Production of 5-aminolevulinic acid from organic industrial wastewater by photosynthetic bacteria

Abstract:

[Objective] We used Rhodopseudomonas strains with high-yield of 5-aminolevulinic acid (ALA) to produce ALA from wastewater of producing monosodium glutamate, citric acid, beer, and soybean product. [Methods] Cultivation was carried out under anaerobic light condition (3000 Lux) at 30℃. For comparison, we tested the addition of levulinic acid (LA), glycin and succinate to the substrate to increase the production of ALA, effect of sterilization of the wastewater for both strains. Cell mass concentration (OD660) and the content of ALA were determined with spectrophotometer. [Re-sults] Without adding levulinic acid (LA), glycin and succinate, the growth of strain 99-28 reached plateau after 72-96 h. The maxiam ALA production was obtained at 96 h. Both the yield of ALA and the Chemical Oxygen Demand (CODcr) removal rate of monosodium glutamate waster water were the highest in all tested wasterwaters. When LA, glycin and succinate were added, ALA production of strain 99-28 was significantly increased whereas the CODcr removal was ad-versely affected. Non-sterial wasterwater slightly reduced the growth and CODcr removal rate of strain 99-28, however the ALA production could be strongly reduced with the addition of LA, glycin and succinate. The growth and CODcr re-moval of mutant strain L-1 was similar with strain 99-28, but its ALA production was much higher than that of strain 99-28. [Conclusion] The Rhodopseudomonas strains screened in our laboratory can use organic wasterwater as substrates to produce ALA and remove CODcr.