MODELING THE CORE METABOLISM OF Komagataeibacter hansenii ATCC 23769 TO EVALUATE NANOCELLULOSE BIOSYNTHESIS

Samara Silva De Souza,Julia De Vasconcellos Castro,Luismar Marques Porto

doi:10.1590/0104-6632.20180353s20170327

Samara Silva De Souza, Julia De Vasconcellos Castro + Show 1 more

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https://doi.org/10.1590/0104-6632.20180353s20170327

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Abstract

Abstract Genome-scale metabolic models based on a combination of genome sequence and biochemical information have strongly influenced the field of systems biology. However, basic principles of the operation of metabolic networks, in particular the central metabolism can be easily studied in smaller metabolic (core) models. Komagataeibacter hansenii ATCC 23769 has been used for bacterial nanocellulose (BNC) biosynthesis, and the recent availability of its genome sequence allowed the development of a metabolic model. The core metabolic model was constructed from an initial draft metabolic reconstruction including 74 reactions and 68 metabolites that provides insights for a better understanding of K. hansenii metabolic pathways. The applicability of the model is finally demonstrated by applying the FBA approach, and the in silico simulation successfully predicted the minimal medium and the growing abilities on different substrates. This core model can facilitate system-level metabolic analysis as well as developments for improving BNC production.

Highlights

Metabolic models have a promising ability to describe cellular phenotypes accurately and to relate the annotated genome sequence to the physiological functions of a cell (Covert et al, 2001; Kim et al, 2015)
We evaluated four scenarios for biologically meaningful predictions: (i) maximization of biomass yield; (ii) maximization of nanocellulose synthesis, product of greatest interest derived from the bacterium K. hansenii; (iii) the maximization of the external metabolites to evaluate the balance consistency; and (iv) the ability to synthesize precursors of biomass by adding demand reactions
By using Flux Balance Analysis (FBA), we investigated the core metabolic network of K. hansenii through simulations

Summary

Introduction

Metabolic models have a promising ability to describe cellular phenotypes accurately and to relate the annotated genome sequence to the physiological functions of a cell (Covert et al, 2001; Kim et al, 2015). Metabolic models are based on a network of chemical reactions that characterize the vast metabolic network of an organism (Almaas et al, 2004; Shimizu, 2009; Wiechert, 2002). A comprehensive protocol was developed to describe each step necessary to build a high-quality genome-scale metabolic reconstruction (Thiele and Palsson, 2010). This protocol was properly structured for large-scale metabolic networks and well-studied organisms when several experimental evidences are available to allow the required significant manual curation (Becker et al, 2007; Cheng et al, 2009).

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