The Optimal Condition on the Growth of Green Haematococcus Pluvialis as one of the Future Natural Resources

Abstract In the developing world nowadays, the need of antioxidants as counteracting free radicals becomes more and more. Astaxanthin is a carotenoid pigment with high antioxidant content. It can be obtained from natural sources or chemical synthesis. Haematococcus pluvialis is one of natural sources of astaxanthin which accumulates large amounts of astaxanthin under stressful condition. The growth of H. pluvialis in the green phase determines the amount of astaxanthin that can produced. It is influenced by various conditions such as amount and type of growing medium, light intensity, pH of medium, temperature, and initial inoculum concentration. The goal of this research is to obtain the optimum condition on the growth of H. pluvialis at the green stage using the experimental design i.e. Central Composite Design (CCD). The variables observed were the effect of the initial inoculum concentration (25-35% -v/v), the concentration of nutrients (1-2 mL/L liquid water), and the types of growth medium (Walne’s and BG-11). Before the experiment, H. pluvialis was cultured until its optical density (OD = 1 – 1.2). The responses observed were the cell density based on optical density (OD) using a spectrophotometer and cell number counted by using haemacytometer every day during 5 days. The results were examined using the Design Expert 7.0. It showed that the optimal growth conditions of H. pluvialis cells was in BG-11 medium with initial inoculum concentration and the number of nutrients were 37, 07% and 1.5 mL/L respectively. The highest cell number was found 23, 75 x 10 6 cells / mL in the 3 rd day. Whereas by using Walne media, the optimum condition was obtained at the initial inoculum concentration and the amount of nutrients were 35% and 2 mL respectively. And the highest cell density number obtained was 17, 5 x 10 6 cells / mL on the 3 rd day.