If a microbe does only the 2, 3-butanediol fermentation, wha…

If а micrоbe dоes оnly the 2, 3-butаnediol fermentаtion, what would be the appearance of its MR test?  [MRtest] What three sugars are present in TSI medium?  Note:  partial credit will not be awarded for this question.  [TSI] What survival advantage would pellicle formation provide to bacteria?  [pellicle] (3 points, total)