Web API - load resources only once in Business Layer

In my n-Layered application Web API is calling the Business Layer(BL) which is a class library project. In the BL I have a folder with several XML templates. For every request that comes to the Web API an instance of BL's class is created which in turn reads one or more XML templates and do some tasks.
I want to know - is there any way that the XML Templates are loaded/parsed only once so that the subsequent requests read the template from memory ?
I do not wish to move the templates to API layer.