454 Physiology 



TABLE 8. 4. RESPIRATORY QUOTIENTS REPORTED FOR 

 VARIOUS PROTOZOA 



Species 



R.Q. 



PHYTOMASTIGOPHOREA 



Astasia longa (strain J) 

 Chilornonas Paramecium 

 Khawkinea halli 



ZOOMASTIGOPHOREA 



Leishmania tropica 



Strigomonas fasciculata 



S. oncopelti 



Trypanosoma cruzi 



T. equiperdum 



T. lewisi 



T. rhodesiense 



SARCODINA 



Amoeba proteus 

 Pelomyxa carolinensis 



SPOROZOA 



Plasmodium knowlesi 



CILIATEA 



Balantidium coli 

 Blepharisma undulans 

 Paramecium aurelia 

 P. caudatum 

 P. multirnicronucleatum 

 Spirostomum ambiguum 

 Tetrahymena pyrijormis 



0.34 (247) 



0.28-0.37 (398); 0.74-0.93 (221) 



0.56 (247) 



0.84-0.95 (531) 

 1.0 (341) 

 1.0 (341) 

 0.74-1.06 (33) 

 0.60 (126) 

 0.74-0.94 (531) 

 0.2 (64) 



1.03 (124) 



0.56-0.87 (526); 0.45-0.94 (430) 



0.87-0.93 (63) 



0.84 (85) 



1.12 (124) 



0.73-0.90 (429) 



0.69 (4); 0.62 (495); 0.70-0.99 (429) 



0.72 (398) 



0.84 (532) 



0.81-1.27 (431) 



differences in condition of the organisms. An R.Q. of 0.87 has been re- 

 ported for well-fed Pelomyxa carolinensis and one of 0.56 for starved speci- 

 mens (526). Age of the culture also is a factor. The R.Q. of Chilornonas 

 Paramecium drops from 0.91-0.93 in 24-hour cultures to 0.75 at 72 hours 

 (221); that of Tetrahymena pyrijormis from 1.21-1.27 at three days to 0.81 

 after seven days (431); that of Trypanosoma cruzi, from a maximum of 

 1.06 to a low of 0.74 after the population reaches its peak. In the last case, 

 the lower quotient is attributed to exhaustion of carbohydrates and subse- 

 quent utilization of proteins (35). The R.Q. also may vary with tempera- 

 ture — 0.73 at 20° to 0.90 at 30° for Paramecium aurelia; 0.70 at 15° to 

 0.99 at 35° for P. caudatum (429); 0.45 at 10° to 0.94 at 30° for Pelomyxa 

 carolinensis (430). 



Oxidations^^ 



Most biological oxidations consist of series of oxidations and re- 

 ductions catalyzed by a variety of enzymes, and may be pictured as 



" For detailed discussions of oxidative enzyme systems, the reader is referred to 

 such sources as Baldwin (10), Lardy (308), and Stephenson (538). 



