' ki^ Editeilgr |OHN S. BURIEW CARNEGIE INSTITUTION OF WASHINGTON PUBLICATION 600 WASHINGTON, D. C ALGAL CULTURE FROM LABORATORY TO PILOT PLANT Edited by JOHN S. BURLEW CARNEGIE INSTITUTION OF WASHINGTON PUBLICATION 600 WASHINGTON, D. C. This book first published July 15,1953 Second printing June 1955 Third printing March 1961 Fourth printing July 1.964 Fifth printing "May 1976 ISBN 0-87279-611-6 FOREWORD The Carnegie Institution's project on the mass culture of algae is a collateral development or offshoot of its program of research on photo- synthesis. One part of this program was concerned with the nature of the products which the plant makes in the photosynthetic process [200]. Several widely different species of plants were used in these investiga- tions, but particular attention was paid to the unicellular alga Chlorella pyrenoidosa [201], because of the broad range of environmental condi- tions under which it can grow, and because this organism has been ex- tensively used as a subject of study of many other aspects of the photo- synthetic problem. The experience gained in the culture of Chloreila was applied to a wartime investigation, namely, the search for an antibacterial substance that might be isolated from the culture solution in which Chlorella was grown [202]. It turned out that the antibiotic activity resulted from a complex photooxidation of the unsaturated fatty acids in the Chlorella itself, and that a similar reaction could be induced in fatty acids from a variety of sources [203, 204, 152]. After the war the investigation of the influence of environmental fac- tors on the chemical composition of Chlorella was resumed. The con- ditions for varying the protein and fat content over wide ranges were established [151]. The nature of the lipides in the Chlorella was also in- vestigated [91], By the winter of 1947-1948 the possibility of growing Chlorella on a large scale for food was being considered seriously. H. A. Spoehr and Harold W. Milner prepared a preliminary analysis of the problem for publication in Carnegie Institution of Washington Year Book No. 47 [206]. The sort of development that they suggested, involving applied research and engineering, lay outside the scope of the Institution's usual activities. The Institution therefore turned over this aspect of the problem to Re- search Corporation of New York, continuing its own fundamental scien- tific, studies on photosynthesis. Research Corporation contracted with Stanford Research Institute in September 1948 for an engineering study of the factors involved in the design of a pilot plant. The small culture unit that was constructed and operated at Stanford showed that continuous culture of Chlorella was possible; but the results were not conclusive enough for Research Corporation to feel justified in financing further experimentation. The work at Stanford Research Insti- tute was therefore terminated in the spring of 1950. During the latter part of 1950 the American Research and Develop- ment Corporation in Boston^ Massachusetts, became interested in the subject of algal culture and made a careful review of the economic as- pects of the subject on the basis of the experiments at Stanford Research Institute. This review showed clearly that there was still much uncer- tainty as to whether large-scale culture was economically feasible. iii iv FOREWORD It was generally agreed at that time that further work of a fundamental sort was needed, and that it was especially desirable to discover whether any new problems would be introduced by a large increase in the size of a culture unit. It was essential also to obtain larger quantities of the alga than had so far been available, so that its potential usefulness could be evaluated. In order to accomplish these purposes, the Carnegie Corpora- tion of New York joined with the Institution in making funds available for Arthur D. Little, Inc., a consulting research and development organiza- tion in Cambridge, Massachusetts, to set up a pilot plant for the culture of Chlorella. The staff of the Department of Plant Biology turned its attention to the problem of the factors that affect the rate of growth of Chlorella as one aspect of its program of fundamental research on photosynthesis. The Institution also sponsored laboratory investigations of algal culture at the University of Texas by Dr. Jack Myers, who spent the summer of 1951 as a visiting investigator at the Department of Plant Biology. The Institution also, in July 1951, granted a fellowship to Dr. Robert W. Krauss, of the University of Maryland, extending him support for his fundamental re- search on algal nutrition. In addition to this research, Dr. Krauss is collaborating with the Institution in culturing a variety of different algae. By no means all the problems involved in algal culture have been solved; but partial answers to the principal questions have been obtained. The alga Chlorella has been grown and harvested continuously on a large scale; it has nutritive value in animal feeding; possibly it or one of the other algae contains useful chemical raw materials; and estimates have been made as to possible yields of Chlorella in commercial quantities, based on the best data at present available. At this stage of our program it is desirable to publish a fairly com- plete account of the work to date, so that our accumulated experience may be conveniently available. Such an account should be an aid to all the workers in the field and especially should help any organizations that may be interested in setting up pilot plants for the culture of algae. Most of the present monograph is made up of reports of investigations under the auspices of the Carnegie Institution of Washington. We are privileged, however, to include also accounts of some parallel investi- gations in other countries. It is hoped that, as a progress report of a rapidly developing field of science and engineering, this book will serve to stimulate even more interest in the subject, and will result in increased progress toward the large-scale culture of algae. The manuscripts of the chapters originally planned for this monograph were received during the first quarter of 1952. The first chapter, which summarizes them, was also written at that time. Later that year the Car- negie Institution had the privilege of having Professor H. Tamiya as a guest worker at its Department of Plant Biology, through a fellowship supported by the Office of Naval Research of the United States Government. Profes- sor Tamiya has prepared an account of studies of the growth of algae in mass culture that he and his colleagues had performed at the Tokugawa FOREWORD v Institute for Biological Research, Tokyo. A delay in the publication of the monograph made it possible to include this new material, which is present- ed as chapters 16 and 18. It was not possible, however, to incorporate a discussion of it in the summary. Furthermore, it was not feasible to ask the other authors to revise their respective chapters so as to include more recent results. Active participation by other groups is essential for the ultimate suc- cess of the development of algal culture. The Carnegie Institution has felt that it had an obligation to lead the way in exploring the new field, for a discovery of great potential importance to humanity had been made through the fundamental research in one of its laboratories, and this discovery might have remained unused for many years unless further action was taken. Indeed, exactly this had happened much earlier in the case of hybrid corn. The basic knowledge concerning hybrid corn was published by George H. Shull, of the Institution's Department of Experimental Evolution, in 1909, but almost ten years went by before any effort was made to apply that knowledge for the benefit of man. Rather than let the development of algal culture proceed by chance, the Institution has been actively carrying it on to the point where enough in- formation is at hand to assess it fairly. At this stage we are not able to recommend any particular type of installation or to state positively the economic possibilities of this method of producing foodstuffs. The ramifi- cations of the subject are so wide that we cannot yet be sure what form the future development may take. The need of the world for additional sources of high-protein food is so great, especially in overpopulated areas, that serious effort in tracking down every promising lead is certainly warranted. Such great advances in technology have already come from the coupling of engineering with biology that it seems inevitable that the production of food, at least in certain areas, will eventually be carried out by "process" industries. The large-scale culture of algae may well become the first of them. In regions of the world where population is especially dense, and fertile land is limited, it is entirely possible that process-industry methods of pro- ducing food may furnish a respite from the threat of famine and so con- tribute toward more salutary conditions for civilized living. If algal cul- ture can serve such a purpose, it is well worth development for that rea- son alone. It is hoped that such a development may take the form ultimately of a multitude of individually owned, relatively small establishments, combin- ing the culture of algae perhaps with utilization of the product for animal feeding on the spot. The new industry that would result would thus enter into our economic life in such a manner as not to produce disruption, but rather to strengthen individual enterprise. Whatever form an algal culture industry takes eventually, the programs for its commercial development may need patent protection in order that venture capital may be secured for necessary risks.