title: Lactic acid production from cheese whey by immobilized bacteria.
abstract: The performance of immobilized Bifidobacterium longum in sodium alginate beads and on a spiral-sheet bioreactor for the production of lactic acid from cheese whey was evaluated. Lactose utilization and lactic acid yield of B. longum were compared with those of Lactobacillus helveticus. B. longum immobilized in sodium alginate beads showed better performance in lactose utilization and lactic acid yield than L. helveticus. In the spiral-sheet bioreactor, a lactose conversion ratio of 79% and lactic acid yield of 0.84 g of lactic acid/g of lactose utilized were obtained during the first run with the immobilized L. helveticus. A lactose conversion ratio of 69% and lactic acid yield of 0.51 g of lactic acid/g of lactose utilized were obtained during the first run with immobilized B. longum in the spiral-sheet bioreactor. In producing lactic acid L. helveticus performed better when using the Spiral Sheet Bioreactor and B. longum showed better performance with gel bead immobilization. Because B. longum is a very promising new bacterium for lactic acid production from cheese whey, its optimum fermentation conditions such as pH and metabolic pathway need to be studied further. The ultrafiltration tests have shown that 94% of the cell and cheese whey proteins were retained by membranes with a mol wt cutoff of 5 and 20 KDa.
authors.affiliation: Bioenvironmental Engineering Program, Department of Natural Resources and Environmental Design, Department of Human Environment and Family Sciences, North Carolina A&T State University, 1601 East Market Street, Greensboro, NC 27411, USA. ash@ncat.edu
authors.forename: Abolghasem
authors.initials: A
authors.lastname: Shahbazi
authors.forename: Michele R
authors.initials: MR
authors.lastname: Mims
authors.forename: Yebo
authors.initials: Y
authors.lastname: Li
authors.forename: Vestal
authors.initials: V
authors.lastname: Shirley
authors.forename: Salam A
authors.initials: SA
authors.lastname: Ibrahim
authors.forename: Antrison
authors.initials: A
authors.lastname: Morris
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology; D001644:Bifidobacterium / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000295:instrumentation / Q000379:methods*; D018914:Cells, Immobilized / Q000502:physiology; D002611:Cheese / Q000382:microbiology*; D019344:Lactic Acid / Q000096:biosynthesis*; D007778:Lactobacillus / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D007785:Lactose / Q000378:metabolism*; D008567:Membranes, Artificial; D008892:Milk / Q000382:microbiology; D013045:Species Specificity
chemical_list: D008567:Membranes, Artificial; D019344:Lactic Acid; D007785:Lactose