**5. Characterization of SCOBY nanocellulose fibers**

In the enzymatic process of making nanocellulose, it is known that the size of cellulose has succeeded in achieving the characteristics of nanocellulose. However, the production of nanocellulose by enzymatic method has drawbacks, where the breaking of glycosidic bonds and hydrogen bonds in cellulose by cellulase causes a free C structure in cellulose. This free C structure is unstable and tends to form bonds with the surrounding C structures. This condition causes the enzymatic treated nanocellulose to be easily aggregated and has a large size [14]. One way that can be done to avoid this polymerization is the coating process using a buffer, such as CTAB [26] or other compounds, such as chitosan [27]. However, until now there has not been found the right coating process to avoid the polymerization process, because the coating process with CTAB buffer is feared to change the structure of the nanocellulose, while coating using chitosan is feared that it will make the nanocellulose experience an error reading during PSA analysis.

Based on the SEM results in **Figure 7**, it can be seen that the cellulose structure on SCOBY is in the form of microfibrils. The SEM results stated that cellulose has a microfibril structure consisting of amorphous and crystalline structures [1]. The cellulose structure in SCOBY looks more stacked and random. In SEM results, it is known that the cellulose size ranges from 270 nm–740 nm.

**137**

**6. Conclusions**

*The Nanocellulose Fibers from Symbiotic Culture of Bacteria and Yeast (SCOBY) Kombucha...*

The structure of cellulose is crystalline with single pointed ends due to the treatment of cellulase enzymes which can break the 1,4-glycosidic bonds in cellulose and remove the amorphous structure of cellulose, so that most of the cellulose structures change to crystalline structures [27]. In SEM results, it is known that the cellulose size ranges from 480 nm–770 nm. This size does not match the PSA results, which state that the nanocellulose particle size of sample 4.2 is 60 nm. This size difference can occur due to re-aggregation between nanocellulose particles. Aggregation can occur starting shortly after the enzymatic process from cellulase is stopped to the drying process of the nanocellulose in the SEM sample preparation process [23]. A fast analysis process is needed to avoid re-aggregation of the nano-

Cellulose from SCOBY has 5 main functional groups owned by cellulose. The O-H group (3345 cml) is a hydrogen bond that functions to bind the cellulose microfibrils to one another to keep them structured and compact. The CH2 group (2898 cml/1314 cml) is a carboxyl group that can be used to estimate the crystallization rate of cellulose. H-O-H groups (1644–1650 cml) were used to determine the water adsorption rate. The C-O group (1107 cml) is a polyhydroxyl group which can state that SCOBY cellulose is formed from glucose or its derivatives. The C-O-C group (1050–1055 cml) is a glycosidic bond that plays a role in glucose polymer

SCOBY nanocellulose fibers show all the clusters that belong to SCOBY cellulose. These results indicate that the SCOBY nanocellulose fibers were indeed cellulose samples. The difference in FT-IR results between cellulose and nanocellulose SCOBY lies in the absorbance value of the FT-IR results. In general, the FT-IR SCOBY nanocellulose absorbance value was lower than cellulose, especially for the O-H, H-O-H and C-O-C groups. These results indicate that enzymatic treatment on cellulose has succeeded in breaking hydrogen and glycosidic bonds in cellulose so that cellulose can undergo a change in size to 60 nm, which includes the size of nanocellulose. Changes in cellulose size also affect the H-O-H groups in cellulose, where the adsorption power of water on cellulose is smaller [29] (**Figure 8**).

The preparation of nanocellulose from SCOBY Kombucha can be done using crude extract of the cellulase enzyme from Bacillus sp. The optimum amount of

*DOI: http://dx.doi.org/10.5772/intechopen.96310*

cellulose, if the nanocellulose is coated.

*SCOBY nanocellulose FT-IR absorbance curve with a size of 60 nm.*

**Figure 8.**

bonds so that it can form cellulose [28].

**Figure 7.** *The cellulose structure is crystalline with single pointed edges on the SEM results.*

*The Nanocellulose Fibers from Symbiotic Culture of Bacteria and Yeast (SCOBY) Kombucha... DOI: http://dx.doi.org/10.5772/intechopen.96310*

**Figure 8.** *SCOBY nanocellulose FT-IR absorbance curve with a size of 60 nm.*

The structure of cellulose is crystalline with single pointed ends due to the treatment of cellulase enzymes which can break the 1,4-glycosidic bonds in cellulose and remove the amorphous structure of cellulose, so that most of the cellulose structures change to crystalline structures [27]. In SEM results, it is known that the cellulose size ranges from 480 nm–770 nm. This size does not match the PSA results, which state that the nanocellulose particle size of sample 4.2 is 60 nm. This size difference can occur due to re-aggregation between nanocellulose particles. Aggregation can occur starting shortly after the enzymatic process from cellulase is stopped to the drying process of the nanocellulose in the SEM sample preparation process [23]. A fast analysis process is needed to avoid re-aggregation of the nanocellulose, if the nanocellulose is coated.

Cellulose from SCOBY has 5 main functional groups owned by cellulose. The O-H group (3345 cml) is a hydrogen bond that functions to bind the cellulose microfibrils to one another to keep them structured and compact. The CH2 group (2898 cml/1314 cml) is a carboxyl group that can be used to estimate the crystallization rate of cellulose. H-O-H groups (1644–1650 cml) were used to determine the water adsorption rate. The C-O group (1107 cml) is a polyhydroxyl group which can state that SCOBY cellulose is formed from glucose or its derivatives. The C-O-C group (1050–1055 cml) is a glycosidic bond that plays a role in glucose polymer bonds so that it can form cellulose [28].

SCOBY nanocellulose fibers show all the clusters that belong to SCOBY cellulose. These results indicate that the SCOBY nanocellulose fibers were indeed cellulose samples. The difference in FT-IR results between cellulose and nanocellulose SCOBY lies in the absorbance value of the FT-IR results. In general, the FT-IR SCOBY nanocellulose absorbance value was lower than cellulose, especially for the O-H, H-O-H and C-O-C groups. These results indicate that enzymatic treatment on cellulose has succeeded in breaking hydrogen and glycosidic bonds in cellulose so that cellulose can undergo a change in size to 60 nm, which includes the size of nanocellulose. Changes in cellulose size also affect the H-O-H groups in cellulose, where the adsorption power of water on cellulose is smaller [29] (**Figure 8**).

### **6. Conclusions**

The preparation of nanocellulose from SCOBY Kombucha can be done using crude extract of the cellulase enzyme from Bacillus sp. The optimum amount of

*Nanofibers - Synthesis, Properties and Applications*

or endogilanase/exogilanase with CBM simultaneously (**Figure 6**). Several studies have shown that the performance of the endogucanase-exogilanase enzyme can occur synergistically and produce good cellulose hydrolysis products. Other studies have shown that the use of cellulases that have the same cutting-edge (endo-endogluanase or exogluanase) can make the two enzymes inhibit each other [25].

*Cellulase action mechanism; CBH: Cellobiosehydrolase/Exoglukanase; EG: Endoglukanase, NR: Non Reductor;* 

In the enzymatic process of making nanocellulose, it is known that the size of cellulose has succeeded in achieving the characteristics of nanocellulose. However, the production of nanocellulose by enzymatic method has drawbacks, where the breaking of glycosidic bonds and hydrogen bonds in cellulose by cellulase causes a free C structure in cellulose. This free C structure is unstable and tends to form bonds with the surrounding C structures. This condition causes the enzymatic treated nanocellulose to be easily aggregated and has a large size [14]. One way that can be done to avoid this polymerization is the coating process using a buffer, such as CTAB [26] or other compounds, such as chitosan [27]. However, until now there has not been found the right coating process to avoid the polymerization process, because the coating process with CTAB buffer is feared to change the structure of the nanocellulose, while coating using chitosan is feared that it will make the

Based on the SEM results in **Figure 7**, it can be seen that the cellulose structure on SCOBY is in the form of microfibrils. The SEM results stated that cellulose has a microfibril structure consisting of amorphous and crystalline structures [1]. The cellulose structure in SCOBY looks more stacked and random. In SEM results, it is

**5. Characterization of SCOBY nanocellulose fibers**

nanocellulose experience an error reading during PSA analysis.

known that the cellulose size ranges from 270 nm–740 nm.

*The cellulose structure is crystalline with single pointed edges on the SEM results.*

**136**

**Figure 7.**

**Figure 6.**

*R: Reductor [26].*

enzymes used for the manufacture of nanocellulose from SCOBY kombucha is 2: 3 (w/v) SCOBY against crude extract of cellulase enzymes.

SCOBY cellulose fibers, a microbial polysaccharide, has significant potential and suitable for various industrial applications such as food, pharmaceutical, textiles, cosmetic, fashion, and paper. Its material properties has high elasticity, best deformation and comfort properties. SCOBY cellulose fibers forms a strong gel film of crystalline microfibrils and absence of impurities of hemicelluloses and lignin as well as environmentally friendly.
