Biological formation of 5-aminolevulinic acid by photosynthetic bacteria.
In this study, 7 stains of Rhodopseudomonas sp. were selected from 36 photosynthetic bacteria stains storied in our laboratory. Rhodopseudomonas sp. strain 99-28 has the highest 5-aminolevulinic acid(ALA) production ability in these 7 strains. Rhodopseudomonas sp. 99-28 strain was mutated using ultraviolet radiation and a mutant strain L-1, which ALA production is higher than wild strain 99-28 about one times, was obtained. The elements affecting ALA formation of strain 99-28 and L-1 were studied. Under the optimal condition( pH 7.5, supplement of ALA dehydratase(ALAD) inhibitor, levulinic acid(LA) and precursors of ALA synthesis, glycine and succinat, 3000 Ix of light density), ALA formation of mutant L-1 was up to 22.15 mg/L. Strain L-1 was used to treat wastewater to remove COD(Cr) and produce ALA. ALA production was 2.819 mg/L, 1.531 mg/L, 2.166 mg/L, and 2.424 mg/L in monosodium glutamate wastewater(MGW), succotash wastewater(SW), brewage wastewater(BW), and citric acid wastewater(CAW) respectively. More than 90% of COD(Cr) was removed in four kinds of wastewater. When LA, glycin and succinate were supplied, ALA production was dramatically increased, however, COD(Cr) could hardly be removed.
Liu
Xiu-yan
XY
Machine Engineering Department, Hangzhou Dianzi University, Hangzhou 310012, China. mdjxyliu@hotmail.com
Xu
Xiang-yang
XY
Ma
Qing-lan
QL
Wu
Wei-hong
WH
D000622:Aminolevulinic Acid / Q000378:metabolism*; D019149:Bioreactors; D018698:Glutamic Acid; D005998:Glycine / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007982:Levulinic Acids / Q000378:metabolism; D008027:Light; D008293:Malates; D016296:Mutagenesis; D012241:Rhodopseudomonas / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity; D019802:Succinic Acid / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
D007982:Levulinic Acids; D008293:Malates; D018698:Glutamic Acid; C030298:malic acid; D000622:Aminolevulinic Acid; D019802:Succinic Acid; C032246:levulinic acid; D005998:Glycine