Extraction, identification and mechanism of action of antibacterial substances from Galla chinensis against Vibrio harveyi

Figures & data

Table 1. Coded (actual) values of the independent factors and response values of BBD.

No.	X1 Temperature (°C)	X2 Time (min)	X3 L/M ratio (mL/g)	Response inhibition zone (mm)
1	–1 (80)	–1 (120)	0 (20)	17.26
2	+1 (100)	–1 (120)	0 (20)	19.04
3	–1 (80)	+1 (180)	0 (20)	17.73
4	+1 (100)	+1 (180)	0 (20)	20.83
5	–1 (80)	0 (150)	–1 (10)	18.20
6	+1 (100)	0 (150)	–1 (10)	19.07
7	–1 (80)	0 (150)	+1 (30)	19.46
8	+1 (100)	0 (150)	+1 (30)	20.98
9	0 (90)	–1 (120)	–1 (10)	17.10
10	0 (90)	+1 (180)	–1 (10)	18.21
11	0 (90)	–1 (120)	+1 (30)	18.82
12	0 (90)	+1 (180)	+1 (30)	20.13
13	0 (90)	0 (150)	0 (20)	19.54
14	0 (90)	0 (150)	0 (20)	19.31
15	0 (90)	0 (150)	0 (20)	20.75
16	0 (90)	0 (150)	0 (20)	19.48
17	0 (90)	0 (150)	0 (20)	19.95

Figure 1. Effect of different variables on the antibacterial activity of the extracts against V. harveyi: Extraction solvent (a), methanol concentration (b), extraction temperature (c), extraction time (d), liquid/material ratio (e).

Table 2. ANOVA of the effects of temperature, time and liquid/material ratio on the diameters of the inhibition zone of the extracts using the quadratic response surface model.

Source	Sum of squares	df	Mean Square	F value	Prob > F	Sig.
Model	20.27	9	2.25	7.37	0.0077	**
X1	6.61	1	6.61	21.60	0.0023	**
X2	2.74	1	2.74	8.95	0.0202	*
X3	5.80	1	5.80	18.96	0.0033	**
X1X2	0.44	1	0.44	1.42	0.2716
X1X3	0.11	1	0.11	0.35	0.5752
X2X3	0.01	1	0.01	0.033	0.8616
X1^2	0.055	1	0.055	0.18	0.6843
X2^2	4.02	1	4.02	13.14	0.0085	**
X3^2	0.29	1	0.29	0.96	0.3595
Lack of Fit	0.81	3	0.27	0.80	0.5530

* p < 0.05,

** p < 0.01.

Figure 2. HPLC Chromatograms of ASGC (a) and standard solutions of two references (b) including GA (1) and 5GG (2).

Figure 3. Effects of ASGC and GA on the growth of V. harveyi.

Figure 4. Effects of ASGC and GA on the release of 260 nm absorbing substances of V. harveyi.

Figure 5. Effects of ASGC and GA on the electric conductivity of V. harveyi.

Figure 6. Scanning electron microscope images of V. harveyi treated with 1-fold MIC of ASGC and GA.