INDUSTRIAL A N D ENGINEERING CHEMISTRY
1830
Vol. 42, No. 9
likewise hold for the penicillin fermentation, except that the difTABLE11. EFFECTOF INOCULUM PREPARED m INDIVIDUAL ference between fermentors and shake flasks is more pronounced FLASKSm n m BULK in favor of the fermentors. Relative Streptomyoin Activity Uniform subdivided flask inoculum 0.Q6 0.80
Nonuniform inoculum
LlTERATURE CITED
from individual
Fermentor No. 1 2 3 4 5 6
7 8 9 10 11
Average Standard deviation, %
1.14 1.07 1.04 1.08 0.96 0.97 1.15 0.94 1.09 0.76 1.0 *12.9
1:25 0.90 0.62 1.13 0.96 1.46 0.77 0.95 1.0 1.0 *23.7
TABLE111. COMPARISON OF FERMENTORS AND SHAKE FLASKS Relative Streptomycin Activity Laboratory fermentor 1.12 1.07 0.91 0.90 1.05 0.95 1.0
Average Standard deviation, % &9.2
Shake flask 1.03 0.97 0.88 0.87 0.77 1.09 0.94
t11.7
laboratory shake flasks. Typical data contained in Table I11 compare the laboratory fermentor with the shake flask in the streptomycin fermentation. The laboratory shake flask controls were taken from the fermentor as described previously. In a random series, the laboratory fermentors produced about 6% more streptomycin than the control shake flasks. These results
(1) Bartholomew, W. H., Karow, E. O., Sfat, M. R., and Wilhelm, R. H., IND. ENG.CHEM.,42,1801 (1950). (2) Currie, J. N., Kane, J. H., and Finlay, A., U. S. Patent 1,893,819 (1933). (3) Dulaney, E. L., Ruger, M., and Hlavac. C., Mycologia, 41, 388 (1949). (4) Federal Registw. Title 21, Part I, Section 141 (June 3, 1948). (5) Foster, J. W., and Woodruff,H. B., J. Bact., 52,229 (1946). (6) Gailey, L. B., Stefaniak, J. J., Olson, B. H.. and Johnson, M. J., Ibid., 52, 129 (1946). (7) Herrick, H. T., Hillbach, R. H., and May, 0. E., IND.KNG. CHEM.,27, 681 (1935). ( 8 ) Humfeld, H., J. Bact., 52,229 (1946). (9) Ibid., 54, 689 (1947). (10) Nolte, A. J.. Loeseke, H. W. van, and Pully, G. N., IND.EIG. CHEM.,34, 670 (1942). (11) Olson, B. H., and Johnson, M. J., J . Buct., 57,235 (1949). (12) Pavcek, P. L., Peterson, W. H., and Elvehjem, C. A., IND.ENG. CHEM.,29, 536 (1937). (13) Peterson, W. H., Snell, J. F., and Frarier, W. C., Ibid., 37, 30 (1945). (14) Saeman, J. F., Anal. Chem.,, 19, 913 (1947). (15) Saeman, J. F., Locke, E. G., and Diokerman, G. K., “Production of Wood Sugar in Germany and Its Conversion to Yeast and Alcohol,” F I A T Rept. 499 (1945). (16) Savage, 0.M., J. Bact., 57, 429 (1949). (17) Singh, K., Agarwal, P. N., and Peterson, W. H., Arch. Biochena.. 18, 181 (1948). (18) Somogyi, M., J . B i d . Chem., 117,771 (1937). (19) Stubbs, J. J., Lockwood, L. B., Roe, E. T., Tabenkin, B., and Ward, G. E., IND.ENO.CHEM.,32,1626 (1940). (20) Ward, G. E., Lockwood, L. B., Tabenkin, B., and Wells, P. A., Ibid.,30, 1233 (1938). (21) Wells, P. A., Lockwood, L. B., Stubbs, J. J., Roe, E. T., Parges, N., and Gastrock, E. H., Ibid., 31, 1518 (1939). RECEIVED April 21, 1950.
Torula Yeast Grown on Spent Sulfite Liquor A. J. WILEY, GEORGE A. DUBEY, B. F. LUECK, AND L. P. HUGHES Sulphite Pulp Manufacturers’ Research League, Inc., Appleton, Wis.
Chemical analyses and vitamin assays were made on samples of dry torula-type yeast produced commercially a t a Wisconsin pulp mill. The yeast was derived from a single strain of Torulopsis utilis, using continuous-type feeding methods for sustained periods. The yeast was found to be uniform both i n chemical characteristics and in its content of various components of t h e vitamin B complex. Samples of yeast grown on spent sulfite liquor were compared with five samples of yeast grown on sources of sugar other t h a n sulfite liquor. The thiamin content of t h e yeasts from different sources varied somewhat with t h e substrate a n d were generally much lower t h a n would be expected from grain worts. The riboflavin content of t h e yeasts grown on different substrates varied markedly. Data are insufficient t o show whether t h e substrate, t h e strain of yeast, or t h e method of processing most affects t h e riboflavin oontent. Torula-type yeasts generally are capable of high levels of pantothenic acid synthesis, b u t thle vitamin is subject to easy destruction under condi-
tions of final prooessing after leaving t h e fermentor. The ash content of torula yeast seems to be a direct function of the amount of phosphorus nutrient fed to the yeast. Hydrolysis and extraction methods used for crude fat analysis in yeast need to be studied further.
T
HE production of dry, torula-type yeast (Torulopsis utilis) as a supplement for human food and animal and poultry feeds has attained commercia1 scaIe proportions in this and many other countries since the beginning of World War 11. Widespread interest and rapid development of this yeast resulted from critical wartime shortages of foods and feedstuffs, but the basic research leading to process development and the early evaluations of its nutritional worth should be credited to an unusually productive investigation by Fink, Lechner, and their associates (7) at the Institute for Fermentation Industry in Berlin during a &year period preceding 1940. The torula process has since been subjected to laboratory, pilot plant, and commercial scale development in and out of Germany using many daerent sub-
INDUSTRIAL AND ENGINEERINQ CHEMISTRY
September 1950
strates as the source of carbohydrates and with various modifications of the basic yesst growth procedures. The question naturally arises as to whether the qualities of the yeast may not be affected by differences in substrates and methods. With re-estsbliient of full production of foodstuffs under peacetime conditions, emphasis on manufacture of torula yeast has shifted from production of a substitute source of protein suppIies to recognition of important potentialities of this yeast process as an efficient method of treating carbohydrate wastes of the farm, forest, and industry (8). However, commercial production of yeast as a method of abating stream pollution by utilization of sugars otherwise wasted predicates a large scale market outlet which will meet a t least part of the relatively high capital and operating charges inherent in growing and recovering the dry yeast. Therefore, recent work on development of the torula yesst process tends to follow three paths of effort:
1. Reduction of yeast rodu+ion costs
1831
Methods for vitamin m y : Thiamin
Thiochrome method U.S.P. (16) Exceptions: 1. Extract with acid a t 15 pounds prearmre for 15 minutes instead of on steam bath 2. Treat with enzyme 24-48 hours a t 37" C. instead of 3 hours a t 45" C. 3. Use sample plus standard as an additional check Ribo0avin Microbiological method U.S.P. (14) Riboflavin Fluorometric (10) Exceptions: 1. Substitute 2 ml. for 1ml. of 1% KMnOd 2. Substitute 2 ml. for 1 ml. of 3% HsO2 3. Oxidue 2 minutes rather than 1 mlnute Pantothenic acid Microbiological method (11) Nicotiic acid Microbiological method U.S.P. (19) Biotin Microbiolo@cal method using L-arabinosus; modification of Wright and Skeggs method f\"I)\I
Full analytical an8nutntional evaluation of the yeast product 3. Development of special yeast products to meet the requirementa of particular end u888
Pyridoxine HCl (BOcomplex) FoLc acid
This paper is concerned with work done in these laboratories on the second objective. It summarizes certain analytical data comparing samples taken routinely during the first year of commercial scale production of yeast grown on spent sulfite liquor from a Wwconsin pulp mill with various samples of torula yeast from other sourcea.
Table I summarizes chemical characteristics of a 6month series of production-control samples at the Lake States Yeast Corporation yeast plant. All samples represent the same strain of Tonrlopsis utilie.
2.
MATERIALS AND ANALYTICAL METHODS
RESULTS
TABLEI. ANALYSISOF TORULA YEASTPRODUCED COadMERCULLY FROM SPENT SULFm LIQUOR (All data on as-reaeived basis) First 6 Months' Omahon Avarap Standard' analvsu~ devlation
Spent sulfite liquor substrates:
Wisconsin ulp mill A-commercially produced yeast, Lake statee Yeast Eorporation (1949) Wisconsin pu mill B-pilot lant product, Sulphite Pulp Manufacturers' b e a r c h League, fnc. (1949) WiEwonsin pul mill &pilot lant product, Sulphite Pulp Manufacturers' &search League, fnc. (1949) German ulp mill, commercial yeast product, Zellstofabrik Waldhof, dnnheim, Germany (1949) Substrates other than spent sulfite liquor: Citrus- 1juice-pilot plant mduat Citrus Products Station , e r Bureau Wm&K o Winter &ven, Fia. 1947-1948) Douglas fir w+ su pllot lant prohuct, Foreat Products Laboratory, Madlson, 19477 Pear cannery waste-pllot lant roduct, Western Regional Research Laboratory Albany, &alii. 4948) Jamaican cane m o h s w o m m m i a l product, Colonial Food Yeast Limited, Jamaica, B.W.I.(1949) Hawaiian cane molasses--aommercial product (laboratory dried), Carnation-Albers Company, Oakland, Calff. (1949)
r
