Table of Contents
ISRN Microbiology
Volume 2014, Article ID 834054, 4 pages
Research Article

Physiological Constants of the Entomopathogenic Bacterium Xenorhabdus nematophila Determined by Microbial Growth Kinetics

Sartorius Stedim Biotechnology Laboratory, Biotechnology Research and Training Center, University of North Carolina at Pembroke, Pembroke, NC 28372-1510, USA

Received 28 February 2014; Accepted 8 April 2014; Published 23 April 2014

Academic Editors: G. Koraimann, S. J. Suh, and X. Yu

Copyright © 2014 Rinu Kooliyottil et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Xenorhabdus nematophila, an entomopathogenic bacterium that symbiotically associates with the entomoparasitic nematode Steinernema carpocapsae, was studied to determine its physiological parameters of glucose utilization. X. nematophila was cultured in chemically defined media containing various concentrations of glucose under optimal conditions utilizing a two-liter fermentation system. Specific growth rates were obtained from each glucose batch. Specific growth rates and their associated glucose concentrations were used to determine physiological parameters. These parameters include the bacterium’s substrate utilization constant ( ) and its maximum specific growth rate ( ). The bacteria exhibited a value of 2.02 mg/L suggesting that X. nematophila has a high affinity for glucose. The of Xenorhabdus was determined to be 1.03  . Further research is needed to determine if microbial affinities to different substrates have any influence on biological relationships (symbiosis, pathogenicity, parasitism, etc.) between prokaryotes and higher organisms.