Tannin degradation in aquatic systems

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,696
740
113
Mahadevan, A. and Muthukumar, G. 1980. Aquatic Microbiology with Reference to Tannin Degradation. Hydrobiologia, Volume 72, Numbers 1-2 / July.

"Tannins in aquatic environment cause harmful effects to aquatic life. They are inhibitory to microbial growth, respiration and metabolism. A few microorganisms degrade tannins and the factors influencing degradation are discussed."


RICHARD J. DUDLEY, PERRY F. CHURCHILL 1995. Effect and potential ecological significance of the interaction of humic acids with two aquatic extracellular proteases. Freshwater Biology 1995 34:3 485

Tej K. Bhat, Bhupinder Singh and Om P. Sharma 1998
Microbial degradation of tannins – A current perspective
Biodegradation, Issue Volume 9, Number 5 / September, 1998

"Tannins are water-soluble polyphenolic compounds having wide prevalence in plants. Hydrolysable and condensed tannins are the two major classes of tannins. These compounds have a range of effects on various organisms – from toxic effects on animals to growth inhibition of microorganisms. Some microbes are, however, resistant to tannins, and have developed various mechanisms and pathways for tannin degradation in their natural milieu. The microbial degradation of condensed tannins is, however, less than hydrolysable tannins in both aerobic and anaerobic environments. A number of microbes have also been isolated from the gastrointestinal tract of animals, which have the ability to break tannin-protein complexes and degrade tannins, especially hydrolysable tannins. Tannase, a key enzyme in the degradation of hydrolysable tannins, is present in a diverse group of microorganisms, including rumen bacteria. This enzyme is being increasingly used in a number of processes. Presently, there is a need for increased understanding of the biodegradation of condensed tannins, particularly in ruminants."

Regulation of Nitrification in Aquatic Sediments by Organic Carbon
Eric A. Strauss, Gary A. Lamberti
Limnology and Oceanography, Vol. 45, No. 8 (Dec., 2000), pp. 1854-1859
 

Rhizomorph

Junior Poster
Feb 24, 2015
14
1
1
It's also worth noting that tannins are going to be degraded by both aerobes and anaerobes - and the pathways (and rates) of decomposition by these groups of microbes are going to differ. The literature has quite a lot of nice papers on the microbiome of higher termites which is well worth reading. Sure, it's lignocellulose they are degrading -- but there's some similarities between lignin degradation and the degradation of tannins. Interesting stuff though!! -- Rhizomorph.
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,696
740
113
One thing that is notable in real systems with high tannins(Florida rivers/lakes/swamps/marshes etc: the levels do not just keep building up.So something is degrading them at a relatively stable rate. Light has been suggested but that alone does not account for the losses.
 

Rhizomorph

Junior Poster
Feb 24, 2015
14
1
1
I've not done much work on prokaryotic degradation of tannins -- but I have done work on fungi that degrade this compound. In the lab at least they grow on it as sole source of carbon without too much trouble. In aquatic systems though, it's probably primarily degraded by bacteria. Not sure which types though.
 

trong

Lifetime Charter Member
Lifetime Member
Mar 14, 2007
68
1
8
This may sound like a hillbilly describing a meteor as a pretty light in the sky getting closer, but here goes. I've done no work in science other than read and observe. I probably shouldn't even be in this conversation! Tannins can be described and labeled , but they are probably as complicated as describing Kh and its effects on Ph.( Multi pronged) Are they alive? Perhaps a byproduct of life. The birth of natural decay. Acidic. Maybe oxidized by alkali to create a sugar for energy in the biological process. I'm sure I'm sheading no new light on this but what the hell. I dont know much about this, but I have enjoyed sharing my 2 cents anonymously. Stupid as it may be.