Unlocking the Potential of Glutinol: Structural Diversification and Antifungal Activity against Phytopathogenic Fusarium Strains.

Unlike most common pentacyclic plant triterpenes, glutinol has a methyl group at position C-9 and a Δ5 double bond. At the same time, it lacks a methyl at C-10. These features significantly modify its chemical behavior compared to other triterpenes, particularly under oxidative conditions. Although the isolation of glutinol from various plant species has been documented, its chemistry remains largely unexplored. In this study, glutinol was isolated from the bark of Balfourodendron riedelianum as a starting material for top-down strategies of structural diversification, which included ring fusion, oxidation, aromatization, and ring cleavage reactions. Glutinol, together with a library of 22 derivatives, was evaluated for antifungal activity against three phytopathogenic Fusarium strains, F. solani, F. graminearum, and F. tucumaniae. Some of the derivatives displayed antifungal activity; in particular, compound 12, featuring a triazine ring, displayed the best fungicidal properties against F. solani and F. graminearum, while the ring B cleavage product 23 showed the best activity against F. tucumaniae. This study highlights the potential of glutinol as a scaffold for structural diversification, and these results may contribute to the design of novel fungicidal agents against phytopathogenic strains.

Factors influencing fumonisin B1 contamination in maize: insights from two production regions in Costa Rica.

Maize (Zea mays L.) is an important cereal crop worldwide. Contaminated maize kernels pose a significant mycotoxin exposure risk for humans in Latin America. Fumonisins, the most prevalent mycotoxin in maize, typically occur during pre-harvest conditions leading to significant economic losses. Various factors, including weather conditions, may influence this contamination. This study aimed to determine the association between fumonisin B1 (FB1) contamination, prevalence of Fusarium verticillioides, weather conditions and kernel quality in the two primary maize production areas in Costa Rica (Brunca and Chorotega). All maize samples (100%) showed FB1 contamination, with higher concentrations in samples from Brunca region, consistent with the presence of F. verticilliodes. Weather conditions appeared to play an important role in this contamination, since Brunca region had the highest mean temperature and relative humidity after maize silking (R1) and the total monthly rainfall in this region was significantly higher during the last two months of maize cultivation (grain-filling and physiological maturity stages R3 to R6). Interestingly, this study found a negative correlation between grain damage and kernel contamination with FB1 and F. verticillioides. The concentration of mineral nutrients in kernels from both regions was largely similar. Most nutrients in kernels exhibited a negative correlation with FB1, particularly nitrogen. Zinc and phosphorus were the only nutrients in kernels showing a positive correlation with FB1 in samples from the Brunca region. The results highlight elevated levels of FB1 contamination in maize and contribute to a better understanding of pre-harvest factors influencing FB1 contamination in tropical conditions.

Fusarium Keratitis: A Systematic Review (1969 to 2023).

BACKGROUND: Mycotic keratitis (MK) represents a corneal infection, with Fusarium species identified as the leading cause. Fusarium is a genus of filamentous fungi commonly found in soil and plants. While many Fusarium species are harmless, some can cause serious infections in humans and animals, particularly Fusarium keratitis, that can lead to severe ocular infections, prevalent cause of monocular blindness in tropical and subtropical regions of the world. Due to its incidence and importance in ophthalmology, we conducted a systematic analysis of clinical cases to increase our understanding of Fusarium keratitis by gathering clinical and demographic data. METHODS: To conduct an analysis of Fusarium keratitis, we looked through the literature from the databases PubMed, Embase, Lilacs, and Google Scholar and found 99 papers that, between March 1969 and September 2023, corresponded to 163 cases of Fusarium keratitis. RESULTS: Our analysis revealed the Fusarium solani species complex as the predominant isolate, with females disproportionately affected by Fusarium keratitis. Notably, contact lens usage emerged as a significant risk factor, implicated in nearly half of cases. Diagnosis primarily relied on culture, while treatment predominantly involved topical natamycin, amphotericin B, and/or voriconazole. Surprisingly, our findings demonstrated a prevalence of cases originating from the United States, suggesting potential underreporting and underestimation of this mycosis in tropical regions. This shows the imperative for heightened vigilance, particularly in underdeveloped regions with substantial agricultural activity, where Fusarium infections may be more prevalent than currently reported. CONCLUSION: Our study sheds light on the clinical complexities of Fusarium keratitis and emphasizes the need for further research and surveillance to effectively tackle this vision-threatening condition. Furthermore, a timely identification and early initiation of antifungal treatment appear to be as important as the choice of initial treatment itself.

Reference genes for RT-qPCR analysis in Musa acuminata genotypes contrasting in resistance to Fusarium oxysporum f. sp. cubense subtropical race 4.

Banana (Musa spp.) is the most widely consumed fruit globally. Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is a highly threatening disease to banana production. Resistance genes to Foc exist in wild Musa genotypes such as Musa acuminata subsp. burmannicoides var. Calcutta 4. Whilst real-time PCR (RT-qPCR) is appropriate for accurate analysis of gene expression in pathways involved in host defence responses, reference genes with stable expression under specific biotic stress conditions and host tissue types are necessary for normalization of sample variation. In this context, the stability in potential host reference genes ACT1, APT, EF1α, GAPDH, αTUB, RAN, UBIQ1, UBIQ2, ßTUB1, ßTUB3, L2 and ACTA1 was evaluated in total RNA samples from root tissues in Calcutta 4 (resistant) and Musa sp. cultivar Prata-anã (susceptible) extracted during interaction with Foc subtropical race 4 (STR4). Expression stability was calculated using the algorithms geNorm, NormFinder and BestKeeper. ßTUB3 and L2 were identified as the most stable in Calcutta 4, with ACTA1 and GAPDH the most stable in Prata-anã. These reference genes for analysis of gene expression modulation in the Musa-Foc STR4 pathosystem are fundamental for advancing understanding of host defence responses to this important pathogen.

Increased Dissemination of Aflatoxin- and Zearalenone-Producing Aspergillus spp. and Fusarium spp. during Wet Season via Houseflies on Dairy Farms in Aguascalientes, Mexico.

Crops contamination with aflatoxins (AFs) and zearalenone (ZEA) threaten human and animal health; these mycotoxins are produced by several species of Aspergillus and Fusarium. The objective was to evaluate under field conditions the influence of the wet season on the dissemination of AF- and ZEA-producing fungi via houseflies collected from dairy farms. Ten dairy farms distributed in the semi-arid Central Mexican Plateau were selected. Flies were collected in wet and dry seasons at seven points on each farm using entomological traps. Fungi were isolated from fly carcasses via direct seeding with serial dilutions and wet chamber methods. The production of AFs and ZEA from pure isolates was quantified using indirect competitive ELISA. A total of 693 Aspergillus spp. and 1274 Fusarium spp. isolates were obtained, of which 58.6% produced AFs and 50.0% produced ZEA (491 ± 122; 2521 ± 1295 µg/kg). Houseflies and both fungal genera were invariably present, but compared to the dry season, there was a higher abundance of flies as well as AF- and ZEA-producing fungi in the wet season (p < 0.001; 45.3/231 flies/trap; 8.6/29.6% contaminated flies). These results suggest that rainy-weather conditions on dairy farms increase the spread of AF- and ZEA-producing Aspergillus spp. and Fusarium spp. through houseflies and the incorporation of their mycotoxins into the food chain.

Response of Fusarium oxysporum soil isolate to amphotericin B and fluconazole at the proteomic level.

Fusarium oxysporum is a cross-kingdom pathogen that infects humans, animals, and plants. The primary concern regarding this genus revolves around its resistance profile to multiple classes of antifungals, particularly azoles. However, the resistance mechanism employed by Fusarium spp. is not fully understood, thus necessitating further studies to enhance our understanding and to guide future research towards identifying new drug targets. Here, we employed an untargeted proteomic approach to assess the differentially expressed proteins in a soil isolate of Fusarium oxysporum URM7401 cultivated in the presence of amphotericin B and fluconazole. In response to antifungals, URM7401 activated diverse interconnected pathways, such as proteins involved in oxidative stress response, proteolysis, and lipid metabolism. Efflux proteins, antioxidative enzymes and M35 metallopeptidase were highly expressed under amphotericin B exposure. Antioxidant proteins acting on toxic lipids, along with proteins involved in lipid metabolism, were expressed during fluconazole exposure. In summary, this work describes the protein profile of a resistant Fusarium oxysporum soil isolate exposed to medical antifungals, paving the way for further targeted research and discovering new drug targets.

Structural and Functional Characterization of New Lipid Transfer Proteins with Chitin-Binding Properties: Insights from Protein Structure Prediction, Molecular Docking, and Antifungal Activity.

Faced with the emergence of multiresistant microorganisms that affect human health, microbial agents have become a serious global threat, affecting human health and plant crops. Antimicrobial peptides have attracted significant attention in research for the development of new microbial control agents. This work's goal was the structural characterization and analysis of antifungal activity of chitin-binding peptides from Capsicum baccatum and Capsicum frutescens seeds on the growth of Candida and Fusarium species. Proteins were initially submitted to extraction in phosphate buffer pH 5.4 and subjected to chitin column chromatography. Posteriorly, two fractions were obtained for each species, Cb-F1 and Cf-F1 and Cb-F2 and Cf-F2, respectively. The Cb-F1 (C. baccatum) and Cf-F1 (C. frutescens) fractions did not bind to the chitin column. The electrophoresis results obtained after chromatography showed two major protein bands between 3.4 and 14.2 kDa for Cb-F2. For Cf-F2, three major bands were identified between 6.5 and 14.2 kDa. One band from each species was subjected to mass spectrometry, and both bands showed similarity to nonspecific lipid transfer protein. Candida albicans and Candida tropicalis had their growth inhibited by Cb-F2. Cf-F2 inhibited the development of C. albicans but did not inhibit the growth of C. tropicalis. Both fractions were unable to inhibit the growth of Fusarium species. The toxicity of the fractions was tested in vivo on Galleria mellonella larvae, and both showed a low toxicity rate at high concentrations. As a result, the fractions have enormous promise for the creation of novel antifungal compounds.

Wheat debranning: effects on mycotoxins, phenolic content, and antioxidant activity.

The debranning process, at an industrial scale, was applied to grains of two wheat cultivars to determine its effect on Fusarium mycotoxin content and antioxidant activity. Grain samples from the BRS Marcante and BRS Reponte wheat cultivars, naturally contaminated by Fusarium, were used in the study. The dry wheat samples were processed on the polisher once or twice and evaluated by hardness index, chemical composition (moisture, protein, and ash), deoxynivalenol (DON) and zearalenone (ZON) levels, phenolic content, and antioxidant activity. In the BRS Marcante cultivar, the debranning process only slightly reduced the DON and ZON contents in whole-wheat flours compared with the previous cleaning treatment (no-debranned). In the BRS Reponte cultivar, the DON concentration decreased by 36% at a debranning ratio of 5%, obtained by polishing, compared with prior cleaning treatment (no-debranned). In addition, the polishing reduced the ZON level by 56% compared with the cleaned wheat. The debranning process did not reduce the antioxidant capacity. Therefore, debranning is a suitable technology to obtain safer and healthier food by minimizing the mycotoxin content and retaining antioxidant capacity.

Cutaneous fusarium disease and leukaemias: A systematic review.

The present study analyses the clinical characteristics of patients diagnosed with cutaneous fusarium through a systematic review of cases reported in literature. A total of 39 cases were included, of which 53% were men, 30% were women, and in 17% the sex was not specified. The age ranged from 5 to 85 years. Most cases were reported in Brazil, followed by Japan and United States of America. The most common agent was Fusarium solani, in 37.5% of the patients. Most of the affected individuals had acute myeloid leukaemia and some of the predisposing factors, which included induction chemotherapy, febrile neutropenia, and bone marrow transplantation. The clinical topography of the lesions was located in 27.5% and disseminated in 72.5%, with the most observed clinical feature outstanding the presence of papules and nodules with central necrosis in 47% of the cases. Longer survival was demonstrated in those treated with more than three antifungals. It is concluded that cutaneous fusarium is a complex and challenging clinical entity, infection in patients with leukaemias underscores the need for thorough care to decrease morbidity and mortality.

Agave Wilt Susceptibility by Reduction of Free Hexoses in Root Tissue of Agave tequilana Weber var. azul Commercial Plants in the Fructan Accumulation Process.

Agave tequilana stems store fructan polymers, the main carbon source for tequila production. This crop takes six or more years for industrial maturity. In conducive conditions, agave wilt disease increases the incidence of dead plants after the fourth year. Plant susceptibility induced for limited photosynthates for defense is recognized in many crops and is known as "sink-induced loss of resistance". To establish whether A. tequilana is more prone to agave wilt as it ages, because the reduction of water-soluble carbohydrates in roots, as a consequence of greater assembly of highly polymerized fructans, were quantified roots sucrose, fructose, and glucose, as well as fructans in stems of agave plants of different ages. The damage induced by inoculation with Fusarium solani or F. oxysporum in the roots or xylem bundles, respectively, was recorded. As the agave plant accumulated fructans in the stem as the main sink, the amount of these hexoses diminished in the roots of older plants, and root rot severity increased when plants were inoculated with F. solani, as evidence of more susceptibility. This knowledge could help to structure disease management that reduces the dispersion of agave wilt, dead plants, and economic losses at the end of agave's long crop cycle.

Antifungal effect and some properties of cell-free supernatants of two Bacillus subtilis isolates against Fusarium verticillioides.

Fusarium verticillioides causes significant decrease in corn yield and quality, and produces fumonisins, which represent a serious risk to human and animal health. Bacillus species can be an effective and environmentally friendly alternative for F. verticillioides biological control. In this study, some properties of cell-free supernatants (CFSs) of two Bacillus spp. identified as Bacillus subtilis (NT1, NT2) as well as the antifungal effect against F. verticillioides 97L were evaluated. B. subtilis NT1 and NT2 were isolated from commercially available fermented whole soybeans (Natto). Antifungal activity was observed in both CFSs of B. subtilis isolates (50-59 mm) obtained by co-culture suggesting that antifungal compound production depends on interaction between bacteria and fungi. Cell-free supernatants from the two B. subtilis isolates inhibited mycelial growth (77%-94%) and conidial germination (22%-74%) of F. verticillioides 97L. In addition, CFSs caused significant morphological changes such as distorted and collapsed hyphae with wrinkled surfaces and the presence of a large amount of extracellular material compared to the control without CFSs. Both B. subtilis isolates (NT1 and NT2) produced extracellular proteases, biosurfactants and polar low molecular weight compounds that probably act synergistically and may contribute to the antifungal activity. Antifungal compounds showed heat and pH stability and resistance to proteolytic enzymes. Furthermore, antifungal compounds showed high polarity, high affinity to water and a molecular weight less than 10 kDa. These results indicated that the two B. subtilis (NT1 and NT2) have potential as biocontrol agents for F. verticillioides.

Utilization of Fusarium Solani lipase for enrichment of polyunsaturated Omega-3 fatty acids.

Omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), offer numerous health benefits. Enriching these fatty acids in fish oil using cost-effective methods, like lipase application, has been studied extensively. This research aimed to investigate F. solani as a potential lipase producer and compare its efficacy in enhancing polyunsaturated omega-3 fatty acids with commercial lipases. Submerged fermentation with coconut oil yielded Lipase F2, showing remarkable activity (215.68 U/mL). Lipase F2 remained stable at pH 8.0 (activity: 93.84 U/mL) and active between 35 and 70 °C, with optimal stability at 35 °C. It exhibited resistance to various surfactants and ions, showing no cytotoxic activity in vitro, crucial for its application in the food and pharmaceutical industries. Lipase F2 efficiently enriched EPA and DHA in fish oil, reaching 22.1 mol% DHA and 23.8 mol% EPA. These results underscore the economic viability and efficacy of Lipase F2, a partially purified enzyme obtained using low-cost techniques, demonstrating remarkable stability and resistance to diverse conditions. Its performance was comparable to highly pure commercially available enzymes in omega-3 production. These findings highlight the potential of F. solani as a promising lipase source, offering opportunities for economically producing omega-3 and advancing biotechnological applications in the food and supplements industry.

Unraveling the antifungal composition of bitter orange decoction against the melon pathogen Fusarium jinanense.

Bitter orange (Citrus aurantium) is an important source of essential oils with high antimicrobial activities, however the composition and antifungal potential of the decoction peels is little explored. This study assessed the peel decoction's chemical profile at the secondary metabolism level and its antifungal activity against the melon phytopathogen Fusarium jinanense. The decoction's antifungal potential was investigated using a bioassay-guided fractionation approach based on Solid-Phase Extraction (SPE) and LC-HRMS/MS analysis. Coumarins and flavones were the most abundant classes of compounds in the high-value fractions responsible for up to 61% of the mycelial inhibition of F. jinanense. Overall, this study has presented for the first time the chemical composition, the antifungal potential of the decoction of C. aurantium peels and the compounds associated with these results. This strategy can guide the exploration of under-explored food sources and add value to compounds or fractions enriched with bioactive compounds.

Fusarioid keratitis and other superficial infections: A 10-years prospective study from Northeastern Brazil.

BACKGROUND: Fusarium and allied genera (fusarioid) species are common colonizers of roots and aerial plant parts, or act as phytopathogens in forestry and horticultural or grain crops. However, they can also cause a wide range of infections in humans, including onychomycosis, cutaneous and invasive infections. Fusarioid keratitis is characterized by an infection of the cornea with a suppurative and ulcerative appearance, which may cause damage to vision and permanent blindness. The aim of the present study was to investigate the prevalence of fusarioid species, biofilm formation and antifungal susceptibility profiling of clinical isolates recovered from patients with keratitis and dermatomycoses. METHODOLOGY/PRINCIPAL FINDINGS: The study was performed between March, 2012-December, 2022. Demographic, clinical and epidemiological data of patients were also collected. In the present study, most of the patients with keratitis were male (74%), had a median age of 42 years old, worked with plant material or debris and 26% of them reported eye trauma. Regarding dermatomycosis, most of patients were female and exhibited toenail lesions. Forty-seven isolates belonged to the genus Neocosmospora (78.33%), nine to the Fusarium fujikuroi (15%) and four to the Fusarium oxysporum (6.66%) species complexes. Several strains were moderate biofilm producers, specifically among Fusarium annulatum. Most strains showed increased MICs to amphotericin B and ketoconazole and low MICs to itraconazole. MICs ranged from 0.25 to 16 µg/mL for amphotericin B, 0.0625 to >16 µg/mL for ketoconazole and 0.125 to 8 for itraconazole. CONCLUSIONS/SIGNIFICANCE: It is possible to conclude that fusarioid keratitis in Northeastern Brazil is an important and neglected disease, given the high number of cases, increased need for keratoplasty and poor outcome of the disease.

Evaluation of ALA-capped silver, copper, and silver-copper nanoparticles for controlling fungal plant pathogens.

Phytopathogenic fungi significantly threaten global food security, causing substantial yield and quality losses. Sustainable solutions are urgently needed to combat these agricultural pathogens. This study explored the potential of silver (Ag), copper (Cu), and combined Ag/Cu nanoparticles capped with aminolevulinic acid (ALA) as antifungal agents. The nanoparticles (ALAAg, ALACu, and ALAAgCu) were synthesized via photoreduction and characterized using various techniques (UV-Vis, TEM, XRD, Zeta potential). Their antifungal activity against four key plant pathogens (Alternaria grandis, Colletotrichum truncatum, Corynespora cassiicola, and Fusarium oxysporum) was evaluated using poisoned food techniques. Notably, ALAAgCuNPs demonstrated superior antifungal activity compared to a conventional fungicide against two fungal strains. Even at lower concentrations, ALAAgCuNPs exhibited fungistatic effects comparable to those of the control. These promising results suggest the potential of ALAAgCu NPs as a broad-spectrum, potentially eco-friendly alternative for fungal control in plants and seeds. This approach is crucial for ensuring crop health, harvest quality, and food safety.

Fusarium keratitis in a Brazilian tropical semi-arid area: Clinical-epidemiological features, molecular identification and antifungal susceptibility.

BACKGROUND: Fungal keratitis is a severe eye infection that can result in blindness and visual impairment, particularly in developing countries. Fusarium spp. are the primary causative agents of this condition. Diagnosis of Fusarium keratitis (FK) is challenging, and delayed treatment can lead to serious complications. However, there is limited epidemiological data on FK, especially in tropical areas. OBJECTIVES: This study aimed to describe the clinical, laboratorial and epidemiological characteristics of FK in a tropical semi-arid region of Brazil. PATIENTS/METHODS: Adult patients with laboratory-confirmed FK diagnosed between October 2019 and March 2022 were evaluated. Fusarium isolates were characterized at molecular level and evaluated regarding antifungal susceptibility. RESULTS: A total of 226 clinical samples from patients suspected of keratitis were evaluated; fungal growth was detected in 50 samples (22.12%); out of which 42 were suggestive of Fusarium spp. (84%). Molecular analysis of a randomly selected set of 27 isolates identified F. solani species complex (n = 14); F. fujikuroi sensu lato (n = 6) and F. dimerum sensu lato (n = 7); a total of 10 haplotypes were identified among the strains. All but one Fusarium strains were inhibited by amphotericin B, natamycin and fluconazole. Most patients were male (71.42%; 30 out of 42), aged from 27 to 73 years old. Trauma was the most important risk factor for FK (40.47%; 17 out of 42). Patients were treated with antifungals, corticoids and antibiotics; keratoplasty and eye enucleation were also performed. CONCLUSIONS: The study provided insights into the characteristics of FK in tropical regions and emphasized the importance of enhanced surveillance and management strategies.

Genetic diversity of the banana Fusarium wilt pathogen in Cuba and across Latin America and the Caribbean.

Fusarium wilt of bananas (FWB) is a severe plant disease that leads to substantial losses in banana production worldwide. It remains a major concern for Cuban banana cultivation. The disease is caused by members of the soil-borne Fusarium oxysporum species complex. However, the genetic diversity among Fusarium species infecting bananas in Cuba has remained largely unexplored. In our comprehensive survey, we examined symptomatic banana plants across all production zones in the country, collecting 170 Fusarium isolates. Leveraging genotyping-by-sequencing and whole-genome comparisons, we investigated the genetic diversity within these isolates and compared it with a global Fusarium panel. Notably, typical FWB symptoms were observed in Bluggoe cooking bananas and Pisang Awak subgroups across 14 provinces. Our phylogenetic analysis revealed that F. purpurascens, F. phialophorum, and F. tardichlamydosporum are responsible for FWB in Cuba, with F. tardichlamydosporum dominating the population. Furthermore, we identified between five and seven distinct genetic clusters, with F. tardichlamydosporum isolates forming at least two subgroups. This finding underscores the high genetic diversity of Fusarium spp. contributing to FWB in the Americas. Our study sheds light on the population genetic structure and diversity of the FWB pathogen in Cuba and the broader Latin American and Caribbean regions.

Antifungal and Antivirulence Activity of Vanillin and Tannic Acid Against Aspergillus fumigatus and Fusarium solani.

Aspergillus fumigatus and Fusarium solani infections have become severe health threat; both pathogens are considered a priority due to the increasing emergence of antifungal-resistant strains and high mortality rates. Therefore, the discovery of new therapeutic strategies has become crucial. In this study, we evaluated the antifungal and antivirulence effects of vanillin and tannic acid against Aspergillus fumigatus and Fusarium solani. The minimum inhibitory concentrations of the compounds were determined by the microdilution method in RPMI broth in 96-well microplates according to CLSI. Conidial germination, protease production, biofilm formation, and in vivo therapeutic efficacy assays were performed. The results demonstrated that vanillin and tannic acid had antifungal activity against Aspergillus fumigatus, while tannic acid only exhibited antifungal activity against Fusarium solani. We found that vanillin and tannic acid inhibited conidial germination and secreted protease production and biofilm formation of the fungal pathogens using sub-inhibitory concentrations. Besides, vanillin and tannic acid altered the fungal membrane permeability, and both compounds showed therapeutic effect against aspergillosis and fusariosis in an infection model in Galleria mellonella larvae. Our results highlight the antivirulence effect of vanillin and tannic acid against priority pathogenic fungi as a possible therapeutic alternative for human fungal infections.

Unveiling the Biocontrol Potential of Rhizoplane Bacillus Species against Sugarcane Fusarium Wilt through Biochemical and Molecular Analysis.

BACKGROUND: Biocontrol is regarded as a viable alternate technique for managing sugarcane wilt disease caused by Fusarium sacchari. Many fungal antagonists against F. sacchari, have been reported, but the potential of bacterial antagonists was explored to a limited extent, so the present study evaluated the antagonistic potential of rhizoplane Bacillus species and their mode of action. RESULTS: A total of twenty Bacillus isolates from the rhizoplane of commercially grown sugarcane varieties were isolated. The potential isolate SRB2 had shown inhibition of 52.30, 33.33, & 44.44% and SRB20 of 35.00, 33.15, & 36.85% in direct, indirect, and remote confrontation respectively against F. sacchari. The effective strains were identified as Bacillus inaquosorum strain SRB2 and B. vallismortis strain SRB20, by PCR amplification of 16S-23S intergenic region. The biochemical studies on various direct and indirect biocontrol mechanisms revealed the production of IAA, Protease, Cellulase, Siderophores, and P solubilization. The molecular analysis revealed the presence of antimicrobial peptides biosynthetic genes like fenD (Fengycin), bmyB (Bacyllomicin) ituC (Iturin) and spaS (Subtilin) which provided a competitive edge to these isolates compared to other Bacillus strains. Under greenhouse experiments, the sett bacterization with SRB2, significantly (P < 0.001) reduced the seedling mortality by > 70% followed by SRB20 in F. sacchari inoculated pots. CONCLUSION: The study revealed that the isolates B. inaquosorum SRB2 and B. vallismortis SRB20 can be used as potential bioagents against sugarcane Fusarium wilt.

Effectiveness of Bacillus subtilis ANT01 and Rhizobium sp. 11B on the control of fusarium wilt in pineapple (Ananas comosus).

Pineapple (Ananas comosus) is commonly infected by Fusarium oxysporum, causal agent of the fusarium wilt disease. Conventionally, growers use synthetic fungicides to control the disease, which lead to environmental pollution, hazardous effects on non-target organisms and risks on human health. The aim of this work was to assess the effectiveness of Bacillus subtilis ANT01 and Rhizobium sp. 11B to control fusarium wilt on pineapple plants. Four treatments derived from a complete factorial design were tested under field conditions. Treatments composed of B. subtilis ANT01 and the combination B. subtilis ANT01-Rhizobium sp. 11B decreased disease severity by 94.4% and 86.1%, respectively. On the other hand, the treatment prepared with Rhizobium sp. 11B alone showed a reduction of 75.0%. Size of leaves and nutritional condition (SPAD units) of the biocontrol agents-treated plants showed no statistical differences. Moreover, B. subtilis ANT01 decreased by 46% the initial soil population of F. oxysporum, while Rhizobium sp. 11B, B. subtilis ANT01 plus Rhizobium sp. 11B and control, showed a population reduction of 12.5%, 24.2% and 23.0%, respectively. These results make evident the potential of B. subtilis ANT01 as biocontrol agent of the pathogen under field conditions.