Biotechnology and Bioprocess Engineering 16: 1134-1143 (2011) DOI 10.1007/s12257-011-0513-9 Isolation and Characterization of the New Klebsiella pneumoniae J2B Strain Showing Improved Growth Characteristics with Reduced Lipopolysaccharide Formation Mariadhas Valan Arasu, Vinod Kumar, Somasundar Ashok, Hyohak Song, Chelladurai Rathnasingh, Hee Jong Lee, Doyoung Seung, and Sunghoon Park Received: 13 October 2011 / Accepted: 13 October 2011 © The Korean Society for Biotechnology and Bioengineering and Springer 2011 Abstract Klebsiella pneumoniae is a suitable biocatalyst for the production of 1,3-propanediol (1,3-PDO) and 3- hydroxypropionic acid (3-HP) from glycerol. However, its commercial applications have been impeded due to its poor growth characteristics and the excessive production of lipopolysaccharide (LPS). To overcome these limitations, a new K. pneumoniae J2B (KpJ2B) strain was isolated from municipal waste anaerobic digester samples. The shake flask cultivation of this new strain under aerobic conditions showed a specific growth rate of 0.92/h, which is 1.13 times higher than that achieved using the well studied K. pneumoniae DSMZ2026 (KpDSMZ). When the new strain was grown in a bioreactor under aerobic conditions using a fed-batch mode for 36 h, the biomass concentration (4.03 g/L CDW) and productivity (0.15 g/L/h) were almost 2.2 times higher than the corresponding values with KpDSMZ. Growth was accompanied by the production of 1,3-PDO (186 mM), lactic acid (235 mM), ethanol (170 mM), and acetic acid (92.2 mM) at significant levels, indicating the resistance of the strain to the inhibitory effects of these metabolites. A comparison of the SEM images and 2-keto- 3-deoxyoctonate content (KpJ2B, 1.4 µg/g CDW; KpDSMZ, 1.9 µg/g CDW) confirmed the lower LPS content in the KpJ2B strain. Furthermore, this new isolate exhibited higher sensitivity towards a range of antibiotics and better sedimentation properties than the KpDSMZ strain. This suggests that KpJ2B is an attractive strain for industrial applications. Keywords: Klebsiella pneumoniae J2B, Klebsiella pneu- moniae DSMZ2026, 1,3-propanediol, growth, lipopolysac- charides 1. Introduction Glycerol is an important chemical feedstock in the food and cosmetic industries. In the past, its production from plant oils and petroleum was limited and the price was expensive as above US $1,000 per ton. Recently, due to the rapid growth of biodiesel industry, its supply, especially crude glycerol, increased drastically and, as a result, the market prices have decreased substantially [1]. The crude glycerol contains many impurities and cannot be used for the food and cosmetic industries without extensive puri- fication which is costly [2]. In comparison, its application as a carbon substrate for microbial cultivation is not limited by the presence of these impurities. Therefore, the biological production of important chemicals, such as 1,3- propanediol (1,3-PDO), 3-hydroxypropionic acid (3-HP) and 1,3-dihydroxyacetone, from glycerol has attracted considerable attention [3]. A number of microorganisms, such as Citrobacter fre- undii , Klebsiella pnemoniae, Clostridium pasteurianum [4], Clostridium butyricum, Enterobacter agglomerans [5], and Enterobacter aerogenes [6], metabolize glycerol efficiently to produce valuable chemical intermediates, such as 1,3- PDO. Among these microbes, K. pneumoniae, has been Mariadhas Valan Arasu, Vinod Kumar, Somasundar Ashok, Sunghoon Park * Department of Chemical and Biomolecular Engineering, Pusan National University, Busan 609-735, Korea Tel: +82-51-510-3386; Fax: +82-51-515-2716 E-mail: parksh@pusan.ac.kr Hyohak Song, Chelladurai Rathnasingh, Hee Jong Lee, Doyoung Seung Research and Development Center, GS Caltex Corporation, Daejeon 305- 380, Korea RESEARCH PAPER