BACKGROUND Microbial biosorption is recognized as a resourceful process for the remediation of pollution from contaminated environs. To investigate radionuclide bioremediation, carbohydrate contained extracellular polymeric substance (EPS) and strontium ion (Sr+) tolerant marine actinobacterium has been isolated and identified as Streptomyces sp. CuOff24 through 16S rDNA sequencing. RESULTS EPS was extracted, characterized and the biosorption of the long half-life radionuclide of Sr2+ was also performed. EPS could remove 82% of Sr2+ from the experimental solution of 100 mg L-1 of strontium chloride (SrCl2). Furthermore, EPS composition also obtained with the presence of Sr2+ radionuclide and major contents of carbohydrate (68.6%) followed by protein (12.3%), nucleic acid (10.4%) and unidentified compounds 8.7%) were quantified. The spectroscopy study also confirmed the presence of carbohydrate functional groups presence in the EPS surface were probably to be involved in Sr2+ adsorption. CONCLUSION Overall results conclude that, marine actinobacterial EPS could be used for the large-scale remediation of radionuclides contaminated environment. (c) 2019 Society of Chemical Industry