Reference

Mutagenicity testing of certified food colors and related azo, xanthene and triphenylmethane dyes with the Salmonella/microsome system

Mutagenicity testing of certified food colors and related azo, xanthene and triphenylmethane dyes with the Salmonella/microsome system. Brown, Joseph P.; Roehm, Gerald W.; Brown, Ronald J. (Dynapol, Palo Alto, Calif., USA). Mutat. Res., 56(3), 249-71 (English) 1978. CODEN: MUREAV. ISSN: 0027-5107. DOCUMENT TYPE: Journal CA Section: 17 (Foods) Section cross-reference(s): 4 Thirty-seven azo, xanthene, and triphenylmethane dyes, including FD and C colors currently approved for use in the U.S.A. and a no. of delisted food colors, were tested in the Salmonella/microsome system. In addn. to direct plate tests with 5 tester strains (TA1535, TA100, TA1537, TA1538, TA98), the azo dyes were also assayed after chem. redn. to their component amines. Also, a selected group of azo dyes was subjected to liq. tests (both aerobic with microsomes and anaerobic) and to plate tests involving initial 16 h anaerobic incubations to facilitate microbial redn. of the azo bond. None of the presently listed FD and C colors was mutagenic in any of the test modifications. Among formerly listed colors only Butter Yellow (p-dimethylaminoazobenzene) [60-11-7], a recognized animal carcinogen, was mutagenic in the aerobic liq. test. Several other azo dyes were either directly mutagenic, viz. Acid Alizarin Yellow R [2243-76-7] and Alizarin Yellow GG [584-42-9]; required microsomal activation, viz. Acid Alizarin Red B [1836-22-2] and Methyl Red [493-52-7]; or required chem. redn. and microsomal activation, viz. Acid Alizarin Violet N [2092-55-9] and Sudan IV [85-83-6]. Of the non-azo dyes tested only 2 xanthene dyes appeared to be mutagenic, viz. 9-(2-sulfophenyl)-6-hydroxy-3-isoxanthenone [4424-03-7] and its 2,4,5,7-tetrabromo deriv. [42522-72-5].

Detoxification and partial mineralization of the azo dye Mordant Orange 1 in a continuous upflow anaerobic sludge-blanket reactor

Detoxification and partial mineralization of the azo dye Mordant Orange 1 in a continuous upflow anaerobic sludge-blanket reactor. Donlon, B.; Razo-Flores, E.; Luijten, M.; Swarts, H.; Lettinga, G.; Field, J. (Department Environmental Technology, Wageningen Agricultural University, Wageningen 6700 EV, Neth.). Applied Microbiology and Biotechnology, 47(1), 83-90 (English) 1997 Springer.Some commonly used reagents like 99-09-2 and 2243-76-7 are used in this experiment. CODEN: AMBIDG. ISSN: 0175-7598. DOCUMENT TYPE: Journal CA Section: 60 (Waste Treatment and Disposal) Section cross-reference(s): 41 In batch toxicity assays, azo dye compds. were many times more toxic than their cleavage products (arom. amines) towards methanogenic activity in anaerobic granular sludge. Considering the ability of anaerobic microorganisms to reduce azo groups, detoxification of azo compds. towards methanogens can be expected to occur during anaerobic wastewater treatment. In order to test this hypothesis, the anaerobic degrdn. of Mordant Orange 1 (MO1) by granular sludge was investigated in three sep. continuous upflow anaerobic sludge-blanket reactors. One reactor, receiving no co-substrate, failed after 50 days presumably because of a lack of reducing equivs. However, the two reactors receiving either glucose or a volatile fatty acid (acetate, propionate, butyrate) mixt., could eliminate the dye during operation for 217 days. The azo dye was reductively cleaved to less toxic arom. amines (1,4-phenylenediamine and 5-aminosalicylic acid), making the treatment of MO1 feasible at influent concns. that were >25 times higher than their 50% inhibitory concns. In the reactor receiving glucose as cosubstrate, 5-aminosalicylic acid could only be detected at trace levels in the effluent after day 189 of operation. Batch biodegradability assays with the sludge sampled from this reactor confirmed the mineralization of 5-aminosalicylic acid to methane. .