Pegar apenas a hora de um datatime

Preciso pegar apenas a hora de um datatime e converte no formato dia/mes/ano. Como faço isso?

Segue o codigo:

 <?php
 include "conexao.php";
 $sql_visualizar = mysql_query("SELECT * FROM publicacoes");
 while($linha = mysql_fetch_array($sql_visualizar)){?>

 <form method="post" action="noticias2.php">
 <input name="idnoticias" type="hidden" value="<?php echo $linha['id'] ?>" />

 <div class="blog-item">
 <div class="row">
 <div class="col-lg-2 col-sm-2">
 <div class="date-wrap">
 <span class="date">10</span>
 <span class="month">Setembro</span>
 </div>

 <form method="post" action="noticias2.php">
 <input name="idnoticias" type="hidden" value="<?php echo $linha['id'] ?>" />

 <div class="comnt-wrap">
 <span class="comnt-ico">
 <i class="icon-time"></i>
 </span>
 <span class="value"><?php echo $linha['datahora'] ?></span>
 </div>

 </div>
 <div class="col-lg-10 col-sm-10">
 <div class="blog-img">
 <img src="img/blog/<?php echo $linha['imagem1'] ?>" alt=""/>
 </div>

 </div>
 </div>
 <div class="row">
 <div class="col-lg-2 col-sm-2 text-right">
 <div class="author">
 By <a href="#">Admin</a>
 </div>
 <br><br><br></br>
 <div class="shate-view">
 <ul class="list-unstyled">
 <li><a href="javascript:;">209 View</a></li>
 <li><a href="javascript:;">23 Share</a></li>

 </ul>
 </div>
 </div>
 <div class="col-lg-10 col-sm-10">
 <h1><a href="blog_detail.html"><?php echo $linha['titulo'] ?></a></h1>

 <p><?php echo substr ($linha['descricao'],0, 300);?></p>

 <a href="notcias2.php" class="btn btn-danger">Continuar lendo</a>
 </div>
 </div>
 </div>

 </form>

 <?php }
 ?>