otu_category_significance.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/otu_category_significance.py - from package: qiime

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

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