Article Abstract:
A nucleic acid sequence-based amplification system is a sensitive, specific and reliable method for detection of gene mRNA sequences in Listeria monocytogenes strains and isolates in a variety of dairy and egg products. The system detects low numbers of L. monocytogenes cells inoculated into the food samples after a 48 hr enrichment period in modified listeria enrichment broth. The system reliably detects nucleic acids in samples, and gives positive results in the assays of numerous listeria strains and isolates from the food samples.
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Article Abstract:
The Streptomyces lividans tripeptidyl aminopeptidase (Tap) gene was cloned, allowing DNA cross-hybridization in other Streptomyces strains. Overexpression of the gene revealed a 55,000 molecular weight protein with amino-terminal degradative activity. Lipases, acyl transferases and esterases were found to have significant sequence homology with the Tap region containing the supposed serine residue active site. An amino-terminal signal sequence and a tripeptide which could be cleaved autocatalytically were also identified.
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Article Abstract:
The substitution of the natural promoter of the beta-mannanase gene by lacp improves mannanase production by Streptomyces lividans. This increases mannanase production 15 times as compared to production by the clone S. lividans IAF36, and 350 times as compared to production by the wild-type strain S. lividans 1326. The enzyme can also be synthesized on mannan-lacking carbon sources, such as xylan and whey, by using lacp in the shuttle vector pIAF199.
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