Journal of Pure and Applied MicrobiologyVol. 9 No. 1

Beneficial Effect of Spaceflight Experience on Producing of Endoproteinase Lys-C by Lysobacter enzymogenes

Xuelin Zhang1*, Linbin Yan2*, Lijia Li2*, Shushan Lin2, Jun Guo1, Jia Li1, Yi Yu1, Xuege Jiang1, Yan Liu1, Guogang Xu, Yinghua Guo1, Junfeng Wang1, Tianzhi Li1 and Changting Liu1#

1Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing, 100853, China. 2DongYangGuang Park, ZhenAn Road No.368, Shang Sha Village, Chang?an Town, Dongguan, 523000, China.

Received on 06 November 2014 and accepted on 02 January 2014



Endoproteinase Lys-C is an important tool enzyme in industrial produce, mainly gained from Lysobacterenzymogenesat a low efficiency and a long fermentation period. The special environmental factors of outer space may stimulate engineering bacteria to bear high-yield mutant strains. In this study, we sent L.enzymogenes into space via the Chinese Shenzhou-10 spacecraft for approximate 15 days,finding that the total cell number reduced to (24 ? 3.5) ?105cfu/ml after spaceflight, only 13.5% of that in the ground control sample. However, Lys-C activityin ground control bacteria was 0.087 U/ml after fermentation for 120 hours, which was its optical fermentation time for maximal yield, while that in spaceflight sample increased by 17.2%-40.2%,with theoptical fermentation time shortened by 24-48 hours. Further investigatingthe genetic stability of spaceflight sample revealed that both enzyme-producing ability and optical fermentation time after 1, 3, 5, 7, 9, 11 and 15 passages didn?t change,revealing good stability of the spaceflight mutant strain. In summary, spaceflight experience could stably increase the yield of Lys-C by L.enzymogenes and shorten the optical fermentation time of Lys-C, which will benefit its industrial produce.

Keywords : Endopeptidaselys-C; Bacteria; Spaceflight;Fermentation.