text: user1911: I am trying to build a machine learning training set for bacterial protein sequences that form biofilm, and that cannot. I collected the positive sequences from the GO ontology website but for negative sequences I am not sure which sequences to incorporate into my training set.
  Can anyone point me to resources for proteins sequences that are known to be not capable of forming biofilms?
  
  user196: One option is to treat all proteins that are not explicitly known to form a biofilm as proteins that are incapable of doing so, but this will likely result in many false negatives.
  You could take a look at one-class classification and positive-unlabeled (PU) learning. Both are techniques specifically designed for these kind of problems where only one of the two classes is known. (In this case: only biofilm forming proteins are known.)
  
original_text: 1911: <p>I am trying to build a machine learning training set for bacterial protein sequences that form biofilm, and that cannot. I collected the positive sequences from the GO ontology website but for negative sequences I am not sure which sequences to incorporate into my training set.</p>
  
  <p>Can anyone point me to resources for proteins sequences that are known to be not capable of forming biofilms?</p>
   196: <p>One option is to treat all proteins that are not explicitly known to form a biofilm as proteins that are incapable of doing so, but this will likely result in many false negatives.</p>
  
  <p>You could take a look at <a href="https://en.wikipedia.org/wiki/One-class_classification" rel="nofollow noreferrer">one-class classification and positive-unlabeled (PU) learning</a>. Both are techniques specifically designed for these kind of problems where only one of the two classes is known. (In this case: only biofilm forming proteins are known.)</p>
  