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

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 R-2 values as 0959, 0982 and 0952, the prediction correlation factor (r) values as 0979, 0988 and 0966, and the residual predictive deviation (RPD) values as 488, 622 and 386, respectively. Furthermore, the PLS models were employed to evaluate H.pluvialis mutants, with the r values as 0973, 0983 and 0976, and the RPD values as 345, 759 and 407, 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. Significance and Impact of the StudyHaematococcus pluvialis has potential application for its ability to accumulate natural antioxidant astaxanthin. In this study, we initiated the application of near-infrared spectroscopy (NIRS) in the analysis of total biomass and astaxanthin content of different mutant strains, demonstrating that NIRS can be very useful in the screening of axataxanthin-hyperproducing mutant strains.