Moroccan actinobacteria with promising activity against toxic cyanobacteria Microcystis aeruginosa

Abstract

In recent decades, harmful cyanobacterial blooms (HCBs) have become a severe hazard for human health mainly in drinking water resources and are responsible for serious ecological disturbances in freshwater ecosystems. The present study aims to explore the potential of actinobacteria isolated from a sediment samples collected from Moroccan salt river to control HCBs mainly through Microcystis aeruginosa lysis. In order to investigate the possible anticyanobacterial response mechanisms, the antioxidant enzyme activities of M. aeruginosa cells were analyzed. Anti-cyanobacterial activity was tested using the agar cylinder method against the toxic cyanobacteria Microcystis aeruginosa. Among the twenty-three isolates tested, only one showed promising anti-cyanobacterial activities with inhibition zone (ZI) equal to 22.00 mm, minimum inhibitory concentration (MIC) equal to 19.53 mg/L and minimum bactericidal concentration MBC equal to 39.06 mg/L. Phylogenetic analysis of the near-complete 16S rRNA gene sequence indicated that the strain DS1R1 belongs to the genus Streptomyces and has highest similarity (100%) to Streptomyces sp. Indeed, M. aeruginosa growth, chlorophyll-a and protein content were significantly reduced by Streptomyces sp. DS1R1 extract. Superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) were significantly elevated after treatment with Streptomyces sp. DS1R1 extract. These experimental findings provided insights in the development of a new eco-friendly procedure based on the use of actinobacteria for toxic cyanobacterial blooms bio-control.

Isolation, Identification, and Antibacterial Properties of Prodigiosin, a Bioactive Product Produced by a New Serratia marcescens JSSCPM1 Strain: Exploring the Biosynthetic Gene Clusters of Serratia Species for Biological Applications

“…Multiple sequence alignments of these sequences were carried out using the MUSCLE algorithm, executed with the MEGA11 software [ 72 ]. The phylogenetic tree was constructed using the maximum likelihood method with the Kimura two-parameter model, and the resulting tree phylogeny was evaluated using bootstrap analysis with 500 replicates [ 73 , 74 ]. The generated tree was created and visualized on the iTOL server (Interactive Tree of Life) [ 75 ].…”

Acyl Chain Specificity of Marine Streptomyces klenkii PhosPholipase D and Its Application in Enzymatic Preparation of Phosphatidylserine

“…However, until now, only about 20 PLDs from Streptomyces were experimentally characterized. Streptomyces are found in a wide range of aquatic and terrestrial environments, it have the metabolic pathways with the abundant hydrolytic enzymes [ 12 , 13 ]. However, most of the reported PLDs originated from Streptomyces live in terrestrial soil environments.…”