Chlorophyll-a, β-Carotene, and Xanthophyll Contents in Six Green Microalgae from parts of Lagos Lagoon, Nigeria

Abstract

Indigenous tropical microalgae remain underexplored despite their potential as sources of high-value bioactive compounds. Therefore, the objective of this paper was to undertake a comparative assessment of chlorophyll-a, β-carotene, and xanthophyll contents in six indigenous green microalgal isolates and the first phase of a systematic evaluation of pigment potential in microalgal groups from parts of the Lagos Lagoon system, Lagos state, Nigeria. Pigment concentrations were quantified spectrophotometrically following acetone and hexane-based extraction protocols. Chlorophyll-a concentrations ranged from 0.102 to 12.403 µg ml⁻¹ (0.038–5.083 mg 100 g⁻¹ fresh weight). β-Carotene values varied between 0.077 and 2.320 mg 100 ml⁻¹ (0.307–9.509 mg 100 g⁻¹), while xanthophyll content ranged from 0.002 to 2.741 mg 100 g⁻¹. Significant interspecific variation in pigment composition was observed, with some isolates exhibiting pigment yields comparable to commercially exploited strains. Pigment concentrations did not align with previously reported biohydrogen production trends among the studied isolates. Asteracys sp. exhibited high biohydrogen productivity despite relatively low pigment content, highlighting functional variability among indigenous green microalgal strains. These findings highlight the biotechnological promise of indigenous green microalgae from tropical lagoon ecosystems and establish a baseline for subsequent comparative studies on diatoms and cyanobacteria from the same system.