Understanding the functional response of bacteria to their natural environment is one of the current challenges in microbiology. Over the past decades several techniques have been developed to study gene expression in complex natural habitats. Most of these methods, however, are laborious, and validation of results under in situ conditions is cumbersome. Here we report the improvement of the recombinase-based in vivo expression technology (R-IVET) by the implementation of two additional reporter genes. The first one is an -galactosidase gene (melA), which facilitates the rapid identification of in vivo-induced genes. Second, the bacterial luciferase genes (luxAB) are transcriptionally coupled to the resolvase gene, which allows rapid validation and characterization of in vivo-induced genes. The system is implemented and validated in the industrially important lactic acid bacterium Lactococcus lactis. We demonstrate the applicability of the advanced R-IVET system by the identification and validation of lactococcal promoter elements that are induced in minimal medium compared to the commonly used rich laboratory medium M17. R-IVET screening led to the identification of 19 promoters that predominantly control expression of genes involved in amino acid and nucleotide metabolism and in transport functions. Furthermore, the luciferase allows high-resolution transcription analysis and enabled the identification of complex medium constituents and specific molecules involved in promoter control. Rapid target validation exemplifies the high-throughput potential of the extended R-IVET system. The system can be applied to other bacterial species, provided that the reporter genes used are functional in the organism of interest.
- American Society for Microbiology
- High-throughput identification and validation of in ...
Bacterial Control in Water - Perfectly Clean Water Without the use of Toxic Chemicals - Case Study
We believe technology can help create a better futureFor years the world has been facing an increased pressure on the supply of safe drinking water due to a growing population and demands of industrial growth in many countries worldwide. We have furthermore recognized that outbreaks of food poisoning, from bacteria such as E.coli, Campylobacter, Salmonella and Listeria, can have serious consequences in the food and water industry.Our strategy is to develop fully automated ECA generators, based on a plug and play...
Biodegradation of dairy wastewater using bacterial and fungal local isolates
Dairy wastewater contains high levels of organics and other pollutants. The present study was carried out to investigate the biodegradation process of dairy effluents using some locally isolated bacteria and fungi. Four different dairy effluent samples were collected from Obour and 6th October industrial cities, Egypt. Five bacterial species (Pseudomonas aeruginosa, Bacillus subtilis, Lactobacillus delbrueckii, Staphylococcus aureus and Enterococcus hirae) and three fungal strains (Alternaria sp., Fusarium sp....
Nature inspires a better way to block biofilms
In many industries where equipment comes in contact with water, including those that rely on water treatment membranes, equipment fouling is a huge problem. Biofilm fouling occurs when living organisms — including bacteria, algae, and even mollusks — become attached to boat hulls, harbor structures, and other equipment. The resulting damage can be costly.Coatings and other chemical approaches to stopping the growth can harm the environment, and the creatures being blocked can eventually develop a...
Toxicity and biofilm-based selection for methyl tert-butyl ether bioremediation technology
Extractive membrane biofilm reactor (EMBFR) technology offers productive solutions for volatile and semi-volatile compound removal from water bodies. In this study, the bacterial strains Paenibacillus etheri SH7T (CECT 8558), Agrobacterium sp. MS2 (CECT 8557) and Rhodococcus ruber strains A5 (CECT 8556), EE6 (CECT 8612) and EE1 (CECT 8555), previously isolated from fuel-contaminated sites, were tested for adherence on tubular semipermeable membranes in laboratory-scale systems designed for methyl tert-butyl ether...
Rapid start-up of one-stage deammonification MBBR without addition of external inoculum
In recent years, the anammox process has emerged as a useful method for robust and efficient nitrogen removal in wastewater treatment plants (WWTPs). This paper evaluates a one-stage deammonification (nitritation and anammox) start-up using carrier material without using anammox inoculum. A continuous laboratory-scale process was followed by full-scale operation with reject water from the digesters at Bekkelaget WWTP in Oslo, Norway. A third laboratory reactor was run in operational mode to verify the suitability...