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Dr. Jorquera is graduated from Osaka University of Japan with formation in microbial ecology and environmental microbiology. Currently, Dr. Jorquera act as head at the Applied Microbial Ecology Laboratory (EMALAB) from Universidad de La Frontera. The mission of EMALAB is contribute to our knowledge on the abundance, composition and role of bacterial communities present in agro and extreme ecosystems of Chile. Since 2006, the investigations performed by EMALAB have been financed by 26 projects, with both Chilean and international funds, resulting in 40 articles published in international journals during last 5 years. The investigations develop at the EMALAB are also characterized by an active collaboration with microbiologists from Japan, USA, Austria, China, Germany, Australia, Italy, Canada and New Zealand. In addition, Dr. Jorquera have been responsible of 14 courses as well as supervision of 25 under-graduate and post-graduate thesis.
Use of compost is a common agricultural practice. It improves soil fertility by adding nutrients and plant growth promoting (PGP) microorganisms. The role of bacterial-fungal interactions for compost-driven fertilization, however, is still poorly understood. In this study, we investigated whether putative PGP bacteria associate to and disperse along mycelia of fungal isolates. A ‘Fungal highway column system’ was used to isolate and characterize fungal—bacterial couples derived from commercial compost (C), non-composted bulk soil (BS) and rhizosphere soil with compost application (RSC). Bacterial-fungal couples were identified by 16S and 18S rRNA gene sequencing and isolated bacteria were tested for representative PGP traits. Couples of fungi and associated migrator bacteria were isolated from C and RSC only. They included the fungal genera Aspergillus, Mucor, Ulocladium, Rhizopus and Syncephalastrum, and the bacterial genera Rhodococcus, Bacillus, Pseudomonas, Agrobacterium, Glutamicibacter and Microbacterium. Many of migrator bacteria in RSC and C showed PGP traits (e.g., tryptophane—induced auxin synthesis or phytate mineralizing activity) suggesting that fungi contained in C and RSC allow for dispersal of putative PGP bacteria. Next to being provider of nutrients, compost may therefore be source for PGP bacteria and fungal mycelia serving as networks for their efficient dispersal.
Susett González-González; Marcia Astorga-Eló; Marco Campos; Lukas Wick; Jacquelinne Acuña; Milko Jorquera. Compost Fungi Allow for Effective Dispersal of Putative PGP Bacteria. Agronomy 2021, 11, 1567 .
AMA StyleSusett González-González, Marcia Astorga-Eló, Marco Campos, Lukas Wick, Jacquelinne Acuña, Milko Jorquera. Compost Fungi Allow for Effective Dispersal of Putative PGP Bacteria. Agronomy. 2021; 11 (8):1567.
Chicago/Turabian StyleSusett González-González; Marcia Astorga-Eló; Marco Campos; Lukas Wick; Jacquelinne Acuña; Milko Jorquera. 2021. "Compost Fungi Allow for Effective Dispersal of Putative PGP Bacteria." Agronomy 11, no. 8: 1567.
Tomato (Solanum lycopersicum L.) is an important vegetable cultivated around the world. Under field conditions, tomato can be negatively affected by water scarcity in arid and semiarid regions. The application of native plant growth-promoting rhizobacteria (PGPR) isolated from arid environments has been proposed as an inoculant to mitigate abiotic stresses in plants. In this study, we evaluated rhizobacteria from Cistanthe longiscapa (syn Calandrinia litoralis and Calandrinia longiscapa), a representative native plant of flowering desert (FD) events (Atacama Desert, Chile), to determine their ability to reduce water scarcity stress on tomato seedlings. The isolated bacterial strains were characterized with respect to their PGPR traits, including P solubilization, 1-aminocyclopropane-1-carboxylate deaminase activity, and tryptophan-induced auxin and exopolysaccharide production. Three PGPR consortia were formulated with isolated Bacillus strains and then applied to tomato seeds, and then, the seedlings were exposed to different levels of water limitations. In general, tomato seeds and seedlings inoculated with the PGPR consortia presented significantly (P ≤ 0.05) greater plant growth (48 to 60 cm of height and 171 to 214 g of weight) and recovery rates (88 to 100%) compared with those without inoculation (37 to 51 cm of height; 146 to 197 g of fresh weight; 54 to 92% of recovery) after exposure to a lack of irrigation over different time intervals (24, 72 and 120 h) before transplantation. Our results revealed the effectiveness of the formulated PGPR consortia from FD to improve the performance of inoculated seeds and seedlings subjected to water scarcity; thus, the use of these consortia can represent an alternative approach for farmers facing drought events and water scarcity associated with climate change in semiarid and arid regions worldwide.
Marcia Astorga-Eló; Susett Gonzalez; Jacquelinne J. Acuña; Michael J. Sadowsky; Milko A. Jorquera. Rhizobacteria from ‘flowering desert’ events contribute to the mitigation of water scarcity stress during tomato seedling germination and growth. Scientific Reports 2021, 11, 1 -12.
AMA StyleMarcia Astorga-Eló, Susett Gonzalez, Jacquelinne J. Acuña, Michael J. Sadowsky, Milko A. Jorquera. Rhizobacteria from ‘flowering desert’ events contribute to the mitigation of water scarcity stress during tomato seedling germination and growth. Scientific Reports. 2021; 11 (1):1-12.
Chicago/Turabian StyleMarcia Astorga-Eló; Susett Gonzalez; Jacquelinne J. Acuña; Michael J. Sadowsky; Milko A. Jorquera. 2021. "Rhizobacteria from ‘flowering desert’ events contribute to the mitigation of water scarcity stress during tomato seedling germination and growth." Scientific Reports 11, no. 1: 1-12.
Azospirillum-based plant and soil inoculants are widely used in agriculture. The inoculated Azospirillum strains are commonly tracked by both culture-dependent and culture-independent methods, which are time-consuming or expensive. In this context, clustered regularly interspaced short palindromic repeats (CRISPR) loci structure is unique in the bacterial genome, including some Azospirillum species. Here, we investigated the use of CRISPR loci to track specific Azospirillum strains in soils systems by PCR. Primer sets for Azospirillum sp. strain B510 were designed and evaluated by colony and endpoint PCR. The CRISPRloci-PCR approach was standardized for Azospirillum sp. strain B510, and its specificity was observed by testing against 9 different Azospirillum strains, and 38 strains of diverse bacterial genera isolated from wheat plants. The CRISPRloci-PCR approach was validated in assays with substrate and wheat seedlings. Azospirillum sp. strain B510 was detected after of two weeks of inoculation in both sterile and nonsterile substrates as well as rhizosphere grown in sterile substrate. The CRISPRloci-PCR approach was found to be a useful molecular tool for specific tracking of Azospirillum at the strain level. This technique can be easily adapted to other microbial inoculants carrying CRISPR loci and can be used to complement other microbiological techniques.
Joaquin Rilling; Fumito Maruyama; Michael Sadowsky; Jacquelinne Acuña; Milko Jorquera. CRISPR loci-PCR as Tool for Tracking Azospirillum sp. Strain B510. Microorganisms 2021, 9, 1351 .
AMA StyleJoaquin Rilling, Fumito Maruyama, Michael Sadowsky, Jacquelinne Acuña, Milko Jorquera. CRISPR loci-PCR as Tool for Tracking Azospirillum sp. Strain B510. Microorganisms. 2021; 9 (7):1351.
Chicago/Turabian StyleJoaquin Rilling; Fumito Maruyama; Michael Sadowsky; Jacquelinne Acuña; Milko Jorquera. 2021. "CRISPR loci-PCR as Tool for Tracking Azospirillum sp. Strain B510." Microorganisms 9, no. 7: 1351.
Microbiota associated with bivalves have drawn considerable attention because studies have suggested their relevance to the fitness and growth of marine bivalves. Although the mussel Choromytilus chorus is a valuable resource for Chilean aquaculture and fisheries, its microbiota is still unknown. In this study, the composition and predicted functions of the bacterial community in tissues of C. chorus specimens grown in an estuary (Nehuentue) and a bay (Hueihue) were investigated. Using 16S rRNA genes as targets, the bacterial abundance in tissues was estimated by quantitative PCR and sequenced via Illumina MiSeq. The abundances of bacteria ranged from 103 to 105 copies of 16S rRNA genes g−1 tissue. In the Nehuentue estuary, the bacterial communities in the tissues were dominated by the Tenericutes phylum, whereas the Tenericutes and Proteobacteria phyla dominated in mussels from Hueihue Bay. Higher numbers of operational taxonomic units (OTUs) were observed in tissues from the Nehuentue Estuary than in those from Hueihue Bay. Differences in bacterial community compositions in tissues between both locations were confirmed by nonmetric multidimensional scaling (nMDS) and Venn diagram analysis. In addition, linear discriminant analysis effect size (LEfSe) revealed that the Mollicutes class and Actynomycetales order were key phylotypes in tissues from the Nehuentue Estuary and Hueihue Bay, respectively. Our analysis also predicted a high abundance of sequences assigned to heterotrophy; however, relatively high functional diversity was also found in tissues from Hueihue Bay. This work represents our first attempt to elucidate the C. chorus microbiota in contrasting Chilean aquatic environments.
Tamara Valenzuela; Joaquin Rilling; Giovanni Larama; Jacquelinne Acuña; Marco Campos; Nitza Inostroza; Macarena Araya; Katherine Altamirano; So Fujiyoshi; Kyoko Yarimizu; Fumito Maruyama; Milko Jorquera. 16S rRNA–Based Analysis Reveals Differences in the Bacterial Community Present in Tissues of Choromytilus chorus (Mytilidae, Bivalvia) Grown in an Estuary and a Bay in Southern Chile. Diversity 2021, 13, 209 .
AMA StyleTamara Valenzuela, Joaquin Rilling, Giovanni Larama, Jacquelinne Acuña, Marco Campos, Nitza Inostroza, Macarena Araya, Katherine Altamirano, So Fujiyoshi, Kyoko Yarimizu, Fumito Maruyama, Milko Jorquera. 16S rRNA–Based Analysis Reveals Differences in the Bacterial Community Present in Tissues of Choromytilus chorus (Mytilidae, Bivalvia) Grown in an Estuary and a Bay in Southern Chile. Diversity. 2021; 13 (5):209.
Chicago/Turabian StyleTamara Valenzuela; Joaquin Rilling; Giovanni Larama; Jacquelinne Acuña; Marco Campos; Nitza Inostroza; Macarena Araya; Katherine Altamirano; So Fujiyoshi; Kyoko Yarimizu; Fumito Maruyama; Milko Jorquera. 2021. "16S rRNA–Based Analysis Reveals Differences in the Bacterial Community Present in Tissues of Choromytilus chorus (Mytilidae, Bivalvia) Grown in an Estuary and a Bay in Southern Chile." Diversity 13, no. 5: 209.
Forest wetlands are biodiversity hotspots that perform functions of vital ecological importance, but they are among the world's most threatened ecosystems. Due to their high diversity of habitats and species, the study of their benthic macroinvertebrate communities is challenging, and there is no consensus on which sampling methods allow a better representation of these communities. Here we compared the performance of 3 sampling methods (hand net, corer and litterbags) in 2 temporary and 3 permanent forested wetlands in southern Chile, which were bimonthly sampled throughout a year, with 108 samples per wetland. Our results indicated that the greatest abundance and diversity were collected with the hand net, followed by the litterbags and the corer. The composition of communities collected by the hand net and litterbags were more similar between them than that of communities collected by the corer (where Chironomidae and Oligochaeta were common). We suggest that the combined use of the hand net and corer could provide a good representation of macroinvertebrate communities in forest wetlands, as they would allow recording most of the diversity, including taxa that are both sensitive and tolerant to stressors.
Francisco Correa-Araneda; Daniela Núñez; Ma Elisa Díaz; Francisco Gómez-Capponi; Ricardo Figueroa; Jaquelinne Acuña; Luz Boyero; Carlos Esse. Comparison of sampling methods for benthic macroinvertebrates in forested wetlands. Ecological Indicators 2021, 125, 107551 .
AMA StyleFrancisco Correa-Araneda, Daniela Núñez, Ma Elisa Díaz, Francisco Gómez-Capponi, Ricardo Figueroa, Jaquelinne Acuña, Luz Boyero, Carlos Esse. Comparison of sampling methods for benthic macroinvertebrates in forested wetlands. Ecological Indicators. 2021; 125 ():107551.
Chicago/Turabian StyleFrancisco Correa-Araneda; Daniela Núñez; Ma Elisa Díaz; Francisco Gómez-Capponi; Ricardo Figueroa; Jaquelinne Acuña; Luz Boyero; Carlos Esse. 2021. "Comparison of sampling methods for benthic macroinvertebrates in forested wetlands." Ecological Indicators 125, no. : 107551.
Cold stress decreases the growth and productivity of agricultural crops. Psychrotolerant plant growth-promoting bacteria (PGPB) may protect and promote plant growth at low temperatures. The aims of this study were to isolate and characterize psychrotolerant PGPB from wild flora of Andes Mountains and Patagonia of Chile and to formulate PGPB consortia. Psychrotolerant strains were isolated from 11 wild plants (rhizosphere and phyllosphere) during winter of 2015. For the first time, bacteria associated with Calycera, Orites, and Chusquea plant genera were reported. More than 50% of the 130 isolates showed ≥33% bacterial cell survival at temperatures below zero. Seventy strains of Pseudomonas, Curtobacterium, Janthinobacterium, Stenotrophomonas, Serratia, Brevundimonas, Xanthomonas, Frondihabitans, Arthrobacter, Pseudarthrobacter, Paenarthrobacter, Brachybacterium, Clavibacter, Sporosarcina, Bacillus, Solibacillus, Flavobacterium, and Pedobacter genera were identified by 16S rRNA gene sequence analyses. Ten strains were selected based on psychrotolerance, auxin production, phosphate solubilization, presence of nifH (nitrogenase reductase) and acdS (1-aminocyclopropane-1-carboxylate (ACC) deaminase) genes, and anti-phytopathogenic activities. Two of the three bacterial consortia formulated promoted tomato plant growth under normal and cold stress conditions. The bacterial consortium composed of Pseudomonas sp. TmR5a & Curtobacterium sp. BmP22c that possesses ACC deaminase and ice recrystallization inhibition activities is a promising candidate for future cold stress studies.
Paulina Vega-Celedón; Guillermo Bravo; Alexis Velásquez; Fernanda Cid; Miryam Valenzuela; Ingrid Ramírez; Ingrid-Nicole Vasconez; Inaudis Álvarez; Milko Jorquera; Michael Seeger. Microbial Diversity of Psychrotolerant Bacteria Isolated from Wild Flora of Andes Mountains and Patagonia of Chile towards the Selection of Plant Growth-Promoting Bacterial Consortia to Alleviate Cold Stress in Plants. Microorganisms 2021, 9, 538 .
AMA StylePaulina Vega-Celedón, Guillermo Bravo, Alexis Velásquez, Fernanda Cid, Miryam Valenzuela, Ingrid Ramírez, Ingrid-Nicole Vasconez, Inaudis Álvarez, Milko Jorquera, Michael Seeger. Microbial Diversity of Psychrotolerant Bacteria Isolated from Wild Flora of Andes Mountains and Patagonia of Chile towards the Selection of Plant Growth-Promoting Bacterial Consortia to Alleviate Cold Stress in Plants. Microorganisms. 2021; 9 (3):538.
Chicago/Turabian StylePaulina Vega-Celedón; Guillermo Bravo; Alexis Velásquez; Fernanda Cid; Miryam Valenzuela; Ingrid Ramírez; Ingrid-Nicole Vasconez; Inaudis Álvarez; Milko Jorquera; Michael Seeger. 2021. "Microbial Diversity of Psychrotolerant Bacteria Isolated from Wild Flora of Andes Mountains and Patagonia of Chile towards the Selection of Plant Growth-Promoting Bacterial Consortia to Alleviate Cold Stress in Plants." Microorganisms 9, no. 3: 538.
1-Aminociclopropane-1-carboxylate (ACC)-degrading bacteria having been widely studied for their use in alleviating abiotic stresses in plants. In the present study, we isolated and characterized ACC-degrading bacteria from the rhizosphere, phyllosphere, and endosphere of the Antarctic vascular plants Deschampsia antarctica and Colobanthus quitensis. One hundred and eighty of the 578 isolates (31%) were able to grow on minimal medium containing ACC, with 101 isolates (23, 37, and 41 endosphere-, phyllosphere- and rhizosphere-associated isolates, respectively) identified as being genetically unique by enterobacterial repetitive intergenic consensus (ERIC)-PCR. Subsequently, freeze/thaw treatments and ice-recrystallization-inhibition (IRI) activity assays were performed, the results of which revealed that 77 (13%) of cold-tolerant isolates exhibited putative ACC deaminase activity. Significant (p ≤ 0.05) differences in IRI activity were also observed between the studied plant niches. Surprisingly, all the cold-tolerant isolates showed ACC deaminase activity, independent of the plant niches, with 12 isolates showing the highest ACC deaminase activities of 13.21–39.56 mmol α KB mg protein−1 h−1. These isolates were categorized as ‘cold-tolerant hyper-ACC-degrading bacteria’, and identified as members of Pseudomonas, Serratia, and Staphylococcus genera. The results revealed the occurrence of cold-tolerant hyper-ACC-degrading bacteria in diverse plant niches of Antarctic vascular plants, that could be investigated as novel microbial inoculants to alleviate abiotic stresses in plants.
Macarena A. Araya; Tamara Valenzuela; Nitza G. Inostroza; Fumito Maruyama; Milko A. Jorquera; Jacquelinne J. Acuña. Isolation and Characterization of Cold-Tolerant Hyper-ACC-Degrading Bacteria from the Rhizosphere, Endosphere, and Phyllosphere of Antarctic Vascular Plants. Microorganisms 2020, 8, 1788 .
AMA StyleMacarena A. Araya, Tamara Valenzuela, Nitza G. Inostroza, Fumito Maruyama, Milko A. Jorquera, Jacquelinne J. Acuña. Isolation and Characterization of Cold-Tolerant Hyper-ACC-Degrading Bacteria from the Rhizosphere, Endosphere, and Phyllosphere of Antarctic Vascular Plants. Microorganisms. 2020; 8 (11):1788.
Chicago/Turabian StyleMacarena A. Araya; Tamara Valenzuela; Nitza G. Inostroza; Fumito Maruyama; Milko A. Jorquera; Jacquelinne J. Acuña. 2020. "Isolation and Characterization of Cold-Tolerant Hyper-ACC-Degrading Bacteria from the Rhizosphere, Endosphere, and Phyllosphere of Antarctic Vascular Plants." Microorganisms 8, no. 11: 1788.
Vibrio species display variable and plastic fitness strategies to survive and interact with multiple hosts, including marine aquaculture species that are severely affected by pathogenic Vibrios. The culturable Vibrio sp. strain ArtGut-C1, the focus of this study, provides new evidence of such phenotypic plasticity as it accumulates polyhydroxybutyrate (PHB), a biodegradable polymer with anti-pathogen activity, particularly in the marine larviculture phase. The strain was isolated from the gut of laboratory-reared Artemia individuals, the live diet and PHB carrier used in larviculture. Its main phenotypic properties, taxonomic status and genomic properties are reported based on the whole-genome sequencing. Vibrio sp. ArtGut-C1 yielded 72.6% PHB of cells dry weight at 25°C. The genomic average nucleotide identity (ANI) shows it is closely related to V. diabolicus (ANI: 88.6%). Its genome contains 5,236,997-bp with 44.8% GC content, 3,710 protein-coding sequences, 96 RNA, 9 PHB genes functionally related to PHB metabolic pathways, and several genes linked to competing and colonizing abilities. This culturable PHB-accumulating Vibrio strain shows high genomic and phenotypic variability. It may be used as a natural pathogen biocontrol in the marine hatchery and as a potential cell factory for PHB production.
Marco Yévenes; Mauricio Quiroz; Fumito Maruyama; Milko Jorquera; Gonzalo Gajardo. Vibrio sp. ArtGut-C1, a polyhydroxybutyrate producer isolated from the gut of the aquaculture live diet Artemia (Crustacea). Electronic Journal of Biotechnology 2020, 49, 22 -28.
AMA StyleMarco Yévenes, Mauricio Quiroz, Fumito Maruyama, Milko Jorquera, Gonzalo Gajardo. Vibrio sp. ArtGut-C1, a polyhydroxybutyrate producer isolated from the gut of the aquaculture live diet Artemia (Crustacea). Electronic Journal of Biotechnology. 2020; 49 ():22-28.
Chicago/Turabian StyleMarco Yévenes; Mauricio Quiroz; Fumito Maruyama; Milko Jorquera; Gonzalo Gajardo. 2020. "Vibrio sp. ArtGut-C1, a polyhydroxybutyrate producer isolated from the gut of the aquaculture live diet Artemia (Crustacea)." Electronic Journal of Biotechnology 49, no. : 22-28.
Harmful algae blooms (HABs) cause acute effects on marine ecosystems due to their production of endogenous toxins or their enormous biomass, leading to significant impacts on local economies and public health. Although HAB monitoring has been intensively performed at spatiotemporal scales in coastal areas of the world over the last decades, procedures have not yet been standardized. HAB monitoring procedures are complicated and consist of many methodologies, including physical, chemical, and biological water sample measurements. Each monitoring program currently uses different combinations of methodologies depending on site specific purposes, and many prior programs refer to the procedures in quotations. HAB monitoring programs in Chile have adopted the traditional microscopic and toxin analyses but not molecular biology and bacterial assemblage approaches. Here we select and optimize the HAB monitoring methodologies suitable for Chilean geography, emphasizing on metabarcoding analyses accompanied by the classical tools with considerations including cost, materials and instrument availability, and easiness and efficiency of performance. We present results from a pilot study using the standardized stepwise protocols, demonstrating feasibility and plausibility for sampling and analysis for the HAB monitoring. Such specific instructions in the standardized protocol are critical obtaining quality data under various research environments involving multiple stations, different analysts, various time-points, and long HAB monitoring duration.
Kyoko Yarimizu; So Fujiyoshi; Mikihiko Kawai; Luis Norambuena-Subiabre; Emma-Karin Cascales; Joaquin-Ignacio Rilling; Jonnathan Vilugrón; Henry Cameron; Karen Vergara; Jesus Morón-López; Jacquelinne J. Acuña; Gonzalo Gajardo; Oscar Espinoza-González; Leonardo Guzmán; Milko A. Jorquera; Satoshi Nagai; Gemita Pizarro; Carlos Riquelme; Shoko Ueki; Fumito Maruyama. Protocols for Monitoring Harmful Algal Blooms for Sustainable Aquaculture and Coastal Fisheries in Chile. International Journal of Environmental Research and Public Health 2020, 17, 7642 .
AMA StyleKyoko Yarimizu, So Fujiyoshi, Mikihiko Kawai, Luis Norambuena-Subiabre, Emma-Karin Cascales, Joaquin-Ignacio Rilling, Jonnathan Vilugrón, Henry Cameron, Karen Vergara, Jesus Morón-López, Jacquelinne J. Acuña, Gonzalo Gajardo, Oscar Espinoza-González, Leonardo Guzmán, Milko A. Jorquera, Satoshi Nagai, Gemita Pizarro, Carlos Riquelme, Shoko Ueki, Fumito Maruyama. Protocols for Monitoring Harmful Algal Blooms for Sustainable Aquaculture and Coastal Fisheries in Chile. International Journal of Environmental Research and Public Health. 2020; 17 (20):7642.
Chicago/Turabian StyleKyoko Yarimizu; So Fujiyoshi; Mikihiko Kawai; Luis Norambuena-Subiabre; Emma-Karin Cascales; Joaquin-Ignacio Rilling; Jonnathan Vilugrón; Henry Cameron; Karen Vergara; Jesus Morón-López; Jacquelinne J. Acuña; Gonzalo Gajardo; Oscar Espinoza-González; Leonardo Guzmán; Milko A. Jorquera; Satoshi Nagai; Gemita Pizarro; Carlos Riquelme; Shoko Ueki; Fumito Maruyama. 2020. "Protocols for Monitoring Harmful Algal Blooms for Sustainable Aquaculture and Coastal Fisheries in Chile." International Journal of Environmental Research and Public Health 17, no. 20: 7642.
Plant-associated microbiomes have been suggested as pivotal for the growth and health of natural vegetation and agronomic plants. In this sense, plant-associated microbiomes harbor a huge diversity of microorganisms (such as bacteria and fungi) which can modulate the plant host response against pathogens and changing environmental conditions through a complex network of genetic, biochemical, physical, and metabolomics interactions. Advances on next-generation omic technologies have opened the possibility to unravel this complex microbial diversity and their interactive networks as never described before. In parallel, the develop of novel culture-dependent methods are also crucial to the study of the biology of members of plant-associated microbiomes and their bioprospecting as sources of bioactive compounds, or as tools to improve the productivity of agriculture. This Special Issue aims to motivate and collect recent studies which are focused on exploring the diversity and ecology of plant-associated microbiomes and their genetic and metabolic interactions with other microorganisms or their plant hosts, as well as their potential biotechnological applications in diverse fields, such as inoculants for agriculture.
Jacquelinne J. Acuña; Milko A. Jorquera. Diversity, Interaction, and Bioprospecting of Plant-Associated Microbiomes. Diversity 2020, 12, 390 .
AMA StyleJacquelinne J. Acuña, Milko A. Jorquera. Diversity, Interaction, and Bioprospecting of Plant-Associated Microbiomes. Diversity. 2020; 12 (10):390.
Chicago/Turabian StyleJacquelinne J. Acuña; Milko A. Jorquera. 2020. "Diversity, Interaction, and Bioprospecting of Plant-Associated Microbiomes." Diversity 12, no. 10: 390.
Microbial entities (such bacteria, fungi, archaea and viruses) within outdoor aerosols have been scarcely studied compared with indoor aerosols and nonbiological components, and only during the last few decades have their studies increased. Bacteria represent an important part of the microbial abundance and diversity in a wide variety of rural and urban outdoor bioaerosols. Currently, airborne bacterial communities are mainly sampled in two aerosol size fractions (2.5 and 10 µm) and characterized by culture-dependent (plate-counting) and culture-independent (DNA sequencing) approaches. Studies have revealed a large diversity of bacteria in bioaerosols, highlighting Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes as ubiquitous phyla. Seasonal variations in and dispersion of bacterial communities have also been observed between geographical locations as has their correlation with specific atmospheric factors. Several investigations have also suggested the relevance of airborne bacteria in the public health and agriculture sectors as well as remediation and atmospheric processes. However, although factors influencing airborne bacterial communities and standardized procedures for their assessment have recently been proposed, the use of bacterial taxa as microbial indicators of specific bioaerosol sources and seasonality have not been broadly explored. Thus, in this review, we summarize and discuss recent advances in the study of airborne bacterial communities in outdoor environments and the possible factors influencing their abundance, diversity, and seasonal variation. Furthermore, airborne bacterial activity and bioprospecting in different fields (e.g., the textile industry, the food industry, medicine, and bioremediation) are discussed. We expect that this review will reveal the relevance and influencing factors of airborne bacteria in outdoor environments as well as stimulate new investigations on the atmospheric microbiome, particularly in areas where air quality is a public concern.
Tay Ruiz-Gil; Jacquelinne J. Acuña; So Fujiyoshi; Daisuke Tanaka; Jun Noda; Fumito Maruyama; Milko A. Jorquera. Airborne bacterial communities of outdoor environments and their associated influencing factors. Environment International 2020, 145, 106156 .
AMA StyleTay Ruiz-Gil, Jacquelinne J. Acuña, So Fujiyoshi, Daisuke Tanaka, Jun Noda, Fumito Maruyama, Milko A. Jorquera. Airborne bacterial communities of outdoor environments and their associated influencing factors. Environment International. 2020; 145 ():106156.
Chicago/Turabian StyleTay Ruiz-Gil; Jacquelinne J. Acuña; So Fujiyoshi; Daisuke Tanaka; Jun Noda; Fumito Maruyama; Milko A. Jorquera. 2020. "Airborne bacterial communities of outdoor environments and their associated influencing factors." Environment International 145, no. : 106156.
The El Tatio Geyser Field (ETGF), located in Northern Chile, is the main geyser field in the southern hemisphere. Despite this, details of its microbial ecology are still unknown. Here, we briefly report on the composition and predicted functions of the bacterial community in spouting pool sediments from the ETGF as revealed by high-throughput sequencing of 16S rRNA genes. Results of this analysis showed that while there were differences in richness and diversity between samples, bacterial communities were primarily dominated by the phyla Proteobacteria, followed Firmicutes, Bacteroidetes, Acidobacteria, and Chloroflexi. Analyses of predicted functional activity indicated that the functions were mostly attributed to chemoheterotrophy and aerobic chemoheterotrophy, followed by sulfur (respiration of sulfur compounds and sulfate) and nitrogen (nitrate reduction, respiration of nitrogen and nitrate) cycling. Taken together, our results suggest a high diversity in taxonomy and predictive functions of bacterial communities in sediments from spouting pools. This study provides fundamentally important information on the structure and function predictive functions of microbiota communities in spouting pools. Moreover, since the ETGF is intensively visited and impacted by tens of thousands of tourists every year, our results can be used to help guide the design of sustainable conservation strategies.
Qian Zhang; Marco Campos; Giovanni Larama; Jacquelinne J. Acuña; Bernardita Valenzuela; Francisco Solis; Pedro Zamorano; Rubén Araya; Michael J. Sadowsky; Milko A. Jorquera. Composition and predicted functions of the bacterial community in spouting pool sediments from the El Tatio Geyser field in Chile. Archives of Microbiology 2020, 203, 389 -397.
AMA StyleQian Zhang, Marco Campos, Giovanni Larama, Jacquelinne J. Acuña, Bernardita Valenzuela, Francisco Solis, Pedro Zamorano, Rubén Araya, Michael J. Sadowsky, Milko A. Jorquera. Composition and predicted functions of the bacterial community in spouting pool sediments from the El Tatio Geyser field in Chile. Archives of Microbiology. 2020; 203 (1):389-397.
Chicago/Turabian StyleQian Zhang; Marco Campos; Giovanni Larama; Jacquelinne J. Acuña; Bernardita Valenzuela; Francisco Solis; Pedro Zamorano; Rubén Araya; Michael J. Sadowsky; Milko A. Jorquera. 2020. "Composition and predicted functions of the bacterial community in spouting pool sediments from the El Tatio Geyser field in Chile." Archives of Microbiology 203, no. 1: 389-397.
Intercropping could increase the capacity of crops to use soil resources. The aim of this study was to investigate the effects of lupin/wheat intercropping on soil properties, grain yield and nutrient uptake at different plant densities. Lupin and wheat were grown under field conditions as monocrops and intercrops. Soil nutrient availability and relative abundance of functional genes (acdS, phoD, phoC and nifH) were evaluated. The results obtained indicate that the cropping system had a significant effect (p < 0.001) on N and P availability. Lupin monocrop led to significantly higher N availability compared to intercrop. Intercropping resulted in significantly lower Olsen-P and K in soil concentrations compared to monocropping. No significant differences were observed in enzyme activity, except for phosphatase, which was 152% greater in the treatments at high plant density. Foliar nutrients were significantly higher in intercropping compared to monocropping. Acid phosphatase gene phoC was more abundant than the alkaline phosphatase gene phoD, which plays a more relevant role in acidic Andisols. The results confirm that N and P mobilization can improve nutrient absorption on wheat. When intercropped, lupin had positive effects on wheat due to its P mobilization capacity, while no effects were observed on lupin.
Mauricio Schoebitz; Dalma Castillo; Milko Jorquera; Antonio Roldan. Responses of Microbiological Soil Properties to Intercropping at Different Planting Densities in an Acidic Andisol. Agronomy 2020, 10, 781 .
AMA StyleMauricio Schoebitz, Dalma Castillo, Milko Jorquera, Antonio Roldan. Responses of Microbiological Soil Properties to Intercropping at Different Planting Densities in an Acidic Andisol. Agronomy. 2020; 10 (6):781.
Chicago/Turabian StyleMauricio Schoebitz; Dalma Castillo; Milko Jorquera; Antonio Roldan. 2020. "Responses of Microbiological Soil Properties to Intercropping at Different Planting Densities in an Acidic Andisol." Agronomy 10, no. 6: 781.
Flowering desert (FD) events consist of the rapid flowering of a wide variety of native plants in the Atacama Desert of Chile, which is categorized as the driest desert in the world. While ephemeral plants are an integral part of the desert ecosystem, there is little knowledge on plant-microbe interactions that occur during FD events. Consequently, the overall goals of this present study were to investigate changes in the composition and potential functions of rhizobacterial community of Cistanthe longiscapa (Montiaceae) during the 2014 and 2015 FD events and determine the composition, potential functions, and co-occurrence networks of rhizobacterial community associated with the root zone of C. longiscapa during pre- (PF) and full-flowering (FF) phenological stages. Results of this study showed that the Proteobacteria and Actinobacteria were the dominant taxa in rhizosphere soils during the three FD events (2014, 2015, and 2017) examined. In general, greater microbial richness and diversity were observed in rhizosphere soils during the 2015-, compared with the 2014-FD event. Similarly, predicted functional analyses indicated that a larger number of sequences were assigned to information processing (e.g., ion channel, transporters and ribosome) and metabolism (e.g., lipids, nitrogen, and sulfur) during 2015 compared with 2014. Despite the lack of significant differences in diversity among PF and FF stages, the combined analysis of rhizobacterial community data, along with data concerning rhizosphere soil properties, evidenced differences among both phenological stages and suggested that sodium is a relevant abiotic factor shaping the rhizosphere. In general, no significant differences in predicted functions (most of them assigned to chemoheterotrophy, magnesium metabolisms, and fermentation) were observed among PF and FF. Co-occurrence analysis revealed the complex rhizobacterial interactions that occur in C. longiscapa during FD, highlighting to Kouleothrixaceae family as keystone taxa. Taken together this study shows that the composition and function of rhizobacteria vary among and during FD events, where some bacterial groups and their activity may influence the growth and flowering of native plants, and therefore, the ecology and trophic webs in Atacama Desert.
Marcia Astorga-Eló; Qian Zhang; Giovanni Larama; Alexandra Stoll; Michael Sadowsky; Milko A. Jorquera. Composition, Predicted Functions and Co-occurrence Networks of Rhizobacterial Communities Impacting Flowering Desert Events in the Atacama Desert, Chile. Frontiers in Microbiology 2020, 11, 571 .
AMA StyleMarcia Astorga-Eló, Qian Zhang, Giovanni Larama, Alexandra Stoll, Michael Sadowsky, Milko A. Jorquera. Composition, Predicted Functions and Co-occurrence Networks of Rhizobacterial Communities Impacting Flowering Desert Events in the Atacama Desert, Chile. Frontiers in Microbiology. 2020; 11 ():571.
Chicago/Turabian StyleMarcia Astorga-Eló; Qian Zhang; Giovanni Larama; Alexandra Stoll; Michael Sadowsky; Milko A. Jorquera. 2020. "Composition, Predicted Functions and Co-occurrence Networks of Rhizobacterial Communities Impacting Flowering Desert Events in the Atacama Desert, Chile." Frontiers in Microbiology 11, no. : 571.
The use of high-throughput DNA sequencing (HTS) has revealed the great diversity of rhizobacteria in plant rhizospheres; however, only a minor portion (≤ 1%) of rhizobacteria belonging to few taxa can be cultured under laboratory conditions. In recent years, in situ cultivation has opened a window to explore a greater diversity of bacterial taxa in the environment. Here, we explored the total and culturable rhizobacterial communities associated with the rhizosphere of wheat plants by using 16S rRNA-based HTS and in situ cultivation with microwell chambers (MWCs), respectively. Results by HTS revealed to phyla Proteobacteria (29–39%), Acidobacteria (17%), Actinobacteria (11–15%), and Bacteroidetes (5–12%) as the most abundant rhizobacterial taxa in rhizosphere samples. A total of 206 isolates (26 genera) were obtained with MWCs, where coincidentally with HTS, the most abundant phyla were Proteobacteria (70.4%), Firmicutes (24%), Actinobacteria (4%), and Bacteroidetes (1.5%). At the genus level, the most of isolates (72%) belonged to Pseudomonas, followed by Bacillus, Stenotrophomonas, Delftia, and Herbaspirillum. Members of rare taxa (Lelliottia, Rhodococcus, Micrococcus, Variovorax, and Bosea) also were isolated by MWCs. In addition, a high proportion (82%) of isolates showed high similarity with plant beneficial and environmental non-pathogenic bacteria whereas a minor proportion (18%) of isolates showed high similarity to human and plant pathogenic bacteria. This study demonstrates that in situ cultivation represents a useful tool to isolate a greater number of rhizobacterial taxa, which can be investigated under laboratory conditions in bioprospecting (e.g., plant growth–promoting bacteria) and public health (e.g., human opportunist and plant pathogens) studies.
Jacquelinne J. Acuña; Luis Marileo; Macarena A. Araya; Joaquin I. Rilling; Giovanni A. Larama; Maria Luz Mora; Slava Epstein; Milko A. Jorquera. In Situ Cultivation Approach to Increase the Culturable Bacterial Diversity in the Rhizobiome of Plants. Journal of Soil Science and Plant Nutrition 2020, 20, 1411 -1426.
AMA StyleJacquelinne J. Acuña, Luis Marileo, Macarena A. Araya, Joaquin I. Rilling, Giovanni A. Larama, Maria Luz Mora, Slava Epstein, Milko A. Jorquera. In Situ Cultivation Approach to Increase the Culturable Bacterial Diversity in the Rhizobiome of Plants. Journal of Soil Science and Plant Nutrition. 2020; 20 (3):1411-1426.
Chicago/Turabian StyleJacquelinne J. Acuña; Luis Marileo; Macarena A. Araya; Joaquin I. Rilling; Giovanni A. Larama; Maria Luz Mora; Slava Epstein; Milko A. Jorquera. 2020. "In Situ Cultivation Approach to Increase the Culturable Bacterial Diversity in the Rhizobiome of Plants." Journal of Soil Science and Plant Nutrition 20, no. 3: 1411-1426.
Editorial: Bioprospecting and Biotechnology of Extremophiles
Milko A. Jorquera; Steffen P. Graether; Fumito Maruyama. Editorial: Bioprospecting and Biotechnology of Extremophiles. Frontiers in Bioengineering and Biotechnology 2019, 7, 1 .
AMA StyleMilko A. Jorquera, Steffen P. Graether, Fumito Maruyama. Editorial: Bioprospecting and Biotechnology of Extremophiles. Frontiers in Bioengineering and Biotechnology. 2019; 7 ():1.
Chicago/Turabian StyleMilko A. Jorquera; Steffen P. Graether; Fumito Maruyama. 2019. "Editorial: Bioprospecting and Biotechnology of Extremophiles." Frontiers in Bioengineering and Biotechnology 7, no. : 1.
Phosphorus (P) is an essential macronutrient for plant growth and is therefore an important component of agricultural fertilizers, especially for P–deficient soils. As a more environmentally friendly alternative to P–fertilization, phosphobacteria are regularly being proposed as bio–inoculants for plants that are cultivated in P–deficient soils. Although it is known that phosphobacteria inoculation can influence the growth and P nutrition of the host plant, the underlying responses at the molecular level have to date, not been fully elucidated. Here, we evaluated the single and combined effects of a phosphobacteria consortium inoculation and triple superphosphate fertilization on the biomass, P content, anti–oxidant capacity and phosphate–transporters genes of Lolium perenne. Plants were grown over 45 days in presence and absence of P–fertilization and phosphobacteria inoculation in two soils with different P bio–availabilities. Our results reveal that irrespective of P–availability in soils, the phosphobacteria inoculation provides an ‘enhancement effect’ of the P–fertilization on the development, nutrition and the alleviation of oxidative stress, in L. perenne. This was evidenced by higher biomass, increased P content, and lower cellular damage in tissues of the inoculated plants. The inoculation with phosphobacteria decreased the relative gene expression of superoxide dismutase isoforms in tissues of fertilized plants grown in the P–deficient soil. In addition, phosphobacteria inoculation was also associated with a lower relative expression of phosphate–transporter genes of P–fertilized plants. Therefore, instead of being an alternative to P–fertilization, phosphobacteria could rather be a promising complement to P–fertilization in P–deficient soils and potentially reduce fertilizer application rates. Based on our findings, an explicatory model of plant–soil–phosphobacteria interactions on the regulation of anti–oxidant and phosphate–transport capacities in P–deficient, is proposed.
Patricio Javier Barra; Sofia Pontigo; Mabel Delgado; Leyla Parra–Almuna; Paola Duran; Alexander Joseph Valentine; Milko Alberto Jorquera; María De La Luz Mora. Phosphobacteria inoculation enhances the benefit of P–fertilization on Lolium perenne in soils contrasting in P–availability. Soil Biology and Biochemistry 2019, 136, 107516 .
AMA StylePatricio Javier Barra, Sofia Pontigo, Mabel Delgado, Leyla Parra–Almuna, Paola Duran, Alexander Joseph Valentine, Milko Alberto Jorquera, María De La Luz Mora. Phosphobacteria inoculation enhances the benefit of P–fertilization on Lolium perenne in soils contrasting in P–availability. Soil Biology and Biochemistry. 2019; 136 ():107516.
Chicago/Turabian StylePatricio Javier Barra; Sofia Pontigo; Mabel Delgado; Leyla Parra–Almuna; Paola Duran; Alexander Joseph Valentine; Milko Alberto Jorquera; María De La Luz Mora. 2019. "Phosphobacteria inoculation enhances the benefit of P–fertilization on Lolium perenne in soils contrasting in P–availability." Soil Biology and Biochemistry 136, no. : 107516.
Antarctic have been suggested as an attractive source for antibiotics discovery and members of Streptomyces genus have historically been studied as natural producers of antimicrobial metabolites. Nonetheless, our knowledge on antibiotic-producing Streptomyces from Antarctic is very limited. In this study, the antimicrobial activity of organic extracts from Antarctic Streptomyces strains was evaluated by disk diffusion assays and minimum inhibitory concentration. The strain Streptomyces sp. So13.3 showed the greatest antibiotic activity (MIC = 15.6 μg/mL) against Gram-positive bacteria and growth reduction of Gram‒negative pathogens. The bioactive fraction in the crude extract was revealed by TLC‒bioautography at Rf = 0.78 with molecular weight between 148 and 624 m/z detected by LC-ESI-MS/MS. The strain So13.3 was taxonomically affiliated as Streptomyces fildesensis. Whole genome sequencing and analysis suggested a 9.47 Mb genome size with 42 predicted biosynthetic gene clusters (BGCs) and 56 putative clusters representing a 22% of total genome content. Interestingly, a large number of them (11 of 42 BGCs and 40 of 56 putative BGCs), did not show similarities with other known BGCs. Our results highlight the potential of the Antarctic Streptomyces strains as a promising source of novel antimicrobials, particularly the strain Streptomyces fildesensis So13.3, which first draft genome is reported in this work.
Kattia Núñez-Montero; Claudio Lamilla; Michel Abanto; Fumito Maruyama; Milko A. Jorquera; Andrés Santos; Jaime Martinez-Urtaza; Leticia Barrientos. Antarctic Streptomyces fildesensis So13.3 strain as a promising source for antimicrobials discovery. Scientific Reports 2019, 9, 7488 .
AMA StyleKattia Núñez-Montero, Claudio Lamilla, Michel Abanto, Fumito Maruyama, Milko A. Jorquera, Andrés Santos, Jaime Martinez-Urtaza, Leticia Barrientos. Antarctic Streptomyces fildesensis So13.3 strain as a promising source for antimicrobials discovery. Scientific Reports. 2019; 9 (1):7488.
Chicago/Turabian StyleKattia Núñez-Montero; Claudio Lamilla; Michel Abanto; Fumito Maruyama; Milko A. Jorquera; Andrés Santos; Jaime Martinez-Urtaza; Leticia Barrientos. 2019. "Antarctic Streptomyces fildesensis So13.3 strain as a promising source for antimicrobials discovery." Scientific Reports 9, no. 1: 7488.
Several studies have demonstrated the relevance of endophytic bacteria on the growth and fitness of agriculturally-relevant plants. To our knowledge, however, little information is available on the composition, diversity, and interaction of endophytic bacterial communities in plants struggling for existence in the extreme environments of Chile, such as the Atacama Desert (AD) and Patagonia (PAT). The main objective of the present study was to analyze and compare the composition of endophytic bacterial communities associated with roots and leaves of representative plants growing in Chilean extreme environments. The plants sampled were: Distichlis spicate and Pluchea absinthioides from the AD, and Gaultheria mucronata and Hieracium pilosella from PAT. The abundance and composition of their endophytic bacterial communities was determined by quantitative PCR and high–throughput sequencing of 16S rRNA, respectively. Results indicated that there was a greater abundance of 16S rRNA genes in plants from PAT (1013 to 1014 copies g−1 DNA), compared with those from AD (1010 to 1012 copies g−1 DNA). In the AD, a greater bacterial diversity, as estimated by Shannon index, was found in P. absinthioides, compared with D. spicata. In both ecosystems, the greater relative abundances of endophytes were mainly attributed to members of the phyla Proteobacteria (14% to 68%), Firmicutes (26% to 41%), Actinobacteria (6 to 23%) and Bacteroidetes (1% to 21%). Our observations revealed that most of operational taxonomic units (OTUs) were not shared between tissue samples of different plant species in both locations, suggesting the effect of the plant genotype (species) on the bacterial endophyte communities in Chilean extreme environments, where Bacillaceae and Enterobacteriacea could serve as keystone taxa as revealed our linear discriminant analysis.
Qian Zhang; Jacquelinne J. Acuña; Nitza G. Inostroza; Maria Luz Mora; Sergio Radic; Michael J. Sadowsky; Milko A. Jorquera. Endophytic Bacterial Communities Associated with Roots and Leaves of Plants Growing in Chilean Extreme Environments. Scientific Reports 2019, 9, 1 -12.
AMA StyleQian Zhang, Jacquelinne J. Acuña, Nitza G. Inostroza, Maria Luz Mora, Sergio Radic, Michael J. Sadowsky, Milko A. Jorquera. Endophytic Bacterial Communities Associated with Roots and Leaves of Plants Growing in Chilean Extreme Environments. Scientific Reports. 2019; 9 (1):1-12.
Chicago/Turabian StyleQian Zhang; Jacquelinne J. Acuña; Nitza G. Inostroza; Maria Luz Mora; Sergio Radic; Michael J. Sadowsky; Milko A. Jorquera. 2019. "Endophytic Bacterial Communities Associated with Roots and Leaves of Plants Growing in Chilean Extreme Environments." Scientific Reports 9, no. 1: 1-12.
1-Aminocyclopropane-1-carboxylate deaminase (ACCD)-producing rhizobacteria are widely studied as plant growth-promoting rhizobacteria (PGPR) to alleviate a variety of stresses in plants. However, the presence of ACCD-producing rhizobacteria in plants that naturally occur in stressful ecosystems as well as the potential PGPR activity in agriculturally relevant plants has been poorly explored thus far. We isolated and characterized ACCD-producing rhizobacteria from Parastrephia quadrangularis, a native plant from the Andean Altiplano in Chile. The effects of selected ACCD-producing rhizobacteria on biomass and superoxide dismutase (SOD) activity of wheat seedlings subjected to salt stress (0.25 M and 0.45 M NaCl) were also evaluated. Ten out of 30 isolates showed ACCD activity (0.83–3.32 μmol α-ketobutyrate mg−1h−1) and were identified as members of the Enterobacteriales order (mainly Serratia and Klebsiella). The ACCD-producing rhizobacteria also showed salt tolerance (from 2.5 to 7.5% NaCl) and other PGPR traits, such as the production of auxin (from 20.3 to 41 μg mL−1) and siderophores (from 3.35 to 67.7%). Wheat seedlings inoculated with two selected ACCD-producing Klebsiella isolates (8LJA and 27IJA) significantly (P ≤ 0.05) increased the biomass (45–62%) content and SOD activity in roots (18–35%) with and without salt stress. This study demonstrated that PGPR were associated with native plants in the Andean Altiplano and offers a promising potential source of novel PGPR to alleviate salt stress in plants.
Jacquelinne J. Acuña; Marco Campos; María De La Luz Mora; Deb P. Jaisi; Milko A. Jorquera. ACCD-producing rhizobacteria from an Andean Altiplano native plant (Parastrephia quadrangularis) and their potential to alleviate salt stress in wheat seedlings. Applied Soil Ecology 2019, 136, 184 -190.
AMA StyleJacquelinne J. Acuña, Marco Campos, María De La Luz Mora, Deb P. Jaisi, Milko A. Jorquera. ACCD-producing rhizobacteria from an Andean Altiplano native plant (Parastrephia quadrangularis) and their potential to alleviate salt stress in wheat seedlings. Applied Soil Ecology. 2019; 136 ():184-190.
Chicago/Turabian StyleJacquelinne J. Acuña; Marco Campos; María De La Luz Mora; Deb P. Jaisi; Milko A. Jorquera. 2019. "ACCD-producing rhizobacteria from an Andean Altiplano native plant (Parastrephia quadrangularis) and their potential to alleviate salt stress in wheat seedlings." Applied Soil Ecology 136, no. : 184-190.