Table 3 Analysis of gene numbers of the key metabolic pathways among the five microalgae

 Fatty acid biosynthesis

23

26

27

24

26

 Fatty acid elongation

7

8

10

8

8

 Fatty acid degradation

16

21

15

18

18

 Steroid biosynthesis

9

12

14

9

10

 Steroid hormone biosynthesis

5

4

4

4

3

 Glycerolipid metabolism

28

28

30

28

21

 Glycerophospholipid metabolism

35

37

35

32

30

 Ether lipid metabolism

5

9

7

6

5

 Sphingolipid metabolism

18

16

14

16

17

 Arachidonic acid metabolism

14

13

13

10

7

 Alpha-linolenic acid metabolism

10

13

14

11

9

 Biosynthesis of unsaturated fatty acids

10

15

14

12

11

 Carotenoid biosynthesis

12

11

14

12

10