【摘要】 探索了透明质酸 (Hyaluronicacid)产生菌—兽疫链球菌 (Streptococcuszooepidemicus)原生质体制备与再生的最佳条件。研究了酶浓度、酶解时间、高渗液的选择、预处理及高渗预培养等因素的影响。确定了最佳条件为 :经 1 2 %甘氨酸预处理及高渗预培养共同作用2h后 ,用 5 0U mL溶菌酶 ,在NaCl高渗体系中 ,于 39℃作用 60min。在此条件下 ,原生质体形成率可达 94 6% ,再生率可达 1 8 5 %。用不同功率的He Ne激光照射不同时间诱变原生质体 ,当功率密度为 40mW cm2 ,照射时间为 30 0s时 ,其致死率可达 99 88%。从存活变异株中筛选出一株高产透明质酸菌株 ,其产量 ( 2 2 1g L)达原始菌株 ( 0 49g L)的 4 5倍。更多还原

【Abstract】 Conditions about protoplast preparation and regeneration of Streptococcus zooepidemicus,which could produce hyaluronic acid, were studied , including the concentration of lysozyme, lytic time, different osmotic stabilizers and the preculture under the high osmotic pressure . As a result, the formation and regeneration rate of protoplasts could reach up to 94.6% and 18.5% respectively under the optimum conditions, before the digestion of lysozyme (50U/mL,39℃, 60 min) the strain was cultured for 2 hours in 0.6 mol/L NaCl high osmotic pressure liquid medium containing 1.2% Gly. Among different treatments of various laser power and irradiating time, He-Ne laser which acted for 300 seconds with 40mW /cm 2 caused lethality rate as high as 99.88%. Finally, a mutated strain was gained, whose production of HA is 2.21g/L, just 4.5 times as much as the original strain.更多还原