Possibility of adding as many Content Databases to our SharePoint from Central Administration GUI is the one thing more over there is no way to add specific Content Database to new Site Collection from level of Central Administration. In this case and as often soulution to this is powershell script which can handle it without a problem.
First of all we have to Add Content Database from CA level i.e. lets call it “Marketing Department” and we can run script which does create a New Site Collection in this case “Marketing Team Website” and attatched “Markieting Department” Content Database to it. From the DBA point of view there is a way better to maintenance those databases which relates by name to direct Sites Collentions.
New-SpSite URL https://mysharepoint/sites/Marketing -owneralias “DOMAIN\SpAdmin” -ContentDatabase Marketing Department -Name Marketing Team Website