Specimens were repeatedly obtained for mycological examination from the skin, throat, urine, and feces of the six astronauts who conducted the Apollo 14 and Apollo 15 lunar exploration missions. Analysis of preflight data demonstrates that the process of severely restricting opportunities from colonization for 3 weeks before flight resulted in a 50% reduction in the number of isolated species. Postflight data indicate that exposure to the space flight environment for up to 2 weeks resulted in an even greater reduction with a relative increase in the potential pathogen Candida albicans. No incidences of microbial shock were observed when crewmembers were quarantined for 16 days after completion of the space flight. Intercrew transfer of particular species could not be demonstrated because most species were not consistently recovered.

S U M M A R YPhysarum rigidum grew and sporulated in pure culture at pH 4-2 on a partially defined medium containing : mineral salts, glucose, yeast extract, haematin, casein hydrolysate. The inoculum equiv. 0.22 mg. protein/z5 ml. grew to equiv. 21 '5 mg. protein/25 ml. in about I 2 days. Physarumflavicomum varieties I and 2 also grew and sporulated on this medium. The yeast extract and haematin were essential for growth; the casein hydrolysate was not. Omission of glucose resulted in a 50% decrease in growth yield. Ethanol, galactose, glycerol, lactose, mannitol, mannose, potato starch, raffinose or sorbitol could replace glucose, but the growth yield was decreased. Fructose, inulin, sucrose and the pentoses and carboxylic acids tested did not support growth.

Mycological analyses were made on specimens obtained from the skin, oral rinse, urine, and feces of three subjects participating in a 56 day Skylab simulation test. Samples were taken over a 175 day period divided into three phases consisting of a prechamber, intrachamber, and postchamber period. A total of 69 species of filamentous fungi and 22 species of yeast and yeast-like fungi were recovered and identified. There was a marked decrease in the isolation incidence of both the filamentous and yeast and yeast-like fungi during the intrachamber period. This, taken with the fact that 71% of the filamentous species and 55% of the yeast and yeast-like species were isolated no more than twice, reflects the transitory nature of the relationship between the human body and most fungi. However, there was a relative increase in the potential pathogens Candida albicans and Candida parapsilosis during the intrachamber period. Over 50% of all fungi recovered were isolated from the nasal and oral cavities. There was no evidence of intercrew transfer of a particular species during the intrachamber period nor was there any evidence of microbial shock during the postchamber period.

Samples for mycological analysis were collected from surfaces in the Skylab spacecraft before launch and during flight for each manned mission. Fungal contamination levels were low during the first two flights; however, the species recovered were different for each mission. On the third mission, widespread contamination of the Skylab spacecraft with Aspergillus and Pencillium spp. was detected. This contamination was traced to several contaminated space suit undergarments.

SUMMARYThree geographical collections (isolates) of myxomycetes originally identified as PhysarumJlavicomum were found to be heterothallic and the clones established from each isolate were divided into two mating types. Previous studies of six isolates of P.Javicomum showed that they could be divided into three groups. Mating occurred within groups but not between groups, and within each group there were two or more mating types. When the new isolates were crossed to the original isolates, they conformed to two of these three groups. This study established the existence of multiple alleles at the incompatibility locus in group 3. Mating-type alleles of the Fl generation of group 3 segregated in a I : I ratio at meiosis. Isolates belonging to group I were also separated from the other two groups on morphological and physiological bases. The morphological description fits that of P. rigidum more nearly than P. Jlavicomum and group I isolates were placed in the species P. rigidurn. Groups z and 3 were separated genetically and physiologically but morphologically the separation was not distinct. These groups were referred to as P.Jlavicomum varieties I and 2.