Irradiance Optimation for Growing Spirulina fusiformis: Biomass, Phycocyanin, and Protein Production

Abstract

The optimization of cyanobacterium microalgae cultivation technology to provide the need for food or feedstocks has recently attracted many investigators. An optimum operation on microalgae cultivation is important to reduce the excessive workload on the aquatic environment. Therefore, this study describes how the varied irradiance (2000 lux, 4000 lux, 6000 lux, 8000 lux, and 10,000 lux) treatments on a bubble column photobioreactor system affected biomass production, phycocyanin, and protein from cyanobacterium Spirulina fusiformis. The objective of this study was to obtain the optimum irradiance for producing maximum biomass, phycocyanin, and protein simultaneously. The results demonstrated some findings those were: 1) irradiance 10,000 lux made doubling time of growth earliest (only 24 hours) while 2,000 lux doubled within five days later; 2) light response curve showed that the increase of biomass concentration was linear with the increasing of irradiance; 3) a predictive model (Response Surface Method) proof that the most optimum quantity of the biomass (0.58 ±0.035 gL-1 dry weight), chlorophyll-a (0.090 ±0.023 % dry weight), and phycocyanin (2.44 ±0.00 gL-1 dry weight) were obtained on 10,000 lux, while protein contents of 79.18±5.47 % dry weight attained on the irradiance of 6000 lux. The maximum productivity of the biomass, chlorophyll-a, phycocyanin, and protein was ~Pbiomass of 24.95 mgL-1day-1; Pchl-a of 2.25E-02 mgL-1day-1; Pphycocyanin of 1.88E-02 mgL-1day-1; and Pprotein of 17.56 mgL-1day-1. Enhancement of irradiance up to 5 folds lead to the increasing of biomass chlorophyll-a, phycocyanin, and protein productivity, attained to 1.7, 5.01, 4.13, and 2.81 folds, respectively. The irradiance had a significant influence on the production of the metabolites; therefore, the irradiance must be optimized.

Outdoor Inclined Plastic Column Photobioreactor: Growth, and Biochemicals Response of Arthrospira platensis Culture on Daily Solar Irradiance in a Tropical Place

“…It has been shown that the paranet application can effectively diminish and even eliminate heat accumulation problems related to extremely high natural solar irradiance, such as a 50% shading level at 31.85 cm diameter column size and a 70% shading level at 12.74 cm diameter column size. This finding is consistent with a previous report that showed higher photosynthetic activity of an A. platensis outdoor culture with 25% irradiance shading [35] Some reports have emphasized heat accumulation as a major problem in closed photobioreactor systems, particularly in outdoor applications, while using cooling systems to overcome the problem will require significant investment and operational costs [25]. This study reveals a possible way to overcome this problem by means of paranet shading and its combination with the column size.…”

“…Satya et also observed a trend of an in-line increase in chlorophyll and phycocyanin content with the protein synthesis in Spirulina fusiformis culture, although the increasing trend that was observed with rising light intensity up to 10,000 lux (~81.9 W/m 2 ) is in contrast with the observation in this experiment. This contrast observation is possibly due to different light availability and can be explained in terms of a light response curve model, as the light range up to 10,000 lux (~81.9 W/m 2 ) in a laboratory culture is below the saturated point for the algal physiology [25], while in this outdoor experiment the average daily irradiance range was considerably higher, up to more than 25,000 lux (~204.9 W/m 2 ) (Figure 2).…”

“…Based on this idea, this study was conducted to find out how shading affects the cyanobacterial metabolisms and to figure out the best way to control light for growing cyanobacterium in more stable outdoor environments. [25], in which the modification was accomplished by lowering the NaHCO 3 concentration down to 12 g/L and KNO 3 to 1 g/L [25]. The chemicals were of technical grade except for the trace element solutions.…”

Nutritional Content and Growth Ability of Duckweed Spirodela polyrhiza on Various Culture Media

“…Integrated aquaculture is a technology that has been widely applied by small household industries in freshwater environments, especially in Asia [14]. Such as the research conducted in Research Center for Limnology, Indonesia Institute of Sciences that showed an improvement in pond production efficiency by providing an additional natural feed of minute duckweed Lemna perpusilla biomass that grown in self generated media obtained from the fish cultivation system [14,15,16].…”