Nanotechnology Research Group, Chemical and Biochemical Processing Division, Central Institute for Research on Cotton Technology, Adenwala Road, Matunga, Mumbai 400 019, India.
Enzyme Microb Technol. 2013 Jan 10;52(1):20-5. doi: 10.1016/j.enzmictec.2012.09.002. Epub 2012 Sep 18.
Degradation of cellulose by anaerobic microbial consortium is brought about either by an exocellular process or by secretion of extracellular enzymes. In this work, a novel route for synthesis of nanocellulose is described where in an anaerobic microbial consortium enriched for cellulase producers is used for hydrolysis. Microcrystalline cellulose derived from cotton fibers was subjected to controlled hydrolysis by the anaerobic microbial consortium and the resultant nanocellulose was purified by differential centrifugation technique. The nanocellulose had a bimodal size distribution (43±13 and 119±9 nm) as revealed by atomic force microscopy. A maximum nanocellulose yield of 12.3% was achieved in a span of 7 days. While the conventional process of nanocellulose preparation using 63.5% (w/w) sulfuric acid resulted in the formation of whisker shaped nanocellulose with surface modified by sulfation, controlled hydrolysis by anaerobic microbial consortium yielded spherical nanocellulose also referred to as nano crystalline cellulose (NCC) without any surface modification as evidenced from Fourier transform infrared spectroscopy. Also, it scores over chemo-mechanical production of nanofibrillated cellulose by consuming less energy due to enzyme (cellulase) assisted catalysis. This implies the scope for use of microbial prepared nanocellulose in drug delivery and bio-medical applications requiring bio-compatibility.
厌氧微生物群落将纤维素降解为要么通过细胞外过程，要么通过细胞外酶的分泌。在这项工作中，描述了一种合成纳米纤维素的新途径，其中使用富含纤维素酶产生菌的厌氧微生物群落进行水解。从棉纤维中得到的微晶纤维素通过厌氧微生物群落的受控水解进行处理，并用差速离心技术对得到的纳米纤维素进行纯化。原子力显微镜显示，纳米纤维素具有双峰尺寸分布（43±13nm 和 119±9nm）。在 7 天的时间内，纳米纤维素的最大产率达到 12.3%。虽然使用 63.5%（w/w）硫酸的传统纳米纤维素制备方法会导致形成表面磺化的须状纳米纤维素，但通过厌氧微生物群落的受控水解可以得到球形纳米纤维素，也称为纳米晶体纤维素（NCC），没有任何表面修饰，这从傅里叶变换红外光谱中可以得到证明。此外，由于酶（纤维素酶）辅助催化，它比化学机械法生产的纳米纤维纤维素消耗更少的能量，因此具有在需要生物相容性的药物输送和生物医学应用中使用微生物制备的纳米纤维素的潜力。
