I1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

OD

680

(nm

)

0 5 10 15 20

V

II

VI

III

VII

IV(a)

10.4

10.2

10.0

9.8

9.6

9.4

9.2

9.0

8.8

8.6

pH

0 5 10 15 20

(b)

Time (Day)

A

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

OD

680

(nm

)

0 1 2 3 4 5 6 7 8 9 10 11 12 13

(a)B C D E

10.4

10.2

10.0

9.8

9.6

9.4

9.2

9.0

8.8

pH

0 1 2 3 4 5 6 7 8 9 10 11 12 13

(b)

Time (day)