| 摘要 |
The industrial cultivation of unicellular green algae (Chlorella or Senedesmus) involves: (i) inoculating a number of portions of the unicellular green algae into a corresponding number of portions of a sterile aqueous or solid medium containing (a) nutrient inorganic salts, (b) at least one sugar and/or at least one organic acid, and (c) at least one amino acid, or natural material containing amino acids; (ii) allowing the algae to grow while the aqueous or solid medium is kept unilluminated and is kept under an aerolaic condition; (iii) isolating at least one of the strains showing the best growth; (iv) repeating steps (i) to (iii) at least once to obtain at least one strain showing good growth characteristics in unilluminated media; (v) inoculating the best strain obtained into an aqueous medium containing components (a), (b) and (c); and (vi) allowing the algae to grow while the aqueous medium is kept uniluminated and is agitated and/or aerated. The aqueous medium used in stage (v) may be of a different composition from that used in stages (1) to (iv). Once the algal concentration has reached a maximum in stage (vi), the aqueous medium may be diluted at least once with further aqueous medium as used in stage (v). The ratio of available carbon to available nitrogen in the growth medium should preferably be less than 6:1. The cultivation takes place at a temperature in the range 20-30 DEG C. The amino acid may be casamino acids, cystine, cysteine, methionine, serine, glycine, lysine, tryptophane, or such amino acid-containing materials as soy beans, yeast, fish meal, meat extract, milk, casein, waste liquor from fermented milk, wheat bran and extracts from rice bran. The other constituents of the nutrient media are generally similar to those disclosed in Specification 1,109,658, but include additionally potassium nitrate.
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