The influence of different concentrations of Pb ions on biosynthetical ability of Streptomyces recifensis var. lyticus 2P-15, which is the producer of compound complex of extracellular enzymes and growth stimulators, was studied. It has been showed, that Pb ions introduced in agar medium have had a stimulative effect on production of surface and depth mycelia. The Pb ions, which have been inoculated into liquid fermentative medium in concentration of 1,0–2,0 mg/l realized directed synthesis of bacterio- and proteolytic enzymes, had an influence on qualitative and quantitative composition of produced enzymes.Досліджено вплив різних концентрацій іонів свинцю на біосинтетичні властивості штаму Streptomyces recifensis var. lyticus 2Р-15 – продуцента складного комплексу екстрацелюлярних ферментів і стимулятора росту. Показано, що іони свинцю, які вносились у тверде середовище, стимулюють утворення поверхневого міцелію та спорового посівного матеріалу. Іони свинцю, що вносились до складу рідкого ферментаційного середовища в концентрації 1,0–2,0 мг/л, стимулюють синтез бактеріо- та протеолітичних ферментів, впливаючи на кількісний і якісний склад синтезованих ферментів. The influence of different concentrations of Pb ions on biosynthetical ability of Streptomyces recifensis var. lyticus 2P-15, which is the producer of compound complex of extracellular enzymes and growth stimulators, was studied. It has been showed, that Pb ions introduced in agar medium have had a stimulative effect on production of surface and depth mycelia. The Pb ions, which have been inoculated into liquid fermentative medium in concentration of 1,0–2,0 mg/l realized directed synthesis of bacterio- and proteolytic enzymes, had an influence on qualitative and quantitative composition of produced enzymes