scholarly journals Selection of bacteria and fungi for control of soilborne seedling diseases of maize

2021 ◽  
Author(s):  
Tobias Pfeiffer ◽  
Astrid von Galen ◽  
Petra Zink ◽  
Sebastian Hübner ◽  
Ada Linkies ◽  
...  
Keyword(s):  
Seed Treatment ◽  
Plant Pathogens ◽  
Growth Promotion ◽  
Protective Effects ◽  
Clonostachys Rosea ◽  
Screening Experiments ◽  
Maize Roots ◽  
Bacteria And Fungi ◽  
The Impact

AbstractPlant-based screening experiments were conducted with the aim of identifying biocontrol bacteria and fungi for seed treatment of maize. Candidate microorganisms were evaluated for their protective effects against soilborne infections by species of Fusarium, Globisporangium (syn. Pythium) and Rhizoctonia. The microorganisms tested were bacteria and fungi from maize roots or other sources, including some active microbial components of commercial biocontrol products. Due to the method of isolation chosen, the majority of bacteria from maize roots were spore formers, most of them species of the genera Bacillus,Brevibacillus and Paenibacillus. In pot tests with the potting substrate inoculated with F. culmorum, the level of control provided by seed treatment with the most efficacious bacterial and fungal isolates was comparable or close to the chemical reference seed treatment thiram. The most effective bacteria were species of Pseudomonas, Burkholderia and Streptomyces. Among a subset of approx. 100 bacteria studied, the in vivo and in vitro activities against F.culmorum were only weakly correlated, although some strains deviated from this pattern. The most effective fungi were two strains of Clonostachys rosea and isolates of Trichoderma. The latter and a strain of Gliocladium virens provided also protection against R.solani. Activity against Globisporangium ultimum was recorded for one isolate of Trichoderma and the two strains of C. rosea. A reduction in the impact of seedborne F. culmorum was also observed after seed treatment with two strains of F. oxysporum f. sp. strigae. The results are discussed in relation to previous reports on rhizosphere bacteria of maize and their use in biocontrol of plant pathogens or for plant growth promotion.

Associated microflora of medicinal ferns: biotechnological potentials and possible applications

2016 ◽  
Vol 5 (03) ◽  
pp. 4927 ◽  
Author(s):  
Shubhi Srivastava ◽  
Paul A. K.
Keyword(s):  
Secondary Metabolites ◽  
Growth Promotion ◽  
Biological Activities ◽  
Hydrolytic Enzymes ◽  
In Vitro Production ◽  
Wide Range ◽  
Negative Effect ◽  
Bacteria And Fungi

Plant associated microorganisms that colonize the upper and internal tissues of roots, stems, leaves and flowers of healthy plants without causing any visible harmful or negative effect on their host. Diversity of microbes have been extensively studied in a wide variety of vascular plants and shown to promote plant establishment, growth and development and impart resistance against pathogenic infections. Ferns and their associated microbes have also attracted the attention of the scientific communities as sources of novel bioactive secondary metabolites. The ferns and fern alleles, which are well adapted to diverse environmental conditions, produce various secondary metabolites such as flavonoids, steroids, alkaloids, phenols, triterpenoid compounds, variety of amino acids and fatty acids along with some unique metabolites as adaptive features and are traditionally used for human health and medicine. In this review attention has been focused to prepare a comprehensive account of ethnomedicinal properties of some common ferns and fern alleles. Association of bacteria and fungi in the rhizosphere, phyllosphere and endosphere of these medicinally important ferns and their interaction with the host plant has been emphasized keeping in view their possible biotechnological potentials and applications. The processes of host-microbe interaction leading to establishment and colonization of endophytes are less-well characterized in comparison to rhizospheric and phyllospheric microflora. However, the endophytes are possessing same characteristics as rhizospheric and phyllospheric to stimulate the in vivo synthesis as well as in vitro production of secondary metabolites with a wide range of biological activities such as plant growth promotion by production of phytohormones, siderophores, fixation of nitrogen, and phosphate solubilization. Synthesis of pharmaceutically important products such as anticancer compounds, antioxidants, antimicrobials, antiviral substances and hydrolytic enzymes could be some of the promising areas of research and commercial exploitation.

scholarly journals Alternative Control of Phragmidium rubi-idaei Infecting Two Rubus Species

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1452
Author(s):  
Raluca-Maria Pârlici ◽  
Aurel Maxim ◽  
Stefania Mirela Mang ◽  
Ippolito Camele ◽  
Lucia Mihalescu ◽  
...  
Keyword(s):  
Organic Farming ◽  
Plant Pathogens ◽  
Field Experiments ◽  
Control Sample ◽  
Field Tests ◽  
In Vitro Tests ◽  
Rust Disease ◽  
Conidia Germination ◽  
The Impact

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.

scholarly journals The impact of indole-3-lactic acid on immature intestinal innate immunity and development: a transcriptomic analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wuyang Huang ◽  
Ky Young Cho ◽  
Di Meng ◽  
W. Allan Walker
Keyword(s):  
Lactic Acid ◽  
Mechanistic Model ◽  
Transcriptomic Analysis ◽  
Dependent Manner ◽  
Protective Effects ◽  
Very Preterm Infants ◽  
Anti Inflammatory ◽  
The Impact

AbstractAn excessive intestinal inflammatory response may have a role in the pathogenesis of necrotizing enterocolitis (NEC) in very preterm infants. Indole-3-lactic acid (ILA) of breastmilk tryptophan was identified as the anti-inflammatory metabolite involved in probiotic conditioned media from Bifidobacteria longum subsp infantis. This study aimed to explore the molecular endocytic pathways involved in the protective ILA effect against inflammation. H4 cells, Caco-2 cells, C57BL/6 pup and adult mice were used to compare the anti-inflammatory mechanisms between immature and mature enterocytes in vitro and in vivo. The results show that ILA has pleiotropic protective effects on immature enterocytes including anti-inflammatory, anti-viral, and developmental regulatory potentials in a region-dependent and an age-dependent manner. Quantitative transcriptomic analysis revealed a new mechanistic model in which STAT1 pathways play an important role in IL-1β-induced inflammation and ILA has a regulatory effect on STAT1 pathways. These studies were validated by real-time RT-qPCR and STAT1 inhibitor experiments. Different protective reactions of ILA between immature and mature enterocytes indicated that ILA’s effects are developmentally regulated. These findings may be helpful in preventing NEC for premature infants.

scholarly journals Exogenous Alginate Protects Staphylococcus aureus from Killing by Pseudomonas aeruginosa

2019 ◽  
Vol 202 (8) ◽  
Author(s):  
Courtney E. Price ◽  
Dustin G. Brown ◽  
Dominique H. Limoli ◽  
Vanessa V. Phelan ◽  
George A. O’Toole
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Physical Space ◽  
Late Time ◽  
Protective Effects ◽  
Content Type ◽  
Alginate Production ◽  
The Impact

ABSTRACT Cystic fibrosis (CF) patients chronically infected with both Pseudomonas aeruginosa and Staphylococcus aureus have worse health outcomes than patients who are monoinfected with either P. aeruginosa or S. aureus. We showed previously that mucoid strains of P. aeruginosa can coexist with S. aureus in vitro due to the transcriptional downregulation of several toxic exoproducts typically produced by P. aeruginosa, including siderophores, rhamnolipids, and HQNO (2-heptyl-4-hydroxyquinoline N-oxide). Here, we demonstrate that exogenous alginate protects S. aureus from P. aeruginosa in both planktonic and biofilm coculture models under a variety of nutritional conditions. S. aureus protection in the presence of exogenous alginate is due to the transcriptional downregulation of pvdA, a gene required for the production of the iron-scavenging siderophore pyoverdine as well as the downregulation of the PQS (Pseudomonas quinolone signal) (2-heptyl-3,4-dihydroxyquinoline) quorum sensing system. The impact of exogenous alginate is independent of endogenous alginate production. We further demonstrate that coculture of mucoid P. aeruginosa with nonmucoid P. aeruginosa strains can mitigate the killing of S. aureus by the nonmucoid strain of P. aeruginosa, indicating that the mechanism that we describe here may function in vivo in the context of mixed infections. Finally, we investigated a panel of mucoid clinical isolates that retain the ability to kill S. aureus at late time points and show that each strain has a unique expression profile, indicating that mucoid isolates can overcome the S. aureus-protective effects of mucoidy in a strain-specific manner. IMPORTANCE CF patients are chronically infected by polymicrobial communities. The two dominant bacterial pathogens that infect the lungs of CF patients are P. aeruginosa and S. aureus, with ∼30% of patients coinfected by both species. Such coinfected individuals have worse outcomes than monoinfected patients, and both species persist within the same physical space. A variety of host and environmental factors have been demonstrated to promote P. aeruginosa-S. aureus coexistence, despite evidence that P. aeruginosa kills S. aureus when these organisms are cocultured in vitro. Thus, a better understanding of P. aeruginosa-S. aureus interactions, particularly mechanisms by which these microorganisms are able to coexist in proximal physical space, will lead to better-informed treatments for chronic polymicrobial infections.

Endophytic Bacteria of Cotton and Sweet Corn for Providing Growth Promotion and Biological Disease Control

1996 ◽  
Author(s):  
Joseph W. Kloepper ◽  
Ilan Chet
Keyword(s):  
Seed Treatment ◽  
Protein Production ◽  
Sweet Corn ◽  
Growth Promotion ◽  
Sclerotium Rolfsii ◽  
Chitinolytic Enzymes ◽  
Low Concentrations ◽  
Bacillus Spp ◽  
Biological Control Potential

Endophytes were isolated from 16.7% of surface-disinfested seeds and 100% of stems and roots of field-growth plants. Strains from Israel with broad-spectrum in vitro antibiosis were mainly Bacillus spp., and some were chitinolytic. Following dipping of cut cotton roots into suspensions of these strains, endophytes were detected up to 72 days later by isolation and by autoradiograms of 14C-labelled bacteria. Selected endophytes exhibited biological control potential based on significant reductions in disease severity on cotton inoculated with Rhizoctonia solani or Fusarium oxysporum f. sp. vasinfectum as well as control of Sclerotium rolfsii on bean. Neither salicylic acid nor chitinase levels increased in plants as a result of endophytic colonization, suggesting that the observed biocontrol was not accounted for by PR protein production. Some biocontrol endophytes secreted chitinolytic enzymes. Model endophytic strains inoculated into cotton stems via stem injection showed only limited movement within the stem. When introduced into stems at low concentrations, endophytes increased in population density at the injection site. After examining several experimental and semi-practical inoculation systems, seed treatment was selected as an efficient way to reintroduce most endophytes into plants.

scholarly journals A Composite Bioinoculant Based on the Combined Application of Beneficial Bacteria and Fungi

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 220 ◽  
Author(s):  
Henrietta Allaga ◽  
Bettina Bóka ◽  
Péter Poór ◽  
Viktor Dávid Nagy ◽  
Attila Szűcs ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Plant Pathogens ◽  
Azotobacter Vinelandii ◽  
Pathogenic Fungi ◽  
Screening Strategy ◽  
Plant Residues ◽  
Beneficial Bacteria ◽  
Tomato Plants ◽  
Bacteria And Fungi

A composite soil bioinoculant containing beneficial bacteria and fungi was developed for biocontrol of plant pathogens, phosphorous mobilization, stem degradation, humification, and nitrogen fixation. A Trichoderma asperellum isolate with outstanding in vitro antagonistic abilities toward a series of plant pathogenic fungi was included as a potential biocontrol component. The selected strain was also shown to promote growth and increase photosynthetic activity of tomato plants. For phosphorous mobilization and stem degradation, a Trichoderma atrobrunneum strain was selected, which produced cellulose-degrading enzymes even in the absence of stem residues, while this ability increased 10–15-fold in the presence of ground maize stem. The strain was also shown to produce large amounts of enzymes liberating organically bound phosphorous, as well as cellulase and xylanase activities in solid-state fermentation on various plant residues. A Streptomyces albus strain with excellent peroxidase-producing abilities was selected as a potential humus-producing component, while an Azotobacter vinelandii strain with the potential to provide excess nitrogen for crops was included for nitrogen fixation. The assembled soil bioinoculant had positive effect on the uptake of certain important macro- and microelements (potassium, sodium, and manganese) from the soil by field-grown tomato plants. The applied screening strategy proved to be applicable for the assembly of a composite soil bioinoculant with notable application potentials.

scholarly journals Implications of Antimicrobial Combinations in Complex Wound Biofilms Containing Fungi

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Eleanor M. Townsend ◽  
Leighann Sherry ◽  
Ryan Kean ◽  
Donald Hansom ◽  
William G. Mackay ◽  
...  
Keyword(s):  
Foot Ulcer ◽  
Diabetic Foot Ulcer ◽  
Biofilm Model ◽  
Discernible Effect ◽  
Complex Wound ◽  
Bacteria And Fungi ◽  
Wound Biofilms ◽  
The Impact ◽  
Antimicrobial Combinations

ABSTRACT Diabetic foot ulcer treatment currently focuses on targeting bacterial biofilms, while dismissing fungi. To investigate this, we used an in vitro biofilm model containing bacteria and fungi, reflective of the wound environment, to test the impact of antimicrobials. Here we showed that while monotreatment approaches influenced biofilm composition, this had no discernible effect on overall quantity. Only by combining bacterium- and fungus-specific antibiotics were we able to decrease the biofilm bioburden, irrespective of composition.

scholarly journals The Impact of Forest Fungi on Promoting Growth and Development of Brassica napus L.

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2475
Author(s):  
Grażyna B. Dąbrowska ◽  
Zuzanna Garstecka ◽  
Alina Trejgell ◽  
Henryk P. Dąbrowski ◽  
Wiktoria Konieczna ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Growth And Development ◽  
Plant Pathogens ◽  
Fungal Species ◽  
Brassica Napus L ◽  
Number Of Microorganisms ◽  
The Impact

Inoculation of plants with fungi has been shown to increase yields by improving germination, seedling vigor, plant growth, root morphogenesis, photosynthesis, and flowering through direct or indirect mechanisms. These mechanisms include solubilization and mineralization of nutrients, facilitating their uptake by plants, regulation of hormone balance, production of volatile organic compounds and microbial enzymes, suppression of plant pathogens, and mitigation of abiotic stresses. In the presented experiments, the effect of selected forest soil fungi on the growth and development of Brassica napus L. seedlings was investigated. Inoculation was carried out in vivo and in pot experiments with ectomycorrhizal and saprophytic fungi typical of forest soils: Collybia tuberosa, Clitocybe sp., Laccaria laccata, Hebeloma mesophaeum, and Cyathusolla. It was shown that all analyzed fungi produced IAA. In the in vitro experiment, B. napus inoculated with L. laccata showed stimulated root growth and greater number of leaves compared to control plants. A similar stimulatory effect on lateral root formation was observed in cuttings grown in pots in the presence of the C. olla fungus. In the pot experiment, the seedlings inoculated with the L. laccata fungus also showed increased growth of shoots and biomass. The effect of inoculation with the tested fungal strains, especially C. olla, on the growth and development of oilseed rape was probably indirect, as it also contributed to an increase in the number of microorganisms, especially soil bacteria. The expression of the metallothioneins in B. napus (BnMT1-BnMT3) varied depending on the fungal species. The presence of C. olla significantly increased BnMT2 expression in oilseed rape. It was found that BnMT1 expression increased and BnMT3 transcripts decreased in plants growing in the presence of L. laccata. This indicates the involvement of BnMT in the adaptation of oilseed rape to growth in fungi presence.

scholarly journals Lacticaseibacillus rhamnosus GG and Saccharomyces cerevisiae boulardii supplementation exert protective effects on human gut microbiome following antibiotic administration in vitro

2021 ◽  
pp. 1-16
Author(s):  
C. Duysburgh ◽  
P. Van den Abbeele ◽  
M. Morera ◽  
M. Marzorati
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gut Microbiome ◽  
Gastrointestinal Symptoms ◽  
Lactobacillus Rhamnosus ◽  
Antibiotic Administration ◽  
Protective Effects ◽  
Human Gut ◽  
Human Gut Microbiome ◽  
The Impact

Antibiotic-induced dysbiosis of the microbial community has been associated with several gastrointestinal symptoms. The impact of repeated administration of Lacticaseibacillus rhamnosus GG (CNCM-I-4798) (formerly known as Lactobacillus rhamnosus GG), Saccharomyces cerevisiae boulardii (CNCM-I-1079) and their combination (associated in Smebiocta/Smectaflora Protect®) in supporting recovery of gut microbiota functionality and composition during and following amoxicillin:clavulanic acid administration was evaluated in vitro. Antibiotic dosage negatively affected SCFA production, coinciding with detrimental effects on Bacteroidetes, Firmicutes and Bifidobacterium spp. in the simulated proximal colon, while Akkermansia muciniphila was significantly reduced in the distal colon. L. rhamnosus GG and S. boulardii were able to thrive in both colon regions upon dosing, with S. boulardii even showing protective effects on the survival of L. rhamnosus GG during antibiotic administration. The impact of the probiotic strains on microbiome recovery revealed that supplementation with L. rhamnosus GG and/or S. boulardii resulted in a stimulating effect on the most abundant bacterial groups within the bacterial community of each donor. For one of the donors tested, co-dosing of L. rhamnosus GG and S. boulardii resulted in superior short-chain fatty acid recovery accompanied by a stronger increase in abundance of Bifidobacteriaceae. Overall, the current study provides first evidence that combined supplementation of L. rhamnosus GG and S. boulardii might be an interesting candidate in limiting detrimental effects of amoxicillin:clavulanic acid on the human gut microbiome, though further studies are warranted to confirm these findings.

scholarly journals Pathogenetic Impact of Bacterial–Fungal Interactions

2019 ◽  
Vol 7 (10) ◽  
pp. 459 ◽  
Author(s):  
Filomena Nogueira ◽  
Shirin Sharghi ◽  
Karl Kuchler ◽  
Thomas Lion
Keyword(s):  
Immune System ◽  
Clinical Manifestations ◽  
Antimicrobial Treatment ◽  
Human Pathogens ◽  
Human Fungal Pathogen ◽  
Bacteria And Fungi ◽  
Fungal Interactions ◽  
The Impact

Polymicrobial infections are of paramount importance because of the potential severity of clinical manifestations, often associated with increased resistance to antimicrobial treatment. The intricate interplay with the host and the immune system, and the impact on microbiome imbalance, are of importance in this context. The equilibrium of microbiota in the human host is critical for preventing potential dysbiosis and the ensuing development of disease. Bacteria and fungi can communicate via signaling molecules, and produce metabolites and toxins capable of modulating the immune response or altering the efficacy of treatment. Most of the bacterial–fungal interactions described to date focus on the human fungal pathogen Candida albicans and different bacteria. In this review, we discuss more than twenty different bacterial–fungal interactions involving several clinically important human pathogens. The interactions, which can be synergistic or antagonistic, both in vitro and in vivo, are addressed with a focus on the quorum-sensing molecules produced, the response of the immune system, and the impact on clinical outcome.

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