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1.
Bezerra RP Matsudo MC Converti A Sato S de Carvalho JC 《Biotechnology and bioengineering》2008,100(2):297-305
This study dealt with the influence of both the feeding time and light intensity on the fed-batch culture of the cyanobacterium Spirulina (Arthrospira) platensis using ammonium chloride as a nitrogen source. For this purpose, a 2(2) plus star central composite experimental design combined with response surface methodology was employed, and the maximum cell concentration (X(m)), the cell productivity (P(X)), and the yield of biomass on nitrogen (Y(X/N)) were selected as the response variables. The optimum values of X(m) (1,833 mg L(-1)) and Y(X/N) (5.9 g g(-1)) estimated by the model at light intensity of 13 klux and feeding time of 17.2 days were very close to those obtained experimentally under these conditions (X(m) = 1,771 +/- 41 mg L(-1); Y(X/N) = 5.7 +/- 0.17 g g(-1)). The cell productivity was a decreasing function of the ammonium chloride feeding time and a quadratic function of the light intensity. The protein and lipid contents of dry biomass collected at the end of cultivations were shown to decrease with increasing light intensity. 相似文献
2.
Bezerra RP Montoya EY Sato S Perego P de Carvalho JC Converti A 《Bioresource technology》2011,102(3):3215-3219
Semicontinuous cultures were carried out at different dilution rates (D) and light intensities (I) to determine the maximum productivity of Arthrospira platensis cultivated in helicoidal photobioreactor up to the achievement of pseudo-steady-state conditions. At I=108 μmol photons m(-2) s(-1), the semicontinuous regime ensured the highest values of maximum cell concentration (X(m)=5772±113 mg L(-1)) and productivity (P(XS)=1319±25 mg L(-1) d(-1)) at the lowest (D=0.1 day(-1)) and the highest (D=0.3 day(-1)) dilution rates, respectively. A kinetic model derived from that of Monod was proposed to determine the relationship between the product of light intensity to dilution rate (ID) and the cell productivity, which were shown to exert a combined influence on this parameter. This result put into evidence that pseudo-steady-state conditions could be modified according to circumstances, conveniently varying one or other of the two independent variables. 相似文献
3.
Inga Zinicovscaia Liliana Cepoi Tatiana Chiriac Tatiana Mitina Dmitrii Grozdov Nikita Yushin 《International journal of phytoremediation》2017,19(11):1053-1058
The cyanobacterium Arthrospira (Spirulina) platensis was used to study the process of silver biosorption. Effects of various parameters such as contact time, dosage of biosorbent, initial pH, temperature, and initial concentration of Ag(I) were investigated for a batch adsorption system. The optimal biosorption conditions were determined as pH 5.0, biosorbent dosage of 0.4 g, and initial silver concentration of 30 mg/L. Equilibrium adsorption data were analyzed by the Langmuir and Freundlich models – however, the Freundlich model provided a better fit to the experimental data. The kinetic data fit the pseudo-second-order model well, with a correlation coefficient of 0.99. The analysis of thermodynamic parameters (ΔG°, ΔH° and ΔS°) revealed that the adsorption process of silver ion by spirulina biomass was exothermic and spontaneous (ΔG° < 0), and exothermic (ΔH° < 0) process. The biosorption capacity of biomass A. platensis serves as a basis for the development of green technology for environmental remediation. 相似文献
4.
Rodrigues MS Ferreira LS Converti A Sato S de Carvalho JC 《Bioresource technology》2011,102(11):6587-6592
Previous work demonstrated that a mixture of NH4Cl and KNO3 as nitrogen source was beneficial to fed-batch Arthrospira (Spirulina) platensis cultivation, in terms of either lower costs or higher cell concentration. On the basis of those results, this study focused on the use of a cheaper nitrogen source mixture, namely (NH4)2SO4 plus NaNO3, varying the ammonium feeding time (T = 7-15 days), either controlling the pH by CO2 addition or not. A. platensis was cultivated in mini-tanks at 30 °C, 156 μmol photons m−2 s−1, and starting cell concentration of 400 mg L−1, on a modified Schlösser medium. T = 13 days under pH control were selected as optimum conditions, ensuring the best results in terms of biomass production (maximum cell concentration of 2911 mg L−1, cell productivity of 179 mg L−1 d−1 and specific growth rate of 0.77 d−1) and satisfactory protein and lipid contents (around 30% each). 相似文献
5.
Arthrospira (Spirulina) platensis was tested for biosorption properties. Preliminary experiments concerning biosorption kinetics were performed on Cr(III) ions. Equilibrium of biosorption was tested for Cr(III), Mn(II) and Mg(II) ions, since these elements are crucial for animals with metabolic disorders. In our study, Spirulina was proposed as a feed additive for animals suffering from diseases characterized by insulin dysregulation, abnormal adipose distribution and a high risk for laminitis. Maximum biosorption capacity of A. platensis, determined from Langmuir equation, was 45.2 for Cr(III), 44.3 for Mn(II) and 42.0 mg/g for Mg(II) ions. Biosorption of Mg(II) ions by microalga has never been studied so far. Finally, the raw and enriched microalgal biomass was examined by ICP-OES to determine its multielamental analysis before and after biosorption, FTIR to indicate functional groups that participated in biosorption and SEM-EDX to illustrate the binding of metal ions on the surface of algal biomass. ICP-OES showed that the content of elements significantly increased in the enriched A. platensis. FTIR spectroscopy evidenced that biosorption of metal ions was mainly due to carboxylate groups present on the microalgal cell wall. SEM analysis clearly showed that biosorption occurred. Arthrospira platensis turned out to be a good biosorbent of metal ions. 相似文献
6.
Avigad Vonshak Supat Laorawat Boosya Bunnag Morakot Tanticharoen 《Journal of applied phycology》2014,26(3):1309-1315
The basic requirement for establishing economically viable large-scale production of algal biomass, be it for food, feed, high-value product, or energy, is the ability to produce the biomass at a low price. To achieve this goal, an efficient production protocol is needed that ensures that the potential productivity is obtained at any given time. When productivity is defined by the ability to utilize the available solar radiation that drives photosynthesis, the production protocol must be optimized to meet this requirement. In the current study, we demonstrate that by modifying the light available to Arthrospira platensis cells cultured outdoors by a variety of options like modifying the standing biomass concentration, changing the mixing rate, or shading can change the potential photosynthetic activity and apparent activity. By optimizing the light available to algae cells under outdoor conditions, productivity can be increased by approximately 50 %, from 15.6 g m?2 day?1 in a culture that suffers from overexposure to light to 22.4 g m?2 day?1 in a culture in which light downregulation is minimized. Therefore, by using a variety of methodologies to estimate photosynthetic activity, we demonstrate that overexposing the cells to light may result in downregulation of the photosynthetic activity leading to photoinhibition and lower biomass productivity. 相似文献
7.
Stéphan Jacquet Xu Zhong Ammini Parvathi Angia Sriram Pradeep Ram 《Journal of applied phycology》2013,25(1):195-203
Cyanobacteria constitute a versatile group of photosynthetic bacteria of immense commercial and ecological importance. Some species of this group are cultivated and sold as food because of their high nutritional value. This is typically the case for Arthrospira platensis. We describe, for the first time, a virus infecting this economically important filamentous cyanobacterium isolated from culture pools located in the South of France. This virus could be observed and discriminated easily from other particles with flow cytometry. Based on morphology and molecular investigation, it was proposed that the virus belongs to the cyanopodovirus group with a capsid and short tail of about 120 and 20 nm, respectively. Finally, the virus appeared to be highly specific (very narrow host range) to A. platensis. 相似文献
8.
Factors indicating culture status of two Spirulina platensis strains were monitored in a batch mode cultivation for 36 days. Changing mode in all factors showed a common turning point, indicating shift of cell or culture status. Mean biomass productivity was highly sustained until day 22, chlorophyll a concentration peaked on day 22, pH value was >12 on day 22, coil number was abruptly shortened on day 22, and floating activity was sustained at greater than 79% after day 22, indicating that day 22 is a criterion reflecting phase-transfer in cell physiology in a batch culture system. Many of these changes may have been caused by increased pH, suggesting that pH control is essential for mass production of S. platensis. Fluctuations in floating activity were likely induced by the number of cellular gas vacuoles. Consequently, coil number per trichome and floating activity of S. platensis could readily act as simple indicators for determination of culture status or harvesting time of cells. 相似文献
9.
Francisco J.L. Gordillo Carlos Jiménez Félix L. Figueroa F. Xavier Niell 《Journal of applied phycology》1998,10(5):461-469
The consequences of the addition of CO2 (1%) in cultures of S. platensis are examined in terms of biomass yield, cell composition
and external medium composition. CO2 enrichment was tested under nitrogen saturating and nitrogen limiting conditions. Increasing
CO2 levels did not cause any change in maximum growth rate while it decreased maximum biomass yield. Protein and pigments
were decreased and carbohydrate increased by high CO2, but the capability to store carbohydrates was saturated. C:N ratio
remained unchanged while organic carbon released to the external medium was enhanced, suggesting that organic carbon release
in S. platensis is an efficient mechanism for the maintenance of the metabolic integrity, balancing the cell C:N ratio in
response to environmental CO2 changes. CO2 affected the pigment content: Phycocyanin, chlorophyll and carotenoids were reduced
in around 50%, but the photosynthetic parameters were slightly changed. We propose that in S. platensis CO2 could act promoting
degradation of pigments synthetised in excess in normal CO2 conditions, that are not necessary for light harvesting. Nitrogen
assimilation was significantly not affected by CO2, and it is proposed that the inability to stimulate N assimilation by CO2
enrichment determined the lack of response in maximum growth rate.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
10.
Mousavi Mina Mehrzad Jamshid Najafi Mohsen Fathi Zhiani Rahele Shamsian Seyed Ali Akbar 《Journal of applied phycology》2022,34(5):2271-2281
Journal of Applied Phycology - Nitrogen plays a key role in the production of biomass and valuable pigments from Arthrospira platensis. The present research aimed to examine the effect of Zarrouk... 相似文献
11.
Photosynthetic and respiratory electron transport and their interplay with ion transport have been studied in Arthrospira platensis, a filamentous alkaliphilic cyanobacterium living in hypersaline lakes. As typical for alkaliphiles, A. platensis apparently does not maintain an outward positive pH gradient at its plasma membrane. Accordingly, sodium extrusion occurs
via an ATP-dependent primary sodium pump, in contrast to the Na+/H+ antiport in most cyanobacteria. A. platensis is strongly dependent on sodium/bicarbonate symport for the uptake of inorganic carbon. Sodium extrusion in the presence
of the Photosystem II inhibitor diuron indicates that a significant amount of ATP is supplied by cyclic electron transport
around Photosystem I, the content of which in A. platensis is exceptionally high. Plastoquinol is oxidized by two parallel pathways, via the cytochrome b
6
f complex and a putative cytochrome bd complex, both of which are active in the light and in the dark.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
12.
13.
Phycoferritin from the nutritionally important blue-green alga Arthrospira platensis has been isolated, by application of conventional biochemical techniques. The molecular mass, yield, iron and total neutral
carbohydrate contents of the purified protein were 470 kDa, 0.044 mg g−1 of Arthrospira, 1.4 and 20%, respectively. The iron content was much lower when compared to bacterial and mammalian ferritins. The P: Fe
ratio of Arthrospira phycoferritin was 1: 3.5, a value akin to bacterioferritins. Native gel-electrophoresis revealed the presence of isoforms.
Subunit analysis by SDS-PAGE and Western blotting showed a protein subunit with an apparent molecular mass of 18 kDa. Oligomeric
forms of the protein subunit were also present. The phycoferritin exhibited cross-reactivity with anti-pea seed ferritin suggesting
phylogenetic relationship with that of higher plants. Carbohydrate analysis of phycoferritin by GC-MS revealed the presence
of sugars such as galactose, glucose and mannose similar to that of mammalian ferritins. Interestingly, the analysis also
revealed sugars such as rhamnose, xylose and talose, which has not been reported in the structure of ferritins. Except for
very low histidine content in phycoferritin, the rest of the amino acid composition resembled to ferritins of other species.
UV-visible spectral analysis of the phycoferritin revealed the presence of haem groups, a property characteristic of bacterioferritins.
The fluorescence intensity of phycoferritin was higher than equine spleen ferritin. Circular dichroic spectra revealed a lower
degree of helicity. 相似文献
14.
Urea has been considered as a promising alternative nitrogen source for the cultivation of Arthrospira platensis if it is possible to avoid ammonia toxicity; however, this procedure can lead to periods of nitrogen shortage. This study shows that the addition of potassium nitrate, which acts as a nitrogen reservoir, to cultivations carried out with urea in a fed-batch process can increase the maximum cell concentration (X(m) ) and also cell productivity (P(X) ). Using response surface methodology, the model indicates that the estimated optimum X(m) can be achieved with 17.3 mM potassium nitrate and 8.9 mM urea. Under this condition an X(m) of 6077 ± 199 mg/L and a P(X) of 341.5 ± 19.1 mg L(-1) day(-1) were obtained. 相似文献
15.
C. van Eykelenburg 《Antonie van Leeuwenhoek》1980,46(2):113-127
The ultrastructure of the cyanobacterium Spirulina platensis was studied in relation to temperature, light intensity and nitrate concentration. The organism was able to grow in media supplied with nitrate in concentrations up to 250mm. High nitrate concentrations increased the yield and growth rate at temperatures above 35°C. Occurrence, distribution and abundance of cyanophycin granules, polyglucan granules, cylindrical bodies, carboxysomes and mesosomes varied widely in relation to the factors studied. At low temperatures (up to 17°C) cyanophycin was the abundant organelle, especially at high nitrate concentrations, whereas in the temperature range 17–20°C polyglucan was found in large quantities particularly at low nitrate concentrations. Special attention was paid to the cylindrical bodies, the ultrastructure of which was dependent on temperature. Three types of ultrastructure were distinguished each with several possible shapes. 相似文献
16.
Peizhen Li Liang Zhao Xiaomin Xu Chenyang Xu Chunlei Jin Yi Xu Jiaopeng Zhou Ying Zhang Kangfu Lei Jun Ying Ping Ren Lei Yang Ruowang Pan Zuyuan Xu Huifeng Wang Qiyu Bao Li Ding 《Journal of applied phycology》2014,26(1):199-207
Ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO), a key enzyme involved with photosynthetic carbon assimilation, catalyzes the carboxylation and oxidization of ribulose-1,5-bisphosphate. Interestingly, the promoter region of this gene from Arthrospira platensis could drive the expression of a downstream gene in Escherichia coli. In this study, using green fluorescent protein as a reporter of gene expression, the structure and function of the promoter region of the RuBisCO gene of A. platensis was analyzed. There are three hypothetical promoter elements predicted in the 200 bp upstream of the open reading frame (ORF) of RuBisCO. Through deletion analysis of the promoter, it was demonstrated that one of these elements was the active promoter, which was located between ?94 and the ORF of RuBisCO. The ?35 box of the RuBisCO promoter (TTGACT) was very similar to that of the rpoD gene (TTGACA) of E. coli, with only the sixth nucleotide divergent. Site-directed mutational analysis showed that when the sixth nucleotide (T) was changed to A, the activity of the promoter remained unchanged. However, when the first and second Ts were mutated, the activities of the promoters decreased drastically. Determining the structure and function of promoters would help elucidate the molecular mechanisms of the gene expression and regulation. 相似文献
17.
将钝顶螺旋藻培养在含有不同NaCl浓度(0、0.4、0.8mol·L^-1)的培养基中,并置于室外全波段太阳辐射、阳光辐射滤除uvB以及光合有效辐射(PAR)三种辐射条件下,以探讨阳光uV辐射和盐胁迫对钝顶螺旋藻的耦合效应。结果表明,阳光uv辐射显著抑制钝顶螺旋藻的光化学效率,且随着盐浓度的提高,其受抑制程度加剧。D1蛋白含量在高水平PAR和uV辐射下都明显降低,而高盐浓度(0.8mol·L^-1NaCl)导致其含量进一步下降。此外,阳光uv辐射与盐胁迫的耦合作用使得藻丝发生明显断裂。 相似文献
18.
螺旋藻对于环境的变化有很强的适应性.以钝顶螺旋藻为实验材料,测定螺旋藻在受到较强光照胁迫时藻体的电导率以及脯氨酸、丙二醛和过氧化氢酶系的含量.在3000 lx光照下,螺旋藻6个藻株的电导率以及脯氨酸、丙二醛和过氧化氢酶系的含量比在1000 lx光照下明显升高,螺旋藻的电导率最高上升了2~6倍;细胞内的脯氨酸含量最多增加5倍,最少增加13%;丙二醛的含量增加40%~100%;过氧化氢酶的含量上升范围在19%~80%,过氧化物酶的含量上升范围在20%~100%.说明螺旋藻在受到光胁迫时自身会启动相关保护机制,产生一定的抗逆性,以适应环境的变化. 相似文献
19.
The quantitative and qualitative effects of light on carotenoid production by Spirulina were studied. Maximum total carotenoid production was measured in cells grown under white light at an irradiance of 432 μmol photon m?2 s?1, the onset of light saturation for this organism as determined by growth rates. A true maximum may exist at irradiances above 1500 μmol photon m?2 s?1 under white light. Individual carotenoids responded differently to light conditions. Under white light, β-carotene and echinenone were most abundant at the lowest and highest irradiance levels tested. Myxoxanthophyll and lutein/zeaxanthin did not change over the same irradiance range. Under red and blue light, we found decreased values of myxoxanthophyll, while β-carotene increased and lutein/zeaxanthin and echinenone showed little change. In general, maximum carotenoid production requires optimization of the culture conditions that favor growth. 相似文献
20.
Dry biomass of Spirulina platensis re-hydrated for 48 h was employed as a biosorbent in tests of cadmium(II) removal from water. Various concentrations of biomass (from 1 to 4 g l−1) and metal (from 100 to 800 mg l−1) were tested. Low biomass levels (Xo 2 g l−1) ensured metal removal up to 98% only at Cd0= 100 and 200 mg l−1, while Xo 2.0 g l−1 were needed at Cd0 = 400 mg l−1 to achieve satisfactory results. Whereas Xo = 4.0 g l−1 was effective to remove up to Cd0 = 500 mg l−1, a further increase in metal concentration (Cd0 = 600 and 800 mg l−1) led to progressive worsening of the system performance. At a given biomass levels, the kinetics of the process was better at low Cd2+ concentrations, while, raising the adsorbent level from 1.0 to 2.0 g l−1 and then to 4.0 g l−1, the rate constant of biosorption increased by about one order of magnitude in both cases and the adsorption capacity of the system progressively decreased from 357 to 149 mg g−1. 相似文献