The bacteria shown in the image is Gram negative because of following characteristic-
0. The wall is two-layered.
,
1. The wall is wavy.
,
2. Outer membrane is present.
Gram negative bacteria are those which do not retain the Grams stain which consist of alkaline solution of crystal violet,then treated with 0.5% iodine solution followed by washing with water or acetone.
The bacteria which retain blue or purple color are gram positive bacteria.
Ex of Gram negative bacteria-E.coli