Three New Synthetic Algal Culture Media to Grow Them All †

Three new synthetic algal culture media are described that have been used to cultivate ~12,000 diverse strains of (micro)algae, one culture medium for marine and brackish-water algae (ASP-MEL (Artificial Seawater Provasoli-MELKONIAN)), and two culture media for freshwater/terrestrial algae (SFM (Synthetic Freshwater Medium) and W-MEL (Waris-MELKONIAN)). The genesis of the three media since their original formulation and the rationale for modifications of these media over the past 50 years are outlined. A complex trace element mix derived from an enriched natural seawater culture medium (L1) is used in all three media, and allows the omission of soil water extract from one freshwater culture medium (W-MEL). It is suggested that the inclusion of selenite renders soil extract in algal culture media superfluous. Prospects and limitations of the three synthetic algal culture media as general-purpose media for large collections are discussed.