• Korean Chemical Engineering Research
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• v.57 no.2
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• pp.301-304
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• 2019

Microwave was designed for lipid extraction from green algae (Spirulina platensis). Microalgae-solvent (various solvents) were extracted and heated using microwave at 600 W for around 40 min. The maximum yield obtained within this period was 12.530% of lipid compared to just 1.293% for Soxhlet extraction. Lipid analysis revealed that those with higher essential fatty acid content consist of saturated fatty acid (SAFA) and polyunsaturated fatty acid (PUFA) which could be used for biodiesel production.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.143-149
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• 2006

A extract from Spirulina platensis of seawater and freshwater was obtained by using the water and ethanol. Extraction yields of seawater S. platensis were observed about 3% higher than freshwater S. platensis. Cytotoxicity (HEK293) and inhibition ratio of cancer cell line (A549, AGS, MCF7, Hep3B) in adding of the extracts from the S. platensis of seawater and freshwater were measured by SRB assay. Cytotoxicity of all of the extracts in adding 1.0 mg/ml was below 26%. Ctotoxicity of the extracts from the seawater S. platensis were about 6% less than freshwater S. platensis. Inhibition ratio of cancer cell growth was inhibited by adding 1.0 mg/ml of the extracts that was obtained about 80%. Inhibition effect of cancer cell growth in adding seawater S. platensis was observed higher than freshwater S. platensis. Differentiation ratio of HL-60 cells in adding the extracts of seawater S. platensis was observed highly that was 160.9%.

• BMB Reports
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• v.40 no.5
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• pp.644-648
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• 2007

Exposure of algae or plants to irradiance from above the light saturation point of photosynthesis is known as high light stress. This high light stress induces various responses including photoinhibition of the photosynthetic apparatus. The degree of photoinhibition could be clearly determined by measuring the parameters such as absorption and fluorescence of chromoproteins. In cyanobacteria and red algae, most of the photosystem (PS) II associated light harvesting is performed by a membrane attached complex called the phycobilisome (PBS). The effects of high intensity light (1000-4000 ${\mu}mol$ photons $m^{-2}s^{-1}$) on excitation energy transfer from PBSs to PS II in a cyanobacterium Spirulina platensis were studied by measuring room temperature PC fluorescence emission spectra. High light (3000 ${\mu}mol$ photons $m^{-2}s^{-1}$) stress had a significant effect on PC fluorescence emission spectra. On the other hand, light stress induced an increase in the ratio of PC fluorescence intensity of PBS indicating that light stress inhibits excitation energy transfer from PBS to PS II. The high light treatment to 3000 ${\mu}mol$ photons $m^{-2}s^{-1}$ caused disappearance of 31.5 kDa linker polypeptide which is known to link PC discs together. In addition we observed the similar decrease in the other polypeptide contents. Our data concludes that the Spirulina cells upon light treatment causes alterations in the phycobiliproteins (PBPs) and affects the energy transfer process within the PBSs.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1248-1254
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• 2006

The effect of Spirulina platens is and probiotics as feed additives on the growth of the shrimp Fenneropenaeus chinensis was investigated in comparison with a control. The shrimp were cultured in rearing tanks in a seawater pond for 35 days from September 1, 2004. As regards the water quality, the probiotic treatment (T2, commercial diet and 3% probiotics) produced a lower TDN (total dissolved nitrogen) and TDP (total dissolved phosphorus), making it effective in water quality improvement. Nonetheless, the phytoplankton flora succeeded from diatoms to cyanobacteria, regardless of the feed additives. Treatment T3, including 3% S. platensis, produced the highest mean body weight, which was 39% higher than that for all the other treatments (P<0.05). Accordingly, it was found that the use of Spirulina and probiotics as feed additives increased the shrimp body weight and improved the water quality, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.621-629
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• 2013

Since algae had been issued an environmental problem, water blooms, deepened due to increase of retention water basin in Korea as well as a biomass resource for producing biofuel, this study conducted a series of experiments for Spirulina platensis using the flotation process with micro-bubble. To elevate utilization of collected-algae, this study focused on omitting or minimizing coagulant's doses as changing a cultivation period and condition affected on physical property change of algae. Two coagulants, PAC and Chitosan, were used to test the collecting rate of algae and the result found no difference between two rates. For flotation experiments without adding the coagulant, dried algae weight (passing 14 days after cultivation for 20 days) detected high separation efficiency 98.2 % and it (passing 7 days after long-term cultivation for 28 days) presented good separation efficiency 91.9 %. Chlorophyll's separation efficiency showed a similar tendency with the case of the dried algae weight. In endogeny conditions, a light source and a carbon source were not considerably affected on the flotation separation efficiency. Thus, this study confirms that algae biomass may be collected without the coagulant during the endogeny condition period after enough cultivation time, 3 weeks.

• Microbiology and Biotechnology Letters
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• v.35 no.1
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• pp.45-51
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• 2007

Arthrospira (Spirulina) platensis is one of the commercially important filamentous cyanobacteria. The heterotrophic cultivation of Arthrospira can be an alternative strategy for commercial mass production. In heterotrophic culture, the specific growth rate of A. platensis M9108, a glucose-resistant mutant of A. platensis PCC 9108, was $0.014h^{-1}$ which was 1.8 higher than that oi the previous report. The mutant possessed the facility to assimilate and to metabolize glucose efficiently under heterotrophic condition. However, the r-linolenic acid content of 6 Arthrospira strains was not increased in heterotrophic culture. Four Arthrospira strains out of 6 tested strains were able to utilize maltose as a carbon source under heterotrophic condition. The biomass production of these strains on maltose was similar to that on glucose. The specific growth rate of A. platensis M9108 increased with glucose concentration up to 5.0 g/L and then decreased at a glucose concentration of 10.0 g/L. Additionally, A. platensis M9108 under heterotrophic condition showed no aggregation during the cultivation in contrast to A. platensis PCC 9108.

• Microbiology and Biotechnology Letters
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• v.25 no.1
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• pp.106-108
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• 1997

Blue green algaes (NIES 19, 39, 46) have been cultivated to product sigle cell protein. After 7 days of cultivation under 5000 (W/M$^{2}$) of ligth intensity, final cell concentration was 2.8 (g/L) and chlorophyll a was 4.9 (mg/L). When initial concentration of NaHCOC was 1.7% and NaNO$_{3}$ was0.25%, maximum cell concentration was obtained. Spirulina platensis NIES 39 showed faster growth rate than NIES 46. While most 39 sedimented, most 46 floated.

• Journal of Microbiology and Biotechnology
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• v.21 no.4
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• pp.359-365
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• 2011

Cyanobacterial strains of the genus Spirulina have recently been identified as an excellent source of sulfolipids, some of which possess anti-HIV properties. Thus, to investigate the distribution of sufolipid biosynthesis pathways in Spirulina, a genetic screening/phylogentic study was performed. Five different strains of Spirulina [Spirulina (Jiangmen), Spirulina sp., S. platensis, S. maxima, and Spirulina seawater] sourced from different locations were initially classified via 16S rDNA sequencing, and then screened for the presence of the sulfolipid biosynthesis genes sqdB and sqdX via a PCR. To assess the suitability of these strains for human consumption and safe therapeutic use, the strains were also screened for the presence of genes encoding nonribosomal peptide synthases (NRPSs) and polyketide synthases (PKSs), which are often associated with toxin pathways in cyanobacteria. The results of the 16S rDNA analysis and phylogenetic study indicated that Spirulina sp. is closely related to Halospirulina, whereas the other four Spirulina strains are closely related to Arthrospira. Homologs of sqdB and sqdX were identified in Spirulina (Jiangmen), Spirulina sp., S. platensis, and the Spirulina seawater. None of the Spirulina strains screened in this study tested positive for NRPS or PKS genes, suggesting that these strains do not produce NRP or PK toxins.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.519-524
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• 1996

The kinetics of growing microalga, Spirulina platensis was investigated to treat swine wastes with optimum growth conditions. Temperature was varied from 15 to 40$\circ$C at three different light intensities, 6 W/m$^{2}$, 12 W/m$^{2}$ and 24 W/m$^{2}$. The specific growth rate was increased as temperature increased up to 30$\circ$C. The activation energy was estimated as 13.5 kcal/mol by an Arrhenius relationship. 0.24 (1/day) of specific growth rate was obtained from batch cultivation with 30% swine wastes, compared to 0.31 (1/day) from clean culture. It was found that Spirulina platensis was able to reduce 70-93% of PO$_{4}$$^{3-}$ -P, 67-93% of inorganic nitrogen, 80-90% of COD and 37-56% organic nitrogen by adding various concentrations of swine wastes for 12 days of batch cultivation. Rate constants for removing nitrates and phosphates in treating swine wastes were estimated as 0.17 (1/day) and 0.14 (1/day) in the first order reaction, respectively. 1.52 (g/L) of maximum cell density was maintained at 0.20 (1/day) of dilution rate in continuous culture, adding 20% swine wastes for 30 days. The chemical composition of the biomass obtained from the process showed 58.7% of protein, 11.0% of lipid and 15.6% of ash.

• Ocean and Polar Research
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• v.35 no.4
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• pp.407-414
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• 2013

One of the most important challenges facing the Spirulina mass cultivation industry is to find a way to reduce the high production costs involved in production. Although the most commercial medium (Zarrouk's medium) for Spirulina cultivation is too expensive to use, it contains higher amount of $NaHCO_3$ (16.80 g $L^{-1}$), trace metals and vitamin solutions. The purpose of this study was to increase the efficiency of Spirulina platensis biomass production by developing a low-cost culture medium at an isolated tropical island such as Chuuk State, Federated States of Micronesia (FSM). This study set out to formulate a lowcost medium for the culture of S. platensis, by substituting nutrients of Zarrouk's medium using fertilizer- grade urea and soil extract with a different concentration of carbon source under natural weather condition. In order to select a low-cost culture medium of S. platensis, 10 culture media were prepared with different concentrations of nitrogen (urea and $NaNO_3$) and $NaHCO_3$. The highest maximum specific growth rate (${\mu}max$) and mass production were 0.50 $day^{-1}$ and 1.05 g $L^{-1}$ in modified medium ($NaHCO_3$ 7.50 g $L^{-1}$, urea 2.00 g $L^{-1}$ without $NaNO_3$) among all the synthesized media. Protein (56.14%) and carbohydrate (16.21%) concentrations of the lyophilized standard samples were estimated with highest concentration of glutamic acid (14.93%). This study revealed that the use of a low concentration of urea and $NaHCO_3$ with soil extract was an affordable medium for natural mass cultivation in the FSM.