Engineered yeast as a method for bioremediation

Patent metadata

Field	Value
Publication number	US-2018237321-A1
Application number	US-201815887305-A
Country	US
Kind code	A1
Filing date	Feb 2, 2018
Priority date	Feb 2, 2017
Publication date	Aug 23, 2018
Grant date	—

Abstract

Metal bioremediation and metal mining strategies can include compositions and methods.

First claim

What is claimed is:

1 . A composition for remediating a metal to treat water comprising:
a cell; and a first oligomer of a metal binding protein expressed on a surface of the cell via a linker;
wherein the linker is tethered to the first oligomer of the metal binding protein and to a surface of the cell;
wherein the metal binding protein has specificity for a metal; and
wherein the first oligomer of the metal binding protein expressed on the surface of the cell is capable of aggregating with a second oligomer of the metal binding protein in the water upon binding a metal.

2 . The composition of claim 1 , wherein the cell is yeast.

3 . The composition of claim 1 , wherein the linker is a monomer of the metal binding protein.

4 . The composition of claim 1 , wherein the second oligomer of the metal binding protein is secreted from the cell.

5 . The composition of claim 1 , wherein the metal is a divalent metal.

6 . The composition of claim 1 , wherein the metal is a transition metal.

7 . The composition of claim 1 , wherein the metal is nickel, iron, copper, cobalt, lead, cadmium or mercury.

8 . The composition of claim 1 , wherein the metal binding protein is glutamine synthetase.

9 . The composition of claim 1 , wherein the metal binding protein is fused with a high affinity protein including a metal binding domain, wherein the metal binding domain has specificity for the metal.

10 . The composition of claim 9 , wherein the high affinity protein is a plant metallothionein.

11 . The composition of claim 2 , wherein the metal binding protein is expressed in a yeast host strain.

12 . A method of remediating a metal to treat water comprising:
preparing a composition comprising:
a cell; and
a first oligomer of a metal binding protein expressed on a surface of the cell via a linker;
wherein the linker is tethered to the first oligomer of the metal binding protein and to a surface of the cell;
wherein the metal binding protein has specificity for a metal; and
wherein the first oligomer of the metal binding protein expressed on the surface of the cell is capable of aggregating with a second oligomer of the metal binding protein in the water upon binding a metal; and

contacting water with the composition.

13 . The method of claim 12 , further comprising adding the second oligomer of the metal binding protein in the water.

14 . The method of claim 12 , wherein the cell is yeast.

15 . The method of claim 12 , wherein the linker is a monomer of the metal binding protein.

16 . The method n of claim 13 , wherein the second oligomer of the metal binding protein is secreted from the cell.

17 . The method of claim 12 , wherein the metal is a divalent metal.

18 . The method of claim 12 , wherein the metal is nickel, iron, copper, cobalt, lead, cadmium or mercury.

19 . The method of claim 12 , wherein the metal binding protein is glutamine synthetase.

20 . The method of claim 12 , wherein the metal binding protein is fused with a high affinity protein including a metal binding domain, wherein the metal binding domain has specificity for the metal.

21 . The method of claim 20 , wherein the high affinity protein is a plant metallothionein.

22 . The method of claim 12 , wherein the second oligomer of the metal binding protein is secreted from the cell via a signal peptide.

23 . The method of claim 22 , wherein the signal peptide is S. cerevisiae 's α-mating-factor.

24 . The method of claim 22 , wherein the signal peptide is AGA1/2 or EXG1.

25 . The method of claim 12 , wherein the method is performed at 20° C. or lower temperature.

26 . The method of claim 12 , wherein the metal binding protein is expressed in a yeast host strain.

27 . The method of claim 26 , wherein the yeast host strain is Pichia Pastoris.

28 . A method of making a composition for remediating a metal to treat water comprising:
selecting a cell; expressing a metal binding protein on a surface of the cell; and tethering a first oligomer of a metal binding protein expressed on a surface of the cell via a linker;
wherein the linker is tethered to the first oligomer of the metal binding protein and to a surface of the cell;
wherein the metal binding protein has specificity for a metal; and
wherein the first oligomer of the metal binding protein expressed on the surface of the cell is capable of aggregating with a second oligomer of the metal binding protein in the water upon binding a metal.

29 . A method of mining a metal comprising:
preparing a composition comprising:
a cell; and
a first oligomer of a metal binding protein expressed on a surface of the cell via a linker;
wherein the linker is tethered to the first oligomer of the metal binding protein and to a surface of the cell;
wherein the metal binding protein has specificity for a metal; and
wherein the first oligomer of the metal binding protein expressed on the surface of the cell is capable of aggregating with a second oligomer of the metal binding protein in the water upon binding a metal;
contacting water with the composition; and lysing the cell to obtain the metal.

30 . The method of claim 29 , wherein the metal is a noble metal.

31 . The method of claim 30 , wherein the noble metal is gold, silver or platinum.

32 . The method of claim 29 , wherein the metal is a rare-earth metal.

33 . The method of claim 32 , wherein the rare-earth metal is cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu), neodymium (Nd), praseodymium (Pr), promethium (Pm), samarium (Sm), scandium (Sc), terbium (Tb), thulium (Tm), ytterbium (Yb) or yttrium (Y).

34 . A composition for remediating a metal to treat water comprising:
a cell expressing
a membrane metal transporter, wherein the membrane metal transporter has specificity for a metal;
a vacuole transporter; and
a metal sequestration protein.

35 . The composition of claim 34 , wherein the cell is yeast.

36 . The composition of claim 35 , wherein an ubiquitination ligase is deleted in the yeast.

37 . The composition of claim 35 , wherein the ubiquitination ligase is BSD2.

38 . The composition of claim 34 , wherein the membrane transporter is SMF1.

39 . The composition of claim 34 , wherein the vacuole transporter is CCC1.

40 . The composition of claim 34 , wherein the metal sequestration protein is a phytochelatin synthase.

41 . The composition of claim 38 , wherein SMF1 is mutated to be sensitive to the metal.

42 . The composition of claim 41 , wherein the metal is strontium, lead or mercury.

43 . The composition of claim 38 , wherein SMF1 is mutated to destroy primary ubiquitination sites.

44 . The composition of claim 34 , wherein the membrane transporter is Sul1 or Sul2.

45 . The composition of claim 44 , wherein the metal is chromate.

46 . The composition of claim 34 , wherein the membrane transporter is CTR1.

47 . The c

Assignees

• Massachusetts Inst Technology

Inventors

• Sun George Le-Le
• Belcher Angela M

Classifications

• C07K14/825

  Metallothioneins · CPC title

• C02F2101/203

  Iron or iron compound · CPC title

• E21C41/14

  Fixed Constructions · mapped topic

• C02F3/342 Primary

  characterised by the enzymes used · CPC title

• E21C41/32 Primary

  Reclamation of surface-mined areas (machines or methods for treating or working soil for agricultural purposes A01B77/00, A01B79/00; machines for back-filling E02F5/22) · CPC title