Variation of nutrient profile inChlamydomonas reinhardtiiduring storage at four typical temperatures

Abstract

Post-harvest loss during storage and processing must be minimized to maintain algal nutrient value and enhance nutrient recovery. The lipid content, in particular, is of great concern due to its major role in the nutrient evaluation and biofuel applications. In this study, the degradation of neutral lipids in the green alga Chlamydomonas reinhardtii was investigated under storage at four temperatures (−80°C, −20°C, 4°C and 20°C). Preservation with concentrated algae paste or with culture was tested.Contrary to the slow lipid degradation rate observed in previous work, the present study shows a rapid lipid degradation rate. Within the first 24 hours, the lipid concentration declined 45% and 60% during storage as culture at 4°C and 20°C, respectively, and declined 73%, 74%, 48% and 69% during storage as pellets at −80°C, −20°C, 4°C and 20°C respectively. The degradation rate of protein and carbohydrate was also determined. Based on our results, the preferred storage method for lipid is dark sealed cooling, for protein is freezing or cooling and for carbohydrate is freezing with algal paste.