Table 2.

Various modifications, product specifications, and advantages of different reactors for BC production.

Modification	Production Specification and Advantages	BC Production	References
Enriched Oxygen Bioreactors
Bubble column (controlled pH) Aeration rate:1.0 vvm (30 L/min)	Attributes: Low concentrated solution state culture; Low shear stress; Low mechanical properties: 17.15 to 11.66 MPa; Low crystallinity: 86 to 79.6%, Low degree of polymerization and molecular weight Advantages: High oxygen transfer rate	0.07–0.09 g/L/h	Choi et al. [192]
High oxygen concentration	Attribute: After 30 h the production decreased Advantages: Higher productivity; High oxygen transfer rate; Low power requirement.	0.20 g/L/h	Chao et al. [193]
Internal loop airlift with controlled pH/ fresh and glucose medium	Attribute: The highest concentration: 10.4 g/L at 60–70 g/L fructose Advantages: Formed a unique ellipse; Low mechanical strength; High hydrodynamic characteristic; High volumetric oxygen transfer	0.22 g/L/h	Chao et al. [194]
Internal loop airlift with enriched oxygen	Advantages: Unique ellipse was formed; High hydrodynamic characteristic; High volumetric oxygen transfer	0.116 g/L/h	Chao et al. [195]
Shaking flask with controlled pH/ Hestrin & Schramm medium	Attribute: A membrane-type BC was produced Advantages: Varying the net plates number would result in high Young’s modulus and water holding capacity	-	Wu and Li [121]
Rotating disc bioreactors
A rotating disk bioreactor	Attribute: A consistent product Advantages: Produced strong and intact cellulosic matrix, BC pore size of 10–15 μm; High tensile strength	-	Mormino & Bungay [196] Zahan et al. [197]
Rotating disk bioreactor supported by plastic composites	Attribute: A semi-continuous process Advantages: Low mechanical property (Young’s modulus of 372.5 MPa); Low crystallinity: 66.9%; similar thermostability and water content with BC produced by static culture	0.01 g/L/day	Lin et al. [198]
Rotating disk bioreactor with different additions supported by plastic composites	Attribute: A semi-continuous process Advantages: Similar strain but lower stress for carboxymethylcellulose and avicel, respectively; High water retention properties of 98.6–99%; Disc rotation speed and oxygen concentration improved the fermentation process; Fructose concentration was decreased from 50 to 10 g/L; No re-inoculation	0.64 g/slice with 0.8% carboxymethylcellulose and avicel	Lin et al. [199]
Rotating magnetic field	Advantages: Yield BC with an altered degree of porosity and microstructure; Increased biochemical properties; Positive impact on the growth of bacteria; Increased water retention by 26% as compared to the control sample; high density with tangled and long fibres	-	Fijałkowski et al. [200,201,202,203]
Other bioreactors for BC production
Spin filter supporting bioreactor	Advantages: BC concentration was increased from 5.65 to 11.52 g/L/140 h; An abundance of Cel + cells were converted into Cel- mutants	0.02 to 0.06 g/L/h	Jung et al. [204]
Fed-batch principle	Advantages: The gradient of a graph in the load-displacement diagram: (aerosol bioreactor = 34.7 N/10 mm, usual surface culture = 8.9 N/10 mm); High tensile strength: 114 N; High-quality cellulose; the degree of polymerization of BC is 5200; Best time interval: 6 h; BC layer or slices (3–4 cm); Culture box: low cost	-	Hornung et al. [205]
Biofilm reactor	Advantages: High crystallinity: 93% with a crystal size of 5.2 nm; high biomass density; Water retention ability up to 95 %; better thermal performance	7.05 g/L	Cheng et al. [206]
Biofilm reactor with additives	Advantages: Continuous BC production; High biomass density; High Young’s modulus and tensile strength; High crystallinity: 80% with a crystal size of 4.2 nm; potential application of BC paper sheets	13 g/L	Cheng et al. [207]