Production of Cellulose by Bacteria

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Objective(s)

The objective of this Agriculture and Agri-Food Canada (AAFC) project is to determine the feasibility of the energy-efficient, economic production of bacterial cellulose using a novel cellulosic bacterium species. The bacterial isolate and the cellulose it produces will be characterized.

Description

Cellulose, an abundant structural biopolymer forming the main component of plant cell walls, is used in a variety of industrial applications including paper, textile, and fuel production. The bacterial isolate under investigation is one of only two known strains, the other a type strain from the American Type Culture Collection. This project consists of developing a process for bacterial cellulose production, characterizing the isolated bacterium's genome and organization, and constructing DNA probes to isolate additional strains. Cellulose process parameters including most suitable strain and substrate(s), temperature during the preparation of inocula for fermentation, and appropriate cultural practices will be assessed to ensure consistent yields during the production of cellulose. Of particular interest will be to characterize the location of genes implicated in cellulose synthesis, develop strains that do not revert to non-cellulose production phenotype, and further assess the phenotypic stability of additional isolated strains and their ability to produce cellulose. Disparate habitats will be sampled using sensitive techniques including colony hybridization or fluorescent in situ hybridization for the detection of bacterial strains. Specifically, a 16S rRNA-targeted oligonucleotide (short sequence) probe-based method will be used to isolate additional strains of the cellulosic bacterium which will further be characterized by phenotype and genotype. Crystalline structures and the crystallinity index for cellulose produced by the isolate(s) will also be determined using X-ray diffraction patterns and compared with cellulose produced by the species Acetobacter xylinum (currently used in industrial fermentations) in order to assess similarity, crystallinity, and functional properties. Challenges anticipated by this research include the presence of only one additional bacterial strain for reference, the lack of knowledge regarding the ecology of the species, the isolation of additional strains, and reversion of the isolated bacterium and other strains to a cellulose (-) phenotype.

Scanning Electron Micrograph of
Cellulose Produced by the Novel
Bacterial Isolate

Significant Outcomes

Characterization of the isolated bacterial species and the mechanisms underlying cellulose production will provide an increased understanding of the genetic and phenotypic characteristics of the species. This will facilitate the isolation of additional bacterial strains with similar properties and allow for comparison studies with other strains. The development of a process for the production of cellulose from the bacterial isolate will serve as a basis for producing bacterial cellulose efficiently, economically, and with maximum yields on an industrial scale. Furthermore, it will allow for the use of bacterial cellulose as an alternative to plant cellulose leading to the preservation of forest resources.