Microalga having aggregation ability

Patent metadata

Field	Value
Publication number	US-10745718-B2
Application number	US-201716309220-A
Country	US
Kind code	B2
Filing date	Apr 21, 2017
Priority date	Jun 17, 2016
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

In ethyl alcohol production using the self-fermentation of a microalga, a step of concentrating or collecting an algal body by centrifugal treatment, filtering treatment or the like is made unnecessary or simple to save labor for effort and equipment therefor is saved. The microalga belongs to Chlamydomonas sp., and is a variant strain which has an ability to produce ethyl alcohol under dark and anaerobic conditions and has acquired an ability to proliferate while aggregating. The microalga is proliferated and maintained under dark and anaerobic conditions to generate ethyl alcohol in this method for producing ethyl alcohol.

First claim

The invention claimed is:

1. A microalga belonging to Chlamydomonas reinhardtii , wherein the microalga is a variant strain of Chlamydomonas reinhardtii , which has an ability to produce ethyl alcohol under dark and anaerobic conditions and has an ability to proliferate while aggregating, wherein the variant strain of Chlamydomonas reinhardtii is acquired by a method comprising exposing Chlamydomonas reinhardtii to a growth environment comprising a combination of a dark condition of 0 to 5 μmol/m 2 ·sec and at least one of a condition of exhaustion of essential nutrient sources and an air-tight condition, wherein the microalga is a Honda DREAMO strain (accession number FERM BP-22306) which has an ability to produce ethyl alcohol under dark and anaerobic conditions and to proliferate while aggregating.

2. A method for producing ethyl alcohol, wherein the microalga according to claim 1 is proliferated and maintained under dark and anaerobic conditions to generate ethyl alcohol.

3. The method for producing ethyl alcohol according to claim 2 , wherein the microalga is proliferated in a container containing a liquid medium to obtain an algal body aggregate in which algal bodies proliferate while aggregating or an algal body aggregate in which algal bodies are aggregated by spontaneous sedimentation after proliferation, and the algal body aggregate is maintained under dark and anaerobic conditions to generate ethyl alcohol.

4. The method for producing ethyl alcohol according to claim 3 , wherein accumulation of starch in cells of the alga is recovered, and then the algal body aggregate after the generation of ethyl alcohol is further maintained under dark and anaerobic conditions to generate ethyl alcohol.

5. The method for producing ethyl alcohol according to claim 2 , wherein the microalga is proliferated with a liquid medium in contact with the microalga carried by a carrier to obtain an algal body aggregate in which algal bodies proliferate while aggregating on the carrier, and the algal body aggregate is maintained under dark and anaerobic conditions to generate ethyl alcohol.

6. The method for producing ethyl alcohol according to claim 5 , wherein accumulation of starch in cells of the alga is recovered, and then the algal body aggregate after the generation of ethyl alcohol is further maintained under dark and anaerobic conditions to generate ethyl alcohol.

Assignees

• Honda Motor Co Ltd

Inventors

• Shiobara Nozomi
• Kinoshita Shohei

Classifications

• Y02E50/10

  Biofuels, e.g. bio-diesel · CPC title

• Y02P20/133

  Renewable energy sources, e.g. sunlight · CPC title

• C12R2001/89

  Algae {; Processes using algae} · CPC title

• C12N1/125

  Unicellular algae isolates · CPC title

• Y02P20/59

  Biological synthesis; Biological purification · CPC title