Here's the solution:
<drools:ksession id="jpaSingleSessionCommandService" type="stateful" kbase="knowledgeBase">
<drools:configuration>
<drools:work-item-handlers>
<drools:work-item-handler name="Notification" ref="refToNotificationWorkItemHandler" />
</drools:work-item-handlers>
<drools:jpa-persistence>
<drools:transaction-manager ref="transactionManager" />
<drools:entity-manager-factory ref="entityManagerFactory" />
</drools:jpa-persistence>
</drools:configuration>
</drools:ksession>
<drools:ksession id="jpaSingleSessionCommandService" type="stateful" kbase="knowledgeBase">