Molecular Certification in Chicken Meat Chan- Nutritional Evaluation of Bt-corn in Pigs . the Effect of Lighting Program and Light In- Tensity on the Performance and the Incidence of Leg Ab- Normalities of Broiler

The United States generates nearly 325 billion gallons of wastes and by-products during the processing of foods. Whey is a by-product produced in cheese industry and it is estimated that as much as 40-50% of the whey produced is disposed of as sewage or applied to agricultural lands. The remaining 50-60% is being used primarily for animal feed or for human food. Whey contains high quantity of lactose and other nutrients, which can be easily utilized by lactic acid bacteria to produce organic acids and value added products. The objectives of this work were to determine the ability of spiral-sheet to immobilize Lactobacillus helveticus (L. helveticus) and to determine the performance membrane for the continuous production of lactic acids using cheese whey as by-product. Active culture of L. helveticus (ATCC15009) was weekly transferred into fresh MRS and maintained at 4C. This culture was inoculated into 9 liters of MRS and incubated at 37 C for 16-18 hours. Fermented broth was transferred into the spiral-sheet bioreactor and was allowed to immobilize for 24 hours. After successful immobilization, MRS broth was withdrawn and replaced by fresh 4.8% lactose-MRS broth under aseptic conditions. Bioreactor was connected to Bioflo III (2-liter fermentor which has a control loop for temperature and pH) with continuous medium circulation at 37 C and agitation rate at 100rpm. Samples were withdrawn every 6 hours for lactose and lactic acid analysis using HPLC. Changes in pH were monitored during fermentation process. During fermentation the pH value was dropped from 6.2 to 3.8, which inhibited the bacterial activity. During the following experiments, we adjusted the pH to 6.50 by neutralizing the acid with 5-N ammonium hydroxide. Under the controlled pH condition, lactose conversion rate was 59.00%. These results showed that immobilization of L. helveticus on spiral-sheet reactor was a successful operation for the continuous production of lactic acid.