Production and Characterization of Bacterial Cellulose with Different Nutrient Source and Surface–Volume Ratios

Abstract

In this research, commercially available, carrot juice was explored as alternative feedstock for production of bacterial cellulose (BC) by Gluconacetobacter hansenii (ATCC® 23769™). Two types of culture media were used: Hestrin-Schramm (HS) and the carrot juice medium and these culture media were incubated statically for 10 days. The effect of different volumes of media on the microbial process and the utilization of substrates by the bacteria, were also examined. The produced BC was analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR).

Biocellulose Production by Gluconacetobacter hansenii ATCC 23769: Application of Statistical Experimental Designs and Cellulose Membrane Characterization.

“…XRD pattern demonstrates three relatively intense reflections at 14.72°, 17.01° and 23.12° namely (100), (010) and (110), respectively, which recognized according to the triclinic indexation (Fig.4). These results are in agreement to other studies [9,41,43]. Also, BC obtained from the G.hansenii ATCC 23769 shows a typical crystalline and amorphous regions form of cellulose I, which is similar to that reported by other studies [44,45].…”

“…CI of BC membrane of G.hansenii ATCC 23769 reached to 82.7% according to the previous method. This result is nearly similar to some previous studies (under different medium and culture conditions), where CI measured 83 and 84 % using Carrot and HS medium, respectively [41]. Also, CI measured 70 to 80% under different chemical and physical conditions [43] and 77.4 and 78.3% when using galactose and glucose as carbon source [7].…”

“…The FT-IR spectra of BC membrane obtained from G.hansenii ATCC 23769 was detected at wave numbers ranging from 500 to 4000 cm -1 as can be seen in Fig.5. The band of intense absorption in the BC spectrum at 3345.2 cm -1 was attributed to the presence of hydroxyl group (OH) of cellulose type I and is important for elucidating hydrogen-bonding patterns which are in agreement with some literatures [41,43,47], strong absorption band at 2896.8 cm -1 was also attributed to the presence of stretching of CH this are in agreement with other studies [41,44,47]. The cellulose absorption spectrum is the band at 1638 cm −1 which has been assigned to carboxyl functional group (C=O) [47].…”

“…Through, experimental design G.hansenii ATCC 23769 achieved higher production of BC in short time than applying traditional optimization method. Accordingly, G.hansenii ATCC 23769 under experimental design achieved BC 2.85 g/l where other studies using the same strain obtained BC 1.35 and 0.15 g/l from glucose and galactose respectively [7] and 1.19, 1.35, 1.33 and 1.21 g/l from different volume of carrot juice media [41]. Accordingly, the formula of the optimized medium (g/L) is as follows: mannitol 25, yeast extract 13, ethanol 7 ml/l, pH 7, inoclume size 7%, temperature 26.3°C and incubation time 12 days.…”

“…The cellulose absorption spectrum is the band at 1638 cm −1 which has been assigned to carboxyl functional group (C=O) [47]. While 1389.6 cm −1 (asymmetric angular deformation of C-H bonds), the band at 1055.6 cm −1 to 1066.9 cm −1 stretching of C-O-C and C-O-H bonds in secondary and primary alcohols, respectively [41,43]. The FT-IR features of BC obtained from G.hansenii ATCC 23769 in this study are in agreement with other studies using the same strain under different conditions [41,43].…”