[USCC] Fw: melamine contaminated pet food

[The Rubins]

----- Original Message ----- 
From: Millner, Pat 
To: The Rubins 
Sent: Friday, April 27, 2007 12:51 PM
Subject: RE: melamine contaminated pet food


Why don't you copy and paste it in, since you currently have access and your messages don't bounce back

 

Patricia D. Millner

USDA-ARS-BARC-Sustainable Agricultural Systems and Environmental Microbial Safety Labs

10300 Baltimore Ave., Bldg. 001, Rm 140

Beltsville, MD USA   20705-2350

Tel:  301-504-8387

Fax: 301-504-8370

Pat.Millner at ars.usda.gov

 


--------------------------------------------------------------------------------

From: The Rubins [mailto:rubinhial at cox.net] 
Sent: Friday, April 27, 2007 12:50 PM
To: Millner, Pat
Subject: Re: melamine contaminated pet food

 

Pat:

 

Thanks.  Try to get this reposted on the USCC list serve.

 

Cheers

 

alan

 

  ----- Original Message ----- 

  From: Millner, Pat 

  To: The Rubins 

  Sent: Friday, April 27, 2007 12:45 PM

  Subject: melamine contaminated pet food

   

  I tried several days ago to send this to the list serve, but I received a message in return that my message was rejected.  I contacted the server administrator 3 different ways to try resolving the problem, but haven't received any response as yet.  Recently heard of compost listserve communication problems others were having. 

   

  Some years ago, scientists here (USDA-Pesticide Degradation Lab) were trying to isolate microbes that hydrolyze melamine.  Chemostats designed to encourage proliferation of degradative populations at ambient temperatures yielded only 2-3 strains of a bacterium with the desired activity. 

   

  In addition, Jutzi et al reported several bacteria that mediated hydrolysis of melamine.  However, those bacteria are not thermophiles.  Only one, K. pneumoniae, has strains that tolerate 44.5 C (the low end of the thermophilic composting temperature range).  [see PDF article posted on PubMed PMCID: 1154018 as Biochem. J. (1982) 208, 679-684 679. The degradative pathway of the s-triazine melamine. The steps to ring cleavage. Kathrin JUTZI, Alasdair M. COOK* and Ralf HUITTER].  NOTE: the authors report the degradation occurred under anaerobic conditions.

   

  Abstract:

  1. The degradative pathway of melamine (1,3,5-triazine-2,4,6-triamine) was examined in Pseudomonas sp. strain A. 2. The bacterium grew with melamine, ammeline, ammelide, cyanuric acid or NH+ as sole source of nitrogen, and each substrate was entirely metabolized. Utilization of ammeline, ammelide, cyanuric acid or NH+ was concomitant with growth. But with melamine as substrate, a transient intermediate was detected, which was identified as ammeline by three methods. 3. Enzymes from strain A were separated by chromatography on DEAE-cellulose, and four activities were examined. 4.

  Melamine was converted stoichiometrically into equimolar amounts of ammeline and NH+. 5. Ammeline was converted stoichiometrically into equimolar amounts of ammelide and NH+; ammelide was identified by four methods. 6. Ammelide was converted stoichiometrically into equimolar amounts of cyanuric acid and NH+; cyanuric acid was identified by four methods. 7. Cyanuric acid was converted by an enzyme preparation into an unidentified product with negligible release of NH+. 8. The specific activites of the degradative enzymes (>0.3 mkat/kg of protein) were high enough to explain the growth rate of the organism. 9. The bacterium converted 0.4mM-melamine anaerobically into 2.3mM-NH+. 10. Two other pseudomonads and two strains of Klebsiella pneumoniae were also examined, with similar results. 11. The degradative pathway of melamine appears to be hydrolytic, and proceeds by three successive deaminations to cyanuric acid, which is further metabolized.

   

  In searching Agricola, PubMed, and Scopus, I found no other specific reports indicating that melamine degrades differently or more rapidly or to nontoxic compounds in thermophilic aerobic composting. In the absence of more specific data, showing either more widespread degradative capacity among soil microbes or at thermophilic compost temps/aeration, the applicability of composting as a remediation method for the pet food melamine contamination seems like an opportunity for research rather than as existing, established, reliable method.

   

  Pat Millner

   

   

  Patricia D. Millner

  USDA-ARS-BARC-Sustainable Agricultural Systems and Environmental Microbial Safety Labs

  10300 Baltimore Ave., Bldg. 001, Rm 140

  Beltsville, MD USA   20705-2350

  Tel:  301-504-8387

  Fax: 301-504-8370

  Pat.Millner at ars.usda.gov