Bacterial Luciferase Lux

FIGURE. 3. Genetically engineered bacteria with lux gene glows in culture. 

Bioreporters can contain all five genes of the lux cassette, thereby allowing for a completely independent light generating system that requires no extraneous additions of substrate nor any excitation by an external light 

Chemistry and Physics of Complex Materials Concepts and Applications 

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This section describes the bacterial luciferase (Lux) in the first part and the firefly luciferase (Luc) in the second part. 

Bacterial luciferases are a(3 heterodimers with subunit masses of -40(a) and 35 ((3) kDa.664 680 681 In Vibrio harveyi these are encoded by the lux A and lux B genes. At least five other genes are essential for light production including two regulatory genes.682 683 The... 

Some new luminescent and fluorescent reporters (some of them even non-substrate proteins ) are very attractive because of their easy and fast detection, explaining their current frequent use. The bacterial luciferase isolated from the Vibrio fischeri lux operon contains luxAB encoding the functional subunits and luxCDE for the synthesis and recycling of the aldehyde substrate (Prosser, 1996). Firefly (Photinus pyralis) luciferase, encoded by the luc gene catalyses the oxidative carboxylation of beetle luciferin, in which photons are emitted (LaRossa, 1998). Its short half-life and lack of any post-translational modification makes it ideal to look after effects in gene expression (Naylor, 1999). Detection of... 

In some Vibrio species, bacterial luciferase catalyzes the flavin-mediated oxidation of tetradecanal with concomitant emission of blue-green light. The genes responsible for reactions of the fatty acid reductase complex lux genes) have been cloned and their functions identified. One novel concept for the enumeration and identification of microorganisms requires the introduction of the lux genes into the... 

Luminous bacteria are bioluminescent microorganisms whose luciferase genes (lux), proteins and intact cells are widely used in applied research and commercial products. Acknowledging the commercial value of luminescent cells also in entertainment and education, we have conducted research on luminous bacteria from marine samples and have isolated Photobacterium phosphoreum (strain RL-1) from coastal marine sediment. In order to maximize the luminescence activity of RL-1, we examined a series of extracts prepared from dried marine foodstuff. Because chitinous compounds and some amino acids are known to be abundant in dried squid and shrimp, we also tested the effects of those compounds on the luminescence activity. Among the supplemental compounds tested, chitosan, cysteine, and aspartic acid were found to enhance the luminescence activity of RL-1. The present results indicate that some amino acids and chitinous compounds are effective supplements for further enhancing bacterial light production in an enriched medium (SWC ). 

The luciferase genes (lux operon) from the marine bacterium, Vibrio fischeri, have also been cloned and used as an indicator of promoter activity (25). The bacterial enz)rme, however, consists of two separate polypeptides, both of which are essential for activity. In this respect, the bacterial genes are less suitable for expression in eukaryotes than the firefly enzyme which is encoded by a single gene. 

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