PRINCIPAL INVESTIGATOR (S ): Robert Staehle 



EXPERIMENT TITLE/NUMBER : Bacteria and Spores, ED31 



PROGRAM/MISSION : Skylab 2, 4 



CLASSIFICATION : Microorganism - ( Bacillus subtilis . Escherichia coli ) , 



( Bacillus mvcoides ) 



DISCIPLINE(S) : Cell biology 



OBJECTIVES : To observe and photograph bacterial colonies to determine if null 

 gravity has any effect on survival, growth rate, mutations and morphology. 



PROTOCOL : The bacteria were suspended in a water solution of polyvinyl 

 alcohol (PVA) and were placed on a disk of filter paper. Fifteen petri dishes 

 containing nutrient agar, together with one petri dish containing 15 filter 

 disks of bacteria were flown. Inflight, a single bacteria and spore 

 impregnated disk was placed in each agar-filled petri dish and incubated at 

 77 F for 68 hours on Skylab 2 and 88 hours on Skylab 4. Bacillus subtilis and 

 E scherichia coli were flown on Skylab 2. Bacillus subtilis and Bacillus 

 mvcoides were used for the Skylab 4 experiment. Color photographs were made 

 periodically throughout incubation. 



EQUIPMENT : Petri dishes and container, incubator, camera. 



RESULTS : Neither Bacillus mvcoides nor Escherichia coli developed during 

 incubation, but a small portion of Bacillus subtilis developed on both 

 missions. Fewer colonies developed inflight than in the controls, and those 

 that developed were usually larger, grew faster, displayed gram strain 

 variance and morphology change. Fungal contamination was reported. The 

 inflight colonies exhibited more pronounced topography and were more sensitive 

 to several antibotics during postflight testing. 



CONCLUSIONS : Real-time observation of bacterial growth has shown definite 

 changes in behavior induced by growth in the Skylab environment. These 

 changes may be either environmental or genetic in nature, or both. Work 

 continues to better define these changes and to identify their causes. 



PUBLICATIONS : 197, 377, 500 



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