denoiser.py: command not found

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/denoiser.py - from package: qiime

You may install the required package with command apt-get install {package}

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