Abstract: The present invention provides a method for manufacturing organic acid by high-efficiency fermentation, which comprises the steps of continuous culture of organic acid bacteria and collection of organic acid produced from the culture employing a cell-recycle multiple-stage continuous fermentor with serially connected fermentors, each of which comprises a fermentor containing a ferment container, temperature controller, stirrer, and pH controller; pumps for efflux-circulation of media from the fermentor; and, cell separator for separation and circulation of media from the pumps. According to the present method, the high-concentration lactic acid of 90 g/L can be produced with the high productivity of 50 g/L/h, which can reduce the facility cost and production cost in the bulk manufacturing process.

Abstract: The present invention provides to a method for removing nitrogen and phosphorous in wastewater simultaneously from wastewater by employing fermentation broth obtained by anaerobic fermentation of organic solid wastes. The method for removing nitrogen and phosphorous in wastewater of the invention comprises the steps of subjecting organic waste material to anaerobic fermentation at 30 to 40° C. for 2 to 4 days by using anaerobic sludge to obtain fermentation broth; and, adding the fermentation broth to a sequencing batch reactor with alternating anaerobic-aerobic-anoxic cycles under anaerobic and anoxic conditions in a separate manner. In accordance with the present invention, nitrogen in the influent wastewater can be removed more than 95% in total and phosphorous concentration can be kept below 1 ppm regardless of the concentration of organic materials in the influent wastewater.

Abstract: The present invention relates to a process for preparing &ggr;-polyglutamic acid (&ggr;-PGA) from high-viscous culture broth, more particularly, to an economical and efficient process for preparing &ggr;-polyglutamic acid from high-viscous culture broth with easy removal of microorganisms and a subsequent concentrating process employing a filtration membrane. The present invention provides the process for preparing &ggr;-polyglutamic acid from high-viscous culture broth which comprises the steps of: culturing &ggr;-polyglutamic acid-producing microorganism for 15-30 hours under condition of pH 5.0-7.5 and 30-40° C. to obtain high-viscous culture broth with a concentration of 20-30 g/L; removing microorganism from the high-viscous culture broth thus obtained by adjusting pH to 2-4 or 7-9 and centrifuging at 3,000-9,000 rpm for 10-50 minutes; and, obtaining &ggr;-polyglutamic acid by concentrating the culture broth employing filter and precipitating &ggr;-polyglutamic acid by addition of alcohol.