Modified microorganism having enhanced biomass synthesis capacity and a method thereof

Patent metadata

Field	Value
Publication number	US-9902963-B2
Application number	US-201515111554-A
Country	US
Kind code	B2
Filing date	Feb 4, 2015
Priority date	Feb 5, 2014
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

The present disclosure provides a modified microorganism having an enhanced biomass synthesis capacity. The present disclosure also relates to a method for manufacturing a modified microorganism having an enhanced biomass synthesis capacity. The enhanced biomass synthesis capacity is due to the overexpression of the gene capable of inducing DNA repair mechanism. The gene responsible for the DNA repair is overexpressed when DNA damage is most and DNA repair mechanism is required.

First claim

The invention claimed is:

1. A method for enhancing biomass synthesis capacity in a microorganism, said method characterized by the following steps:
a. synthesizing a gene encoding a protein capable of inducing DNA repair;

wherein said gene is a yeast RAD52 gene encoding Rad52 protein, selected from the group consisting of native yeast RAD52 gene and recombinant yeast RAD52 gene;
b. cloning said synthesized gene along with a promoter capable of regulating the expression of said gene in DNA damaging conditions in an expression vector;
c. introducing said expression vector comprising said gene and said promoter into the microorganism;
d. growing said microorganism in a medium containing a selective agent; and
e. exposing said microorganism to stress to facilitate overexpression of said gene and obtaining the microorganism with enhanced biomass synthesis capacity.

2. The method of claim 1 , wherein said yeast is Saccharomyces cerevisiae and wherein the yeast RAD52 gene is a codon optimized gene with Sequence ID No. 1.

3. The method of claim 1 , wherein said microorganism in step (c) is selected from the group comprising prokaryotes and eukaryotes, preferably a photosynthetic microorganism.

4. The method of claim 1 , wherein said microorganism is an alga, selected from the group comprising Dunaliella, Chlorella, Nannochloropsis and Chlamydomonas.

5. The method of claim 1 , wherein said promoter is at least one light inducible promoter selected from the group comprising Dunaliella, Synechococcus elongatus PCC 7942 and rbcS promoter.

6. The method of claim 1 , wherein said expression vector is pChlamy_1.

7. The method of claim 1 , wherein said selective agent in the medium is at least one compound selected from the group comprising antibiotic compound, antifungal compound and toxic compound.

8. The method of claim 1 , wherein said antibiotic compound is at least one selected from the group consisting of zeocin, kanamycin, chloramphenicol and hygromycin.

9. The method of claim 1 , wherein in step (e), said microorganism is exposed to at least one stress selected from the group comprising ultraviolet radiation (UV), salinity, light, unfavorable temperature, alkalinity, nutrient limitation, oxidative stress, senescence, sulfur deficiency, carbon deficiency, nitrogen use inefficiency, virus, bacteria and fungus.

10. A method for manufacturing a modified microorganism having enhanced biomass synthesis capacity, said method comprising by the following steps:
a. synthesizing a gene encoding a protein capable of inducing DNA repair;

wherein said gene is a yeast RAD52 gene encoding Rad52 protein, selected from the group consisting of native yeast RAD52 gene and recombinant yeast RAD52 gene;
b. cloning said synthesized gene along with a promoter capable of regulating the expression of said gene in DNA damaging conditions in an expression vector;
c. introducing said expression vector comprising said gene and said promoter into the microorganism;
d. growing said microorganism on a medium containing a selective agent; and
e. exposing said microorganism to stress to facilitate overexpression of said gene to obtain the microorganism having enhanced biomass synthesis capacity,

wherein, the biomass synthesized by the modified microorganism is increased relative to the unmodified microorganism.

11. A method for increasing algal biomass; said method comprising the following steps:
a. synthesizing a gene encoding a protein capable of inducing DNA repair;

wherein said gene is a yeast RAD52 gene encoding Rad52 protein, selected from the group consisting of native yeast RAD52 gene and recombinant yeast RAD52 gene;
b. cloning said synthesized gene along with a promoter capable of regulating the expression of said gene in DNA damaging conditions in an expression vector;
c. introducing said expression vector comprising said gene and said promoter into an alga
d. growing said alga in a medium containing a selective agent; and
e. exposing said alga to stress to facilitate overexpression of said gene to obtain enhanced algal biomass.

12. A modified microorganism manufactured by the process claimed in claim 10 .

13. A modified strain of Chlamydomonas reinhardtii CC125-45-03 having CCAP Accession Number 11/172.

14. The method of claim 8 , wherein the antibiotic compound comprises hygromycin.

Assignees

• Reliance Industries Ltd

Inventors

• Prasad Venkatesh
• Kumar Raja
• Das Gautam
• Dasgupta Santanu

Classifications

• C12N15/79

  Vectors or expression systems specially adapted for eukaryotic hosts · CPC title

• C07K14/395 Primary

  from Saccharomyces · CPC title

• C12N15/67 Primary

  General methods for enhancing the expression · CPC title

• C12N1/12

  Unicellular algae; Culture media therefor (as new plants A01H13/00) · CPC title