40 THE ROLE OF ALGAE AND PLANKTON IN MEDICINE 



nutrition. Though most of the studies have been with Chlorella, other 

 microalgae are comparable. It has been calculated that a quarter pound 

 of Chlorella will supply all the daily minimal human vitamin needs except 

 for ascorbic acid. Table VI, taken from Burlew, 41 details the vitamin 

 content of two samples of Chlorella. 



TABLE VI. — Vitamin Assay of Dried Chlorella 



Pilot Plant Laboratory 

 Vitamin Sample Sample 



Carotene (mg./lb.) — 218.0 



Thiamin (mg. /lb.) 11.0 4.5 



Riboflavin (mg./lb.) 26.2 16.3 



Niacin (mg./lb.) 54.0 109.0 



Pyridoxine (mg./lb.) — 10.4 



Pantothenic acid (mg./lb.) 3.6 9.1 



Choline (mg./lb.) — 1370.0 



Biotin (meg. /lb.) — 67.0 



Vitamin Bi 2 (meg. /lb.) 45.0 10.0 



Lipoic acid (acetate units/lb.) 1.5 — 



Algae require basically the same nutrients as higher plants — nitrogen, 

 phosphorus, potassium, sulfur, magnesium, and iron. Unlike the higher 

 plants, all except a few algae can dispense with calcium. Potassium and 

 magnesium (and occasionally calcium) are important in the photosyn- 

 thetic process because their bicarbonates can make available supplemental 

 carbon dioxide. In addition, algae also have need for certain trace elements 

 or micronutrients. Myers 41 has specified algal requirements for manganese, 

 zinc, calcium, boron, and copper. The exact metabolic role of these has 

 not been elucidated. Neither has it been for the following substances, 

 which have also been identified in algal cells: antimony, arsenic, beryllium, 

 cobalt, germanium, iodine, lead, manganese, molybdenum, nickel, rubi- 

 dium, silver, strontium, tin, titanium, tungsten, uranium, vanadium, and 

 yttrium. (Does not this listing of elements sound more like a roll-call 

 of our present-day electronics and metallurgical industries, and are not the 

 biologic and the mechanistic worlds drawing closer?) It has been deter- 

 mined that, because of selective absorption, the cellular content of manga- 

 nese, strontium, uranium, and yttrium is above that of the surrounding 

 media. The only known role of molybdenum is that of fixing nitrogen in 

 Anabaena. 



Even though their functions are obscure, the addition of trace elements 

 to algal culture media has become standard operating procedure. An 

 excellent means for providing continuously adequate micronutrients are 



