The present invention relates to methods of making a cyclic amide. The methods include the step of heating a fermentation broth in a manner effective to produce a cyclic amide, wherein the fermentation broth includes an amino acid or salt thereof. The cyclic amide monomers can be polymerized in a manner effective to form a polyamide. One advantage of the present invention is that lysine and/or salt thereof can be heated to form α-amino-ε-caprolactam while the lysine is still in the fermentation broth. The lysine and/or salt thereof do not need to be purified from the fermentation broth prior to being heated to form α-amino-ε-caprolactam. For example, the fermentation broth does not need to be subjected to an ion exchange process prior to being heated to form α-amino-ε-caprolactam. Avoiding such an ion exchange process can substantially reduce manufacturing costs.