I use the following settings to toggle src block syntax highlighting:

#+begin_src emacs-lisp

;;; export to PDF with src blocks syntax highlighting.
(setq org-latex-listings 'minted)
(add-to-list 'org-latex-packages-alist '("newfloat" "minted" "color"))
(add-to-list 'org-latex-pdf-process
              '("latexmk -shell-escape -bibtex -f -pdf %f"))
(setq org-latex-minted-options
       '(("frame" "lines")
         ("linenos" "true")
         ("bgcolor" "bg")
         ))
#+end_src


In attachment, has the org-mode template file.