Microbial natural products are among the main sources of compounds used in the medical biotechnology field for the purpose of drug development. However, as antibiotic resistance in pathogenic microorganisms is known to be increasing dramatically, there exists a need to develop new antibiotics. Actinomycetia have proven to be a good source of biologically active compounds, although the rediscovery of previously known compounds significantly slows down the introduction of new antibiotics. As a consequence, increasing attention is being paid to the isolation of actinomycete strains from previously unexplored sources, which can significantly increase the likelihood of discovering new biologically active compounds. This study investigated the diversity and bioactive potential of 372 actinomycete strains isolated from the rhizosphere soil of Juniperus excelsa M. Bieb. The examined actinomycete strains belonged to 11 genera, namely, Actinoplanes, Actinorectispora, Amycolatopsis, Kribbella, Micrococcus, Micromonospora, Nocardia, Promicromonospora, Rhodococcus, Saccharopolyspora and Streptomyces. The bioactive potential of each isolated actinomycete strain was determined on the basis of its ability to produce antimicrobial metabolites against Gram-positive and Gram-negative bacteria and yeast. Some 159 strains (42.74%) exhibited antimicrobial activity against at least one of the tested microbial strains. The dereplication analysis of the extract of the Streptomyces sp. Je 1-651 strain, which exhibited strong antimicrobial activity, led to the annotation of spiramycins and stambomycins. Moreover, the phylogenetic analysis based on the 16S rRNA gene sequence of the Je 1-651 strain revealed it to be close to the S. ambofaciens.
- MeSH
- Actinobacteria * MeSH
- Actinomycetales * genetika MeSH
- antibakteriální látky farmakologie metabolismus MeSH
- antiinfekční látky * MeSH
- fylogeneze MeSH
- gramnegativní bakterie genetika MeSH
- grampozitivní bakterie MeSH
- jalovec (rod) * genetika MeSH
- půda MeSH
- půdní mikrobiologie MeSH
- rhizosféra MeSH
- RNA ribozomální 16S genetika MeSH
- Streptomyces * genetika MeSH
- Publikační typ
- časopisecké články MeSH
Bacteria-assisted bioremediation is widely recognized as a low-cost method to minimize the consequences of soil pollution with toxic metals originating from industrial sites. Strains used in bioremediation have to deal with high metal load via biosorption, reduction, bioprecipitation, metal sequestration, and/or chelation. Actinobacteria, and streptomycetes in particular, are considered a perspective group for bioremediation as natural soil inhabitants with extensive secondary metabolism. Nevertheless, there is no reference information on survival of the model streptomycetes in the presence of the most abundant metal pollutants. Also, there are no reports describing the selection approaches towards improvement of bioremediation properties. In this work, the resistance of Streptomyces coelicolor M145 and Streptomyces sioyaensis Lv81 to certain transition metals and their growth under different pH values are described for the first time. Spontaneous chromate-resistant S. sioyaensis Lv81-138 strain was selected in the course of this work. Strain Lv81-138 is the most efficient actinobacterial Cr(VI) reducer reported so far, capable of converting 12 mmol/L of Cr(VI) into Cr(III) in a medium supplemented with 50 mmol/L K2CrO4.
- MeSH
- bakteriální léková rezistence * MeSH
- biotransformace MeSH
- chromany metabolismus toxicita MeSH
- koncentrace vodíkových iontů MeSH
- kovy metabolismus toxicita MeSH
- kultivační média chemie MeSH
- látky znečišťující životní prostředí metabolismus toxicita MeSH
- mikrobiální viabilita účinky léků MeSH
- mutace * MeSH
- oxidace-redukce MeSH
- Streptomyces účinky léků růst a vývoj metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
