Abstract: A method of continuously producing 5-aminolevulinic acid employs the photosynthetic bacteria-derived photosynthetic membrane vesicle, succinyl-CoA synthetase, and 5-aminolevulinic acid synthase. The enzymatic synthesis of 5-aminolevulinic acid directly from succinic acid and glycine may be simple, but the synthesis is not inexpensive due to the supply of ATP and CoA, which are relatively expensive reactants. The photosynthetic membrane vesicle is used together with succinyl-CoA synthetase and 5-aminolevulinic acid synthase, thereby enabling the re-use of adenosine diphosphate or CoA in reaction. Accordingly, relatively expensive 5-aminolevulinic acid can be efficiently produced at low manufacturing costs from succinic acid and glycine.

Abstract: A bacterial strain secreting fatty acids, the strain inducing fatty acids to be extracellularly secreted by using phospholipase expressed in the periplasmic space of cell. When a method of producing fatty acids by using the bacterial strain secreting fatty acids is used, fatty acids extracellularly secreted are continuously obtained without apoptosis, leading to lower costs and higher production efficiency. Phospholipase, unlike thioesterase, which is a typical fatty-acid degrading enzyme, decomposes phospholipid to produce free fatty acids. Accordingly, by using the substrate specificity of two different phospholipases, a fatty acid having a specific composition can be selectively produced. Unlike in a typical method in which fat is obtained from cells or tissues, fatty acids secreted during cell growth are obtainable by biding to a hydrophobic material without an extraction process using an organic solvent in large quantities.

Abstract: The present disclosure relates to methods for producing hydrogen using photosynthetic bacteria comprising a step of culturing the photosynthetic bacteria in the presence of alcohol at the condition under which the photosynthesis occurs. The present methods are cost-effective and have a high applicability due to the increased hydrogen productivity compared to the conventional methods in addition to not being sensitive by the inhibitory action by ammonium ion present in the culture. Thus the present methods are particularly useful for producing hydrogen using organic wastes which contains large amount of ammonia therein.

Abstract: Disclosed is a method for screening an antioxidant using mutant bacteria and chlorophyllide, and an antioxidant screened by the same method. The method provides for screening of an antioxidant by monitoring growth profiles of specific mutant bacteria in filter discs or medium blocks containing chlorophyllide added thereto, and an antioxidant screened by the same method. By monitoring growth profiles of mutant bacteria using mutant bacteria and chlorophyllide, screening of an antioxidant is possible on an industrial scale. In particular, the antioxidant screening method is useful for selective screening of an amphiphilic antioxidant. Therefore, it is possible to screen and commercialize low-toxic and effective antioxidants used in various food and cosmetic additives, as well as therapeutic medicines.

Abstract: Disclosed is a method for screening an antioxidant using mutant bacteria and chlorophyllide, and an antioxidant screened by the same method. More specifically, provided is a method for easy screening of an antioxidant by monitoring growth profiles of specific mutant bacteria in filter discs or medium blocks containing chlorophyllide added thereto, and an antioxidant screened by the same method. The present invention enables easy screening of an antioxidant on an industrial scale, by monitoring growth profiles of mutant bacteria via the use of mutant bacteria and chlorophyllide. In particular, the antioxidant screening method in accordance with the present invention is very useful for selective screening of an amphiphilic antioxidant. Therefore, the present invention is applicable to screen and commercialize low-toxic and effective antioxidants which will be used in various food and cosmetic additives as well as therapeutic medicines.

Abstract: The present invention discloses a method for fabricating a capacitor of a semiconductor device. In the conventional art, a bit line may be shifted or bent differently from the definition on a mask due to the stress resulting from a material difference between the bit line and BPSG film. However, in the present invention, the bit line is formed after depositing an oxide material on a contact plug, thereby preventing the shift or bending phenomenon and the short phenomenon between the metal interconnection contact and bit line.

Abstract: The present invention discloses a method for forming transistors for semiconductor devices that can prevent degradation of device properties by interrupting a current path from a drain junction region to a source junction region with an insulating channel barrier structure. The method includes the steps of: forming a device isolating film for defining an active region, and simultaneously forming a channel barrier film at the lower portion of a gate electrode formation region; partially etching the upper portion of the channel barrier film to form a recess; filling the recess above the upper portion of the channel barrier film with silicon; patterning a gate oxide film and a gate electrode on the stacked structure of the channel barrier film and silicon; and forming the transistor by forming source/drain junction regions in the exposed semiconductor substrate.