title: In vitro biodegradation of cyanotoxins in the rumen fluid of cattle.
abstract: BACKGROUND
  In countries around the Baltic Sea grazing ruminants have access to and drink, surface water from lakes, rivers and in several coastal regions. The water quality of these naturally occurring reservoirs affects performance and health of livestock. In the Baltic Sea both microcystin (MC) and nodularin (NOD) occurs as cyclic peptides and have hepatotoxic effects. Although cattle obviously have died after consuming contaminated water very little information is available as to how susceptible ruminants are to the toxins produced by cyanobacteria. The critical question as to whether the rumen microflora might constitute a protective shield is unresolved. For this reason our aim is to investigate a possible degradation rate of these toxins in rumen.
  
  
  RESULTS
  The ability of rumen microorganisms to degrade certain important cyanotoxins (MC-LR, YR, RR and NOD) was studied in vitro by incubating with rumen fluid at three different concentrations (0.05, 0.5 and 5 μg/mL) for 3 h. The degradation efficiencies were determined by LC-MS (ESI) positive mode. Degradation was observed in the following order MC-RR 36%, NOD 35%, MC-RR 25% and MC-LR 8.9% at lower concentrations within 3 h. However, average degradation was observed at concentration of 0.5 μg/mL. No degradation was observed in higher concentrations for entire 3 h. The present results reveal that the degradation was both dose and time dependent.
  
  
  CONCLUSIONS
  In conclusion the present results suggest that the rumen microbial flora may protect ruminants from being intoxicated by Cyanotoxins.
authors.affiliation: Department of Anatomy, Physiology and Biochemistry, Faculty of Veterinary Medicine and Animal Science, SLU, Box 7011 750 07 Uppsala, Sweden. manjunath.manubolu@slu.se.
authors.forename: Manjunath
authors.initials: M
authors.lastname: Manubolu
authors.forename: Samanthi R P
authors.initials: SR
authors.lastname: Madawala
authors.forename: Paresh C
authors.initials: PC
authors.lastname: Dutta
authors.forename: Kjell
authors.initials: K
authors.lastname: Malmlöf
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000382:microbiology*; D002417:Cattle / Q000378:metabolism*; D005260:Female; D008387:Marine Toxins; D052998:Microcystins / Q000737:chemistry / Q000378:metabolism*; D010456:Peptides, Cyclic / Q000737:chemistry / Q000378:metabolism*; D012417:Rumen / Q000382:microbiology*
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; C063998:nodularin; C063855:microcystin RR; C057862:cyanoginosin LR