The Chemical Transformation of the Cellular Toxin INT (2-(4-Iodophenyl)-3-(4-Nitrophenyl)-5-(Phenyl) Tetrazolium Chloride) as an Indicator of Prior Respiratory Activity in Aquatic Bacteria.

In the ocean, the prokaryote respiration rates dominate the oxidation of organics, but the measurements may be biased due to pre-incubation size filtration and long incubation times. To overcome these difficulties, proxies for microbial respiration rates have been proposed, such as the in vitro and in vivo estimation of electron transport system rates (ETS) based on the reduction of tetrazolium salts. INT (2-(4-Iodophenyl)-3-(4-Nitrophenyl)-5-(Phenyl) Tetrazolium Chloride) is the most commonly applied tetrazolium salt, although it is toxic on time scales of less than 1 h for prokaryotes.

Substrate-Limited and -Unlimited Coastal Microbial Communities Show Different Metabolic Responses with Regard to Temperature.

Bacteria are the principal consumers of dissolved organic carbon (DOC) in the ocean and predation of bacteria makes organic carbon available to higher trophic levels. The efficiency with which bacteria convert the consumed carbon () into biomass (i.e.

INT (2-(4-Iodophenyl)-3-(4-Nitrophenyl)-5-(Phenyl) Tetrazolium Chloride) Is Toxic to Prokaryote Cells Precluding Its Use with Whole Cells as a Proxy for In Vivo Respiration.

Prokaryote respiration is expected to be responsible for more than half of the community respiration in the ocean, but the lack of a practical method to measure the rate of prokaryote respiration in the open ocean resulted in very few published data leaving the role of organotrophic prokaryotes open to debate. Oxygen consumption rates of oceanic prokaryotes measured with current methods may be biased due to pre-incubation size filtration and long incubation times both of which can change the physiological and taxonomic profile of the sample during the incubation period. In vivo INT reduction has been used in terrestrial samples to estimate respiration rates, and recently, the method was introduced and applied in aquatic ecology.