Your search should work. But, for bash, you will need to quote the parameters.
Something like:
ldapsearch -x -h localhost -p 389 -D uid=xxxadmin,ou=administrators,ou=topologymanagement,o=netscaperoot -v -w 12345 -b "ou=Usuarios,ou=Alunos,ou=XXXX,o=xxXXXxx" -f "(!(objectClass=ntUser))" 1.1
Tested both openLDAP
@(#) $OpenLDAP: ldapsearch (Ubuntu) (Mar 17 2014 21:19:27) $buildd@aatxe:/build/buildd/openldap-2.4.31/debian/build/clients/tools
(LDAP library: OpenLDAP 20431)
ldapsearch -x -h localhost -p 389 -D "cn=admin" -W -b "dc=example,dc=com" -s sub -a always -z 1000 "(!(objectClass=inetOrgPerson))" "objectClass"
and OpenDJ
ldapsearch --version
OpenDJ 2.7.0-20140727
Build 20140727000040Z
ldapsearch -h localhost -p 389 -D "cn=admin" -b "dc=example,dc=com" -s sub -a always -z 1000 "(!(objectClass=inetOrgPerson))" "objectClass"
-jim