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IntroductionPhytopathogenic fungi are a considerable concern for agriculture, as they can threaten the productivity of several crops worldwide. Meanwhile, natural microbial products are acknowledged to play an important role in modern agriculture as they comprehend a safer alternative to synthetic pesticides. Bacterial strains from underexplored environments are a promising source of bioactive metabolites.MethodsWe applied the OSMAC (One Strain, Many Compounds) cultivation approach, in vitro bioassays, and metabolo-genomics analyses to investigate the biochemical potential of Pseudomonas sp. So3.2b, a strain isolated from Antarctica. Crude extracts from OSMAC were analyzed through HPLC-QTOF-MS/MS, molecular networking, and annotation. The antifungal potential of the extracts was confirmed against Rhizoctonia solani strains. Moreover, the whole-genome sequence was studied for biosynthetic gene clusters (BGCs) identification and phylogenetic comparison.Results and DiscussionMolecular networking revealed that metabolite synthesis has growth media specificity, and it was reflected in bioassays results against R. solani. Bananamides, rhamnolipids, and butenolides-like molecules were annotated from the metabolome, and chemical novelty was also suggested by several unidentified compounds. Additionally, genome mining confirmed a wide variety of BGCs present in this strain, with low to no similarity with known molecules. An NRPS-encoding BGC was identified as responsible for producing the banamides-like molecules, while phylogenetic analysis demonstrated a close relationship with other rhizosphere bacteria. Therefore, by combining -omics approaches and in vitro bioassays, our study demonstrates that Pseudomonas sp. So3.2b has potential application to agriculture as a source of bioactive metabolites.

Elicitação do metabolismo secundário de Streptomyces lunalinharesii através do co-cultivo com Rhizoctonia solani / Naydja Moralles Maimone.-versão revisada de acordo com a resolução CoPGr 6018 de 2011.-Piracicaba, 2020. 83 p. Dissertação (Mestrado)-USP / Escola Superior de Agricultura "Luiz de Queiroz". 1. Metabólitos secundários 2. Bioprospecção 3. Actinobactérias endofíticas 4. Molecular networking 5. Metabolômica I. Título EPÍGRAFE Durante muito, muito tempo, ninguém disse nada. Com o canto do olho, Phouchg via pela janela o mar de rostos cheios de expectativa na praça. "Nós vamos ser linchados, não vamos?", sussurrou. "A pergunta não foi fácil", disse o Pensador Profundo, com modéstia. "Quarenta e dois!", berrou Loonquawl. "É tudo o que você tem a nos dizer depois de sete milhões e quinhentos mil anos de trabalho?" "Eu verifiquei cuidadosamente", disse o computador, "e não há dúvida de que a resposta é essa. Para ser franco, acho que o problema é que vocês jamais souberam qual é a pergunta." "Mas era a Grande Pergunta! A Questão Fundamental da Vida, o Universo e Tudo Mais", gritou Loonquawl. "É", disse o Pensador Profundo, num tom de voz de quem tem enorme paciência para aguentar pessoas estúpidas, "mas qual é exatamente a pergunta?" Um silêncio de estupefação aos poucos dominou os homens, que olharam para o computador e depois se entreolharam.