Open AccessInsertion of an E. coli lacZ gene in Acetobacter xylinus for the production of cellulose in whey
Author(s) -
BattadBernardo Evelyn,
McCrindle Sharon L,
Couperwhite Iain,
Neilan Brett A
Publication year - 2004
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(04)00007-2
Subject(s) - lactose , bacterial cellulose , lac operon , mutagenesis , beta galactosidase , acetobacter , mutant , cellulose , biochemistry , strain (injury) , biology , transposable element , galactose , escherichia coli , chemistry , microbiology and biotechnology , gene , fermentation , anatomy
A mini‐Tn 10 : lacZ:kan was inserted into a wild‐type strain of Acetobacter xylinus by random transposon mutagenesis, generating a lactose‐utilising and cellulose‐producing mutant strain designated ITz3. Antibiotic selection plate assays and Southern hybridisation revealed that the lacZ gene was inserted once into the chromosome of strain ITz3 and was stably maintained in non‐selective medium after more than 60 generations. The modified strain had, on the average, a 28‐fold increase in cellulose production and a 160‐fold increase in β‐galactosidase activity when grown in lactose medium. β‐Galactosidase activity is present in either lactose or sucrose medium indicating that the gene is constitutively expressed. Cellulose and β‐galactosidase production by the modified strain was also evaluated in pure and enriched whey substrates. Utilisation of lactose in whey substrate by ITz3 reached 17 g l −1 after 4 days incubation.