Table 1.
Yield and physicochemical properties of BNC subject to the microbial producer and cellulosic feedstock used compared to the control.
| Properties | Komagataeibacter xylinus B-12429 | Komagataeibacter xylinus B-12431 | Medusomyces gisevii Sa-12 | ||||||
|---|---|---|---|---|---|---|---|---|---|
| MH | OHH | Control | MH | OHH | Control | MH | OHH | Control | |
| BNC yield in 14 days of biosynthesis, % of the RS, ±0.2% | 3.3 | 3.5 | 2.4 | 3.0 | 4.1 | 1.2 | 6.3 | 10.0 | 10.0 |
| Volumetric productivity of BNC in 14 days of biosynthesis on a dry matter basis, g/L, ±0.1 g/L | 0.59 | 0.63 | 0.43 | 0.54 | 0.74 | 0.22 | 1.13 | 1.80 | 1.80 |
| Mean width of BNC microfibrils, nm | 91.1 | 90.8 | 89.6 | 82.1 | 90.1 | 82.8 | 88.6 | 82.4 | 87.0 |
| Degree of polymerization subject to BNC biosynthesis time, ±50 | |||||||||
| 7 days | 880 | 860 | 900 | 2400 | 2600 | 1900 | 1550 | 1760 | 2600 |
| 14 days | 800 | 820 | 880 | 1920 | 1940 | 2200 | 1470 | 1450 | 2200 |
| Strength properties | |||||||||
| Breaking strength, MPa, ±0.5 MPa | 23.9 | 41.2 | 5.7 | 83.7 | 65.6 | 128.3 | 21.5 | 26.2 | 33.2 |
| Conventional yield limit, MPa, ±0.5 MPa | 3.9 | 3.0 | 1.2 | 10.9 | 5.8 | 8.4 | 3.0 | 3.7 | 5.6 |
| Relative elongation at maximum load, %, ±0.1% | 1.4 | 1.1 | 0.5 | 2.6 | 1.9 | 2.7 | 1.2 | 1.7 | 1.5 |
| Relative elongation at yield, %, ±0.1% | 0.3 | 0.3 | 0.1 | 0.5 | 0.3 | 0.4 | 0.4 | 0.7 | 0.6 |
| Sample thickness, µm, ±0.5 µm | 10.0 | 17.5 | 7.5 | 5.0 | 15.0 | 5.0 | 30.0 | 50.0 | 20.0 |
| Elastic modulus, MPa, ±10.0 MPa | 1212 | 1142 | 1033 | 2180 | 2215 | 2143 | 510 | 529 | 933 |
| Thermogravimetric data | |||||||||
| Onset temperature of decomposition, °C, ±1.0 °C | 305.8 | 294.8 | 290.7 | 301.7 | 302.1 | 300.5 | 317.6 | 329.3 | 307.1 |
| Content of cellulose allomorphs and degree of polymerization, as measured via SEM | |||||||||
| Iα allomorph, %, ±1.0% | 100.0 | 100.0 | 99.2 | 92.8 | 94.2 | 93.5 | 100.0 | 100.0 | 100.0 |
| Iβ allomorph, %, ±1.0% | 0.0 | 0.0 | 0.8 | 7.2 | 5.8 | 6.5 | 0.0 | 0.0 | 0.0 |
| Crystallinity index (in reflection geometry), %, ±5% | 74 | 87 | 76 | 90 | 91 | 94 | 94 | 93 | 86 |
| Crystallinity index (in transmission geometry), %, ±5% | 75 | 90 | 88 | 100 | 89 | 100 | 92 | 87 | 88 |
Notes: (1) MH—miscanthus hydrolyzate; OHH—oat-hull hydrolyzate; (2) controls were the Hestrin–Schramm medium for Komagataeibacter xylinus B-12429 and B-12431 and the control medium supplemented with black tea extract for Medusomyces gisevii Sa-12; (3) some data on BNCs synthesized by Medusomyces gisevii Sa-12 were reported previously [25,26].