Full Length Research Paper

Construction of an expression vector for Lactococcus lactis based on an indigenous cryptic plasmid

Hooi Wei Yeng¹, Mariana Nor Shamsudin^2,3 and Raha Abdul Rahim^1,2*

¹Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia 43400 UPM Serdang Selangor, Malaysia.

²Institute of Biosciences, Universiti Putra Malaysia 43400 UPM Serdang Selangor, Malaysia.

³Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.

*Corresponding author. E-mail: raha@biotech.upm.edu.my.

Tel.: +603-8946 7513/7474. Fax: +603-8946 7510.

Accepted 11 June, 2009

   Abstract

To construct an expression vector for Lactococcus lactis, the EmPMT fragment which contained the erythromycin resistance gene, P₃₂ promoter, multiple cloning site (MCS) and terminator (T) was subcloned into the small cryptic plasmid pAR141. The resulting vector, designated as pAR1411, was found to be stably maintained in L. lactis MG1363 after transformation for at least 100 generations under non-selective conditions. The vector was also demonstrated to be able to express the gene coding for chloramphenicol acetyltransferase (cat) in L. lactis.

Key words: Plasmid vector, transformation, expression.