Open AccessPhysiological interactions between a mesophilic cellulolytic Clostridium and a non‐cellulolytic bacterium
Author(s) -
Cavedon Katherine,
CanaleParola Ercole
Publication year - 1992
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1992.tb04815.x
Subject(s) - cellulose , mesophile , cellulase , bacteria , clostridium , klebsiella , energy source , food science , nitrogen fixation , microbiology and biotechnology , chemistry , bacterial cellulose , hydrolysis , biochemistry , biology , organic chemistry , escherichia coli , coal , genetics , gene
A mesophilic cellulolytic bacterium ( Clostridium strain C7) capable of N 2 fixation and a non‐cellulolytic bacterium ( Klebsiella strain W1), both isolated from freshwater environments rich in decaying plant material, were co‐cultured in a chemically defined, vitamin‐deficient medium containing cellulose as the carbon and energy source. In the co‐culture, an extracellular cellulase complex produced by the Clostridium hydrolyzed cellulose to soluble sugars that served as fermentable substrates for the Klebsiella . In turn, the Klebsiella excreted growth factors, identified as biotin and p ‐aminobenzoic acid, which were required by the Clostridium . Furthermore, demonstration of NH 4 + ‐repressible acetylene reduction by co‐cultures growing in medium lacking combined nitrogen showed that the Clostridium fixed N 2 , thus allowing growth of the Klebsiella , which was not a nitrogen fixer. The mutualistic relationships observed in the co‐cultures may be representative of interactions that take place in natural environments in which cellulose‐containing plant materials are biodegraded.