France, Jan. 2 -- On 1 January, Bulgaria became the 21st European Union country to adopt the single currency. The outgoing government of the Balkan nation of 6.4 million people presents the move as a milestone that should strengthen the economy and help curb corruption.

On the streets of the capital Sofia, however, optimism is mixed with unease. While some Bulgarians see the euro as a logical step in the country's European integration, others worry about its impact on everyday life.

In a shop in central Sofia, women's fashion designer Mirella Bratova told RFI adopting the euro will simplify her business.

"I have customers in the European Union, but also in the United States. Most of them shop online or in our stores here in Sofia, in t...