The present invention relates to polypeptides having alpha-amylase activity and polynucleotides having a nucleotide sequence which encodes for the polypeptides. The invention also relates to a polypeptide having carbohydrate-binding affinity and polynucleotides having a nucleotide sequence which encodes for the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the nucleic acid constructs as well as methods for producing and using the polypeptides.