Abstract: 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 my/L, 1.531 rog/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.
