LASER MUTAGENESIS AND SELECTION OF STREPTOCOCCUS ZOOEPIDEMICUS PROTOPLASTS
- VernacularTitle:兽疫链球菌原生质体激光诱变及高产菌株筛选
- Author:
Li-Rong TENG
;
Yan-Hou LIU
;
Jia ZHANG
;
Bing LIANG
;
Feng WANG
;
- Publication Type:Journal Article
- Keywords:
Hyaluronic acid, Streptococcus zooepidemicus, Protoplast, Laser mutagenesis
- From:
Microbiology
1992;0(01):-
- CountryChina
- Language:Chinese
-
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.
