Diffraction evidence for the structure of cellulose microfibrils in bamboo, a model for grass and cereal celluloses

Background: Cellulose from grasses and cereals makes up much of the potential raw material for biofuel production. It is not clear if cellulose microfibrils from grasses and cereals differ in structure from those of other plants. The structures of the highly oriented cellulose microfibrils in the cell walls of the internodes of the bamboo Pseudosasa amabilis are reported. Strong orientation facilitated the use of a range of scattering techniques. Results: Small-angle neutron scattering provided evidence of extensive aggregation by hydrogen bonding through the hydrophilic edges of the sheets of chains. The microfibrils had a mean centre-to-centre distance of 3.0 nm in the dry state, expanding on hydration. The expansion on hydration suggests that this distance between centres was through the hydrophilic faces of adjacent microfibrils. However in the other direction, perpendicular to the sheets of chains, the mean, disorder-corrected Scherrer dimension from wide-angle X-ray scattering was 3.8 nm. It is possible that this dimension is increased by twinning (crystallographic coalescence) of thinner microfibrils over part of their length, through the hydrophobic faces. The wide-angle scattering data also showed that the microfibrils had a relatively large intersheet d-spacing and small monoclinic angle, features normally considered characteristic of primary-wall cellulose. Conclusions: Bamboo microfibrils have features found in both primary-wall and secondary-wall cellulose, but are crystallographically coalescent to a greater extent than is common in celluloses from other plants. The extensive aggregation and local coalescence of the microfibrils are likely to have parallels in other grass and cereal species and to influence the accessibility of cellulose to degradative enzymes during conversion to liquid biofuel

Bamboo: An Engineered Alternative for for Buildings in the Global South

Bamboo is the only Graminea adapted to the life as forest. Bamboos can be found around the globe and are naturally occurring in Africa, America and Asia in tropical, subtropical and warm temperate areas around the equator. Bamboos are giant grasses that propagate rapidly by the expansion of underground rhizomes. In general, bamboos are known for their rapid growth with a rate of up to 25 cm/day in certain species of woody bamboos such as Guadua angustifolia Kunth (bamboo). Although there are some species of solid bamboos, morphologically bamboo can be generally described as a hollow tapered tube (culm), with internodes separated by nodes, which is supported by an intricate rhizome system (Fig. 15.1). The culm is the main organ of the aerial part of bamboos, which is also comprised of branches, sheaths and foliage leaves, with flowering occurs sporadically. The rhizome and culm neck form the subterranean part. Culms store about 80% of the carbohydrates required by young plants for their growth, whilst rhizomes store the remaining 20%