Cephalosporium Acremonium Research Articles

The potent effect of selenium nanoparticles: insight into the antifungal activity and preservation of postharvest strawberries from gray mold diseases.

Most microorganisms that cause food decay and the lower the shelf life of foods are fungi. Nanotechnologies can combat various diseases and deal with the application of nanomaterial to target cells or tissues. In this study selenium nanoparticles (Se-NPs) were synthesized using ascorbic acid and characterized by ultraviolet-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction and zeta potential. The different concentrations of As/Se-NPs were tested against various fungi, including Alternaria linicola, Alternaria padwickii, Botrytis cinerea, Bipolaris sp., Cephalosporium acremonium, Fusarium moniliform and Fusarium semitectum. This study tested the influence of coated As/Se-NPs on healthy strawberry fruits and those infected with Botrytis cinerea during 16 days of storage, with regard to shelf life, decay percentage, weight loss, total titratable acidity percentage, total soluble solids content (TSS) and anthocyanin content. Energy-dispersive X-ray analysis showed only two elements: selenium and oxygen. TEM images showed that the nanoparticles ranged in size between 26 to 39 nm and were rhombohedral in shape. Se-NPs showed antifungal activity against all tested fungi, the most effective being against Botrytis cinerea, Cephalosporium acremonium and Fusarium semitectum. During storage periods of strawberries fruits coated with As/Se-NPs, the shelf life was increased, and the number of decaying fruits was less than in control (uncoated) and coated infected fruits. The decline in weight loss was lower in coated fruits than in control fruits. These findings demonstrated that As/Se-NPs could effectively maintain the postharvest quality of strawberries, even when the fruit was infected with B. cinerea. © 2024 Society of Chemical Industry.

Mineralization of Ni2+-Bearing Mn Oxide through Simultaneous Sequestration of Ni2+ and Mn2+ by Enzymatically Active Fungal Mn Oxides

A fungus, Acremonium strictum KR21-2, produces biogenic manganese oxides (BMOs) that can oxidize exogenous Mn2+ ions to form different BMO phases. When other guest ions are present during the BMO formation, it can strongly affect the mineralogical characteristics of the resultant BMO phase. The impact of coexisting Ni2+ ions on the mineralogy of BMO phases formed through enzymatic Mn(II) oxidation and its sequestration ability is not yet fully understood. To better understand it, repeated sequestration experiments were conducted using BMOs in Ni2+/Mn2+ binary, single Ni2, and single Mn2+ solution systems with a pH range of 6.0 to 7.5. It was observed that simultaneous sequestration of Ni2+ and Mn2+ was efficient, with irreversible Ni2+ incorporation at pH values above 7.0. The resultant BMO phases showed that Ni2+-bearing Mn oxides resembling feitknechitite (β-MnOOH) were developed through enzymatic Mn(II) oxidation. At pH values below 6.5, the turbostratic birnessite structure was maintained even in Ni2+/Mn2+ binary solutions, and subsequently, the Ni2+ sequestration efficiency was low. The pseudo-first-order rate constants of enzymatically inactivated BMOs for Mn2+ sequestration were two orders of magnitude lower than those of active BMOs, indicating the crucial role of the enzymes in precipitating Ni2+-bearing Mn oxide phases. These findings provide new insights into the mechanism of Ni2+ interaction with Mn oxide through microbial activity under circumneutral pH conditions.

Isolation and identification of fungal diseases infecting carrot plants in Sokoto State of Nigeria

Carrot plants are often afflicted with myriad of diseases that tend to lessen their eventual yield. With the increasing pressure to provide food for the world sever growing population there is need to curtail the adverse effect of these diseases. This study was aimed at investigating the epidemiological prevalence of some fungal diseases effecting carrot vegetables in selected areas in Sokoto state. To realize these, diseased carrots picked from the study areas were investigated to identify the pathogens affecting them. The carrot samples (leaves and roots) were collected from Moreh, Badageni and Ruggar Liman farm areas for fungal isolation and identification. The result revealed ten fungal species from six genera of Aspergillus, Fusarium, Penicillium, Mucor, Alternaria and Acremonium. Out of the fungal species isolated, Fusarium oxysporum was found to have the highest frequency of occurrence with 31.87% and Acremonium strictum had the least with (1.10%). All the farms had one pathogen or the other and are present in both the leaves and roots. Badageni farm had the highest occurrence of the isolates mostly on the leaves followed closely by Moreh farm. The findings revealed that carrots in Sokoto were susceptible to fungal attacks, and Fusarium species appeared to be the most active of all pathogens associated with the fungal diseases as such, carrots should be well washed and if possible cooked well before eating.

Cephalosporin resistance, tolerance, and approaches to improve their activities.

Cephalosporins comprise a β-lactam antibiotic class whose first members were discovered in 1945 from the fungus Cephalosporium acremonium. Their clinical use for Gram-negative bacterial infections is widespread due to their ability to traverse outer membranes through porins to gain access to the periplasm and disrupt peptidoglycan synthesis. More recent members of the cephalosporin class are administered as last resort treatments for complicated urinary tract infections, MRSA, and other multi-drug resistant pathogens, such as Neisseria gonorrhoeae. Unfortunately, there has been a global increase in cephalosporin-resistant strains, heteroresistance to this drug class has been a topic of increasing concern, and tolerance and persistence are recognized as potential causes of cephalosporin treatment failure. In this review, we summarize the cephalosporin antibiotic class from discovery to their mechanisms of action, and discuss the causes of cephalosporin treatment failure, which include resistance, tolerance, and phenomena when those qualities are exhibited by only small subpopulations of bacterial cultures (heteroresistance and persistence). Further, we discuss how recent efforts with cephalosporin conjugates and combination treatments aim to reinvigorate this antibiotic class.

Validasi Metode dan Penetapan Kadar Sirup Kering Cefadroxil dengan Metode FTIR-ATR

Cefadroxil is a broad-spectrum bactericidal antibiotic belonging to the first group of cephalosporins produced by the fungus Cephalosporium acremonium. This study aims to validate the method and determine the concentration of cefadroxil dry syrup using FTIR-ATR. The method used is FTIR-ATR with aquabides as a solvent. Parameter Validation of the analysis method carried out includes linearity, accuracy, precision, Limit of Detection (LOD) and Limit of Quantification (LOQ). The results of the linearity test show a value of r = 0.999 which indicates linear. The accuracy obtained is 97 - 105.5%. Precision with an Relative Standard Deviation (RSD) value of 0.54%, LOD of 469.72 µg/mL and LOQ of 1423.6 µg/mL. The results of determining the levels of cefadroxil dry syrup with three samples, namely sample A 100.2%; sample B 100.5%; sample C 100.1%. Based on the research results, it can be concluded that the FTIR-ATR method is valid and the sample concentration complies with the provisions of the Indonesian Pharmacopoeia Edition VI, namely the concentration of cefadroxil in dry syrup preparations is not less than 90% and not more than 120%.

Synthesis of new flavonoid derivatives based on 3-hydroxy-4′-dimethylamino flavone and study the activity of some of them as antifungal

Chalcone was prepared in a new route by reacting o-hydroxyacetophenone with 4-dimethylaminobenzaldehyde using piperidine as a catalyst. 3-Hydroxy-2-[4-(dimethylamino)phenyl] benzopyran-4-one were prepared by Algar-Flynn-Oyamada method by cyclization of chalcone using Hydrogen peroxide. A series of alkyl and ester derivatives of the flavonoid 3-hydroxy-2-[4-(dimethylamino)phenyl] benzopyran-4-one were prepared by reacting the above mentioned compound with different chemical reagents (Methyl iodide, Allyl bromide, Benzyl chloride, Bromoacetylcoumarin, Chloroacetamide, Chloroacetyl chloride, Phthalic anhydride, Maleic anhydride, Phthalimide, Cinnamoyl chloride) with potassium carbonate and acetone or DMF as a solvent. The physical and spectroscopic properties of the new compounds were studied by (FT-IR, 13C-NMR and 1H-NMR) spectral methods. The purity of the synthesized compounds were confirmed using TLC thin layer chromatography. The biological activity of some synthetic flavonoids (A2, A5, A7, A8, A9, A12) at two different concentrations (0.5 mg/ml, 0.25 mg/ml) were studied on three types of fungi: Aspergillus flavus, Acremonium strictum, Penicillium expansum. Some of this compounds showed high activity against the tested fungi.

Sequestration of Oxyanions of V(V), Mo(VI), and W(VI) Enhanced through Enzymatic Formation of Fungal Manganese Oxides

Biogenic Mn oxides (BMOs) have become captivating with regard to elemental sequestration, especially at circumneutral pH conditions. The interaction of BMOs with oxyanions, such as vanadate (V), molybdate (VI), and tungstate (VI), remains uncertain. This study examined the sequestration of V(V), Mo(VI), and W(VI) (up to ~1 mM) by BMOs formed by the Mn(II)-oxidizing fungus, Acremonium strictum KR21-2. When A. strictum KR21-2 was incubated in liquid cultures containing either Mo(VI) or W(VI) with soluble Mn2+, the oxyanions were sequestered in parallel with enzymatic Mn(II) oxidation with the maximum capacities of 8.8 mol% and 28.8 mol% (relative to solid Mn), respectively. More than 200 μM V(V) showed an inhibitory effect on growth and Mn(II) oxidizing ability. Sequestration experiments using preformed primary BMOs that maintained the enzymatic Mn(II) oxidizing activity, with and without exogenous Mn2+, demonstrated the ongoing BMO deposition in the presence of absorbent oxyanions provided a higher sequestration capacity than the preformed BMOs. X-ray diffraction displayed a larger decline of the peak arising from (001) basal reflection of turbostratic birnessite with increasing sequestration capacity. The results presented herein increase our understanding of the role of ongoing BMO formation in sequestration processes for oxyanion species at circumneutral pH conditions.

Використання наночастинок і нанотехнологій у картоплярстві

Goal. To analyze the literature data and the results of their own research on the use of nanoparticles and nanotechnologies in potato growing, as well as the results of the combined use of nanoparticles and microbial preparations. Methods. Analysis of literature, virological, microbiological, instrumental, field experiment, biochemical, statistical, and economic analysis. Results. Nanoparticles with virulicidal, bactericidal and fungicidal activity, as well as those that stimulate the growth of bacteria, were determined in vitro. Thus, Ti nanoparticles, the composition of Se + I nanoparticles, and the drug «Avatar-2 Zahyst» obtained by the nanotechnological method had virulicidal activity against the phytopathogenic virus Potato virus Y in the conditions of vegetation experiments. Using the method of transmission electron microscopy, it was established that Ti nanoparticles can concentrate around Potato virus Y virions and adsorb on their surface, this can be a potential explanation for their virulicidal activity. Zn nanoparticles exhibit bactericidal activity against strains of beneficial soil bacteria Bacillus subtilis IMV B7023 and Pseudomonas chlororaphis subsp. aureofaciens ICM B306 (2687) and a strain of bacteria pathogenic for potatoes — Clavibacter michiganensis subsp. sepedonicus Ac1995, reducing their titer by 100%. The composition of Se + I nanoparticles to one degree or another increases the titer of all tested strains of beneficial soil and phytopathogenic bacteria, in particular the strain Bacillus subtilis IMV B7023, which is one of the bioagents of the microbial preparation «Azogran», by 8.46–20.36%. Also, the composition of Se + I nanoparticles showed the strongest antifungal activity, reducing the diameter of colonies of strains of phytopathogenic fungi Fusarium sp. 072 by 25.26–51.75%, Acremonium cucurbitacearum 502 — by 78.95–94.22, and Acremonium strictum 048 — by 52.67–75.00%, as well as the number of colonies of the strain Acremonium cucurbitacearum 502 — by 60,00-86.67%. These properties of nanoparticles, their compositions, and the drug «Avatar-2 Zahyst» were tested in the conditions of a field experiment, and the combined use of nanoparticles with the microbial drug «Azogran» was also investigated. The drug «Avatar-2 Zahyst» was effective against viral, bacterial, and fungal diseases. The combination of the drug «Azogran» with the composition of Se+I nanoparticles turned out to be the best, reducing the frequency of establishment of bacterial and fungal diseases and the degree of their damage, increasing the marketability of tubers, yield, and improving other indicators. In this option, the highest calculated profitability, the value of which was 111.7 and 75.8% in two areas, which is more than in the control by 57.7 and 41.5%, respectively. Among other options, it is worth highlighting the composition of Se + I nanoparticles and the drug «Azogran», however, their effects individually were smaller than in combination. Conclusions. The effectiveness of the composition of Se+I nanoparticles, «Avatar-2 Zahyst» and «Azogran» preparations for the control of potato infectious diseases and the prospects of their use in potato cultivation technology were proven. The positive effect of the composition of Se + I nanoparticles and the drug «Azogran» on the marketability of tubers and yield was shown. The synergy between the composition of Se + I nanoparticles and the drug «Azogran» was established. The most promising was the combined use of nanoparticles and microbial preparations in the technology of growing potatoes.

Genome Sequence Resource of Sarocladium terricola TR, an Endophytic Fungus as a Potential Biocontrol Agent Against Meloidogyne incognita.

Genome Sequence Resource of Sarocladium terricola TR, an Endophytic Fungus as a Potential Biocontrol Agent Against Meloidogyne incognita.

Heterologous Expression of Secondary Metabolite Genes in Trichoderma reesei for Waste Valorization.

Trichoderma reesei (Hypocrea jecorina) was developed as a microbial cell factory for the heterologous expression of fungal secondary metabolites. This was achieved by inactivation of sorbicillinoid biosynthesis and construction of vectors for the rapid cloning and expression of heterologous fungal biosynthetic genes. Two types of megasynth(et)ases were used to test the strain and vectors, namely a non-reducing polyketide synthase (nr-PKS, aspks1) from Acremonium strictum and a hybrid highly-reducing PKS non-ribosomal peptide synthetase (hr-PKS-NRPS, tenS + tenC) from Beauveria bassiana. The resulting engineered T. reesei strains were able to produce the expected natural products 3-methylorcinaldehyde and pretenellin A on waste materials including potato, orange, banana and kiwi peels and barley straw. Developing T. reesei as a heterologous host for secondary metabolite production represents a new method for waste valorization by the direct conversion of waste biomass into secondary metabolites.

Simultaneous Sequestration of Co2+ and Mn2+ by Fungal Manganese Oxide through Asbolane Formation

Biogenic manganese oxides (BMOs) have attractive environmental applications owing to their metal sequestration and oxidizing abilities. Although Co readily accumulates into Mn oxide phases in natural environments, the Co2+ sequestration process that accompanies the enzymatic Mn(II) oxidation of exogenous Mn2+ remains unknown. Therefore, we prepared newly formed BMOs in a liquid culture of Acremonium strictum KR21-2 and conducted repeated sequestration experiments in a Mn2+/Co2+ binary solution at pH 7.0. The sequestration of Co2+ by newly formed BMOs (~1 mM Mn) readily progressed in parallel with the oxidation of exogenous Mn2+, with higher efficiencies than that in single Co2+ solutions when the initial Co2+ concentrations (0.16–0.8 mM) were comparable to or lower than the exogenous Mn2+ concentration (~0.8 mM). This demonstrates a synergetic effect on Co sequestration. Powder X-ray diffraction showed a typical pattern for asbolane only when newly formed BMOs were treated in Mn2+/Co2+ binary systems, implying that the enzymatic Mn(II) oxidation by newly formed BMOs favored asbolane formation. Cobalt K-edge X-ray absorption near-edge structure measurements showed that both Co(II) and Co(III) participated in the formation of the asbolane phase in the binary solutions, whereas most of the primary Co2+ was sequestered as Co(III) in the single Co2+ solutions, which partly explains the synergetic effects on Co sequestration efficiency in the binary solutions. The results presented here provide new insights into the mechanism of Co interaction with Mn oxide phases through asbolane formation by enzymatic Mn(II) oxidation under circumneutral pH conditions.

Effect of particle size on the colonization of biofilms and the potential of biofilm-covered microplastics as metal carriers

Upon release into the aquatic environment, the surface of microplastics (MPs) can be readily colonized by biofilms, which may enhance the adsorption of contaminants. In this study, industrial-grade polystyrene (PS) of about 4 mm in size (MP4000–1), food-grade PS of about 4 mm in size (MP4000–2), and Powder PS of about 75 μm in size (MP75) were co-cultured with a model freshwater fungus, namely Acremonium strictum strain KR21–2, for seven days to form biofilms on their surface. We also determined the changes in surface physicochemical properties of the biofilm-covered MPs (BMPs) and the heavy metal adsorption capacity of the original MPs and BMPs. The results revealed that the biofilms improve the adsorption of heavy metals on MPs, and the particle size of MPs plays a crucial role in biofilm colonization and adsorption of heavy metals by BMPs. MP75 can carry more biofilm on its surface than that of the two MP4000s and form heteroaggregates with biofilms. In addition, there were more functional groups on the surface of BMP75 than on the surface of the two BMP4000s, which could promote the electrostatic interaction and chemical association of heavy metals. Moreover, BMP75 exhibited a higher capacity to adsorb Cu and reduce Cr (VI), which may be related to the functional groups in its biofilm. Overall, this study showed that after biofilms colonization, BMPs of smaller size have more significant potential as a metal vector, and the particle size deserves more scientific attention during the risk assessment.

Optimizing the tray dryer temperature and time of white corn flour culture

This research aimed to optimize the tray dryer temperature and time of white corn flour culture by Response Surface Methodology (RSM). There were two cultures used in this research, namely Amylolytic Culture (AC) and Complete Culture (CC). AC consisted of Penicillium citrinum, Aspergillus niger, Acremonium strictum, and Candida famata, while CC consisted of Penicillium chrysogenum, Penicillium citrinum, Aspergillus niger, Rhizopus stolonifer, Rhizopus oryzae, Fusarium oxysporum, Acremonium strictum, Candida famata, Kodamaea ohmeri and Candida krusei/incospicua. The independent variables in this study were drying temperature and time, where the quality indicators used were total viability of mold and yeast, water content, water activity, and pH. This research used a factor response surface methodology. Data were analyzed by ANOVA with an α level of 95%. The result of this research showed that the optimum drying process for AC starter was 40°C for 10 hrs, with characteristic response viability 8.8×107 CFU/g, water activity 0.43, water content 8.90%, and pH 4.05. CC starter showed an optimum drying process at 49°C for 4.5 hrs, with characteristic response viability 4.9×107 CFU/g, water activity 0.49, water content 7.02%, and pH 3.95. The optimum tray dryer temperatures and times were achieved for AC and CC starters.

Antifungal Activity of a Composition of Selenium and Iodine Nanoparticles

The aim of this study was to investigate antifungal properties of the composition of Se and I nanoparticles (NPs) against strains of phytopathogenic fungi Acremonium cucurbitacearum 502, Acremonium strictum 048 and Fusarium sp. 072. It has been found that the composition of Se and I NPs has antifungal properties against these strains. The highest antifungal activity was against strain A. cucurbitacearum 502, manifesting as the decrease in the number of colonies (by 60.00- 86.67%) and the decrease of the diameter of colonies (by 78.95-94.22%). Antifungal activity against strain A. strictum 048 manifested as the decrease in the diameter of colonies by 52.67-75.00%. The diameter of colonies the strain Fusarium sp. 072 decreased by 25.26-51.75%. Changes in the morphology of the colonies of the strain A. strictum 048 were also noticed. Thus, the composition of Se and I nanoparticles has antifungal activity against fungal strains A. cucurbitacearum 502, A. strictum 048 and Fusarium sp. 072, which are valuable plant pathogens. The composition of Se and I NPs can be recommended for the development of the measures for the control of phytopathogenic fungi.

Preferential Elimination of Ba2+ through Irreversible Biogenic Manganese Oxide Sequestration

Biogenic manganese oxides (BMOs) formed in a culture of the Mn(II)-oxidizing fungus Acremonium strictum strain KR21-2 are known to retain enzymatic Mn(II) oxidation activity. Consequently, these are increasingly attracting attention as a substrate for eliminating toxic elements from contaminated wastewaters. In this study, we examined the Ba2+ sequestration potential of enzymatically active BMOs with and without exogenous Mn2+. The BMOs readily oxidized exogenous Mn2+ to produce another BMO phase, and subsequently sequestered Ba2+ at a pH of 7.0, with irreversible Ba2+ sequestration as the dominant pathway. Extended X-ray absorption fine structure spectroscopy and X-ray diffraction analyses demonstrated alteration from turbostratic to tightly stacked birnessite through possible Ba2+ incorporation into the interlayer. The irreversible sequestration of Sr2+, Ca2+, and Mg2+ was insignificant, and the turbostratic birnessite structure was preserved. Results from competitive sequestration experiments revealed that the BMOs favored Ba2+ over Sr2+, Ca2+, and Mg2+. These results explain the preferential accumulation of Ba2+ in natural Mn oxide phases produced by microbes under circumneutral environmental conditions. These findings highlight the potential for applying enzymatically active BMOs for eliminating Ba2+ from contaminated wastewaters.

Stereochemical characterisation of the non-canonical α-humulene synthase from Acremonium strictum.

The non-canonical fungal α-humulene synthase was investigated through isotopic labelling experiments for its stereochemical course regarding inversion or retention at C-1, the face selectivity at C-11, and the stereoselectivity of the final deprotonation. A new and convenient desymmetrisation strategy was developed to enable a full stereochemical analysis of the catalysed steps to the achiral α-humulene product from stereoselectively labelled farnesyl diphosphate.

The effect of fruit on the extracellular enzyme profiles of fungi.

In recent years, the number of diseases caused by fungal pathogens has increased significantly. Many species of fungi are pathogenic for plants, causing a threat to food production and to humans, and are among the causes of chronic diseases. The aim of the study is to determine the enzyme profiles of fungi, depending on the different types of fruit with which they have contact, and to determine the differences in these profiles in relation to the substrate on which they are grown. Six strains of fungi identified as Cladosporium sphaerospermum, Fusarium poae, Alternaria alternata, Penicillium expansum, Penicillium verucosum and Acremonium strictum, isolated from fruits, were selected and analyzed for enzymatic profiles. The enzymatic activity was assessed using the API ZYM test (bioMerieux, France). In the majority of the 6 fungal strains isolated from fruits, enzymes belonging to glycol-hydrolases were the most active. The exception was Acremonium strictum, where phosphatases dominated. Among most fungal isolates, the enzymes β- glucosidase and N-acetyl-β-glucosaminidase showed the highest activity. The highest β-glucosidase activities were found in Cladosporium sphaerospermum and Penicillium expansum. On the other hand, lipase, α-fucosidase and α-chymotrypsin showed the least activity. The least activity of these enzymes or their complete absence was observed in Fusarium poae, Alternaria alternata, Penicillium expansum and Acremonium strictum. The activity of hydrolytic enzymes in the isolated fungi depended on the addition of fruit and the type of medium. Individual fruits can increase or decrease the activity of the enzymes. Fungi present in fruit have pathogenic properties and can be possible risk factors for fungal infections.

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English

The fungal elicitor AsES requires a functional ethylene pathway to activate the innate immunity in strawberry.

Acremonium strictum Elicitor Subtilisin (AsES) is a fungal elicitor that activates innate immunity, conferring disease resistance in strawberry (Fragaria×ananassa Duch.), Arabidopsis and other plant species. The aim of the present work was to evaluate the involvement of the ethylene (ET) signalling pathway in AsES-mediated immune response in strawberry. Ethylene production and expression of the genes responsible for ET synthesis, perception and response were measured after AsES treatment. ROS (H2 O2 ) accumulation and immunity induced by AsES were studied after ET perception was blocked by 1-methylcyclopropene (1-MCP). Biochemical and molecular results showed that AsES induced a marked increase in local and systemic biosynthesis of ET, both in a biphasic manner. Blocking of ET perception by 1-MCP prior to AsES induction reduced production of ROS (H2 O2 ) and prevented AsES from eliciting defence against fungal pathogens having different lifestyles, such as Botrytis cinerea (necrotrophic) and Colletotrichum acutatum (hemibiotrophic). These findings contribute to elucidate the mode of action of the novel elicitor subtilase, AsES, specifically regarding the role of ET signalling in the activation of plant innate immunity, in addition to the multitude of processes regulated by ET in plants.

Bacterial wetwood of silver birch (Betula pendula roth): symptomology, etiology and pathogenesis

Abstract The article is focused on microbiological and silvicultural properties of bacterial wetwood of silver birch (Betula pendula), also known as European white birch. During the active phase of the disease, bacterial wetwood (i.e. bacterial dropsy, vascular parenchymatous bacteriosis or flux slime) is characterised by crust and periderm bloating, necrotic wet stains and abundance of exudate. The disease is more likely to occur in older (r = 0.56, p < 0.01) and less-dense (r = −0.29, p < 0.01) stands. The statistical model showed that the chance of bacterial wetwood increases with birch age by 0.36% per year. The stands with birch proportion of over 70% demonstrated 15.3% lower infection rate compared to the stands with lower birch presence. The stands with lower stocking demonstrated a higher proportion of infected tree distribution by 7.5% compared to the stands with higher birch representation. The most vulnerable were larger, older B. pendula trees with longitudinally fissured bark that grow on poorer soils and experience frequent water stress. Birch associations with Pteridium aquilinum and Vaccinium myrtillus were more susceptible to infection (31.6% and 44.3%, respectively), whereas associations with Brachypodium sylvaticum, Sphagnum palustre and Calluna vulgaris were at lower risk. Strong ecological and trophic association of bacterial wetwood was present between silver birch and Tremex spp., particularly Tremex fuscicornis. Mycobiota was represented by Rhizopus microsporus, Mucor mucedo, Penicillium aurantiogriseum, Penicillium purpurogenum and Acremonium strictum. Enterobacter, Xanthomonas, Pantoea and Bacillus spp. associated with bacterial wetwood of silver birch were isolated. Enterobacter nimipressuralis was found to be the primary causative agent through means of artificial infection, while other bacteria were found to be either weak pathogens or concomitant. E. nimipressuralis formed the largest number of colony-forming units (CFU) for bark and cambium (164 and 127 CFU, respectively) and was also found in a small amount as a vital obligate in the automicrobiota in healthy birch trees.