soapdenovo-31mer: 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/bin/soapdenovo-31mer - from package: soapdenovo

You may install the required package with command apt-get install {package}
Error in other languages:
soapdenovo-31mer: bevel nie gevind nie
soapdenovo-31mer: comandă negăsită
soapdenovo-31mer: comando não encontrado
soapdenovo-31mer: commande introuvable
soapdenovo-31mer: command not found
soapdenovo-31mer: käsku ei ole
soapdenovo-31mer: không tìm thấy lệnh
soapdenovo-31mer: komanda nerasta
soapdenovo-31mer: Kommando nicht gefunden.
soapdenovo-31mer: kommandot finns inte
soapdenovo-31mer: komut yok
soapdenovo-31mer: nie znaleziono polecenia
soapdenovo-31mer: níor aimsíodh an t-ordú
soapdenovo-31mer: no se encontró la orden
soapdenovo-31mer: no s'ha trobat l'ordre
soapdenovo-31mer: opdracht niet gevonden
soapdenovo-31mer: parancs nem található
soapdenovo-31mer: perintah tidak ditemukan
soapdenovo-31mer: príkaz nenájdený
soapdenovo-31mer: příkaz nenalezen
soapdenovo-31mer: команда не найдена
soapdenovo-31mer: командата не е открита
soapdenovo-31mer: 命令找不到
soapdenovo-31mer: コマンドが見つかりません