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英语翻译
The strain Spirulina platensis UTEX 1926,recently re-classified as Arthrospira (Spirulina) platensis (Nordstedt) Gomont ,was obtained from the University of The strain Spirulina platensis UTEX 1926,recently re-classified as Arthrospira (Spirulina) platensis (Nordstedt) Gomont ,was obtained from the University of Texas Culture Collection.Two different types of media were used.The medium of Schlösser
with NaNO3 as a nitrogen source was utilized for microorganism maintenance and inoculum preparation,whereas a modified medium was utilized for cultivations,where NaNO3 was substituted by urea as nitrogen source.The total fed mass of urea was a function of the total feeding time.Cells for the inoculum were
grown in 500mL Erlenmeyer flasks containing 200mL of medium,kept on rotary shaker at 100min−1,temperature of 30 ◦C and light intensity of 72\2mol photonsm−2 s−1 [25].After achievementof the exponential phase,they were harvested and used to seed elongated minitanks (light-exposed area of 0.123m2) made of PVC laminas simulating large-scale outdoor ponds .Cultivations were carried out at a paddle wheel rotation of 18 min−1,28◦C and a constant working volume of 5.0 L ensured by daily addition of distilled water to replace its evaporation.The continuous light intensity was regulated at 108\2mol photonsm−2 s−1 [23] by means of six 20W fluorescent lamps and an illuminance meter TL-1 (Minolta,Osaka,Japan).Light intensity was initially expressed in klx,and then converted to photosynthetic photon flux density (PPFD),expressed in \2mol photons m−2 s−1,using the conversion
factor proposed by McCree for white fluorescent light (12\2mol photonsm−2 s−1 klx−1).An initial biomass concentration of 50mgL−1 (dry weight) was always used at the start of each fed-batch culture [29] that preceded three successive repeated fed-batch cycles.In order to avoid growth inhibition due to excess of ammonia,the initial nitrogen concentration was set at 2.67mM,and the feeding time of the preliminary
fed-batch phase was set in 14 days .According to the experimental protocol listed in Table 1,in all the repeated fed-batch cultivations,aliquots of a concentrated urea solution were daily added to the medium to give a nitrogen concentration of 1.50mM
.For this purpose,the following equation was used to ensure a constant feeding rate:N = a + bt (1) where N is the nitrogen concentration added up to a time t,a = 2.67mM that present at the beginning of the cultivation and of each cycle,and b = 1.5mMd−1 is a parameter which the fedbatch feeding pattern depends on.According to the ratio between renewed and total volumes (R),the total feeding time (tf) varied from1 to 16 days.
复制粘贴原因,有些符号不准确.段中“mol”前都有个 μ ,m2是指㎡,以此类推m-2等 .主要是专业术语,好的话我会多加30分.
The strain Spirulina platensis UTEX 1926,recently re-classified as Arthrospira (Spirulina) platensis (Nordstedt) Gomont ,was obtained from the University of The strain Spirulina platensis UTEX 1926,recently re-classified as Arthrospira (Spirulina) platensis (Nordstedt) Gomont ,was obtained from the University of Texas Culture Collection.Two different types of media were used.The medium of Schlösser
with NaNO3 as a nitrogen source was utilized for microorganism maintenance and inoculum preparation,whereas a modified medium was utilized for cultivations,where NaNO3 was substituted by urea as nitrogen source.The total fed mass of urea was a function of the total feeding time.Cells for the inoculum were
grown in 500mL Erlenmeyer flasks containing 200mL of medium,kept on rotary shaker at 100min−1,temperature of 30 ◦C and light intensity of 72\2mol photonsm−2 s−1 [25].After achievementof the exponential phase,they were harvested and used to seed elongated minitanks (light-exposed area of 0.123m2) made of PVC laminas simulating large-scale outdoor ponds .Cultivations were carried out at a paddle wheel rotation of 18 min−1,28◦C and a constant working volume of 5.0 L ensured by daily addition of distilled water to replace its evaporation.The continuous light intensity was regulated at 108\2mol photonsm−2 s−1 [23] by means of six 20W fluorescent lamps and an illuminance meter TL-1 (Minolta,Osaka,Japan).Light intensity was initially expressed in klx,and then converted to photosynthetic photon flux density (PPFD),expressed in \2mol photons m−2 s−1,using the conversion
factor proposed by McCree for white fluorescent light (12\2mol photonsm−2 s−1 klx−1).An initial biomass concentration of 50mgL−1 (dry weight) was always used at the start of each fed-batch culture [29] that preceded three successive repeated fed-batch cycles.In order to avoid growth inhibition due to excess of ammonia,the initial nitrogen concentration was set at 2.67mM,and the feeding time of the preliminary
fed-batch phase was set in 14 days .According to the experimental protocol listed in Table 1,in all the repeated fed-batch cultivations,aliquots of a concentrated urea solution were daily added to the medium to give a nitrogen concentration of 1.50mM
.For this purpose,the following equation was used to ensure a constant feeding rate:N = a + bt (1) where N is the nitrogen concentration added up to a time t,a = 2.67mM that present at the beginning of the cultivation and of each cycle,and b = 1.5mMd−1 is a parameter which the fedbatch feeding pattern depends on.According to the ratio between renewed and total volumes (R),the total feeding time (tf) varied from1 to 16 days.
复制粘贴原因,有些符号不准确.段中“mol”前都有个 μ ,m2是指㎡,以此类推m-2等 .主要是专业术语,好的话我会多加30分.
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