Chlorophyll a interference in phycocyanin and allophycocyanin spectrophotometric quantification

Abstract

The accurate quantification of cyanobacteria phycobiliproteins is an important aspect in various research topics, such as cyanobacteria ecology and physiology studies, and especially to calibrate algorithms used in remote sensing of cyanobacterial blooms. Here we present a spectroscopic approach, exploiting spectrophotometric equations, aimed at improving the phycocyanin and allophycocyanin quantification when chlorophyll a is present in the phycobiliprotein aqueous extract.

Effect of ultrasonication-assisted extraction time on the profile of phycocyanin from wet biomass Spirulina plantesis

“…The peaks detected at wavelengths of 380-430 nm and 671 nm indicate the detectable content of chlorophyll a [12]. The concentration of pigment on crude extract which was obtained at 20, 30, 40, 50, and 60 minutes can be seen in figure 3.…”

“…The concentration of phycocyanin and allophycocyanin on crude extract was calculated using the formula as described in [12]. The absorbance of crude extract as measured by UV spectrophotometer is called A measured, which for wavelengths of 620 nm is A620measured and 652 nm is A652 measured.…”

“…The absorbance of crude extract phycocyanin was measured using UV-Vis spectrophotometry at wavelengths of 620 nm (A620measured) and 652 nm (A652measured). The yield of phycocyanin is determined using equation [12] as follows: 𝐴 620 𝑃ℎ𝑠 = Absorbance at a wavelength of 620 nm 𝐴 280 𝑃ℎ𝑠 = Absorbance at a wavelength of 280 nm…”

Long-Term Cultivation of a Native Arthrospira platensis (Spirulina) Strain in Pozo Izquierdo (Gran Canaria, Spain): Technical Evidence for a Viable Production of Food-Grade Biomass

“…On the other hand, chlorophyll a (overall mean value: 0.85 ± 0.04%) and total carotenoids content (overall mean value: 0.25 ± 0.03%) were lower than the values reported for other Arthrospira (1.2-1.4% and 0.4-0.6% for chlorophyll a and total carotenoids, respectively; [18,21,54,75]) and for the potential food supplement species C. reinhardtii [73], which depends on differences in species/strain physiology, environmental conditions and culture media [21,54,73]. Actually, the high C-phycocyanin to chlorophyll ratio obtained in this study open the possibilities for future investigations on the use of A. platensis BEA 1257B for production of the blue natural pigment, since aqueous extracts with low chlorophyll content would largely save time and energy along the purification process [11,89]. Table 3.…”

Contribution to the modelling of the light field distribution within Synechocystis sp. PCC 6803 cultures and its influence on cellular photosynthesis processes

“…However, even at these wavelengths the contribution of chlorophyll cannot be neglected since it can lead to a phycobilin quantification prone to error. Hence protocols have to be updated to account with such interference Lauceri et al (2017).…”