Synechococcus engineering bacterium capable of improving yield of cellulose, and preparation method and application thereof

Abstract

The invention discloses a synechococcus engineering bacterium and a preparation method and application thereof. The synechococcus engineering bacterium is a cesA gene-deficient Synechococcus sp. PCC 7002 mutant; the plasmid or genome of the mutant is integrated with 7 cellulose synthesis related genes (cmcase, ccp, acsA, acsB, acsC, acsD and bglxA) of Gluconacetobacter xylinum ATCC 53582; and the7 genes are started and expressed by a promoter PcpcBA of a cpcBA gene of Synechococcus sp. PCC 7002 or Synechocystis sp. PCC6803. The cellulose content of the engineering bacterium accounts for about 13% of the dry weight of the cell wall; and simultaneously, the cellulose produced by the synechococcus engineering bacterium has a short growth cycle and does not have the pollution problem of lignin in wood, the extraction and purification processes can be greatly simplified, and the degree of pollution to the environment can also be greatly reduced correspondingly, thus the synechococcus engineering bacterium is an ideal biological engineering bacterium for producing cellulose and is further used as a raw material for producing biological ethanol.

Description

technical field [0001] The invention belongs to the field of biotechnology, and in particular relates to a cyanobacteria engineering bacterium with high cellulose production and its preparation method and application. Background technique [0002] Affected by the energy crisis in recent years, countries all over the world are actively exploring various forms of new energy to replace limited fossil energy (coal, oil, natural gas). As a representative of new energy, bioenergy is playing an increasingly important role. At present, bioenergy mainly includes three categories: bioethanol, biodiesel, and biogas. Ethanol is not only an important chemical raw material, but also a highly efficient and low-pollution alternative energy source for petroleum, so its importance is self-evident. Existing ethanol production platforms mainly rely on the fermentation and decomposition of starch and sugar substances, as well as cellulosic materials such as corn stalks and wheat straw. For ex...

AI Technical Summary

Problems solved by technology

However, the high cost of cultivating Acetobacter xylinum and the pollution of the environment by secondary metabolites and waste produced during the growth process make it unsuitable for large-scale cultivation and production

If you simply use the cellulose it secretes to degrade into ethanol as an energy source, it will require a higher price

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