Real-Time and In Situ Evaluation of Phycocyanin Concentration in Spirulina platensis Cultivation System by Using Portable Raman Spectroscopy

Figure 4

Change process of (a) dry cell weight (DCW), (b) the content of phycocyanin in liquid (PCL), and (c) the content of phycocyanin in dry Spirulina (PCD). The CK is the control group, using Spirulina medium with 2.5 g/L concentration of NaNO₃ and 0.5 g/L K₂HPO₄. The experimental group consists of different concentrations of NH₄Cl (N1, 0.1 g/L; N2, 0.2 g/L; N3, 0.3 g/L) and K₂HPO₄ (P1, 0.02 g/L; P2, 0.42 g/L; P3, 0.82 g/L).

(a)

(b)

(c)