1. Understand what is being asked

We need to identify the incorrect statement.

2. Check option A

A: $\alpha$-D-glucose and $\beta$-D-glucose are anomers.

• Anomers are stereoisomers that differ only in configuration at the anomeric carbon.
• In glucose, the anomeric carbon is C-1.
• $\alpha$-D-glucose and $\beta$-D-glucose differ only at C-1.

So, A is correct.

3. Check option B

B: $\alpha$-D-glucose and $\beta$-D-glucose are enantiomers.

• Enantiomers are non-superimposable mirror images of each other.
• $\alpha$-D-glucose and $\beta$-D-glucose are not mirror images.
• They differ only at one stereocenter (the anomeric carbon), so they are anomers, which are a type of diastereomer, not enantiomers.

So, B is incorrect.

4. Check option C

C: Cellulose is a straight chain polysaccharide made up of only $\beta$-D-glucose units.

• Cellulose consists of $\beta$-D-glucose units joined by $\beta(1\to 4)$ glycosidic linkages.
• This gives it a linear, straight-chain structure.

So, C is correct.

5. Check option D

D: The penta acetate of glucose does not react with hydroxyl amine.

• Glucose forms cyclic structures, but free glucose can open to the aldehyde form and react with reagents like hydroxylamine.
• In glucose pentaacetate, the anomeric hydroxyl group is also acetylated, so the ring cannot open to give the free aldehyde group.
• Therefore it does not react with hydroxylamine.

So, D is correct.

6. Conclusion

The only incorrect statement is:

$\boxed{\text{B}}$

$\alpha$-D-glucose and $\beta$-D-glucose are anomers, not enantiomers.