ARTHUR ISAAC KENDALL 241 



transformations in the group of the hexoses and related compounds. Others, as 

 Bacillus granulohacter pcctinovorum, are notewortliy because they are used on a hirge 

 scale to produce acetone and butyl alcohol and other solvents which are indispensable 

 to industry.' The consideration of these, and other technical fermentation procedures, 

 however, is beyond the scope of this discussion. 



BACTERIAL SYNERGISM 



Ten years ago Castellani and Taylor- called attention to a phenomenon, which, 

 while it had undoubtedly been noticed before, had not apparently received the atten- 

 tion it deserved. This phenomenon has recently been stated by Fiallos' as follows: 

 "Two bacilli, neither of which causes the production of gas in certain compounds, may 

 do so when artificially mixed together, provided one of them is capable of producing 

 simple acidity (never gas) in these compounds, and the other, though inert to these 

 compounds (i.e., produces neither acid nor gas), is capable of producing gas from glu- 

 cose." Many observers have studied this phenomenon recently^ and have amply 

 confirmed the facts, but the explanation is not agreed upon; also, several different 

 types of chemical activity are included in this group of reactions. The most common 

 of these is the one described by Fiallos.^ It is quite clear that all of the phenomena 

 thus far discovered are of the nature of coupled reactions. 



The following specific instance may be mentioned: a staphylococcus and Bacillus 

 paratyphosus acting together produce acid and gas from nutrient lactose-fermentation 

 media, although the staphylococcus alone merely produces acid, but no gas from this 

 sugar, and Bacillus paratyphosus fails to utilize the sugar at all. Examples might be 

 multiplied almost indefinitely, but in each instance it will be found that one of the 

 coupled reacting organisms must produce acid but no gas from the carbohydrate; 

 the other coupled organism need have no action whatsoever upon the carbohydrate 

 but must be capable of producing CO, and H, from formates. All the known bacteria 

 that liberate CO, and H2 from formates will also produce gas and acid in the usual 

 nutrient glucose media. The addition of nitrates (sodium or potassium nitrate) in 

 small amounts will prevent the formation of gas either in glucose solution or in for- 

 mate solution. 



Takes and Jollyman^ long ago showed that bacteria which produce gas from 

 nutrient sodium-formate media also produce gas from nutrient glucose solutions with 

 the exception of many, if not most, yeasts; they also showed the converse to be true 

 — namely, that bacteria which do not produce gas from formate do not produce gas 

 from glucose. They also made extensive studies of the effect of nitrates upon the 

 reaction and found that the nitrates interfere with gas production in accordance with 

 the following equation: 



H . COONa+NaN03 = NaHC03-FNaNO. . 



' See, for details, Fred, E. B., Peterson, W. H., and Mulvania, M.: J. Bad., 11, 323. 1926. 

 ' Castellani, A., and Taylor, F. E.: Brit. M. J., 2, 855. 1917; i, 183. 1919. 

 J Fiallos, J. M.: /. Trop. Med., 28, 426. 1925. 



* Much of the later literature is reviewed by Holman, W. L.: J . Infect. Dis., 39, i ^5. 1926. He 

 proposed the term "synergism." Cf. chap, viii in this volume. 



sPakes, W. C. C, and Jollyman, W. H. : /. Cliein. Soc, 79, 386, 450. 1901. 



