ABSTRACT
Fatty acids of Ralstonia solanacearum cultured under different temperatures, times, pH values and cultural media were detected by using gas chromatography (GC) method. Rs-J.1.4-010704-01v, a viru- lent strain of R. solanacearum isolated from ginger was chosen for the experiment. The results showed that the kind of fatty acid of Rs-J.1.4-010704-01v fluctuated from 14 to 33. The contents of its three plentiful fatty acids, C16:1?7c/C15:0 ISO 2OH, C16:0 and C18:1?7c (with retain times of 10.644, 10.950 and 14.177 min, respectively), also varied in a range of 55.66% to 75.69%. The diversification of the bacterium’s fatty acids at various cultural conditions was clustered into four groups by cluster analysis, according to the kinds and percentage contents of the fatty acids detected. The pathogenicities of Rs-J.1.4-010704-01v under 20?C and 25?C were deduced to be mid-virulent, with C16:0 less than C16:1?7c/C15:0 ISO 2OH. The bac- terium showed as a virulent strain under the other cultural conditions including 30?C~40?C, 24 h~96 h, pH 5~9 and four cultural media (LB、NA、TTC and TSB), with C16:0 more than C16:1?7c/C15:0 ISO 2OH.However, the difference between C16:0 and C16:1?7c/C15:0 ISO 2OH raised significantly from 2.35 to 13.23 under 40?C and 48 h~96 h. Meanwhile, the kind of fatty acid increased more than 30 as the cultural time increased. It was concluded that temperature and cultural time had more significant effects on the fatty acid composition of R. solanacearum than pH value and cultural medium.
ABSTRACT
In order to increase the mycelial production of Phellinus linteus, which exhibits potent anticancer activity, some ingredients of the medium used to culture P. linteus were investigated. The optimal medium composition for the production of Phellinus linteus was determined to be as follows: fructose, 40 g/l; yeast extract, 20 g/l; K2HPO4, 0.46 g/l; KH2PO4, 1.00 g/l; MgSO4.7H2O, 0.50 g/l; FeCl2.62O, 0.01 g/l; MnCl2.4H2O, 0.036 g/l; ZnCl2, 0.03 g/l; and CuSO4.7H2O, 0.005 g/l. The optimal culture conditions were determined to be as follows: temperature, 28degrees C; initial pH, 5.5; aeration, 0.6 vvm; and agitation, 100 rpm, respectively. Under optimal composition and conditions, the maximum mycelial biomass achieved in a 5 l jar fermentor was 29.9 g/l.
Subject(s)
Biomass , Bioreactors , Dihydroergotamine , Fructose , Hydrogen-Ion Concentration , Phosphates , Polysaccharides , Potassium Compounds , YeastsABSTRACT
The purpose is to obtain optimal cultural conditions for Ganoderma lucidum in the solid medium mainly containing the residual of Pteridium aquilinum,and to provide theoretical foundation for the further use of this material from Pteridium aquilinum.Response surface methodology was applied to optimize the main culture conditions including proportion of the residual compound in medium,water content in medium and culture temperature.The results showed that proportion of residual of Pteridium aquilinum in medium,water content in medium and cultural condition had noticeably significant effects on daily average growth rate of mycelium of Ganoderma lucidum(p
ABSTRACT
This study revealed that the content of intra and extracellular polysaccharides may be related to the cultural conditions.With decreasing NaHCO 3 or NaNO 3 concentration,the content of intracellular polysaccharide was reduced,Reduction of NaNO 3 concentration still caused the rise of extracellular polysaccharides.The K 2HPO 4 or NaCl concentration also had an effect on the production of both intracellular and extracellular polysaccharides.When PH value of media maintained at 8.0,there was the highest content of intra and extracellular polysaccharides.The same high content also occurred after culture of nine days.In addition the content of intracellular polysaccharide was higher under continuous light than under the light/dark circle.
ABSTRACT
To get high cell density,pH-stat fermentations of L.casei Zhang were carried out in the medium optimized previously under different cultural conditions.The influences of neutralizing agents,the concen-tration of buffer salts and glucose in the medium,pH,aeration and fed batch fermentation on the growth of L.casei Zhang were investigated.Based on the values of maximum specific growth rate,biomass and viable cells count in different cultural conditions,the optimal growth condition was regarded as follows:Glucose level of the medium was 80 g/L ～100 g/L;The pH was kept constant at 5.9 with aqua ammonia and anae-robic condition was kept by sparged with nitrogen periodically;The temperature was set at 37?C and cul-tured for 10 h ～12 h.The biomass and viable cells' number of L.casei Zhang under this culture conditions were 7 g/L and 3.5?1010 CFU/mL respectively,and were 7 times as high as that before optimized,which can meet the requirements of probiotics.
ABSTRACT
This paper dealt with the influences of different media, temperature, light and pH to the amount of oospore formation. The results showed that millet agar, bai yun beau agar and soybean agar provided the favorable condition for oospore formation, the number of oospores was 131.6~149.6 /cm2, but a few oospores was formation on frozen pea agar. The results also suggested that the optimal conditions for oospore formation were 18℃, pH7 and darkness. The oospores failed to be formed tinder fluorescent or black light.