEIn microbial ecology, enclosure studies are often used to investigate the effect of single environmental factors on complex bacterial communities. However, in addition to the manipulation, unintended effects (“bottle effect”) may occur due to the enclosure itself. In this study, we analyzed the bacterial communities that originated from three different salinities of the Baltic Sea, comparing their compositions and physiological activities both at the early stage and after 55 days of incubation. Our results suggested that internal carbon storage strategies impact the success of certain bacterial species, independent of the experimental manipulation. Thus, while enclosure experiments remain valid tools in environmental research, microbial community composition shifts must be critically followed. This investigation of the metaproteome during long-term batch enclosures expanded our current understanding of the so-called “bottle effect,” which is well known to occur during enclosure experiments.


Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1401 ◽  
Author(s):  
Karolina Wojtunik-Kulesza ◽  
Anna Oniszczuk ◽  
Tomasz Oniszczuk ◽  
Maciej Combrzyński ◽  
Dominika Nowakowska ◽  
...  

There is increased interest in following a healthy lifestyle and consuming a substantial portion of secondary plant metabolites, such as polyphenols, due to their benefits for the human body. Food products enriched with various forms of fruits and vegetables are sources of pro-health components. Nevertheless, in many cases, the level of their activities is changed in in vivo conditions. The changes are strictly connected with processes in the digestive system that transfigure the structure of the active compounds and simultaneously keep or modify their biological activities. Much attention has focused on their bioavailability, a prerequisite for further physiological functions. As human studies are time consuming, costly and restricted by ethical concerns, in vitro models for investigating the effects of digestion on these compounds have been developed to predict their release from the food matrix, as well as their bioaccessibility. Most typically, models simulate digestion in the oral cavity, the stomach, the small intestine and, occasionally, the large intestine. The presented review aims to discuss the impact of in vitro digestion on the composition, bioaccessibility and antioxidant activity of food polyphenols. Additionally, we consider the influence of pH on antioxidant changes in the aforementioned substances.


2020 ◽  
Vol 9 (2) ◽  
pp. 78-88
Author(s):  
Mulugeta Mulat ◽  
Raksha Anand ◽  
Fazlurrahman Khan

The diversity of indole concerning its production and functional role has increased in both prokaryotic and eukaryotic systems. The bacterial species produce indole and use it as a signaling molecule at interspecies, intraspecies, and even at an interkingdom level for controlling the capability of drug resistance, level of virulence, and biofilm formation. Numerous indole derivatives have been found to play an important role in the different systems and are reported to occur in various bacteria, plants, human, and plant pathogens. Indole and its derivatives have been recognized for a defensive role against pests and insects in the plant kingdom. These indole derivatives are produced as a result of the breakdown of glucosinolate products at the time of insect attack or physical damages. Apart from the defensive role of these products, in plants, they also exhibit several other secondary responses that may contribute directly or indirectly to the growth and development. The present review summarized recent signs of progress on the functional properties of indole and its derivatives in different plant systems. The molecular mechanism involved in the defensive role played by indole as well as its’ derivative in the plants has also been explained. Furthermore, the perspectives of indole and its derivatives (natural or synthetic) in understanding the involvement of these compounds in diverse plants have also been discussed.


Author(s):  
Katarzyna Staniewska ◽  
Danuta Jakubowska ◽  
Monika Radzymińska

The aim of this study was to determine the impact of socio-demographic variables on consumer attitudes towards food with a reduced sugar content. The study was conducted in educational institutions, a university and educational centers for seniors located in the Warmia-Mazury, using a survey research method, indirect technique (an original interview questionnaire). In total, 750 respondents were interviewed. The majority of respondents, regardless of socio-demographic characteristics, assesses the health benefits of the sugar content reduction as large and rather large. Despite this, a relatively small portion of respondents, varied by gender and age, used in their diets sugar substitutes and was interested in products with a reduced sugar content. According to the most of the respondents, lowering the sugar content of a product affects the deterioration of its flavor.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1452
Author(s):  
Raluca-Maria Pârlici ◽  
Aurel Maxim ◽  
Stefania Mirela Mang ◽  
Ippolito Camele ◽  
Lucia Mihalescu ◽  
...  

Organic berry plantations have been gaining popularity among farmers during recent years. Even so, farmers experience serious challenges in disease control management, which is a concern in organic farming. Phragmidiumrubi-idaei (DC) P. Karst is the pathogen responsible for blackberry and raspberry rust disease, one of the most present and active diseases in plantations. The antifungal certified products found on the organic farming market offer the opportunity for an efficient control strategy over plant pathogens in fruit shrub plantations. In this study, 5 natural based products—namely Altosan, Mimox, Canelys, Zitron, and Zeolite—were tested for their fungistatic effect over P. rubi-idaei. The experiments were carried out under laboratory conditions, performing observations over the impact of organic products, used at different concentration levels, on rust conidia germination. Moreover, field experiments were conducted in order to evaluate the efficiency of different treatments for rust control on raspberry (‘Polka’, ‘Veten’ and ‘Heritage’) and blackberry (‘Thorn Free’, ‘Chester’ and ‘Loch Ness’) varieties. Data analysis based on ANOVA tests showed significant differences between the tested variants and the control sample at p < 0.001. Furthermore, LSD test confirmed differences between all substances tested (p < 0.005). The natural products Canelys (formulated with cinnamon) and Zytron (based on citrus extract) have proven the highest inhibitory capacity for conidia germination during in vitro tests registering values of 80.42% and 78.34%, respectively. The same high inhibitory rates against rust pathogen were kept also in the field tests using the same two natural-based products mentioned earlier. In addition, outcomes from this study demonstrated that Zeolite is not recommended for raspberry or blackberry rust control.


Author(s):  
Éva Leiter ◽  
Tamás Emri ◽  
Klaudia Pákozdi ◽  
László Hornok ◽  
István Pócsi

Abstract Regulation of signal transduction pathways is crucial for the maintenance of cellular homeostasis and organismal development in fungi. Transcription factors are key elements of this regulatory network. The basic-region leucine zipper (bZIP) domain of the bZIP-type transcription factors is responsible for DNA binding while their leucine zipper structural motifs are suitable for dimerization with each other facilitiating the formation of homodimeric or heterodimeric bZIP proteins. This review highlights recent knowledge on the function of fungal orthologs of the Schizosaccharomyces pombe Atf1, Aspergillus nidulans AtfA, and Fusarium verticillioides FvAtfA, bZIP-type transcription factors with a special focus on pathogenic species. We demonstrate that fungal Atf1-AtfA-FvAtfA orthologs play an important role in vegetative growth, sexual and asexual development, stress response, secondary metabolite production, and virulence both in human pathogens, including Aspergillus fumigatus, Mucor circinelloides, Penicillium marneffei, and Cryptococcus neoformans and plant pathogens, like Fusarium ssp., Magnaporthe oryzae, Claviceps purpurea, Botrytis cinerea, and Verticillium dahliae. Key points • Atf1 orthologs play crucial role in the growth and development of fungi. • Atf1 orthologs orchestrate environmental stress response of fungi. • Secondary metabolite production and virulence are coordinated by Atf1 orthologs.


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