Fusarium Strains Research Articles

High Diversity of Fusarium Species in Onychomycosis: Clinical Presentations, Molecular Identification, and Antifungal Susceptibility

Fusarium are uncommon but important pathogenic organisms; they cause non-dermatophyte mould (NDM) onychomycosis. Patients typically respond poorly to treatment owing to Fusarium's native resistance to multiple antifungal drugs. However, epidemiological data for Fusarium onychomycosis are lacking in Taiwan. We retrospectively reviewed the data of 84 patients with positive Fusarium nail sample cultures at Chang Gung Memorial Hospital, Linkou Branch between 2014 and 2020. We aimed to investigate the clinical presentations, microscopic and pathological characteristics, antifungal susceptibility, and species diversity of Fusarium in patients with Fusarium onychomycosis. We enrolled 29 patients using the six-parameter criteria for NDM onychomycosis to determine the clinical significance of Fusarium in these patients. All isolates were subjected to species identification by sequences and molecular phylogeny. A total of 47 Fusarium strains belonging to 13 species in four different Fusarium species complexes (with Fusarium keratoplasticum predominating) were isolated from 29 patients. Six types of histopathology findings were specific to Fusarium onychomycosis, which may be useful for differentiating dermatophytes from NDMs. The results of drug susceptibility testing showed high variation among species complexes, and efinaconazole, lanoconazole, and luliconazole showed excellent in vitro activity for the most part. This study's primary limitation was its single-centre retrospective design. Our study showed a high diversity of Fusarium species in diseased nails. Fusarium onychomycosis has clinical and pathological features distinct from those of dermatophyte onychomycosis. Thus, careful diagnosis and proper pathogen identification are essential in the management of NDM onychomycosis caused by Fusarium sp.

Fusarium-Derived Secondary Metabolites with Antimicrobial Effects.

Fungal microbes are important in the creation of new drugs, given their unique genetic and metabolic diversity. As one of the most commonly found fungi in nature, Fusarium spp. has been well regarded as a prolific source of secondary metabolites (SMs) with diverse chemical structures and a broad spectrum of biological properties. However, little information is available concerning their derived SMs with antimicrobial effects. By extensive literature search and data analysis, as many as 185 antimicrobial natural products as SMs had been discovered from Fusarium strains by the end of 2022. This review first provides a comprehensive analysis of these substances in terms of various antimicrobial effects, including antibacterial, antifungal, antiviral, and antiparasitic. Future prospects for the efficient discovery of new bioactive SMs from Fusarium strains are also proposed.

New antimalarial fusarochromanone analogs produced by the fungal strain Fusarium sp. FKI-9521.

Two new antimalarial compounds, named deacetyl fusarochromene (1) and 4'-O-acetyl fusarochromanone (2), were discovered from the static fungal cultured material of Fusarium sp. FKI-9521 isolated from feces of a stick insect (Ramulus mikado) together with three known compounds fusarochromanone (3), 3'-N-acetyl fusarochromanone (4), and 5 (fusarochromene or banchromene). The structures of 1 and 2 were elucidated as new analogs of 3 by MS and NMR analyses. The absolute configurations of 1, 2, and 4 were determined by chemical derivatization. All five compounds showed moderate in vitro antimalarial activity against chloroquine-sensitive and chloroquine-resistant Plasmodium falciparum strains, with IC50 values ranging from 0.08 to 6.35 µM.

Novel polyketide from Fusarium verticillioide G102 as NPC1L1 inhibitors

One novel polyketide, fusaritide A (1), was isolated from a marine fish-derived halotolerant fungal strain Fusarium verticillioide G102. The structure was determined through extensive spectroscopic analysis and high-resolution electrospray ionization mass spectrometry. Fusaritide A (1) with unprecedented structure reduced cholesterol uptake by inhibiting Niemann-Pick C1-Like 1 (NPC1L1).

Effect of Crop Rotation on Fusarium Mycotoxins and Fusarium Species in Cereals in Sichuan Province (China).

The present study was performed to evaluate the effect of crop rotation on Fusarium mycotoxins and species in cereals in Sichuan Province. A total of 311 cereal samples were randomly collected and analyzed from 2018 to 2019 in Sichuan Province. The results of mycotoxin analysis showed that the major trichothecene mycotoxins in Sichuan Province were nivalenol (NIV) and deoxynivalenol (DON), and the mean concentration of total trichothecenes (including NIV, fusarenone X [4ANIV], DON, 3-acetyldeoxynivalenol [3ADON], and 15-acetyldeoxynivalenol [15ADON]) in wheat was significantly higher than that in maize and rice. The concentration of total trichothecenes in the succeeding crops was significantly higher than that in the previous crops. In addition, wheat grown after maize had reduced incidence and concentration of trichothecene mycotoxins compared with that grown after rice, and ratooning rice grown after rice had increased incidence and concentration of trichothecene mycotoxins. Our data indicated that Fusarium asiaticum with the NIV chemotype was predominant in wheat and rice samples, while the number of the NIV chemotypes of F. asiaticum and Fusarium meridionale and the 15ADON chemotype of Fusarium graminearum in maize were almost the same. Although the composition of Fusarium species was affected by crop rotations, there were no differences when comparing the same crop rotation except for the maize-wheat rotation. Moreover, the same species and chemotype of Fusarium strains originated from different crops in various rotations, but there were no significant differences in pathogenicity in wheat and rice. These results contribute to the knowledge of the effect of crop rotation on Fusarium mycotoxins and species affecting cereals in Sichuan Province, which may lead to improved strategies for control of Fusarium mycotoxins and fungal disease in China.

Fusarium diversity associated with diseased cereals in China, with an updated phylogenomic assessment of the genus.

Fusarium species are important cereal pathogens that cause severe production losses to major cereal crops such as maize, rice, and wheat. However, the causal agents of Fusarium diseases on cereals have not been well documented because of the difficulty in species identification and the debates surrounding generic and species concepts. In this study, we used a citizen science initiative to investigate diseased cereal crops (maize, rice, wheat) from 250 locations, covering the major cereal-growing regions in China. A total of 2 020 Fusarium strains were isolated from 315 diseased samples. Employing multi-locus phylogeny and morphological features, the above strains were identified to 43 species, including eight novel species that are described in this paper. A world checklist of cereal-associated Fusarium species is provided, with 39 and 52 new records updated for the world and China, respectively. Notably, 56 % of samples collected in this study were observed to have co-infections of more than one Fusarium species, and the detailed associations are discussed. Following Koch's postulates, 18 species were first confirmed as pathogens of maize stalk rot in this study. Furthermore, a high-confidence species tree was constructed in this study based on 1 001 homologous loci of 228 assembled genomes (40 genomes were sequenced and provided in this study), which supported the "narrow" generic concept of Fusarium (= Gibberella). This study represents one of the most comprehensive surveys of cereal Fusarium diseases to date. It significantly improves our understanding of the global diversity and distribution of cereal-associated Fusarium species, as well as largely clarifies the phylogenetic relationships within the genus. Taxonomic novelties: New species: Fusarium erosum S.L. Han, M.M. Wang & L. Cai, Fusarium fecundum S.L. Han, M.M. Wang & L. Cai, Fusarium jinanense S.L. Han, M.M. Wang & L. Cai, Fusarium mianyangense S.L. Han, M.M. Wang & L. Cai, Fusarium nothincarnatum S.L. Han, M.M. Wang & L. Cai, Fusarium planum S.L. Han, M.M. Wang & L. Cai, Fusarium sanyaense S.L. Han, M.M. Wang & L. Cai, Fusarium weifangense S.L. Han, M.M. Wang & L. Cai. Citation: Han SL, Wang MM, Ma ZY, Raza M, Zhao P, Liang JM, Gao M, Li YJ, Wang JW, Hu DM, Cai L (2023). Fusarium diversity associated with diseased cereals in China, with an updated phylogenomic assessment of the genus. Studies in Mycology 104: 87-148. doi: 10.3114/sim.2022.104.02.

Acclimatisation of Fusarium langsethiae, F. poae and F. sporotrichioides to elevated CO2: Impact on fungal growth and mycotoxin production on oat-based media

Oats are highly susceptible to infection by Fusarium species, especially F. langsethiae, F. poae and F. sporotrichioides which contaminate the grain with mycotoxins. Climate change is expected to affect fungal colonisation and associated mycotoxin production. The objective of this study was to examine the effect of acclimatisation to elevated CO2 on the growth and mycotoxin production capacity of these fungal species. Strains of F. langsethiae (FL; seven strains), F. poae (FP; two strains) and F. sporotrichioides (FS; one strain) were acclimatised by sub-culturing for 10 generations at either 400 or 1000 ppm CO2 under diurnal temperature conditions. At each sub-culturing, the effect of acclimatisation to elevated CO2 on (a) lag phase prior to growth, (b) growth rate on oat-based media was assessed. Additionally, the production of type A trichothecenes and related toxic secondary metabolites of sub-cultures after 1, 7 and 10 generations were assessed using LC-MS/MS qTRAP. The results showed that Fusarium strains had an increased lag time and growth rate in response to the combined effect of sub-culturing and elevated CO2 levels. T-2 + HT-2 production was affected by elevated CO2 in strain FL4 (7.1-fold increase) and a decrease in strain FL1 (2.0-fold decrease) at the first sub-culturing and FS (1.3-fold decrease) after 7 sub-cultures compared to ambient conditions. The effect of sub-culturing on T-2 + HT-2 production varied depending on the fungal strain. For strain FL4, significantly less T-2 + HT-2 toxins were produced after 10 generations (4.4-fold decrease) as compared to that under elevated CO2 conditions after one sub-culture, and no change was observed under ambient conditions. The FS strain showed significant stimulation of T-2 + HT-2 toxin production after 10 sub-cultured generations (1.1-fold increase) compared to the initial sub-culture of this strain under elevated CO2 conditions. The production of other toxic secondary metabolites was generally not impacted by elevated CO2 conditions or by sub-culture for 10 generations, with the exceptions of FL1 and FP1. FL1 produced significantly more neosolaniol after 10 generations, when compared to those after 1 and 7, regardless of the CO2 conditions. For FP1, elevated CO2 significantly triggered beauvericin production after an initial sub-culture when compared to ambient conditions at the same sub-culture stage (29-fold). FP1 acclimatisation to elevated CO2 led to a decrease of beauvericin production after 10 generations when compared to 1 (6-fold). In contrast, sub-culturing for 10 generations compared to 1 under ambient CO2 conditions resulted in an increase in this toxin (12-fold).

Draft Genome and Biological Characteristics of Fusarium solani and Fusarium oxysporum Causing Black Rot in Gastrodia elata.

Gastrodia elata is a valuable traditional Chinese medicinal plant. However, G. elata crops are affected by major diseases, such as brown rot. Previous studies have shown that brown rot is caused by Fusarium oxysporum and F. solani. To further understand the disease, we studied the biological and genome characteristics of these pathogenic fungi. Here, we found that the optimum growth temperature and pH of F. oxysporum (strain QK8) and F. solani (strain SX13) were 28 °C and pH 7, and 30 °C and pH 9, respectively. An indoor virulence test showed that oxime tebuconazole, tebuconazole, and tetramycin had significant bacteriostatic effects on the two Fusarium species. The genomes of QK8 and SX13 were assembled, and it was found that there was a certain gap in the size of the two fungi. The size of strain QK8 was 51,204,719 bp and that of strain SX13 was 55,171,989 bp. Afterwards, through phylogenetic analysis, it was found that strain QK8 was closely related to F. oxysporum, while strain SX13 was closely related to F. solani. Compared with the published whole-genome data for these two Fusarium strains, the genome information obtained here is more complete; the assembly and splicing reach the chromosome level. The biological characteristics and genomic information we provide here lay the foundation for further research on G. elata brown rot.

Genetic diversity and antifungal activities of the genera Streptomyces and Nocardiopsis inhabiting agricultural fields of Tamil Nadu, India

Actinomycetes receives much attention as plant-beneficial bacteria due to their distinct morpho-physiological, plant growth promoting and antifungal properties. Among the actinomycetes, members of the genus Streptomyces are of specific interest due to their metabolic versatility and ubiquity. The diversity of Streptomyces in different crop fields of Tamil Nadu has not been explored early. In this study, we explored phylogenetic diversity, morphological heterogeneity, and antifungal properties of cultivable actinomycetes isolated from the rhizosphere and bulk soils of different crops collected from 20 distinct districts of Tamil Nadu. A total of 65 actinomycetes were isolated from 40 soil samples including rhizosphere and bulk soils of different crops, and their diversity was analyzed using the 16S rRNA gene sequence. They were then characterized for cultural characteristics and antifungal activity against four fungal strains Fusarium udum, Fusarium oxysporum f.sp. ciceri, Macrophomina phaseolina and Sclerotium rolfsii. Out of the 65 isolates sequenced, 45 were found to be closely related to Streptomyces spp. while the remaining 20 showed similarities with Nocardiopsis spp. Cultural characterization on four different ISP media showed immense diversity among the members of the genera Streptomyces and Nocardiopsis. The strains of Streptomyces spp. and Nocardiopsis spp. showed varying levels of antifungal activity with all strains found antagonistic against both Fusarium udum and Fusarium oxysporum f.sp. ciceris. All the strains obtained in this study have been accessioned at the National Agriculturally Important Microbial Culture Collection (NAIMCC) to increase the database of characterized strains belonging to these two genera in the collection.

Investigation of antifungal activities of myrcene on Fusarium reference strains.

Antifungal effects of myrcene, the plant-based naturel compound, were investigated on Fusarium graminearum PH-1 and Fusarium culmorum FcUK99 references, for the first time. Minimum inhibitory concentration (MIC) and half of MIC (MIC50) of both Fusarium strains against myrcene were found as 25µg/µl and 12.5µg/µl, respectively. MIC50 application decreased the cell viabilities in the ratios of 34.90% and 33.91% in PH-1 and FcUK99, respectively (p < 0.01). The significantly increased catalase (CAT) activity was recorded in MIC50 treated strains (p < 0.01). Apoptosis-like process and cellular oxidative stress were also monitored with acridine orange/ethidium bromide (Ao/Eb) dual staining and 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA) staining. The genomic template stability (GTS) percentages were calculated as 79% for PH-1 and 71% for FcUK99 via random amplified polymorphic DNA (RAPD). Methylation polymorphism values were calculated as 53.8% and 50.6% in PH-1 and 40.4% and 39% in FcUK99 for HapII and MspI, respectively by coupled restriction enzyme digestion-random amplification (CRED-RA). Methylation-sensitive amplified polymorphism (MSAP) revealed that myrcene caused both type I and type III epigenetic modifications in both genomes. MIC50 dose caused up to 13.86 ± 0.42-fold changes in the expressions of cat, mst20, and stuA, whereas downregulation in tri5 was recorded. Myrcene application did not change the retrotransposon movement in both species by the amplifying of idiomorphic retrotransposon patterns through inter-retrotransposon polymorphism-polymerase chain reaction (IRAP-PCR). This study demonstrated that myrcene is an effective compound in the management of phytopathogenic Fusarium species by causing morphological, genetic, epigenetic, and cellular alterations, and has a potential to utilize as an antifungal agent.

Seasonal and Geographical Impact on the Mycotoxigenicity of Aspergillus and Fusarium Species Isolated from Smallholder Dairy Cattle Feeds and Feedstuffs in Free State and Limpopo Provinces of South Africa.

This study evaluated the impact of seasonal and geographical variations on the toxigenicity of Aspergillus and Fusarium strains previously isolated from smallholder dairy cattle feeds and feedstuffs sampled during summer and winter in the Free State and Limpopo provinces of South Africa (SA). In total, 112 potential toxigenic fungal species were obtained and determined for their capability to produce mycotoxins on solid Czapek Yeast Extract Agar (CYA); followed by liquid chromatography-mass spectrometry (LC-MS/MS) analysis. Our result revealed that 41.96% of the fungal species produced their respective mycotoxins, including aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), and zearalenone (ZEN), with higher levels of AFB1 (0.22 to 1045.80 µg/kg) and AFB2 (0.11 to 3.44 µg/kg) produced by fungal species isolated from summer samples than those in winter [(0.69 to 14.44 µg/kg) and (0.21 to 2.26 µg/kg), respectively]. The same pattern was also observed for AFB1 and AFB2 in Limpopo (0.43 to 1045.80 µg/kg and 0.13 to 3.44 µg/kg) and Free State (0.22 to 576.14 µg/kg and 0.11 to 2.82 µg/kg), respectively. More so, ZEN concentrations in summer (7.75 to 97.18 µg/kg) were higher than in winter (5.20 to 15.90 µg/kg). A similar observation was also noted for ZEN in Limpopo (7.80 to 97.18 µg/kg) and Free State (5.20 to 15.90 µg/kg). These findings were confirmed via Welch and Brown-Forsythe tests with significantly (p ≤ 0.05) higher mycotoxin levels produced by fungal strains obtained in samples during summer than those in winter. In contrast, the concentrations of mycotoxins produced by the fungal species from both provinces were not significantly (p > 0.05) different.

ВИРУЛЕНТНОСТЬ ГРИБОВ РОДА FUSARIUM, ПАРАЗИТИРУЮЩИХ НА ЗЕРНОВЫХ КУЛЬТУРАХ В СРЕДНЕВОЛЖЬЕ

Infectious diseases caused by fungi from the Fusarium genus are one of the main reasons for the decrease in yield and quality of grain crops. The aim of the study is to identify the most virulent fungal isolates of the Fusarium genus inhabiting the territory of the Tatarstan Republic and its neighbouring regions of the Volga Federal District. Wheat and rye spikes were collected in the summer of 2022 at the spike ripening stage. Thirteen fungal strains were isolated from obtained plant material and preliminary attributed as Fusarium species based on morphological characteristics. By analyzing the nucleotide sequences of the ITS2 (internal transcribed spacer) region of ribosomal genes, the obtained fungal isolates were confirmed to belong to the Fusarium genus. Most of these isolates were attributed to the species F. sporotrichioides, F. culmorum, F. oxysporum, F. poae, while some isolates were identified at the genus level. Using virulence assays with wheat grain and rye plants in vitro, four isolated fungal strains were characterized as highly virulent. Based on the analysis of ITS2 sequences, the highly virulent Fusarium strains were assigned to F. sporotrichioides (1 strain), F. culmorum (1 strain), and F. oxysporum (2 strains). Other fungal strains (9 isolates) were characterized as low- or moderately virulent. In addition to the pronounced virulence properties, the detected Fusarium species have the potential ability to produce mycotoxins dangerous for humans and farm animals, which actualizes the need for detailed phytosanitary studies on the territory of the Tatarstan Republic and its neighbouring regions of the Volga Federal District.

Chemical Profile and Biological Activities of Fungal Strains Isolated from Piper nigrum Roots: Experimental and Computational Approaches.

The current report describes the chemical investigation and biological activity of extracts produced by three fungal strains Fusarium oxysporum, Penicillium simplicissimum, and Fusarium proliferatum isolated from the roots of Piper nigrum L. growing in Vietnam. These fungi were namely determined by morphological and DNA analyses. GC/MS identification revealed that the EtOAc extracts of these fungi were associated with the presence of saturated and unsaturated fatty acids. These EtOAc extracts showed cytotoxicity towards cancer cell lines HepG2, inhibited various microbacterial organisms, especially fungus Aspergillus niger and yeast Candida albicans (the MIC values of 50-100 μg/mL). In α-glucosidase inhibitory assay, they induced the IC50 values of 1.00-2.53 μg/mL were better than positive control acarbose (169.80 μg/mL). The EtOAc extract of F. oxysporum also showed strong anti-inflammatory activity against NO production and PGE-2 level. Four major compounds linoleic acid (37.346 %), oleic acid (27.520 %), palmitic acid (25.547 %), and stearic acid (7.030 %) from the EtOAc extract of F. oxysporum were selective in molecular docking study, by which linoleic and oleic acids showed higher binding affinity towards α-glucosidase than palmitic and stearic acids. In subsequent docking assay with inducible nitric oxide synthase (iNOS), palmitic acid, oleic acid and linoleic acid could be moderate inhibitors.

Fusarium pseudocircinatum causing stunting and malformation of sunflower plants in Brazil.

Sunflower (Helianthus annuus L.) is among the main oleaginous crops used in Brazil. During January, 2017, at CCA/UFPB laboratory and greenhouses (Areia/Brazil, 6°58'12″ S; 35°42'15″ W), we observed various sunflower seeds (cultivar Olisun 3, 2017-2018 crop) highly infested with Fusarium. Those seeds were from crops in the municipality of Alagoinha -PB/Brazil (06º57'00'' S; 35º32'42'' W), supplied by Empresa Brasileira de Pesquisa Agropecuária/EMBRAPA. The emerged seedlings from these seeds were also contaminated, with 5% to 26% of them exhibiting stunting and malformation. Fusarium strains were isolated from symptomatic plants, and a single spore was used to grow pure colonies on potato-dextrose-agar (PDA) and synthetic-nutrient-poor-agar (SNA) media. Mycelia of PDA colonies were floccous and dense varying from yellow to orange. Fungal colonies developed aerial mycelium, producing orange pigments. On SNA, hyaline macroconidia, measuring 2.9-4.1 x 32.4-65.0 μm, slightly falcate with three to six septa. Oval microconidia, measuring 2.4-3.6 x 5.1-9.0 μm, were abundant in false heads forming on monophyalides. Chlamydospores were absent. Sterile hyphae were rarely formed. Colectively, the morphological features corresponded to species that belong to the Fusarium fujikuroi species complex (Leslie & Summerell, 2006). To assure the species identity, we sequenced the elongation factor 1α region of two representative isolates (i.e., F2 and F3, GenBank access numbers: MZ666934 and MZ666935, respectively) and compared them to the other Fusarium species found at Fusarium-ID and GenBank databases. Subsequently, we performed a maximum likelihood phylogenetic analysis including previously published sequences (Nicolli et al., 2020). Both isolates exhibited 100% similarity with Fusarium pseudocircinatum (MN386745), and clustered with its ex-type at 100% bootstrap values. The isolates were then grown on PDA amended with manitol to adjust the osmotic pressure to -1.0 Mpa, at 25 ± 2 ° C, for seven days (Sousa et al., 2008). A total of 100 disinfested sunflower seeds (cultivar Olisun 3, 2018-2019 crop) were distributed over the colonies and 48h later they were sown on sterile substrate maintained inside a greenhouse. About 30 days after inoculation, the emerged plants exhibited symptoms of stunting and malformation (60%) compared to controls, which were healthy. F. pseudocircinatum was reisolated from the symptomatic plants, completing Koch's postulates and identified based on above morphological and molecular biological methods. This test was performed twice. Fusarium pseudocircinatum is a broadly distributed and ecologicaly diverse species that infects several wild and cultivated plants. For instance, it was reported on seeds of the wild 'Peroba Rosa' (Aspidosperma polyneuron Muell. Arg.) in Brazil (Mazarotto et al. 2020). Infection of sunflowers may cause plant stand failures, thus resulting in yield and economic losses for Brazilian growers. The correct identification of any pathogen, especialy a generalist one such as F. pseudocircinatum, is crucial to develop eficient management strategies. To our best knowledge, this is the first report of F. pseudocircinatum causing stunting and malformation of sunflower plants in Brazil.

A study on microbiota isolated from olive mill wastewater disposal ponds, with emphasis on filamentous fungi and their biodegradative potential in North Sinai Governorate, Egypt

The microbial composition of olive mill wastewater (OMWW) from six disposal ponds at three localities in North Sinai Governorate, Egypt has been studied. Such OMWW samples contained a variable (but high) number of bacteria, yeasts, and mold. Eighty-one isolates related to 9 bacterial species were recovered, and seven common bacterial species were isolated from Bir al Abd, Al-Arish, and Rafah sites sources namely Enterococcus faecalis, Escherichia coli, Bacillus cereus, B. subtilis, Micrococcus luteus, Pseudomonas aeruginosa, and Klebsiella pneumonia. In addition to these species, Vibrio cholerae and Shigella species were isolated from the Bir al Abd site. One hundred and twenty isolates related to 13 fungal species were recovered. Seven members of different fungal genera (Aspergillus, Penicillium, Fusarium, Paecilomyces, Alternaria, Chaetomium, and Rhizopus) were recorded. Four genera were widely distributed, and they were able to grow efficiently in undiluted OMWW as a sole source of nutrients. Strains of Aspergillus, Penicillium, Fusarium, and Paecilomyces showed a marked capacity for OMWW detoxification. The physicochemical studies further revealed the presence of relatively low levels of sodium, potassium, calcium, magnesium, and iron. Nitrate concentration was relatively high, 70.13 mg/L. The biological oxygen demand (BOD) and the chemical oxygen demand (COD) recorded high values that ranged between 2210-2270 mg/L and 22760-22800 mg/L, respectively. High BOD and COD values are important indicators of high organic and inorganic components of OMWW and possible negative environmental consequences. The presence of fungal and bacterial species implied possible degradation of the effluent.

The endophytic Fusarium strains: a treasure trove of natural products.

The complexity and structural diversity of the secondary metabolites produced by endophytes make them an attractive source of natural products with novel structures that can help in treating life-changing diseases. The genus Fusarium is one of the most abundant endophytic fungal genera, comprising about 70 species characterized by extraordinary discrepancy in terms of genetics and ability to grow on a wide range of substrates, affecting not only their biology and interaction with their surrounding organisms, but also their secondary metabolism. Members of the genus Fusarium are a source of secondary metabolites with structural and chemical diversity and reported to exhibit diverse pharmacological activities. This comprehensive review focuses on the secondary metabolites isolated from different endophytic Fusarium species along with their various biological activities, reported in the period from April 1999 to April 2022.

First Report of Fusarium acuminatum Causing Leaf Blight on Garlic in China.

In June 2021, leaf blight symptoms were detected on garlic plants (Allium sativum) in southeastern Jiangsu (Nantong municipality; 120.61° E, 33.25° N) in China. Two-month-old garlic plants exhibited leaf tip die back and light brown lesions in new and old leaves (Figure 1). The symptoms were observed in 40% of the plants in a 60-square-meters commercial field surrounded by rice fields, and were similar to those reported for Botrytis porri, Septoria allii and Stemphylium eturmiunum causing leaf blight on garlic (Dumin et al. 2021; Park et al. 2013; Zhang et al. 2009). Six samples of symptomatic tissue collected in Nantong municipality, approximately 1 cm2 in size, were sterilized in 2% NaOCl for 15 min and washed twice with sterile ddH2O. The pathogen was isolated from all collected samples on PDA medium, containing 50 µg/mL chloramphenicol, at 26°C. Pink colonies with orange pigmentation were observed after 7 days. Internal transcribed spacer (ITS), elongation factor 1-α (EF1-α), RNA polymerase II largest subunit (RPB1) and RNA polymerase II second largest subunit (RPB2) genes were amplified using ITS1/ITS4, EF1-728F/EF1-986R, RPB1-R8/RPB1-F5 and fRPB2-7CF/fRPB2-11aR primers, respectively. A total of 17 isolates were obtained, with nine of the isolates sharing the same sequences (strain NJC21), six of the isolates sharing the same sequences (strain NJC22), and the other two isolates showing different sequences (strains NJC23 and NJC24). The obtained sequences were submitted in GenBank under accession numbers OL655398-OL655401 (ITS), and OL741712-OL741723 (EF1-α, RPB1, RPB2). The obtained ITS sequences shared >99% homology to the ITS gene from F. acuminatum IBE000006 (EF531232), the EF1-α sequences shared 99% homology to the EF1-α gene from F. acuminatum F1514 (LC469785), the RPB1 sequences shared >99% homology to the RPB1 gene from F. acuminatum JW 289003 (MZ921675), and the RPB2 sequences shared 100% homology to the RPB2 gene from F. acuminatum NL19-077002 (MZ921813) or 100% homology to the RPB2 gene from F. acuminatum MD1 (MW164629). A phylogenetic tree was constructed using MEGA7 with related Fusarium strains (Figure 2). Microscope observations after incubation in potato-sucrose-agar (PSA) medium showed the presence of oval microconidia, fusiform macroconidia, septate mycelium and chlamydospores, and agree with the morphology of F. acuminatum (Marek et al. 2013). The pathogenicity was screened with two-week-old wounded and non-wounded garlic plants using a 1 × 106 spores/mL solution (20 µL). Sterile ddH2O was used in the control experiment. The inoculated plants were incubated at 26°C and 60% relative humidity for 3 days, detecting similar lesions compared to those observed in the field. The pathogen was recovered from 5 different lesions, from different plants, and its identity was confirmed by sequence analysis. Recently, F. acuminatum was reported to cause garlic bulb rot in Serbia (Ignjatov et al. 2017). Although F. acuminatum is well known as a causal agent of root rot (Li et al. 2021; Tang et al. 2021), F. acuminatum has also been found causing leaf blight on onion (Parkunan et al. 2013) and muskmelon (Yu et al. 2021). This is the first report of F. acuminatum causing leaf blight on garlic, demonstrating the host and tissue promiscuity of this pathogen. China is the largest producer of garlic in the world with nearly 20 million tons harvested in 2020. This report will help to better understand the pathogens that are affecting garlic production in China.

Comparative characterization of lectins of pathogenic and saprophytic filamentous fungi Fusarium solani

In the present study, we isolated, purified and characterized the lectin of the phytopathogenic fungus Fusarium solani 6 and compared it with the properties of the lectin of the saprophytic strain Fusarium solani 4. Electrophoretically homogeneous lectin was obtained from the mycelium of the fungus F. solani 6 by hydrophobic chromatography and gel filtration. The molecular weight of the native lectin molecule was established to be 30.0 kDa, and it was found that it consists of two identical subunits. Comparison of the physicochemical properties of the lectin of the phytopathogenic strain with the lectin of the saprophytic strain showed that the F. solani 6 lectin was a more thermostable and alkali-resistant protein. F. solani 6 lectin showed affinity for simple sugars, and F. solani 4 lectin - for glycoproteins. In contrast to the lectin of a saprophytic fungus, the treatment of pea seedling roots with F. solani lectin 6 before they were infected with the phytopathogen led to a decrease in the degree of damage to the plant root system and the prevalence of Fusarium. These results open up prospects for further study of the phytopathogen lectin and its potential application as a means of eliciting action.

Change of the mycelial strain Fusarium sambucinum var sambucinum after exposure to ultraviolet irradiation

Change of the mycelial strain Fusarium sambucinum var sambucinum after exposure to ultraviolet irradiation

Characterization of Paenibacillus spp. CBRM17 as antagonist of phytopathogenic fungi and growth promoter of Capsicum chinense Jacq.

Studies of the plant-microorganism relationship have made it posible to explore the potential of rhizospheric bacteria to improve the health and quality of plants. In the present study, Paenibacillus sp. CBRM17 was characterized in vitro for its ability to inhibit the growth of phytopathogenic fungi that cause diseases in horticultural crops in the tropics, finding a reduction in the mycelial growth of Alternaria, Fusarium and Helmintosphorium strains in the range of 50 to 70 %, additionally its biochemical properties related to the promotion of plant growth were characterized, registering the production of 0.36 µg/mL of indole acetic acid (IAA), the solubilization of tricalcium phosphate with solubilization index (SI) of 2.41 mm and solubilization efficiency (SE) of 140.6 %, producing in the supernatant 63.5 mg/L of soluble phosphorus, in addition to being positive for ACC deaminase activity. Inoculations trials of habanero chili (Capsicum chinense Jacq.) seeds with Paenibacillus sp. CBRM17 showed its potential to be used as an inoculant in the growth promotion of this crop, since it increased all growth variables; increasing the total fresh and dry biomass by 93.3 and 96.4 %, respectively.