Berries and biochemicals: picking winners
Berries are feted as natural sources of health-giving and medical compounds. The BacHBerry project investigated how these can be identified and synthesised using bio-engineering processes.
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Nutritionists, food writers and supermarkets encourage us to eat ever-more exotic varieties of berries because they are good for our health. And indeed berry fruits contain a variety of natural (phenolic) molecules, many of which could have important applications in the pharmaceutical and food industries, among others.
However, this pool of ‘chemo-diversity’ is poorly exploited, partly owing to the complexity of searching for one desirable bioactive molecule among many hundreds. The BacHBerry project has developed a systematic approach to identifying and producing such molecules – a number of which are promising research candidates for treating diseases such as Huntington’s and Alzheimer’s. The innovative BacHBerry methodologies offer more certainty to European bio-industries seeking to use the hidden benefits contained in berries and plants.
“People often ask: why not just eat the berries to get the benefits?” says Alexey Dudnik, BacHBerry project coordinator. Apart from the massive amount of agricultural land this would require, berries contain a rich and complex variety of compounds – and only a few might bring health benefits.
“It is cheaper and easier to identify these desired compounds and then produce them in bioreactors,” explains Dudnik. This removes the problem of seasonal availability and means simpler and more eco-friendly extraction procedures can be used.
With improved bio-engineering methods, the purity and consistency of end-products can be improved, which also helps them meet medicinal health standards. “After all, penicillin was derived from fungal mould, but you don’t lick mould if you need an antibiotic!” Dudnik points out.
BacHBerry set out to build a pipeline for discovering and producing novel, sustainable phenolic compounds with applications in nutrition and medicine, but also food and cosmetics. The project chose 113 berry samples from across the world, including from Russian, Chilean and Chinese partners. Some of the samples are used in traditional and herbal medicine.
The berry varieties were then screened to select 28 promising candidates: “These samples had the greatest diversity of bioactive phenolic compounds – hydrocarbon molecules produced by plants and microorganisms – that can play vital roles in defending against disease or serve as pigments,” explains Dudnik.
Extracts from these samples were tested using yeasts that mimic human diseases. Some were found to be active towards Alzheimer’s, Huntington’s, ALS (motor neurone disease), type II diabetes and cancer; as well as exhibiting anti-microbial activity.
From the original 28, extracts from several berries were taken to isolate and identify the bioactive phenolic compounds. Today, the project is busy with the final step: the design and construction of bacterial cell factories for producing selected high-purity, high-value phenolic compounds in bioreactors – a key element for eventual take-up by industry.
“One of the phenols we decided to focus on as a model is resveratrol, which is found in blueberries, raspberries, and in grapes and red wine,” says Dudnik. The compound itself is a powerful antioxidant. Plus there are multiple studies linking regular red-wine consumption to the ‘French paradox’ – the tentative observation that overall the French suffer less heart disease, despite high-fat diets.
“We have also worked on the bacterial production of fisetin, which is known to reduce the risk of Alzheimer’s disease and ameliorate the effects of diabetes in mice. It is derived from strawberries. But you need to eat 37 strawberries daily to get an adequate dose!”
BacHBerry research is not only confined to health benefits; partners are also looking at phenolics for use in new colours to replace suspected toxicity in some synthetic dyes and colourants. The project is also constructing a database of berries, the compounds they contain and their biological activity as a resource for research and industry.
“BacHBerry is providing a major opportunity through new and innovative tools to tap the potential of phenolics in berry fruits,” says Dudnik. “We are overcoming real scientific and technological barriers to allow industry to systematically go from bioprospecting through to bio-production using the BacHBerry ‘pipeline’. In the future it will hopefully allow industry to identify more novel, high-value bioactive compounds that would give a boost to new products across a range of sectors: nutrition, pharmaceutical, food and cosmetics.”