Production of bacterial cellulose using polysaccharide fermentation wastewater as inexpensive nutrient sources

Figures & data

Figure 1. Sugar utilizations during fermentation in HS medium and fermentation wastewater.

Figure 2. COD degradation in wastewater during fermentation.

Figure 3. SEM micrographs of BC samples obtained in HS medium (a,b) and in polysaccharide fermentation wastewater (c,d) after 4 days (a,c) or 10 days (b,d) of fermentation.

Figure 4. FT-IR spectra of BC samples obtained in HS medium (a,b) and in polysaccharide fermentation wastewater (c,d) after 4 days (a,c) or 10 days (b,d) of fermentation.

Figure 5. XRD patterns of BC samples obtained in HS medium (a,b) and in polysaccharide fermentation wastewater (c,d) after 4 days (a,c) or 10 days (b,d) of fermentation.

Table 1. Crystallinity and crystal size of BC samples produced in HS medium and fermentation wastewater.

		Size of crystals (Å)
Samples	Crystallinity (%)	(1ī0) plane	(110) plane	(200) plane
^aBCHS-4th	53.87 ± 2.60^a	84.36 ± 0.67^a	134.75 ± 5.05^a	84.25 ± 1.00^a
^bBCHS-10th	72.10 ± 2.80^b	87.91 ± 3.53^a	171.93 ± 17.37^b	88.27 ± 0.88^b
^cBCFW-4th	50.66 ± 1.73^a	98.59 ± 8.73^b	186.42 ± 12.95^bc	93.27 ± 1.21^c
^dBCFW-10th	56.23 ± 2.68^a	85.73 ± 4.46^a	217.48 ± 12.24^c	84.26 ± 0.77^a

Note: Mean values with standard deviation (±SD), n = 3. Fisher's LSD method was used in ANOVA to define confidence intervals for all pairwise differences between factor level means. Different lower case superscript letters in each column indicate significant difference (P < 0.05).

^a BC sample obtained in HS medium after 4 days of fermentation;

^b BC sample obtained in HS medium after 10 days of fermentation;

^c BC sample obtained in fermentation wastewater after 4 days of fermentation;

^d BC sample obtained in fermentation wastewater after 10 days of fermentation.

Table 2. Mechanical properties of bacterial cellulose sheets produced in different medium.

Samples	Young's modulus (MPa)	Tensile strength (MPa)	Strain at break (%)
^aBCHS-4th	6165.73 ± 1105.64^b	107.67 ± 51.70^a	3.40 ± 0.67^a
^bBCHS-10th	11 951.91 ± 752.10^a	168.49 ± 33.14^b	3.77 ± 0.90^a
^cBCFW-4th	1469.43 ± 379.83^c	19.33 ± 5.10^bc	1.18 ± 0.39^b
^dBCFW-10th	3984.29 ± 1065.43^b	64.84 ± 12.03^c	1.85 ± 0.05^b

Note: Data are mean values ± SD (n = 5); ANOVA and Fisher's LSD were carried out at 5% significance; similar superscripts within the columns represent no significant differences between the treatment groups.

^a BC sample obtained in HS medium after 4 days of fermentation;

^b BC sample obtained in HS medium after 10 days of fermentation;

^c BC sample obtained in fermentation wastewater after 4 days of fermentation;

^d BC sample obtained in fermentation wastewater after 10 days of fermentation.