All animals are heterotrophic, as well as fungi and many bacteria.

Fecal Coliform and coliform

Graduate School of Biomedical Sciences in Galveston, Texas

Heterotrophic Metabolism

Heterotrophic bacteria, which include all pathogens, obtain energy from oxidation of organic
compounds. Carbohydrates (particularly glucose), lipids, and protein are the most commonly oxidized
compounds. Biologic oxidation of these organic compounds by bacteria results in synthesis of ATP as
the chemical energy source. This process also permits generation of simpler organic compounds
(precursor molecules) needed by the bacteria cell for biosynthetic or assimilatory reactions.

All heterotrophic bacteria require preformed organic compounds. These carbon- and
nitrogen-containing compounds are growth substrates, which are used aerobically or anaerobically to
generate reducing equivalents (e.g., reduced nicotinamide adenine dinucleotide; NADH + H+); these
reducing equivalents in turn are chemical energy sources for all biologic oxidative and fermentative
systems. Heterotrophs are the most commonly studied bacteria; they grow readily in media containing
carbohydrates, proteins, or other complex nutrients such as blood. Also, growth media may be
enriched by the addition of other naturally occurring compounds such as milk (to study lactic acid
bacteria) or hydrocarbons (to study hydrocarbon-oxidizing organisms).
Science of The Total Environment
Volume 346, Issues 1-3, 15 June 2005, Pages 213-219

Antibiotic resistance and antibacterial activity in heterotrophic bacteria of mineral water origin

Patrizia Messi, Elisa Guerrieri and Moreno Bondi,  
Department of Biomedical Sciences, University of Modena and Reggio E., Via Campi 287, 41100 Modena, Italy
Received 7 August 2004;  accepted 1 December 2004.  Available online 29 January 2005.


Antibiotic resistance and antibacterial activity were determined on heterotrophic bacteria isolated from mineral
waters. Of the 120 isolates
Pseudomonas spp. (55.8%) was the predominant group followed by
Acinetobacter spp. (14.17%), Flavobacterium spp. (10.83%), Achromobacter spp. (10%), Burkholderia
cepacia (3.3%),
Agrobacterium/radiobacter (2.5%), Moraxella spp. (1.7%), Aeromonas hydrophila (1.7%).
Over 80% of the isolates were resistant to one or more antibiotics and the highest resistance was found for
chloramphenicol, ampicillin, colistin and sulfamethizole (60%, 55%, 50% and 47.5%, respectively). Strains with
multiple antibiotic resistance (MAR) represented 55% of isolates and the most resistant organism belonged to
the genus Pseudomonas.

Of 40 randomly selected strains, 27 (67.5%) had antibacterial activity towards one or more indicators. This
activity, found in a high percentage in the genus Pseudomonas (92%), emerged mainly against closely related
microorganisms. Several producers were active also against Escherichia coli, Salmonella, Listeria
monocytogenes and Staphylococcus aureus.

Forty-six percent of the isolates harboured 1 to 5 plasmids with molecular weights ranging from 2.1 to 41.5