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61.
Determination of biomass dry weight of marine microalgae 总被引:3,自引:0,他引:3
Total biomass dry weight (DW) and ash free dry weight (AFDW) of five species of marine microalgae, Dunaliella sp., Isochrysis
galbana, Nannochloropsis sp., Nitzschiaclosterium and Porphyridium cruentum, retained on filter paper, were determined. Dunaliella
and Isochrysis cells have no cell wall; Nannochloropsis, Nitzschia and Porphyridium possess a cell wall and Nitzschia and
Porphyridium cells are covered by silica and mucilage coating, respectively. In all these algae, DW of non-washed samples
was at least 1.2 times higher than those washed by distilled water,0.9% sodium chloride, 0.5 M ammonium formate or 0.5 M ammonium
bicarbonate. DW of 0.9% sodium chloride washed samples was more than 0.8 times higher than the other three washed samples.
In most of the cases, there was no significant difference between DW of samples washed by ammonium formate and ammonium bicarbonate
solutions (p>0.05). The AFDW of the non-washed algal samples was about twice that washed samples, and could be accounted for
by volatile component in the sea water medium. Isotonic solution of ammonium bicarbonate is a satisfactory washing agent for
algal cells for dry weight determination.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
62.
NaNO3浓度对球等鞭金藻生长及所含脂肪酸的影响 总被引:2,自引:0,他引:2
用NaNO3作氮源,分别作了氮浓度的5个水平对球等鞭金藻H29的相对生长速率、总脂含量及脂肪酸组成的影响实验。实验结果显示,H29的相对生长率和总脂含量随N浓度的增加而增加,在897.6 mg/L时总脂含量达到最大值(23.4%)。而DHA(22:6n-3)和PUFAs(polyunsaturated fatty acids)含量随氮浓度的改变有较大变化,DHA含量总体随N浓度增加而下降,在较低氮浓度(74.8mg/L)时含量达到最大值12.11%。 相似文献
63.
Microalgae for aquaculture: Opportunities and constraints 总被引:10,自引:0,他引:10
Michael A. Borowitzka 《Journal of applied phycology》1997,9(5):393-401
64.
Ramesh D. Gulati 《Hydrobiologia》1995,306(1):1-6
The green algae D. tertiolecta, the flagellate I. galbana and the diatom C. gracilis were grown in batch cultures. The organisms were analysed for lipid class composition at the logarithmic and stationary growth phases using the Chromarod-Iatroscan thin layer chromatography with flame ionization detection (TLC-FID) system.There were major differences in lipid class production among the organisms investigated, but few differences in lipid class distribution between log phase and stationary phase cultures of D. tertiolecta and I. galbana. C. gracilis displayed the general trend exhibited in diatom metabolism, which can be characterized by an increase in triacylglycerol synthesis in situations of stress. 相似文献
65.
Using cultures of a number of different marine algae (diatoms Skeletonema costatum (Grev.) Cleve and Phaeodactylum tricornutum Bohlin, chrysophyte Isochrysis galbana Parke, green flagellate Dunaliella tertiolecta Butcher, dinoflagellate Gonyaulax tamarensis Lebour) the short-term, pattern of 14CO2 assimilation has been investigated. In all except D. tertiolecta the labelling of amino acids and intermediates of the tricarboxylic acid (Krebs) cycle was significantly heavier than that of sugar phosphates. Over periods of 30–120 s labelling in amino acids and Krebs cycle intermediates accounted for 41–95% of the 14C fixed (depending on the alga). Over shorter times (< 10 s) the pattern in the 2 diatoms showed significant labelling of C4 acids (and related com-pounds) and little labelling of sugar phosphates. The reverse wits seen with D. tertiolecta. Also, in the 2 diatoms and in G. tamarensis significant inhibition of photosynthesis by oxygen could only be achieved with 100% oxygen; atmospheric levels having little effect. Parallel measurements of 2 carboxylating enzymes showed that ribulose-1,5-diphosphate carboxylase (RuDPCase) was significantly greater than phospho (enol)pyruvate carboxylase (PEPCase) activity only in the green flagellate. It is suggested that photosynthesis in marine diatoms depends on an active PEPCase utilizing bicarbonate as a substrate and that a less active RuDPCase utilizes CO2. In D. tertiolecta the pattern more closely resembles that of a “Calvin (C3)” plant. The dinoflagellate and the chrysophyte appeared to show a mixed C3 and C4 photosynthesis. 相似文献
66.
Yean-Chang Chen 《Journal of applied phycology》2003,15(5):439-444
The marine microalga Isochrysisgalbana was cultivated and entrapped inalginate beads for long-term storage. Theentrapped cells were alive and maintainedtheir physiological activities after oneyear of storage in absolute darkness at4 °C without a liquid medium. Thenumber of cells in the beads increased morethan 32 times when they were subsequentlyre-cultured in an aqueous medium for fiveweeks, showing that they had remained aliveduring storage. TEM observations showedthat the entrapped cells reduced their cellcovering and pyrenoid size compared withthe normal free-living cells afterlong-term storage. The algal beads werealso applied to feed and water qualitycontrol in clam cultures' leading to amarked decrease in ammonium concentrations.Algal cells escaped from the beads provideda food source for the clams. This mightreduce the cost of clam culture compared totraditional culture methods. Therefore,immobilized I. galbana can be usedfor long-term preservation of algal stockin the laboratory and applied practicallyto clam cultures. 相似文献