Streptomycin is an antibiotic which acts as a protein synthesis inhibitor.  This aminoglycoside acts by binding to the 30S ribocomal subunit, preventing protein production and leading to bacterial cell death.  Streptomycin is more effective against Gram-positive bacteria than Gram-negative and is offered in a powder form. Streptomycin is an antibiotic which acts as a protein synthesis inhibitor.  This aminoglycoside acts by binding to the 30S ribocomal subunit, preventing protein production and leading to bacterial cell death.  Streptomycin is more effective against Gram-positive bacteria than Gram-negative and is offered in a powder form.