Commercial production of astaxanthin from Haematococcus pluvialis using 25,000-liter outdoor photobioreactors

Recent developments in photobioreactor technology have made the production of astaxanthin from Haematococcus pluvialis commercially viable. The core of our astaxanthin production chain is the Aquasearch Growth Module (AGM), a 25,000 L enclosed and computerized outdoor photobioreactor. At Aquasearch's newly expanded facility (dedicated January 1999), three AGMs (total volume 75,000 L) are used to produce large amounts of clean, fast growing, H. pluvialis. The H. pluvialis biomass produced in the AGMs is transferred daily to a pond culture system, where carotenogenesis and astaxanthin accumulation are induced. Following a 5-day induction period, the reddened H. pluvialis cells are harvested by gravitational settling. The harvested biomass, which averages > 2.5 astaxanthin as percent of the dry weight, is transferred to a processing building where a high pressure homogenizer is used to rupture the cells' walls. Once the biomass has been homogenized, it is dried to less than 5% moisture utilizing proprietary drying technology. The dried product is then ready to be packaged according to customer needs. The photobioreactor research program has almost doubled the performance of the AGMs in the first nine months of operations: standing biomass concentration increased from 50 to 90 g m(-2) and production increased from 9 to 13 g m(-2) d(-1) during this period. Here, we discuss the significance of these changes in production parameters to the viability of commercial production of astaxanthin and other high value products from microalgae.