Photosynthetic bacteria (PBS) is a special kind of microbe

it is not only as a good kind of material which has been studied in photosynthesis

but also it has been applied to the treatment of high concentration's organic waste water and a fodder additive in the aquatic breeding. Recently a few active strains which are nontoxic for human being

may be used in health field because it has been discovered some physiologic activities such as anti-radiation

the regulation of immunity etc. For proving the effect of PBS on inhibiting lipid-peroxidation

two typical systems were measured by using the method of chemiluminescence. The system Ⅰ that was imitated easy oxidative components of membrane of cell were constituted by BSA-linoleic acid-Fe

2+

. The chemical structure of linoleic acid molecule has some dual-binding between carbon atoms. The structure can be oxided easily. BSA (bovine serum albumin) also has same character. The existence of Fe

2+

promoted the process of lipid-oxidation. Luminol was added into system Ⅰ for raising sensitive degree. The autoxidation of components in system Ⅰ would cause low-level bioluminescence. The value of the bioluminescence can be measured by the instrument of bio-chemiluminescence (Model GSH-1) and represent the strength of lipid-oxidation. In the system Ⅱ

it was constituted by mouse brain-homogenate and Fe

2+

. The brain homogenate contains rich lipid and poly-unsaturated fatty acid

which initiate the process of lipid-oxidation easily with the existence of Fe

2+

. The strength of the autoxidation was measured by the same method. The culture of the active photosynthetic bacteria No.1 strain was centrifuged into two parts: the cell of bacteria and the supernatant liquid. In the system Ⅰ the rate of inhibiting on the lipid-peroxidation was 13.4% for the undiluted supernatant liquid. It was 56.4% for suspended cell when the concentration of cell was 5mg/L. The effecting function was stronger with the increasing of cell concentration. In the system Ⅱ the rate of inhibition was 10.2% for the undiluted supernatant liquid. However it already reached 74.1% when the concentration of cell was only 5μg/L. It was stronger than that in the system Ⅰ. In an alkali condition triphenoliclog can release superoxide anion. Moreover it initiated successive reactions and caused an autoxidation. In the autoxidation process the value of curve's slant rate(K) presents the rate of the autoxidation. The result showed the suspended cell has the function of inhibiting on the autoxidation obviously. When the concentration of cell was 250mg/L

K

reduced to 0.47 as compared with that

K

equals 1.33 under contrast condition. It has also proved that PSB has a good effect on quenching super oxide anion. In order to discover new microbiological resource and provide a basis of the theory for PSB applied as a new healthy product

we explored the anti-oxidative function from two associated aspects about inhibiting lipid-peroxidation and quenching superoxide anion.