Scientists are predicting that the familiar taste of vanilla or smell of roses, along with thousands of other scents and flavours, will increasingly come from a very unfamiliar source - yeast - a trend that is worrying some farming experts.

A revolution in science means the DNA of plants can be transferred into yeast, bacteria or algae which can produce the required ingredient in laboratories within days.

— Read more at Fragrance-producing yeasts may not smell of roses for farmers at Thomas Reuters Foundation.