Problem solved.
Just remove following from single-portfolio.php:
<footer class="entry-meta"> <?php $cat_list = get_the_term_list( $post->ID, 'portfolio_category', '', ', ', '' ); $tag_list = get_the_term_list( $post->ID, 'portfolio_tag', '', ', ', '' ); $utility_text = ''; if ( ( $cat_list ) && ( '' == $tag_list ) ) $utility_text = __( 'This entry was posted in %1$s.', 'portfoliopress' ); if ( ( '' != $tag_list ) && ( '' == $cat_list ) )
$utility_text = __( 'This entry was tagged %2$s.', 'portfoliopress' );
if ( ( '' != $cat_list ) && ( '' != $tag_list ) )
$utility_text = __( 'This entry was posted in %1$s and tagged %2$s.', 'portfoliopress' );
printf(
$utility_text,
$cat_list,
$tag_list
);?>