Navid R. Moheimani, David Parlevliet, Mark P. McHenry, Parisa A. Bahri and Karne de Boer

Abstract Microalgae cultivation is a promising methodology for solving some of the future problems of biomass production (i. e. renewable food, feed and bioenergy production). There is no doubt that in conjunction with conventional growth sys­tems, novel technologies must be developed in order to produce the large-scale sustainable microalgae products. Here, we review some of the most promising existing microalgae biomass growth technologies and summarise some of the novel methodologies for sustainable microalgae production.

1.1 Introduction

There has recently been extensive research focus on biology, physiology, engi­neering and their integration for microalgae cultivation to produce sustainable products such as biofuel, food, feed and high-value products. Algae belong to many different and unrelated taxonomic groups that all contain chlorophyll a and are able to utilise solar energy and fix CO2 to produce organic compounds (Borowitzka 2012). More than a dozen algal species have been mentioned in the literature as potential candidates for large-scale cultivation. However, conclusive information obtained through commercial trials is not yet available to assess suitability of most of these species. The ideal microalga must be able to grow very well even under high biomass concentration and varying environmental conditions. It must be able to produce high concentration of product of interest (i. e. high-value products, lipids and hydrocarbons). However, it is unknown how many species of algae exist, with

N. R. Moheimani (H)

Algae R&D Center, School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia e-mail: n. moheimani@murdoch. edu. au

D. Parlevliet • M. P. McHenry • P. A. Bahri • K. de Boer

School of Engineering and Information Technology, Murdoch University,

Murdoch, WA 6150, Australia © Springer International Publishing Switzerland 2015

N. R. Moheimani et al. (eds.), Biomass and Biofuels from Microalgae,

Biofuel and Biorefinery Technologies 2, DOI 10.1007/978-3-319-16640-7_1

estimates ranging between several hundred thousand and several million different species—with new types identified all of the time (Guiry 2012). Only a small portion of microalgal species (several thousand) can be kept alive in culture, and only a handful of them have been successfully grown commercially. Table 1.1 summarises the main microalgae species tested for medium — to large-scale pro­duction (especially for feed, high-value products and biofuel).

However, to date, only a few of these species were successfully grown in large scale. Commercial large-scale production of microalgae for bioproducts began in early 1960s and 1970s with Chlorella and Spirulina and followed in the 1980s with production of P-carotene from Dunaliella salina (Borowitzka 2013a). All three species were successfully grown in mixed or unmixed open ponds (Craggs et al. 2013). The ability to grow at highly selective environments is the main reason for the successful growth of these species (Spirulina = high pH and high HCO3-, D. salina = high salinity and Chlorella = high nutrients) (Craggs et al. 2013). Moheimani and Borowitzka (2006) also showed that Chrysotila carterae reliable long-term culture in raceway pond is successful due to the ability of this alga to grow at very high pH. Other species that do not have this selective advantage may need to be grown in closed photobioreactors. The selection of growth technologies or production systems for microalgae will need to be based to a large extent on the microalga of choice and cultivation system.