Publicaciones
2025
1. Gallardo, V., Costa, J., Sepúlveda, M., Cayún, Y., Santander, C., Ponce, E., Bittencourt, J., Arriagada, C., Soto, J., Pedreschi, R., Vicente, V. A., Cornejo, P., and Santos, C. 2025. Lipid Production in Cultivable Filamentous Fungi Isolated from Antarctic Soils: A Comprehensive Study. Microorganisms, 13(3), 504. (WOS. Impact Factor 4.1 Q2). https://doi.org/10.3390/microorganisms13030504
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2. Guillermo Pereira, Diyanira Castillo-Novales, Cristian Salazar, Cristian Atala, and Cesar Arriagada-Escamilla. 2025. Gigaspora roseae and Coriolopsis rigida Fungi Improve Performance of Quillaja saponaria Plants Grown in Sandy Substrate with Added Sewage Sludge. Journal of Fungi 11, no. 1: 2. (WOS. Impact Factor 4.2 Q1). https://doi.org/10.3390/jof11010002
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3. Cesar Arriagada-Escamilla, Javier Ortiz, Nicole Iturra, Javiera Soto and Eduardo Morales. 2025. Jet-Breaking Extrusion of Alginate–Chitosan Capsules for Encapsulation of Plant Growth–Promoting Extremophilic Fungi. Microorganisms 2025,13,1123. (WOS. Impact Factor 4.1 Q2). https://doi.org/ 10.3390/microorganisms13051123
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4. Nicolás Bustamante, Javier Ortiz, Javiera Soto, Nathalia Baptista Dias, Cristian Vega, César Arriagada‐Escamilla. 2025. Evaluating Fungal Metal Tolerance Using MALDI‐TOF MS: A Rapid Alternative to Conventional MIC Methods. Journal of Basic Microbiology. e70064. (WoS Impactados Factor 3.5 Q2). https://doi.org/10.1002/jobm.70064
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Laboratorio de Biorremediación
Departamento de Cs. Forestales
Universidad de La Frontera
Avenida Francisco Salazar 01145
Temuco, Chile
Casilla 54-D
Author Full Names: Victor Gallardo, Jéssica Costa, Marcela Sepúlveda, Excequel Ponce, Juliana Bittencourt, César Arriagada, Vania Aparecida Vicente, Pablo Cornejo, Yasna Cayún, Christian Santander, Javiera Soto, Romina Pedreschi and Cledir Santos
Source Title: MICROORGANISMS
Antarctic soil represents an important reservoir of filamentous fungi (FF) species with the ability to produce novel bioactive lipids. However, the lipid extraction method is still a bottleneck. The objective of the present work was to isolate and identify cultivable FF from Antarctic soils, to assess the most effective methods for fatty acid (FA) extraction,
and to characterise the obtained lipids. A total of 18 fungal strains belonging to the Botrytis, Cladosporium, Cylindrobasidium, Mortierella, Penicillium, Pseudogymnoascus, and Talaromyces genera and the Melanommataceae family were isolated and identified. The Folch, Bligh and Dyer, and Lewis extraction methods were assessed, and methyl esters of FA (FAMEs) were obtained. The Lewis method was the best in recovering FAMEs from fungal biomass. A total of 17 FAs were identified, and their chemical compositions varied depending on fungal species and strain. Oleic, linoleic, stearic, and palmitic acids were predominant for all fungal strains in the three assessed methods. Among the analysed strains, Cylindrobasidium eucalypti, Penicillium miczynskii, P. virgatum, and Pseudogymnoascus pannorum produced high amounts of FA. This suggests that the soils of Antarctica Bay, as well as harbouring known oleaginous fungi, are also an important source of oleaginous filamentous fungi that remain poorly analysed.
DOI: https://doi.org/10.3390/microorganisms13030504
Author Full Names: Guillermo Pereira, Diyanira Castillo-Novales, Cristian Salazar, Cristian Atala, and Cesar Arriagada-Escamilla
The use of living organisms to treat human by-products, such as residual sludge, has gained interest in the last years. Fungi have been used for bioremediation and improving plant performance in contaminated soils. We investigated the impact of the mycorrhizal fungus (MF) Gigaspora roseae and the saprophytic fungus (SF) Coriolopsis rigida on the survival and growth of Quillaja saponaria seedlings cultivated in a sandy substrate supplemented with residual sludge. Q. saponaria is a sclerophyllous tree endemic to Chile, known for its high content of saponins. We inoculated plants with the MF, the SF, and a combination of both (MF + SF). Following inoculation, varying doses of liquid residual sludge equivalent to 0, 75, and 100% of the substrate’s field capacity were applied. After 11 months, we found a positive influence of the utilized microorganisms on the growth of Q. saponaria. Particularly, inoculation with the SF resulted in higher plant growth, mycorrhizal colonization percentage, and higher enzymatic activity, especially after the application of the sludge. This increase was more evident with higher doses of the applied sludge. These results highlight the potential of combined microorganism and residual sludge application as a sustainable strategy for enhancing plant growth and reducing waste.
Source Title: MICROORGANISMS
DOI:https://doi.org/10.3390/jof11010002
Author Full Names: Arriagada-Escamilla, C., Ortiz, J., Iturra, N., Soto, J., & Morales, E.
Source Title: Microorganisms
Drought and metal pollution severely impact plant growth. Root-associated extremophilic fungi can improve plant performance, and their encapsulation improves protection and effectiveness. This study optimized the encapsulation conditions for an extremophilic fungus with plant growth-promoting traits using alginate–chitosan capsules. An endophytic fungus was isolated from the roots of Neltuma chilensis from the Atacama Desert and identified via internal transcribed spacer (ITS) sequencing. Its plant growth promoting traits, including exopolysaccharide, ammonium, siderophore, and indole acetic acid production and phosphorus solubilization, were evaluated. Freeze-dried Penicillium nalgiovense was encapsulated using jet-breaking extrusion, and capsule morphology and fungal survival were assessed via scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM), and viability tests. Using Taguchi’s design, optimal conditions for sphericity (0.914 ±0.002) and mean size (3.232 ±0.087 mm) were achieved with 1% chitosan, a 5 cm distance to the gelation bath, and a 40 Hz vibration frequency. CLSM analysis confirmed the presence of the chitosan outer layer, revealing the capsule’s coating material encapsulating the fungus P. nalgiovense. The encapsulated fungus remained viable across disinfection times, demonstrating effective protection and gradual release. These findings emphasize the need for precise parameter control in fungal encapsulation, providing a basis for developing robust bioinoculants to support plant resilience in
extreme environments.
https://doi.org/10.3390/microorganisms13051123
Author Full Names: Bustamante N, Ortiz J, Soto J, Dias NB, Vega C, Arriagada-Escamilla C.
Source Title: J Basic Microbiol
Metal contamination represents a critical environmental challenge, adversely impacting ecosystems and human health. Microorganisms, including fungi, have developed diverse mechanisms to tolerate and resist metal‐induced stress, making them valuables for bioremediation. This study evaluates the metal tolerance of Absidia glauca, Penicillium bilaiae, and Trichoderma viridescens using minimum inhibitory concentration (MIC) assay and the alternative minimum profile change concentration (MPCC) approach via MALDI‐TOF MS. MIC assay revealed species‐specific tolerances to copper, zinc, and cadmium. A. glauca showed the highest tolerance to copper and cadmium (75 and 9 mg L−1), producing a dry biomass of 0.03 and 0.04 g, respectively. While P. bilaiae exhibited the highest tolerance to zinc (75 mg L−1) producing a dry biomass of 0.06 g. MALDI‐TOF MS provided rapid proteomic information on fungal responses to metals, showing changes in the protein profile as the metal concentration increased. We performed a comparative analysis between the values obtained in the MIC and MPCC, giving a positive correlation in the results of both techniques for Cu, Zn, and Cd (r = 1.00; 0.87 and 0.99 respectively, p < 0.05). In conclusion, MALDI‐TOF MS has proven to be an effective method for analyzing fungal proteomic responses to metal exposure, providing more detailed molecular insights than traditional MIC assays. Future studies should investigate the mechanisms underlying metal resistance, particularly focus on the regulation of specific proteins.
https://doi.org/10.1002/jobm.70064.
Author Full Names: Javiera Soto, Tedy Sanhueza, Javier Ortiz, María de la Luz Mora, Inmaculada Garcia-Romera, César Arriagada
Source Title: Journal of Soil Science and Plant Nutrition
Purpose. This study aimed to isolate and assign at genus level the dark septate endophytes (DSE) that colonize native Ericaceae plants in the Andes Mountains of southern Chile and evaluate their plant growth-promotion traits and their in vitro tolerance to abiotic stress.
Methods. We isolated, identified, and evaluated the characteristics of five DSE, Pezizomycotina sp, Alternaria sp.1, Phialocephala sp., Alternariasp.2, Cladosporium sp. The DSE’s plant growth-promoting capabilities were assessed, encompassing their capacity to produce indoleacetic acid (IAA), phosphate solubilization, ammonia and siderophores. Additionally, their potential to enhance stress tolerance was evaluated through the production of exopolysaccharides (EPS) and ACC deaminase. Moreover, the DSE’s ability to tolerate aluminum and water stress was evaluated.
Results. Alternaria sp.1, Alternaria sp.2 and Cladosporium sp. produce higher concentrations of IAA and ammonium (4.59 mg L-1 and 17.66 µmol mL-1; 9.87 mg L-1 and 24.37 µmol mL-1; 4.11 mg L-1 and 36.28 µmol mL-1, respectively), while Cladosporium sp. was able to solubilize phosphate from iron, aluminum and phytic acid sources. Cladosporium sp. produces the highest concentration of EPS (245 mg L-1). Phialocephala sp. tolerated the highest aluminum concentration (500 mg L-1) and water stress induced by PEG-6000, along with Cladosporiumsp.
Conclusion. We found that the dark septate endophytic fungi isolated from native Andean Ericaceae plants colonizing volcanic deposits in southern Chile possess unique characteristics that enable them to tolerate aluminum and water stress, making them ideal plant growth promoters in stressful environments. They could potentially play a crucial role in adapting plants to challenging environments and contribute to sustainable agriculture practices in this regionhttps://doi.org/10.1007/s42729-024-01898-4
Author Full Names:
Roxana Alvarado, Cesar Arriagada-Escamilla, Javier Ortiz, Reinaldo Campos-Vargas, Pablo Cornejo
Source Title: Microorganisms
This study explores the encapsulation in alginate/bentonite beads of two metal(loid)- resistant bacterial consortia (consortium A: Pseudomonas sp. and Bacillus sp.; consortium B: Pseu- domonas sp. and Bacillus sp.) from the Atacama Desert (northern Chile) and Antarctica, and their influence on physiological traits of Chenopodium quinoa growing in metal(loid)-contaminated soils. The metal(loid) sorption capacity of the consortia was determined. Bacteria were encapsulated using ionic gelation and were inoculated in soil of C. quinoa. The morphological variables, photosynthetic pigments, and lipid peroxidation in plants were evaluated. Consortium A showed a significantly higher biosorption capacity than consortium B, especially for As and Cu. The highest viability of consortia was achieved with matrices A1 (3% alginate and 2% bentonite) and A3 (3% alginate, 2% bentonite and 2.5% LB medium) at a drying temperature of 25 ◦C and storage at 4 ◦C. After 12 months, the highest viability was detected using matrix A1 with a concentration of 106 CFU g−1. Further, a greenhouse experiment using these consortia in C. quinoa plants showed that, 90 days after inoculation, the morphological traits of both consortia improved. Chemical analysis of metal(loid) contents in the leaves indicated that consortium B reduced the absorption of Cu to 32.1 mg kg−1 and that of Mn to 171.9 mg kg−1. Encapsulation resulted in a significant increase in bacterial survival. This highlights the benefits of using encapsulated microbial consortia from extreme environments, stimulating the growth of C. quinoa, especially in soils with metal(loid) levels that can be a serious constraint for plant growth.
https://doi.org/10.3390/microorganisms12102066