Clostridium pfennigii sp. nov. Uses Methoxyl Groups of Monobenzenoids and Produces Butyrate

The new bacterial species Clostridium pfennigii obtained energy for growth by catabolizing pyruvate to acetate and CO2; CO to acetate and butyrate; vanillin to butyrate, protocatechuic aldehyde, and protocatechuate; ferulate to butyrate, caffeate, and hydrocaffeate; and syringate and 3,4,5-trimethoxybenzoate to butyrate and gallate. This new species did not use any other energy source, such as sugars, amino acids, other organic acids (including formate), methanol, ethanol, or H2-CO2. C. pfennigii is a small, motile, anaerobic, gram-positive, monotrichous rod-shaped organism with a lateral to subterminal flagellum, oval subterminal to terminal spores, and a deoxyribonucleic acid guanine-plus-cytosine content of 38 mol%. It did not liquefy gelatin. Based on the features described above, C. pfennigii may be closely related to Acetobacterium woodii. However, strain V5-2T (T = type strain) used pyruvate but did not use sugars or one-carbon compounds other than CO; it produced acetate and butyrate. The stoichiometry of substrate utilization and the growth yields from different energy sources are discussed.