blast_wrapper.py: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/lib/qiime/bin/blast_wrapper.py - from package: qiime

You may install the required package with command apt-get install {package}
Error in other languages:
blast_wrapper.py: bevel nie gevind nie
blast_wrapper.py: comandă negăsită
blast_wrapper.py: comando não encontrado
blast_wrapper.py: commande introuvable
blast_wrapper.py: command not found
blast_wrapper.py: käsku ei ole
blast_wrapper.py: không tìm thấy lệnh
blast_wrapper.py: komanda nerasta
blast_wrapper.py: Kommando nicht gefunden.
blast_wrapper.py: kommandot finns inte
blast_wrapper.py: komut yok
blast_wrapper.py: nie znaleziono polecenia
blast_wrapper.py: níor aimsíodh an t-ordú
blast_wrapper.py: no se encontró la orden
blast_wrapper.py: no s'ha trobat l'ordre
blast_wrapper.py: opdracht niet gevonden
blast_wrapper.py: parancs nem található
blast_wrapper.py: perintah tidak ditemukan
blast_wrapper.py: príkaz nenájdený
blast_wrapper.py: příkaz nenalezen
blast_wrapper.py: команда не найдена
blast_wrapper.py: командата не е открита
blast_wrapper.py: 命令找不到
blast_wrapper.py: コマンドが見つかりません