pick_open_reference_otus.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

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/pick_open_reference_otus.py - from package: qiime

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