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21.
To increase the cell concentration and the accumulation of astaxanthin in the cultivation of Haematococcus pluvialis, effects of different iron eleetrovalencies (Fe2+-EDTA and Fe3+-EDTA) and species (Fe-EDTA, Fe(OH)32x and FeC6H5O7) addition on cell growth and accumulation of astaxanthin were studied. Results show that different iron electrovalencies have various effects on cell growth and astaxanthin accumulation of H. pluvialis. Compared with Fe3+-EDTA, Fe2+-EDTA stimulate more effectively the formation of astaxanthin. The maximum astaxanthin content (30.70 mg/g biomass cell)was obtained under conditions of 18 μmol/L Fe2+-EDTA, despite the lower cell density (2.3x105 cell/ml)in such condition. Fe3+-EDTA is more effective than Fe2+-EDTA in improving the cell growth. Especially,the maximal steady-state cell density, 2.9x105 cell/ml was obtained at 18 μmol/L Fe3+-EDTA addition. On the other hand, all the various species of iron (EDTA-Fe, Fe(OH)32x, FeC6H5O7) are capable to improve the growth of the algae and astaxanthin production. Among the three iron species, FeC6H5O7 performed the best. Under the condition of a higher concentration (36 μmol/L) of FEC6H5O7, the cell density and astaxanthin production is 2 and 7 times higher than those of iron-limited group, respectively. The present study demonstrates that the effects of the stimulation with different iron species increased in the order of FeC6H5O7, Fe(OH)32x/x and EDTA-Fe. 相似文献
22.
采用生态学方法,以黑暗条件为对照,研究了白炽灯、日光灯、金卤灯作为照明光源及不同光照时间对凡纳滨对虾(Litopenaeusvannamei)游离虾青素含量及生长的影响。实验对虾初始湿体重为(2.108±0.036)g,实验持续50天。结果表明,不同光照对于对虾体内游离虾青素含量和生长均存在显著的影响。具昼夜节律金卤灯照明及日光灯恒照处理组对虾体内游离虾青素含量显著较高(P<0.05),对虾体内游离虾青素的含量平均为(3.31±0.20)mg/kg。对虾的特定生长率在具昼夜节律的金卤灯照明时最快(P<0.05),连续日光灯照明组生长最慢(P<0.05)。对虾的生长率与其体内游离虾青素含量呈显著的负相关性(P<0.05),说明对虾在体内积累虾青素的主要目的不是为了促进生长,可能是为了避免强光照对机体的伤害。本研究表明,在金卤灯照明的条件下,对虾具有较高的虾青素含量并且生长较快,因此金卤灯较其他灯具更适宜作为对虾室内养殖的光源。 相似文献
23.
DYNAMIC CHANGES OF INORGANIC NITROGEN AND ASTAXANTI—IIN ACCUMULATION IN HAEMATOCOCCUS PLUVIALIS 总被引：1，自引：1，他引：0
This study on dynamic changes of culture color,astaxanthin and chlorophylls,inorganic N including N-NO3^-,N-NO2^- and N-NH4^ in batch culture of Haematococcus pluvialis exposed to different additive nitrate concentration showed(1)ast/chl ratio was over 0.8 for brown and red algae,but was usually less than 0.5 for green and yellow algae;(2)N-NO3^-,in general,was unstable and decreased,except for a small unexpected increase in nitrate enriched treatment groups;(3)measurable amounts of N-NO2^- and N-NH4^ were observed respectively with three change modes although no extemal nitrite and ammonia were added into the culture;(4)a non-linear correlation between ast/chl ratio(or color)changes and the levels of N-NO3^-,N-NO2^-,N-NH4^ in H.pluvialis culture;(5)up and down variation of the ast/chl ratio occurred simultaneously with a perceptible color change from yellow to brown(or red)when N-NO3^-,N-NO2^- and N-NH4^ fluctuated around 30,5,5μmol/L respectively;(6)existence of three dynamic modes of N-NO3^-,N-NO2^- and N-NH4^ changes,obviously associated with initial extemal nitrate;(7)the key level of total inorganic N concentration regulating the above physiological changes during indoor cultivation was about 50 μmol/L;and(8)0.5-10mmol/L of nitrate was theoretically conducive to cell growth in batch culture. 相似文献
24.
In this paper, we investigated the effects of temperature, oxygen, antioxidants, and corn germ oil on the stability of astaxanthin from Haematococcus pluvialis under different storage conditions, and changes in the composition of astaxanthin esters during storage using high performance liquid chromatography and spectrophotometry. Oxygen and high temperatures （22-25~C） significantly reduced the stability of astaxanthin esters. Corn germ oil and antioxidants （ascorbic acid and vitamin E） failed to protect astaxanthin from oxidation, and actually significantly increased the instability of astaxanthin. A change in the relative composition of astaxanthin esters was observed after 96 weeks of long-term storage. During storage, the relative amounts of free astaxanthin and astaxanthin monoesters declined, while the relative amount of astaxanthin diesters increased. Thus, the ratio of astaxanthin diester to monoester increased, and this ratio could be used to indicate if astaxanthin esters have been properly preserved. If the ratio is greater than 0.2, it suggests that the decrease in astaxanthin content could be higher than 20%. Our results show that storing algal powder from H. pluvialis or other natural astaxanthin products under vacuum and in the dark below 4~C is the most economical and applicable storage method for the large-scale production of astaxanthin from H. pluvialis. This storage method can produce an astaxanthin preservation rate of at least 80% after 96 weeks of storage. 相似文献
25.
采用RT-PCR技术, 从雨生红球藻(Haematococcus pluvialis)中克隆出IPP异构酶基因(ipiHp1), 构建双元载体pCAMBIA3300-egfp-ipiHp1和基因枪转化载体pBlueScript SKⅡ-bar-egfp-ipiHp1, 利用根癌农杆菌侵染法和基因枪转化法, 将目的基因导入雨生红球藻中, 经过含50?g/mL草丁膦BBM培养基筛选得到阳性转化子。通过荧光观察报告基因egfp和PCR扩增分析, 证明ipiHp1基因整合到转化子的基因组中。生物量测定结果表明大部分转化子的生物量与野生型相似。虾青素含量测定发现, 农杆菌侵染法转化的转化子A3虾青素含量与野生型相比有显著变化, 平均值达到16.49mg/g, 与野生型相比提高了5.16%, 而基因枪转化法转化的转化子虾青素含量与野生型无显著性差异。 相似文献
26.
The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature. 相似文献
27.
28.
氧化应激是饲料组胺胁迫对鱼体产生危害的主要途径之一。研究具有强抗氧化能力的虾青素对美洲鳗鲡幼鱼饲料组胺胁迫的缓解效果, 对降低鱼类饲料源胁迫具有重要意义。将400尾初始体重为(25.01±0.17) g/尾的试验鱼随机分为4个处理组, 即对照组、H组、H+Ast4组和H+Ast8组, 分别饲喂基础饲料、高组胺饲料(662 mg/kg)及在高组胺饲料中添加4 mg/kg、8 mg/kg虾青素的试验饲料。结果显示: 与对照组相比, H组美洲鳗鲡幼鱼生长性能和血清非特异性免疫能力显著降低(P<0.05),肠道自由基水平显著升高(P<0.05),肠道有害菌群丰度升高; H+Ast组美洲鳗鲡幼鱼的生长性能、血清非特异性免疫能力显著高于H组(P<0.05),肠道自由基水平显著低于H组(P<0.05), 上述指标H+Ast组与对照组无显著差异(P>0.05)。H+Ast组肠道有益菌群丰度高于H组和对照组。可见, 添加4 mg/kg虾青素即可缓解饲料组胺胁迫导致的美洲鳗鲡幼鱼生长抑制, 提高血清非特异性免疫能力, 降低肠道自由基水平, 有益调节肠道菌群。添加8 mg/kg虾青素对美洲鳗鲡幼鱼上述指标无进一步的改善效果。研究结果可为虾青素缓解美洲鳗鲡饲料组胺胁迫及其在饲料中的推广应用提供参考。 相似文献
29.
Effects of iron electrovalence and species on growth and astaxanthin production of Haematococcus pluvialis 总被引：1，自引：1，他引：0
To increase the cell concentration and the accumulation of astaxanthin in the cultivation of Haematococcus pluvialis, effects of different iron electrovalencies (Fe2+-EDTA and Fe3+-EDTA) and species (Fe-EDTA, Fe(OH)x32x and FeC6H5O7) addition on cell growth and accumulation of astaxanthin were studied. Results show that different iron electrovalencies
have various effects on cell growth and astaxanthin accumulation of H. pluvialis. Compared with Fe3+-EDTA, Fe2+-EDTA stimulate more effectively the formation of astaxanthin. The maximum astaxanthin content (30.70 mg/g biomass cell) was
obtained under conditions of 18 μmol/L Fe2+-EDTA, despite the lower cell density (2.3×105 cell/ml) in such condition. Fe3+-EDTA is more effective than Fe2+-EDTA in improving the cell growth. Especially, the maximal steady-state cell density, 2.9×105 cell/ml was obtained at 18 μmol/L Fe3+-EDTA addition. On the other hand, all the various species of iron (EDTA-Fe, Fe(OH)x32x, FeC6H5O7) are capable to improve the growth of the algae and astaxanthin production. Among the three iron species, FeC6H5O7 performed the best. Under the condition of a higher concentration (36 μmol/L) of FeC6H5O7, the cell density and astaxanthin production is 2 and 7 times higher than those of iron-limited group, respectively. The
present study demonstrates that the effects of the stimulation with different iron species increased in the order of FeC6H5O7, Fe(OH)x32x and EDTA-Fe.
Supported by Xiamen Scientific and Technologic Projects (No. 3052Z20031086), Xiamen University Alumni Association Foundation
in Singapore, and the First National College Students Innovative Experimental Project 相似文献
30.
本研究对产虾青素的南极菌株NJ298进行了鉴定,同时对影响虾青素产量的主要环境因子进行了测试。形态特征、生理生化特征及ITS序列的系统发育分析表明,南极菌株NJ298属于红酵母属(Rhodotorula);虾青素积累主要在NJ298生长的对数期和稳定期;乙酸钠、蛋白胨是合成虾青素的最佳碳、氮源;在0-15℃之间,南极酵母NJ298均可以生长,但是低温更有利于虾青素的积累;pH值在6-8范围内NJ298均可生长,最适pH值为7.5;该菌对盐度要求不严格。 相似文献