Production of value added substances by tropical microalgae

Microalgae recently appeared to be a new source of renewable biofuel that is capable of meeting the global demand for transport fuel due to its ability to accumulate high amount of lipid in their intracellular body. In addition, massive accumulation of ketocarotenoid astaxanthin, which is one of the secondary metabolites produced by microalgae have also gained much attention for its potential applications in pharmaceuticals, nutraceuticals as well as cosmetics products. Four green microalgae morphologically identified as Staurastrum sp., Scenedesmus sp., Desmodesmus sp., and Ankistrodesmus sp. were isolated from Kuala Selangor Nature Park and Hulu Langat River, Selangor. The intracellular lipid bodies of the microalgae were stained with BODIPY 493/503 for the screening of the potential microalgae for biodiesel production. From the staining, more lipid bodies can be seen from Scenedesmus sp. compared to the other three isolated microalgae species. In astaxanthin complex quantification analysis, Ankistrodesmus sp. showed the highest accumulation of astaxanthin complex and therefore has the potential to be utilized for natural supplement applications

Effect of nitrate concentration on cell growth and astaxanthin accumulation in four different species of isolated microalgae in Malaysia

Astaxanthin possess a red color pigment, a type of xanthophylls carotenoid and is mainly found in algae, fish and bird. In this study, cell growth and astaxanthin accumulation from four different isolated microalgae species based on their morphology were investigated. Isolated microalgae were cultured at three different nitrate concentration (1.64, 0.82, and 0.41 mM) and cell growth and astaxanthin were measured spectrophotometrically at 750 and 475 nm respectively. All species showed high growth rates at 1.64 mM nitrate concentration except for Pediastrum sp that is favorable in 0.82 mM nitrate. Among the four species, Ankistrodesmus sp showed the fastest growth rate. For the astaxanthin production, Ankistrodesmus and Pediastrum showed the highest yield. Thus it have a potential in production of astaxanthin in the future work

Biomass production and nutrient removal by spontaneous grown green algae oedogonium sp. from a pond in University of Tsukuba

As one of the methods for nutrient removal from eutrophicated lakes and ponds affected by nonpoint nutrient pollution, the conversion of nutrients into aquatic plant biomass (APB) has drawn increasing attention. In this study, the acquisition and sequestration of nutrients by APB and the application of APB as a resource were discussed. The study site was an eutrophicated inland pond at the University of Tsukuba, Amano-Gawa, which is occasionally covered with the submerged macrophyte green alga Oedogonium sp. This species was found to produce 1048 kg of total biomass in dry weight and 13.1 kg of lipid per harvest

Production of α-linolenic acid by an oleaginous green algae acutodesmus obliquus isolated from Malaysia

The main purpose of this study is to provide information on the biochemical composition of the total lipid extract of three different native freshwater microalgae namely Acutodesmus obliquus CN01, Chlorella sp. Carolina-15-2069, and Chlorella vulgaris NIES-1269 at different growth phases, cultured under standardized conditions that will be useful for commercialization purposes due to the content of α-linolenic acid (ALA), a type of omega-3 fatty acids. We monitored growth, biomass accumulation, chlorophyll content, lipid content and fatty acids composition in all three freshwater microalgae. In addition, this study seeks to throw some light on the lipid content of a newly isolated freshwater green alga Acutodesmus obliquus CN01 which have shown to give significant quantities of ALA, an added nutritional value to this microalga oil. Acutodesmus obliquus CN01 exhibited the fastest growth rate among the three microalgae used. Biomass was shown to be enhanced in the nitrogen enrichment medium. The outcomes from this study indicated that newly isolated Acutodesmus obliquus CN01 from Malaysia cultured under normal condition showed fast growth rate with high lipid content and also high ALA content. Therefore, from this study, Acutodesmus obliquus CN01 was identified as species of choice to be further explored for its potential to produce omega-3 fatty acids

Enhancement of astaxanthin accumulation using black light in Coelastrum and Monoraphidium isolated from Malaysia

Microalgae are important microorganisms which produce potentially valuable compounds. Astaxanthin, a group of xanthophyll carotenoids, is one of the most powerful antioxidants mainly found in microalgae, yeasts, and crustaceans. Environmental stresses such as intense light, drought, high salinity, nutrient depletion, and high temperature can induce the accumulation of astaxanthin. Thus, this research aims to investigate the effect of black light, also known as long-wave ultraviolet radiation or UV-A, as a stressor on the accumulation of astaxanthin as well as to screen the antioxidant property in two tropical green algal strains isolated from Malaysia, Coelastrum sp. and Monoraphidium sp. SP03. Monoraphidium sp. SP03 showed a higher growth rate (0.66 day-1) compared to that of Coelastrum sp. (0.22 day-1). Coelastrum sp. showed significantly higher accumulation of astaxanthin in black light (0.999 g mL culture-1) compared to that in control condition (0.185 g mL-1). Similarly, Monoraphidium sp. SP03 showed higher astaxanthin content in black light (0.476 g mL culture-1) compared to that in control condition (0.363 g mL culture-1). Coelastrum sp. showed higher scavenging activity (30.19%) when cultured in black light condition, indicating a correlation between the antioxidant activity and accumulation of astaxanthin. In this study, black light was shown to possess great potential to enhance the production of astaxanthin in microalgae

Astaxanthin production by tropical microalgae strains isolated from environment in Malaysia

Astaxanthin is one of the most important secondary metabolites with superior antioxidant property and is widely applied in nutraceuticals and pharmaceuticals industry. Recently, the production of astaxanthin from natural source has been mainly focused on the green microalgae, Haematococcus pluvialis, as it can accumulate large amounts of astaxanthin and its esters. However, the slow growth with low biomass yield and easy contamination by other fast-growing organisms are the main problems faced by H. pluvialis. In this study, the preliminary study on growth characteristic and amount of astaxanthin by tropical microalgae strains isolated from environment in Malaysia was reported. Two newly isolated microalgae including Acutodesmus obliquus and Coelastrum sp. were compared under various stress inductive conditions to identify the microalgae culture that can accumulate high amount of astaxanthin. The objective of this study is to compare and characterise astaxanthin accumulation using different species of green microalgae as mentioned above under different stress conditions. Findings of the preliminary studied indicated that the exposure of microalgae culture to high light intensity and nitrogen starvation in mixotrophic culture is a potential inducer of high amount of astaxanthin production. Among the two microalgae studied, Coelastrum sp., exhibited the highest tolerance to stress conditions. Outcomes of this work have shown that, astaxanthin produced in Coelastrum sp. is the most comparable to H. pluvialis and can be the potential alternative to current astaxanthin production

Isolation and characterization of potential tropical oleaginous microalgae for biofuel production

Recent volatility in crude oil prices attributed to increase demand and limited resources, tied with the urge to reduce pollutant emissions and greenhouse gases, have created a major focus in the production of sustainable biofuel. As one of the promising feedstocks, microalgae appeared to be a new source of renewable biofuel that is capable of meeting the global demand for transport fuel. Four green microalgae morphologically identified as Staurastrum sp., Scenedesmus sp., Desmodesmus sp., and Ankistrodesmus sp. were isolated from Kuala Selangor Nature Park and Hulu Langat River, Selangor. The intracellular lipid bodies of the microalgae were stained with BODIPY 493/503 for the screening of the potential microalgae for biofuel production. From the staining, more lipid bodies can be seen from Scenedesmus sp. compared to the other three isolated microalgae species

Development of mass cultivation system of tropical microalgae

Temperature is one of important factor in growing microalgae. In this research, freshwater samples were taken in Malaysia to isolate suitable candidate of species that are able to grow in POME medium and able to survive under high temperature (40°C). For preliminary result, freshwater samples were taken to check the microalgal species that present in Malaysia. There were three species that succeesfully isolated and grown in AF-6 medium which are Ankitrodesmus sp., Scenedesmus sp. and Chlorella sp