In the presumptive test, 9 different tubes of lactose broth with 10 fold variations of the water sample are inoculated. If any lactose-fermenting bacteria grow and produce gas, the medium will turn ...

Note - broth tubes can be made containing sugars other than glucose (e.g. lactose and mannitol). Because the same pH indicator (phenol red) is also used in these fermentation tubes, the same results ...

Wrong. In her new cookbook Breaking Up With Dairy, chef and author Bailey Ruskus reveals that you can have your ice cream and eat it too. 1 Heat 1 tbsp. broth in a large pot over medium-high.