Quality trimming is performed to remove adapter sequences and poly(A) tails. The referenced truseq.fa.gz file contains the adapter sequences for trimming and is included in the resource files from the BBTools suite. The polyA.fa.gz file can be simply generated to include two sequences: a poly(A) sequence of 18 As, and a poly(T ) sequence of 18 Ts
For read one's I am removing :
For read twos I am removing the truseq adapters:
This is according to the Lexogen manual: