Preliminary report on the biological effects of space flight on the producing strain of a new immunosuppressant, Kanglemycin C.
Kanglemycin C (K-C) is a new immunosuppressant isolated from the culture broth of Nocardia mediterranei var. kanglensis 1747-64. To improve the productivity of K-C and to study the biological effects of space flight on its producing strain, spores from five K-C producing strains (U-10, U-15, U-7, M-13, gamma-33) mutated from the wild strain N. mediterranei var. kanglensis 1747-64 were carried into space by an unmanned spaceship, "Shenzhou III" (Divine Vessel III) on March 25, 2002. Comparatively, the strain U-7 was the highest K-C producing strain among the above five starting strains when cultivated in 500-ml Erlenmeyer flasks. After a 6 day and 18 h flight, the treated spores went through serial screening processes to screen for high-yield K-C mutant strains, using thin layer chromatography and high performance liquid chromatography (HPLC). The K-C yield produced by one mutant strain, designated as F-16, derived from the starting strain U-7 was increased by up to 200% when compared to that produced by the starting strain U-7 in 500-ml Erlenmeyer flasks after careful postflight HPLC analysis. Another mutant strain, designated as F-210, derived from the starting strain M-13 showed reduced productivity of K-C as well as exhibited changes in some morphological and physiological characteristics. For example, the broth color of the strain F-210 changed from yellow to purple after 96 h of culture, but that of the ground control strain M-13 remained yellow. Similarly, the mycelium morphological change from filamentous to coccoid of F-210 occurred later than that of ground control M-13. Examination of the survivability of postflight spores indicated that exposure to radiation, during the 162 h of space flight, plays a critical role in the survival rates of spores such that spores exposed to strong radiation exhibited lower survival rates than spores exposed to weak radiation.
Zhou
Jianqin
J
Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Tian Tan Xi Li No 1, Beijing, 100050, People's Republic of China.
Sun
Chenghang
C
Wang
Nanjin
N
Gao
Rongmei
R
Bai
Shuoke
S
Zheng
Huanrong
H
You
Xuefu
X
Li
Rongfeng
R
D009154:Mutation; D009615:Nocardia / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012294:Rifamycins / Q000096:biosynthesis* / Q000737:chemistry; D013026:Space Flight; D013171:Spores, Bacterial / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects
D012294:Rifamycins; C400787:kanglemycin C