Production of the exopolysaccharide from Lactiplantibacillus plantarum YT013 under different growth conditions: optimum parameters and mathematical analysis

Figures & data

Table 1. The sources of the chemicals and nutrients.

Chemicals	Sources	Chemicals	Sources
Glucose	Solarbio, Beijing, China	KH2PO4	Sinopharm, Shanghai, China
Sucrose	Solarbio, Beijing, China	NaH2PO4	Sinopharm, Shanghai, China
Lactose	Solarbio, Beijing, China	Na2HPO4	Sinopharm, Shanghai, China
Starch soluble	Solarbio, Beijing, China	K2HPO4	Sinopharm, Shanghai, China
Soy peptone	Coolaber, Beijing, China	Diammonium hydrogen citrate	Sinopharm, Shanghai, China
Tryptone	Coolaber, Beijing, China	Yeast extract	Solarbio, Beijing, China
Casein peptone	Coolaber, Beijing, China	Magnesium sulphate	Guangfu, tianjin, China
Peptone	Coolaber, Beijing, China	Manganese sulfate	Baishi, tianjin, China
Sodium acetate	Sinopharm, Shanghai, China	Tween 80	Solarbio, Beijing, China

Figure 1. The influence of culture conditions. Effect of (a) pH, (b) inoculation volume, (c) time, (d) temperature on EPS production.

Figure 2. The influence of medium composition. Effect of (a) carbon source, (b) glucose concentration, (c) nitrogen source, (d) soy peptone concentration, (e) phosphate, (f) KH₂PO₄ concentration on EPS production.

Table 2. Best-fit nonlinear model equation and correlation factors (R-square) for EPS production.

Nonlinear equation	Voigt
Eq. (1)(1) $\mathrm{y}=y_0+A\frac{2ln2}{{\pi }^{3/2}}\frac{w_L}{w_G^2}{\int }_{-\mathrm{\infty }}^{\mathrm{\infty }}\frac{e^{-t^2}}{{\left(\sqrt{ln2}\frac{w_L}{w_G}\right)}^2+{\left(\sqrt{4ln2}\frac{x-x_c}{w_G}-t\right)}^2}dt$(1)	y = nlf_voigt(x, y0, xc, A, WG, WL);
y0	−8.98187 ± 179.81388
xc	50.73721 ± 2.663
A	3363.88702 ± 95347.93463
WG	328.83965 ± 3184.44142
WL	5.22866E^−15 ±0
Reduced Chi-square	0.00269
Adjusted R-square	0.88476
Fit status	Succeeded (100)

Figure 3. Fitting results under the best single factor condition. (a) EPS yield of different fermentation time under the best single factor condition; (b) Best-fit nonlinear model equation for EPS production.

Figure 4. EPS sample and its inhibitory effect on AGS cell proliferation. (a) Fluffy and light-yellow EPS samples were obtained by dialysis and freeze-drying. (b) Cytotoxic effects of crude EPS (400 μg/mL) extracted at different culture times on the human AGS cancer cells. Inhibition effects of crude EPS on the human AGS cancer cells for 24, 48 and 72 h, respectively. (c) control group, (d) treated with EPS (400 μg/mL).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.