BacHBerry: BACterial Hosts for production of Bioactive phenolics from bERRY fruits

BACterial Hosts for production of Bioactive phenolics from bERRY fruits (BacHBerry) was a 3-year project funded by the Seventh Framework Programme (FP7) of the European Union that ran between November 2013 and October 2016. The overall aim of the project was to establish a sustainable and economically-feasible strategy for the production of novel high-value phenolic compounds isolated from berry fruits using bacterial platforms. The project aimed at covering all stages of the discovery and pre-commercialization process, including berry collection, screening and characterization of their bioactive components, identification and functional characterization of the corresponding biosynthetic pathways, and construction of Gram-positive bacterial cell factories producing phenolic compounds. Further activities included optimization of polyphenol extraction methods from bacterial cultures, scale-up of production by fermentation up to pilot scale, as well as societal and economic analyses of the processes. This review article summarizes some of the key findings obtained throughout the duration of the project

Structure and mechanism of the ECF-type ABC transporter for thiamin

Guus Erkens’ PhD thesis is about the thiamin (vitamin B1) transport protein ThiT from the bacterium Lactococcus lactis. During his research project he has investigated the recognition of thiamin by ThiT. Also he has determined the three-dimensional structure of ThiT using X-ray crystallography. These results may provide a starting point for the development of antibiotics. The uptake of vitamins requires specific transport proteins residing in the cell membrane. Studying membrane proteins is notoriously difficult. Our knowledge of these protein mechanisms is therefore limited. Alike humans and other organisms bacteria depend on vitamins for their survival. Many bacteria are capable of producing vitamins but often depend on the uptake of vitamins from their environment as well. The determination of the three-dimensional structure of a membrane protein is technically very challenging. Therefore very few membrane protein structures are available. The results presented in this thesis have yielded great insight in the mechanism of ThiT and in vitamin transport in general. Proteins are constructed of long chains folded in a complex three-dimensional pattern. Their function is largely determined by this pattern. In co-operation with other researchers more vitamin transport proteins similar to ThiT have been identified. These findings have lead to a more detailed biochemical study of ThiT. After purifying the protein from Lactococcus lactis cell membranes, the interaction of ThiT with thiamin could be investigated. Thiamin binding to ThiT turned out to be of a very high affinity. Given these results Guus Erkens concluded that high affinity binding allows bacteria to take up thiamin when it is available in very low concentrations.