Code bellow is also available as the powershell file ShareKnowledgeNotificationJobsManagement.ps1

# Gets all existing ShareKnowledge timer jobs names 
Get-SPTimerJob |? Name -like *shareknowledge* | select Name

#Disables particular timer job
Get-SPTimerJob |? Name -eq 'ShareKnowledge Mail Sender' | Disable-SPTimerJob

#Enables particular timer job
Get-SPTimerJob |? Name -eq 'ShareKnowledge Mail Sender' | Enable-SPTimerJob

#Executes particular timer job
Get-SPTimerJob |? Name -eq 'ShareKnowledge Mail Sender' | Start-SPTimerJob

#Starts all ShareKnowledge Notifications jobs
Get-SPTimerJob | ? Name -like '*ShareKnowledge*' | Start-SPTimerJob

#Gets Last run summary for all ShareKnowledge timer jobs
Get-SPTimerJob | ? Name -like '*ShareKnowledge*' | % { $_.HistoryEntries | Select JobDefinitionTitle,WebApplication,Server,Status,StartTime,EndTime,ErrorMessage -First 1 }| ft -Auto