Propagation of Inoculum for Haematococcus pluvialis Microalgae Scale-Up Photobioreactor Cultivation System

Abstract

An increasing number of microalgae strains are used for commercial production of metabolites. When conducting research, the moment of the process scaling tends to be very difficult. One of the most complex issues is related to planning and designing an efficient system for propagation of appropriately high amounts of inoculum required for inoculating cultures on a semi-technical and industrial scale. The following paper aimed at designing an automated station for the preparation of microalgae inoculation material intended for inoculation of the system, comprising of six 90 dm3 volume photobioreactors. The system, comprised of eight airlift photobioreactors of 12 dm3 volume each, installed in mobile storage units connected to the control system in the form of a docking station. Each of the photobioreactors had a separate system used for monitoring temperature and pH, mixing, and LED lighting. The station constituted the last stage of preparing the inoculation material for inoculating technical-scale photobioreactors, used for conducting experiments with Haematococcus pluvialis microalgae. Achieved results, repeatability of the processes, and the ergonomics of the station increased the productivity and quality of the research and development processes.

Bioprocess Strategy of Haematococcus lacustris for Biomass and Astaxanthin Production Keys to Commercialization: Perspective and Future Direction

“…Closed air-lift photo-bioreactors Bold's Basal Medium 23-25 190 The system comprised of 90 dm 3 volume photo-bioreactors was obtained biomass concentration in the range 1.40-1.99 g dm −3 on the eighth day of conducting experiments [11] Vertical bubble column photo-bioreactor (VBC-PBR) BG−11 28 55-280…”

“…Light is a critical factor in microalgal cultivation because it provides the energy required for photosynthesis [11]. When H. lacustris cells are exposed to bright light, the phytoene synthase gene (psy) expression is increased, and the cells transition from the green to the red stage [12].…”

“…When 2500 lux and 500 lux LED blue light were used, the cell size accelerated by 4.1 and 2.5 times, respectively, in the red stage [12]. There are a few lighting colors: sunlight, blue, deep red, green, warm-white, orange-red, and yellow, which have always been used to optimize microalgae cultivation productivity [11]. Since green algae contain chlorophyll a and b, which are major light-harvesting pigments, they are sensitive to blue and red light.…”

“…To maintain agitation in PBR, air and CO 2 were alternately administered. The administrated air and carbon dioxide flow rates were kept constant at 0.5 dm 3 gas per minute [11]. A CO 2 concentration greater than 2.2 mg L −1 is required for high biomass productivity [9].…”

“…The open system makes use of both natural and man-made ponds (raceway ponds), whereas the closed system makes use of closed systems such as photo-bioreactors (PBR) [10]. In microalgae cultivation, optimization can be accomplished by exploiting key process parameters that affect biomass growth and bioactive compound accumulation [11,12]. The interaction of these factors may have a significant impact on biomass production and intracellular culture composition [13].…”