Please use this identifier to cite or link to this item:
Full metadata record
DC FieldValueLanguage
dc.contributor.advisorTari, Cananen
dc.contributor.authorÜstok, Fatma Işık-
dc.descriptionThesis (Master)--Izmir Institute of Technology, Biotechnology, Izmir, 2007en
dc.descriptionIncludes bibliographical references (leaves: 90-97)en
dc.descriptionText in English; Abstract: Turkish and Englishen
dc.descriptionxiii, 120 leavesen
dc.description.abstractFood grade thermostable B -galactosidase preparations are always in demand for a number of industrial applications. Thermostable -galactosidases from LAB having a neutral pH-optimum can be safely used to reduce the lactose content of milk for the lactose intolerant people. In this study, -galactosidase was produced with high productivities by novel Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains isolated from traditional Turkish yogurt samples in Toros mountain region. A full factorial statistical design was used separately for Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains in screening experiments. Among the strains, Lactobacillus delbrueckii subsp. bulgaricus 77 and Streptococcus thermophilus 95/2 were found to have high potential for B-galactosidase and lactic acid production, therefore these were used in the further optimisation studies.The efficiency of different cell disruption methods was investigated on the extraction of -galactosidase. Among these, lysozyme enzyme treatment was determined as the most effective method. Optimisation studies were carried out using response surface methodology to optimize fermentation conditions for pure strains as well as for mixed ones. Therefore, symbiotic relationship between St 95/2 and Lb 77 were investigated as well. Symbiotic relationship provided 39% and 6.1 % more -galactosidase activity and 44 % and 9.73 % more lactic acid production when compared to the optimisation results of pure strains Lb 77 and St 95/2, respectively.Overall, characterization studies showed that enzymes obtained from these strains can be considered as food grade and thermostable since they are obtained from thermophile, food originated novel LAB of local microflora.en
dc.publisherIzmir Institute of Technologyen
dc.publisherIzmir Institute of Technologyen_US
dc.subject.lccTP248.L3 U88 2007en
dc.subject.lcshLactic acid bacteriaen
dc.subject.lcshLactose intoleranceen
dc.titleProduction of B-galactosidase using lactic acid bacteria and optimisation of fermentation paramettersen_US
dc.typeMaster Thesisen_US
dc.institutionauthorÜstok, Fatma Işık-
dc.departmentThesis (Master)--İzmir Institute of Technology, Bioengineeringen_US
item.fulltextWith Fulltext-
item.openairetypeMaster Thesis-
Appears in Collections:Master Degree / Yüksek Lisans Tezleri
Files in This Item:
File Description SizeFormat 
T000654.pdfMasterThesis2.3 MBAdobe PDFThumbnail
Show simple item record

CORE Recommender

Page view(s)

checked on Jun 17, 2024


checked on Jun 17, 2024

Google ScholarTM


Items in GCRIS Repository are protected by copyright, with all rights reserved, unless otherwise indicated.