44 THE ROLE OF ALGAE AND PLANKTON IN MEDICINE 



The enthusiasm for culturing phytoplankton for feeding is based on 

 reports that it is innocuous and that it possesses great nutritional value. 

 These have been well summarized by Fisher and Burlew. 41 Mention has 

 already been made of Jorgensen's feeding plankton soups to lepers in 

 1941, with a resultant improvement in weight and energy. These com- 

 prised cultures of Chroococcus, Homocystinea, Oocystis, Ankistrodesmus, 

 Chlorella, and Scenedesmus. More recently, Jorgensen told one of us 

 (M.S.) that an algal broth, when fed to mice with skin cancer, brought 

 about an appreciable decrease in the size of the lesions; inexplicably, 

 however, test animals maintained on such a diet did not haye a long life 

 span. Currently Jorgensen is feeding his phytoplankton in rather palatable 

 compressed pills. 



Another early feeding experiment was that in 1949 at the Stanford 

 Research Institute. Rats fed on a diet containing a third Chlorella pyrenoi- 

 dosa had a weight gain only one-third that of a control group. This has 

 been attributed either to the unpalatable flavor or to the mechanical diffi- 

 culty resulting from the hygroscopic nature of the food preparation. Henry, 

 at the National Institute for Research in Dairying, in England, fed freeze- 

 dried Chlorella prepared by Geoghegan to young rats. No adverse effects 

 resulted after four months on a 17 per cent Chlorella diet. In a four- week 

 comparative study, the protein efficiency of Chlorella appeared slightly 

 superior to that of dried brewer's yeast and peanut meal, but inferior to 

 that of skim milk. 



In 1951, Combs, 235 at the University of Maryland, tested New Hamp- 

 shire chickens on Chlorella provided by the Carnegie Institution. A 

 marked increase in growth and an improvement in feed efficiency resulted 

 from adding 10 per cent Chlorella to a basal diet in place of soybean meal. 

 This was attributed to the high vitamin content of the alga. However, a 

 growth depressant effect was noted after extended feeding because of im- 

 pacted beak conditions. This occurred much sooner with 20 per cent 

 Chlorella feedings. Similar results were obtained in 1952 with chicks 

 when vacuum-dried Chlorella was tried by a feed supply concern. Most 

 of the difficulties encountered were apparently due to excessive water 

 absorption by the algae. Other methods of preparation would seem to be 

 indicated. 



Tamiya 22 - 41 has included substantial amounts of Chlorella in preparing 

 highly acceptable bread, noodles, soup, tea, and ice cream. He has also 

 used hydrolysates of dried algae as a substitute for soy sauce. His students 

 and even his colleagues admitted no ill effects whatever from repeated 

 ingestion of these concoctions. 



