Biobutanol - Biotechnology in China: Biofuels and Bioenergy - page 88

Fig. 1 The main research activities on biobutanol in China. This figure was summarized from
published articles. IPE-CAS: Institute of Process Engineering, Chinese Academy of Sciences,
Beijing. IM-CAS: Institute of Microbiology, Chinese Academy of Sciences, Beijing. DUT:
Dalian University of Technology, Dalian, Liaoning Province. QIBEBT-CAS: Qingdao Institute
of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong
Province. JNU: Jiangnan University, Wuxi, Jiangsu Province. IPPE-CAS: Shanghai Institute of
Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai. GXU: Guangxi

University, Nanning, Guangxi Province

2.2 Genetic Manipulation Methods

For genetic manipulation of C. acetobutylicum, gene knockout/down methods
have been well developed, such as the homologous recombination method based
on replicable/non-replicable vectors [ 14 , 17 , 18 , 46 ], and antisense RNA (asRNA)
strategies [ 8 , 48 ]. From 2007, Chinese researchers started to contribute to this field,
based on the Group II intron system.

2.2.1 Gene Disruption Using Group II Intron

In 2001, a novel method of gene inactivation based on a group II intron was
adapted for some bacteria [ 27 ]. The system was derived from Lactococcus lactis
Ll.LtrB group II intron. The principle of retrohoming is that the group II intron,