The changes in arachidonic acid (AA) and fatty acids profiles along the growth curve of Parietochloris incisa, a coccoid snow green alga, were studied in a 2.8 cm light-path flat photobioreactor, exposed to strong pho...The changes in arachidonic acid (AA) and fatty acids profiles along the growth curve of Parietochloris incisa, a coccoid snow green alga, were studied in a 2.8 cm light-path flat photobioreactor, exposed to strong photon flux density [PFD, 2400 μEmol/(m 2·s)]. Sixteen fatty acids were identified by gas chromatography showing that AA was the dominant fatty acid (33%-41%) followed by linoleic acid (17%-21%). AA content was closely investigated with respect to total fatty acids (TFA), ash free dry weight (AFDW) of cell mass as well as total culture content. These parameters were influenced significantly in a similar manner by culture growth phase, i.e., slightly decreasing in the lag period, gradually increasing in the logarithmic phase, becoming maximal at the early stationary phase, starting to decrease at the late stationary phase, sharply dropping at the decline phase. The increase in AA per culture volume during the logarithmic phase was not only associated with the increase in AFDW but also connected with a corresponding increase in AA/TFA, TFA/AFDW as well as AA/AFDW. The sharp decrease in AA content of the culture during the decline phase was mainly due to the decrease in AA/TFA, TFA/AFDW and AA/AFDW, although AFDW declined only a small extent. Maximal AA concentration, obtained at the early stationary phase, was 900 mg/L culture volume, and the average daily net increase of AA during 9 days logarithmic growth was 1.7 g/(m 2·day). Therefore, harvesting prior to the decline phase in a batch culture, or at steady state in continuous culture mode seems best for high AA production. The latter possibility was also further confirmed by continuous culture with 5 gradients of harvesting rate.展开更多
The present study is to determine the suitable protoscolices （PSCs） density for long-time culturing in vitro. The PSCs were divided into eight groups with different densities and the viability tests were carried out...The present study is to determine the suitable protoscolices （PSCs） density for long-time culturing in vitro. The PSCs were divided into eight groups with different densities and the viability tests were carried out with 0.1% methylene blue staining. Then the infection ability of cultured PSCs was assessed by the mean cyst weight of mice inoculated intraperitoneally with PSCs after 8 months post-infection.展开更多
The traditional view of the regulation of eicosanoid formation holds that agonists have to activate receptor-coupled phospholipases before eicosanoid syntheiss can be initiated. Action of phospholipases results in an ...The traditional view of the regulation of eicosanoid formation holds that agonists have to activate receptor-coupled phospholipases before eicosanoid syntheiss can be initiated. Action of phospholipases results in an increase in the intracellular concentration of unesterified arachidonic acid (AA). Once unesterified AA is present in sufficient amounts it can be metabolized by a variety of enzymes that catalyze展开更多
文摘The changes in arachidonic acid (AA) and fatty acids profiles along the growth curve of Parietochloris incisa, a coccoid snow green alga, were studied in a 2.8 cm light-path flat photobioreactor, exposed to strong photon flux density [PFD, 2400 μEmol/(m 2·s)]. Sixteen fatty acids were identified by gas chromatography showing that AA was the dominant fatty acid (33%-41%) followed by linoleic acid (17%-21%). AA content was closely investigated with respect to total fatty acids (TFA), ash free dry weight (AFDW) of cell mass as well as total culture content. These parameters were influenced significantly in a similar manner by culture growth phase, i.e., slightly decreasing in the lag period, gradually increasing in the logarithmic phase, becoming maximal at the early stationary phase, starting to decrease at the late stationary phase, sharply dropping at the decline phase. The increase in AA per culture volume during the logarithmic phase was not only associated with the increase in AFDW but also connected with a corresponding increase in AA/TFA, TFA/AFDW as well as AA/AFDW. The sharp decrease in AA content of the culture during the decline phase was mainly due to the decrease in AA/TFA, TFA/AFDW and AA/AFDW, although AFDW declined only a small extent. Maximal AA concentration, obtained at the early stationary phase, was 900 mg/L culture volume, and the average daily net increase of AA during 9 days logarithmic growth was 1.7 g/(m 2·day). Therefore, harvesting prior to the decline phase in a batch culture, or at steady state in continuous culture mode seems best for high AA production. The latter possibility was also further confirmed by continuous culture with 5 gradients of harvesting rate.
基金supported by International Collaboration on Drug and Diagnostics Innovation of Tropical Diseases in China (International S&T Cooperation 2010DFB73280)Technology Development Research for Science Research Institute (2011EG150312)the Youth Project of Shanghai Municipal Health Bureau (87)
文摘The present study is to determine the suitable protoscolices （PSCs） density for long-time culturing in vitro. The PSCs were divided into eight groups with different densities and the viability tests were carried out with 0.1% methylene blue staining. Then the infection ability of cultured PSCs was assessed by the mean cyst weight of mice inoculated intraperitoneally with PSCs after 8 months post-infection.
文摘The traditional view of the regulation of eicosanoid formation holds that agonists have to activate receptor-coupled phospholipases before eicosanoid syntheiss can be initiated. Action of phospholipases results in an increase in the intracellular concentration of unesterified arachidonic acid (AA). Once unesterified AA is present in sufficient amounts it can be metabolized by a variety of enzymes that catalyze
