Rapid screening astaxanthin-hyperproducing Haematococcus pluvialis mutants through near-infrared spectroscopy

Abstract

The unicellular freshwater green microalga Haematococcus pluvialis is the richest source of natural astaxanthin. Since accumulation of astaxanthin differs significantly among various algal strains at different stages, it is therefore critical to develop an effective high-throughput assay for rapid screening astaxanthin-hyperproducing strains. In the present study, near-infrared spectroscopy (NIRS) in combination with biochemical assay was employed for evaluation of the wide-type H. Pluvialis strains. The partial least squares (PLS) models of total biomass, astaxanthin content and astaxanthin expressed as a percentage of dry weight (DW) were developed with the R2 values as 0·959, 0·982 and 0·952, the prediction correlation factor (r) values as 0·979, 0·988 and 0·966, and the residual predictive deviation (RPD) values as 4·88, 6·22 and 3·86, respectively. Furthermore, the PLS models were employed to evaluate H. pluvialis mutants, with the r values as 0·973, 0·983 and 0·976, and the RPD values as 3·45, 7·59 and 4·07, respectively. This work thus demonstrates that NIRS is an easy, fast and non-invasive approach that can be applied in high-throughput screening of astaxanthin-hyperproducing algal mutants.