Abstract
Streptomyces 5.1 is a bacterium isolated from rice soils in the south of the Tolima department (Colombia). This microorganism is characterized by its antagonistic activity against rubber tree phytopathogens like Colletotrichum gloeosporioides, the causal agent of leaf anthracnose. The antifungal activity of this Streptomyces isolate has been associated with secondary metabolites production. However, the identity of those metabolites is unknown because its purification and identification have not been possible through classic chemical studies. Therefore, aiming to contribute in the study of the secondary metabolites produced by 5.1 from a molecular approach, this research seeks to identify -preliminarily- the genomic fingerprint changes associated with the production of antifungal secondary metabolites produced by Streptomyces 5.1 through the evaluation of a mutant library of 5.1 obtained by random mutagenesis using controlled ultraviolet light exposure. The antifungal activity of obtained mutants was evaluated using Colletotrichum gloeosporioides (C1) fungus as a biosensor, isolated by the Biotechnology Institute of Universidad Nacional de Colombia. In this way, the library of mutants of 5.1, initially formed by 300 isolations, was classified into two phenotypic groups of interest: enhanced mutants (1 isolate) and null mutants (11 isolates) of secondary metabolites. The genomic changes in both groups were analyzed by obtaining the genomic profile of the isolates using Repetitive Extragenic Palindromic (Rep-PCR). The obtained profiles evidenced the presence of one additional band in the enhanced mutant, and the absence of a specific band in the non-producing mutants, both in comparison with the original strain. These bands are proposed for a future sequencing study which will define their role in the production process of metabolites with antifungal activity in Streptomyces 5.1.
Highlights
IntroductionAntagonistic microorganisms have been studied in the last fifty years, due to its potential for controlling phytopathogens on crops with agricultural and economic importance (Serrano-Carreón & Galindo-Fentanes, 2007)
Streptomyces 5.1 was originally isolated from rice rhizosphere soil from La Pilar (Venadillo) and El Puente (Armero), both located in the Tolima department, Colombia by the Bioprocesses and Bioprospecting group from the IBUN (Suárez-Moreno et al, 2019)
It was possible to observe the same size, beige round colonies hardly adhered to medium In ISP3 agar medium, a typical growth was found characterized by different size round colonies, wooly mycelium and pink pigmentation on the top produced at the time of sporulation and red pigment produced through the medium
Summary
Antagonistic microorganisms have been studied in the last fifty years, due to its potential for controlling phytopathogens on crops with agricultural and economic importance (Serrano-Carreón & Galindo-Fentanes, 2007). These microorganisms can reduce phytopathogen impact on plants through direct and indirect mechanisms (Bloemberg & Lugtenberg, 2001; Hibbing, Fuqua, Parsek, & Peterson, 2010). Antibiosis has a high potential as a microbial biocontrol mechanism This mechanism is based on the production of a single or a set of molecules (mostly secondary metabolites) by a microorganism that can inhibit the growth or development of another (susceptible) organism(s) (Vaidya, Shah, Vyas, & Chhatpar, 2001; Garon et al, 2006). This inhibition process is associated with DNA, RNA, proteins synthesis interference, or cell wall destabilization (Vaidya et al, 2001; Gohel et al, 2006)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
