5 results on '"Susana Rodriguez"'
Search Results
2. Editorial: Microbial Secondary Metabolites: Recent Developments and Technological Challenges
- Author
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Mostafa E. Rateb, Susana Rodriguez-Couto, Maria de Lourdes Teixeira de Moraes Polizeli, Bhim Singh, and Wen-Jun Li
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Microbiology (medical) ,microbial ,0303 health sciences ,030306 microbiology ,metabolite ,lcsh:QR1-502 ,challenges ,Biotic stress ,Biology ,biology.organism_classification ,Streptomyces somaliensis ,Streptomyces ,Microbiology ,lcsh:Microbiology ,Plant use of endophytic fungi in defense ,Actinobacteria ,03 medical and health sciences ,Editorial ,Gene cluster ,Botany ,change ,Medicinal plants ,secondary ,Marine fungi ,030304 developmental biology - Abstract
Microbial secondary metabolites, like antibiotics, pigments, growth hormones, antitumor agents, and others, are not essential for the growth and development of microorganism, but they have shown a great potential for human and animal health (Ruiz et al., 2010). Among the microorganisms producing the above-mentioned compounds, bacteria, including actinobacteria, and fungi produce a diverse array of bioactive small molecules with significant potential to be used in medicine (O‘Brien and Wright, 2011). These bioactive compounds are mainly produced by the activation of cryptic gene clusters which are not active under normal conditions and, thus, the expression of these clusters would be helpful in the exploitation of the chemical diversity of microorganisms (Pettit, 2011; Xu et al., 2019). Although several reports on microbial secondary metabolites have been published in recent years (Passari et al., 2017; Zothanpuia et al., 2018; Overy et al., 2019), our understanding to enhance the production of bioactive secondary metabolites is still limited. The research topic “Microbial Secondary Metabolites: Recent Developments and Technological Challenges” comprises 25 articles covering important aspects on biodiversity, exploitation and utilization of microbial resources (terrestrial, marine, and endophytic) for the production of secondary metabolites together with their biological functions. The current knowledge and potential of marine fungi for producing anticancer compounds has been reviewed (Deshmukh et al.) and the ability of the sea-derived Streptomyces helimycini for the production of actinomycins is presented (Zhu et al.). In a very interesting study, Wakefield et al. proved that the co-cultivation of fungi and bacteria led to the production of new secondary metabolites. There is a growing interest in looking for unique sources for the exploration of novel microbial populations having prospective to produce bioactive natural products. Thereby, the bacterial and fungal population obtained from Aquilaria malaccensis tree and soil enhanced the production of agarospirol within 3 months of artificial infection (Chhipa and Kaushik). The present research topic includes four important research papers dealing with the production of bioactive secondary metabolites. Thus, a study by Alenezi et al. emphasized that the biological activity of Aneurinibacillus migulans isolates was directly correlated with the production of a new gramicidin. Narsing Rao et al. has focused on the importance of pigments originated from fungi and bacteria and their wide applications in health and industry. The article by Li et al. presented the production of somalimycin, a new antimycin-type depsipeptide, from a mutant of the deep-sea-derived Streptomyces somaliensis. Similarly, Thogersen et al. demonstrated the production of the potentially antibacterial compounds violacein and indolmycin by a maeA mutant of the sea bacterium Pseudoalteromonas luteoviolacea. A cluster of three articles gives emphasis to the biosynthetic gene clusters involved in microorganisms for the production of secondary metabolites. Hence, Derntl et al. demonstrated the role of genes, namely sor1, sor3, and sor4 of the orbicillinoid gene cluster and disclosed the function of sor4 which was not known. Another article by Rojas-Aedo et al. explained the role of the adr gene cluster involved in the biosynthesis of the potent antitumor compoundandrastin A in Penicillium roqueforti. In this article, the authors also have demonstrated that all the 10 genes of adr gene cluster were essential for the production of andrastin A. Lastly, Nah et al. reviewed the potential of the phylum Actinomycetes for natural production (NP) through biosynthetic gene clusters (BGC) heterologous expression systems as well as recent strategies specialized for the large-sized NP BGCs in Streptomyces heterologous hosts. Other important candidates for the production of secondary metabolites are the endophytic microorganisms which were addressed by Mefteh et al. Thus, they presented that plants under biotic stress offered new and unique endophytes with diverse bioactivities as compared to healthy plants. Sharma et al. reported that the application of dietary components like grape skin and turmeric extracts enhanced the production of cryptic and bioactive metabolites, with anti-oxidant and antibacterial potential, by the endophytic fungus Colletotrichum gloeosporioides. Also, the endophytic fungi Chaetomium globosum isolated from Egyptian medicinal plants, proved to have anti-rheumatoid activity (Abdel-Azeem et al.). In summary, the articles gathered in the research topic “Microbial Secondary Metabolites: recent development and Technological Challenges” explore the role of microorganisms from different sources showing biological activities. This will further enhance the present knowledge on the potential of microbial secondary metabolites in health and industry. One challenge which needs to be answered is the development of methods to understand the detailed mechanisms of cryptic genes and their relation to the production of bioactive compounds. Researchers also need to give more emphasis on the co-cultivation of different microorganisms having positive synergistic effect to produce novel bioactive molecules. We believe that this special issue gives some in-depth information about one of the important matters of the microbial world. Finally, our great thanks to all contributions, in total 165 authors, for the cohesive information in the form of reviews and research articles which have been compiled in this ebook. We strongly believe that the information compiled and presented in this ebook will be useful for the readers and will be the basis for the future investigation on “microbial secondary metabolites.”
- Published
- 2019
3. Bacteria Isolated From the Antarctic Sponge Iophon sp. Reveals Mechanisms of Symbiosis in Sporosarcina, Cellulophaga, and Nesterenkonia
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Mario Moreno-Pino, Juan A. Ugalde, Jorge H. Valdés, Susana Rodríguez-Marconi, Génesis Parada-Pozo, and Nicole Trefault
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Antarctic sponges ,symbiotic lifestyles ,sponge microbiome ,Antarctic ecosystem ,sponge-associated bacteria ,Microbiology ,QR1-502 - Abstract
Antarctic sponges harbor a diverse range of microorganisms that perform unique metabolic functions for nutrient cycles. Understanding how microorganisms establish functional sponge–microbe interactions in the Antarctic marine ecosystem provides clues about the success of these ancient animals in this realm. Here, we use a culture-dependent approach and genome sequencing to investigate the molecular determinants that promote a dual lifestyle in three bacterial genera Sporosarcina, Cellulophaga, and Nesterenkonia. Phylogenomic analyses showed that four sponge-associated isolates represent putative novel bacterial species within the Sporosarcina and Nesterenkonia genera and that the fifth bacterial isolate corresponds to Cellulophaga algicola. We inferred that isolated sponge-associated bacteria inhabit similarly marine sponges and also seawater. Comparative genomics revealed that these sponge-associated bacteria are enriched in symbiotic lifestyle-related genes. Specific adaptations related to the cold Antarctic environment are features of the bacterial strains isolated here. Furthermore, we showed evidence that the vitamin B5 synthesis-related gene, panE from Nesterenkonia E16_7 and E16_10, was laterally transferred within Actinobacteria members. Together, these findings indicate that the genomes of sponge-associated strains differ from other related genomes based on mechanisms that may contribute to the life in association with sponges and the extreme conditions of the Antarctic environment.
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- 2021
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4. A Novel OmpR-Type Response Regulator Controls Multiple Stages of the Rhizobium etli – Phaseolus vulgaris N2-Fixing Symbiosis
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Susana Rodríguez, David Correa-Galeote, Mishael Sánchez-Pérez, Mario Ramírez, Mariel C. Isidra-Arellano, María del Rocío Reyero-Saavedra, David Zamorano-Sánchez, Georgina Hernández, Oswaldo Valdés-López, and Lourdes Girard
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OmpR-type regulator ,nodulation ,nitrogen fixation ,symbiosis ,gene expression ,multidrug efflux pumps ,Microbiology ,QR1-502 - Abstract
OmpR, is one of the best characterized response regulators families, which includes transcriptional regulators with a variety of physiological roles including the control of symbiotic nitrogen fixation (SNF). The Rhizobium etli CE3 genome encodes 18 OmpR-type regulators; the function of the majority of these regulators during the SNF in common bean, remains elusive. In this work, we demonstrated that a R. etli mutant strain lacking the OmpR-type regulator RetPC57 (ΔRetPC57), formed less nodules when used as inoculum for common bean. Furthermore, we observed reduced expression level of bacterial genes involved in Nod Factors production (nodA and nodB) and of plant early-nodulation genes (NSP2, NIN, NF-YA and ENOD40), in plants inoculated with ΔRetPC57. RetPC57 also contributes to the appropriate expression of genes which products are part of the multidrug efflux pumps family (MDR). Interestingly, nodules elicited by ΔRetPC57 showed increased expression of genes relevant for Carbon/Nitrogen nodule metabolism (PEPC and GOGAT) and ΔRetPC57 bacteroids showed higher nitrogen fixation activity as well as increased expression of key genes directly involved in SNF (hfixL, fixKf, fnrN, fixN, nifA and nifH). Taken together, our data show that the previously uncharacterized regulator RetPC57 is a key player in the development of the R. etli - P. vulgaris symbiosis.
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- 2020
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5. Transfer of the Symbiotic Plasmid of Rhizobium etli CFN42 to Endophytic Bacteria Inside Nodules
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Luis Alfredo Bañuelos-Vazquez, Daniel Cazares, Susana Rodríguez, Laura Cervantes-De la Luz, Rosana Sánchez-López, Lucas G. Castellani, Gonzalo Torres Tejerizo, and Susana Brom
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plasmid ,conjugative transfer ,nodulation ,symbiosis ,rhizobia ,Microbiology ,QR1-502 - Abstract
Conjugative transfer is one of the mechanisms allowing diversification and evolution of bacteria. Rhizobium etli CFN42 is a bacterial strain whose habitat is the rhizosphere and is able to form nodules as a result of the nitrogen-fixing symbiotic relationship it may establish with the roots of Phaseolus vulgaris. R. etli CFN42 contains one chromosome and six large plasmids (pRet42a – pRet42f). Most of the genetic information involved in the establishment of the symbiosis is localized on plasmid pRet42d, named as the symbiotic plasmid (pSym). This plasmid is able to perform conjugation, using pSym encoded transfer genes controlled by the RctA/RctB system. Another plasmid of CFN42, pRet42a, has been shown to perform conjugative transfer not only in vitro, but also on the surface of roots and inside nodules, using other rhizobia as recipients. In addition to the rhizobia involved in the formation of nodules, these structures have been shown to contain endophytic bacteria from different genera and species. In this work, we have explored the conjugative transfer of the pSym (pRet42d) from R. etli CFN42 to endophytic bacteria as putative recipients, using as donor a CFN42 derivative labeled with GFP in the pRet42d and RFP in the chromosome. We were able to isolate some transconjugants, which inherit the GFP, but not the RFP marker. Some of them were identified, analyzed and evaluated for their ability to nodulate. We found transconjugants from genera such as Stenotrophomonas, Achromobacter, and Bacillus, among others. Although all the transconjugants carried the GFP marker, and nod, fix, and nif genes from pRet42d, not all were able to nodulate. Ultrastructure microscopy analysis showed some differences in the structure of the nodules of one of the transconjugants. A replicon of the size of pRet42d (371 Kb) could not be visualized in the transconjugants, suggesting that the pSym or a segment of the plasmid is integrated in the chromosome of the recipients. These findings strengthen the proposal that nodules constitute a propitious environment for exchange of genetic information among bacteria, in addition to their function as structures where nitrogen fixation and assimilation takes place.
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- 2020
- Full Text
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