Recombinant E. coli Beta Glucuronidase (GUS) protein (a.a. 1-603) [His]

To achieve active management of bathing areas and to reduce risk associated with the presence of fecal pollution, tests capable of rapid on-site assessment of microbiological water quality are required. A protocol for the recovery and detection of fecal pollution indicator bacteria, E. coli, using beta-glucuronidase (GUS) activity was developed. The developed protocol involves two main steps: sample preparation and GUS activity measurement. In the sample preparation step, syringe filters were used with a dual purpose, for the recovery and pre-concentration of E. coli from the water matrix and as mu L reactors for bacteria lysis and GUS extraction. Subsequently, GUS activity was measured using a continuous fluorometric method developed previously. The optimum GUS recovery conditions for the sample preparation step were found to be 100 mL PELB (supplemented with 1 mg mL(-1) lysozyme and 20 mM DTT) at 37 degrees C for 30 min. The protocol was evaluated on environmental samples (fresh and seawater) against an establish GUS assay method (Coliplage((R))). GUS activities corresponding to samples containing as low as 26 MPN E. coli 100 mL(-1) were detected for the seawater sample and as low as 110 MPN E. coli 100 mL(-1) for the freshwater samples. By comparison with the Coliplage r method, this protocol offered an improvement in the measured GUS activities of 3.1 fold for freshwater samples and 4.1 fold for seawater samples. Furthermore, the protocol developed here, has a time-to-result of 75 min, and successfully addresses the requirement for tests capable of rapid assessment of microbiological water quality. (C) 2017 Elsevier B. V. All rights reserved.

The beta-glucuronidase (GUS) gene is to date the most frequently used reporter gene in plants. Marketing of crops containing this gene requires prior evaluation of their biosafety. To aid such evaluations of the GUS gene, irrespective of the plant into which the gene has been introduced, the ecological and toxicological aspects of the gene and gene product have been examined. GUS activity is found in many bacterial species, is common in all tissues of vertebrates and is also present in organisms of various invertebrate taxa. The transgenic GUS originates from the enterobacterial species Escherichia coli that is widespread in the vertebrate intestine, and in soil and water ecosystems. Any GUS activity added to the ecosystem through genetically modified plants will be of no or minor influence. Selective advantages to genetically modified plants that posses and express the E. coli GUS transgene are unlikely. No increase of weediness of E. coli GUS expressing crop plants, or wild relatives that might have received the transgene through outcrossing, is expected. Since E. coli GUS naturally occurs ubiquitously in the digestive tract of consumers, its presence in food and feed from genetically modified plants is unlikely to cause any harm. E. coli GUS in genetically modified plants and their products can be regarded as safe for the environment and consumers.