The present invention relates to a host cell comprising an rhlA gene or an ortholog thereof that is capable of producing hydroxyalkanoyloxy alkanoic acid (HAA) and achieving an HAA concentration of more than 1 g L−1 when cultured. The invention further relates to methods of producing such a host cell and to the use of said host cell for producing HAA. The present invention also relates to methods of producing HAA using said host cell, HAA compositions produced by these methods, as well as methods of producing fatty acid compositions, fatty alcohol compositions, or hydrocarbon compositions comprising producing HAA using said host cell, and fatty acid compositions, fatty alcohol compositions, or hydrocarbon compositions produced by said methods.