Gli Attinomiceti sono noti per la loro capacità di produrre una grande quantità di metaboliti secondari ampiamente utilizzati in medicina e nell'industria. In particolare, il genere Streptomyces è il più impiegato nella produzione di tali metaboliti. I metodi di genome mining hanno rivelato che gli Streptomyces ospitano un gran numero di cluster genici biosintetici (BGCs), il che spiega il loro enorme potenziale biosintetico. Tuttavia, nell'ultimo decennio non è stata scoperta quasi nessuna nuova classe di antibiotici e la maggior parte dei tentativi di isolare nuovi ceppi o composti ha portato al re-isolamento di batteri già noti. Nonostante ciò, i ceppi provenienti da ambienti estremi e precedentemente trascurati sono stati considerati una potenziale fonte di nuovi composti bioattivi. Nella prima parte di questo studio, 15 ceppi isolati da ambienti legati al carbone (ceppi ACRE) sono stati caratterizzati tassonomicamente. L'analisi filogenetica ha mostrato che questi ceppi appartengono ai due generi Streptomyces e Pseudonocardia. Nella seconda parte, due linee batteriche antimicotiche isolate da tali ambienti, Streptomyces sp. S-2 e Streptomyces sp. MW-W600-10, sono state co-coltivate con il fitopatogeno Fusarium culmorum DSM 62188, al fine di misurare l'espressione di quei BGCs che potrebbero essere coinvolti nell'attività antifungina. I cluster sono stati predetti e selezionati utilizzando antiSMASH. Molti di loro hanno mostrato una somiglianza bassa o nulla con altri cluster presenti nel database. Sia rRNA 16S che hrdB sono stati utilizzati come geni di riferimento nell'analisi dell'espressione dei BGCs. I risultati hanno rivelato che alcuni di questi cluster potrebbero essere coinvolti nella produzione di nuovi composti bioattivi, in particolare quelli che mostrano somiglianza con fredericamicina A (100%) e surugamide A/D (57%) per S-2 e una sintetasi peptidica non ribosomiale (NRPS) non presente nei database per MW-W600-10. Ulteriori studi sono necessari per l'identificazione dei metaboliti sintetizzati e la comprensione del potenziale biologico/biotecnologico di entrambi i ceppi.
Actinobacteria are well-known for their ability to produce a plethora of secondary metabolites that are widely used in medicine and industry. In particular, the genus Streptomyces is the most exploited for the production of such metabolites. Genome mining methods revealed that Streptomyces harbour a large number of biosynthetic gene clusters (BGCs), explaining their huge biosynthetic potential. However, almost no new class of antibiotics have been discovered in the last decade and most attempts to isolate new strains or compounds led to the re-isolation of already known bacteria. Nevertheless, strains from extreme and previously neglected environments have been considered to be a potential source of new bioactive compounds. In the first part of this study, 15 strains isolated from coal related environments (ACRE strains) were taxonomically characterized. The phylogenetic analysis showed that these strains belong to the two genera Streptomyces and Pseudonocardia. In the second part, two antifungal strains isolated from such environs, Streptomyces sp. S-2 and Streptomyces sp. MW-W600-10, were co-cultured with the plant pathogen Fusarium culmorum DSM 62188, in order to measure the expression of those BGCs that might be involved in the antifungal activity. Clusters were predicted and selected using antiSMASH tool. Many of them showed low or no similarity to those present in the database. Both 16S rRNA and hrdB were used as reference genes in BGCs expression analysis. Results revealed that some of these clusters might be involved in the production of new bioactive compounds, in particular those showing similarity to fredericamycin A (100%) and surugamide A/D (57%) for S-2, and an unknown non-ribosomal peptide synthetase (NRPS) for MW-W600-10. Further studies are necessary for the identification of synthetized metabolites and the comprehension of the biological/biothecnological potential of both strains.
Analysis of the Expression of Biosynthetic Gene Clusters in Two Streptomyces Strains Isolated from Coal Related Environments
ROCCO, SIMONE
2020/2021
Abstract
Actinobacteria are well-known for their ability to produce a plethora of secondary metabolites that are widely used in medicine and industry. In particular, the genus Streptomyces is the most exploited for the production of such metabolites. Genome mining methods revealed that Streptomyces harbour a large number of biosynthetic gene clusters (BGCs), explaining their huge biosynthetic potential. However, almost no new class of antibiotics have been discovered in the last decade and most attempts to isolate new strains or compounds led to the re-isolation of already known bacteria. Nevertheless, strains from extreme and previously neglected environments have been considered to be a potential source of new bioactive compounds. In the first part of this study, 15 strains isolated from coal related environments (ACRE strains) were taxonomically characterized. The phylogenetic analysis showed that these strains belong to the two genera Streptomyces and Pseudonocardia. In the second part, two antifungal strains isolated from such environs, Streptomyces sp. S-2 and Streptomyces sp. MW-W600-10, were co-cultured with the plant pathogen Fusarium culmorum DSM 62188, in order to measure the expression of those BGCs that might be involved in the antifungal activity. Clusters were predicted and selected using antiSMASH tool. Many of them showed low or no similarity to those present in the database. Both 16S rRNA and hrdB were used as reference genes in BGCs expression analysis. Results revealed that some of these clusters might be involved in the production of new bioactive compounds, in particular those showing similarity to fredericamycin A (100%) and surugamide A/D (57%) for S-2, and an unknown non-ribosomal peptide synthetase (NRPS) for MW-W600-10. Further studies are necessary for the identification of synthetized metabolites and the comprehension of the biological/biothecnological potential of both strains.| File | Dimensione | Formato | |
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https://hdl.handle.net/20.500.14240/155883