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Bongkrek Acid

Bongkrek (or bongkrekic) acid is a toxin produced by the bacterium Burkholderia gladioli pathovar cocovenenans (former names B. cocovenenans, Pseudomonas cocovenenans on fermented coconut products.

Bongkrek acid was first described in 1934 and is responsible for cases of food poisoning in South-East Asia, especially in Indonesia, due to the product Tempe bongkrek, a type of tempeh (fermented soybeans), made with the addition of coconut or made of fermented coconut flour or press-cake (the dry solid residue after producing coconut milk or coconut oil). This was a specialty in some regions in Java, but the production is now officially banned, due to the risk of contamination.

Structure of bongkrek acid (C₂₈H₃₅O₇ , source)

Bongkrek acid is produced from lipids, and production is stimulated by the presence of high concentrations of fat in coconut (products). The fatty acids which are known to stimulate bongkrek acid production are lauric, myristic, oleic and palmitic acid. The bacterium starts to produce the toxin only at rather high concentrations of fatty acids, which probably explains the fact that outbreaks of bongkrek acid poisoning are rare. Below 10% fat in the product no bongkrek acid is produced, even with good growth of the bacterium. Optimal production of the toxin was at 40-50% fat in the dry matter content of the product.

Bongkrek acid is highly toxic as it inhibits the formation of ADP to ATP in the mitochondria (part of the cell). ATP is the molecule used in the body to store energy. The effect is that the body simply cannot generate enough energy to survive and this results in a high fatality rate among the victims of bongkrek acid poisoning. Presently the toxin is widely used to study the pathways and activity of mitochondria.

References :

1. Garcia RA, Hotchkiss JH, Steinkraus KH; The effect of lipids on bongkrekic (Bongkrek) acid toxin production by Burkholderia cocovenenans in coconut media. Food Addit. Contam. 16(1999)63-69
2. Jiao Z, Kawamura Y, Mishima N, Yang R, Li N, Liu X, Ezaki T Need to differentiate lethal toxin-producing strains of Burkholderia gladioli , which cause severe food poisoning: description of B. gladioli pathovar cocovenenans and an emended description of B. gladioli . Microbiol Immunol. 47(2003)915-25
3. Peter J. F. Henderson and Henry A. Lardy; Bongkrekic acid: An Inhibitor of Adenine Nucleotide Translocase of Mitochondria , J. Biol. Chem. 245(1970)1319-1326
4. Van Veen, A. G., and Mertens, W. K., Rec. Trav. Chim. Pays-Bas, 63(1934) 257.
5. Zhao N, Qu C, Wang E, Chen W.; Phylogenetic evidence for the transfer of Pseudomonas cocovenenans (van Damme et al. 1960) to the genus Burkholderia as Burkholderia cocovenenans (van Damme et al. 1960) comb. nov. Int J Syst Bacteriol. 45( 1995)600-603.