DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.
Remarks
The amendments and remarks filed on 07/28/2026 have been entered and considered. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. The rejections and/or objections presented herein are the only rejections and/or objections currently outstanding. Any previously presented objections or rejections that are not presented in this Office Action are withdrawn.
Claims 143-145, 147-149, and 151-172 are pending.
Claims 143-145, 147-149, and 151-154 are amended.
Claims 146 and 150 are canceled.
Claims 165, 168, and 170 are withdrawn.
Claims 143-145, 147-149, 151-164, 166-167, 169 and 171-172 have been examined on the merits.
Priority
This application, U.S. Application No. 18982877, is a continuation of International Application Number PCT/US2023/068612, filed on 06/16/2023, which claims priority under 35 U.S.C. 119(e) from U.S. Provisional Application No. 63352672 filed on 06/16/2022.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 07/28/2026 is acknowledged. The submission is in compliance with the provisions of 37 CFR 1.97., and has been considered by the examiner.
Objections - Withdrawn
Objection to the claim 146 is withdrawn due to the cancellation of the claim filed on 07/28/2026.
Rejections - Withdrawn
The rejection of Claims 147 and 151 under 35 U.S.C. 112(b) is withdrawn due to the amendment to the claims filed on 07/28/2026.
The rejection of Claims 143-145, 147-149, 151-164, 166-167, 169, and 171-172 under 35 U.S.C. 112(a) as failing to comply with the enablement requirement, is withdrawn due to the amendment to the claims filed on 07/28/2026 as well as Examiner’s reconsideration.
Claim Interpretation
Claim 169 recites the symbol “
PNG
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36
30
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Greyscale
” in the structure of the peptide (connected to the NH- group of His) in the claim. According to Applicant’s arguments in the response filed on 12/03/2025 (page 11, para 3), the recited symbol is interpreted as any unspecified part (molecule or atom).
Claim Rejections - 35 USC § 103
Claims 143-145, 147, 149, 151-160 and 172 are rejected under 35 U.S.C. 103 as being unpatentable over Gunasekara et al. (US 2024/0254591, 2024, effective filing date: May 12, 2021, of record) in view of Tzeferis et al. (Hydrometallurgy, 1994, 36(3): 345-360, the full-length publication is attached).
Gunasekara et al. teach a process for recovering trace metal from a metal oxide-containing starting material, i.e. a metallic ore (reading on the “oxide ore” in claim 143) by utilizing metal-oxide reducing bacteria to reduce metal oxides in the ore, wherein the metal oxides comprise iron oxides (abstract, claim 8). The process of Gunasekara et al. comprises the steps: (a) contacting/combining the metallic ore with the metal-oxide reducing bacteria and an aqueous medium/phase comprising substrate mixture to form a mixture; (b) maintaining the mixture for a period of time under suitable condition to reduce the metal oxide and convert at least a portion of the metal oxide to a water-soluble metal salt, and releasing (solubilizing) at least a portion of trace metal in the ore into the aqueous medium; and (c) separating/isolating the aqueous medium, and recovering the trace metal from the aqueous medium (abstract, paras 0006, 0012-14, 0022-0026, examples 1-2, Claim 1, Fig. 2); wherein the metal oxide comprises iron oxide (e.g. FeOOH, Fe(OH)3 or Fe2O3) and/or manganese oxide, and the metal-oxide reducing bacteria are preferably from Shewanellaceae and/or Geobacteraceae, which reduce the iron oxide (i.e. ferric iron) and manganese oxide into a soluble-form iron [i.e. ferrous iron Fe(II)] and a soluble-form manganese Mn(II), which are then combined with chloride ion Cl⁻ (i.e. a ligand that binds the metal) to form an water-soluble iron chloride (FeCl2) or manganese chloride (MnCl2) (abstract, Claims 3-6 and 8-9, paras 0020/lines 6-10, 0025, 0027/lines 7-8, 0030, 0032, 0076-78, 0081, 0113); wherein the mixture (the aqueous medium) comprises a substrate mixture comprising a lactate substrate, a combination of lactate and glucose, or an acetate substrate (reading on the reducing agent in claims 143 and 151) (paras 0113/lines 10-12, 0115/page 8/last 6 lines, and 0039); wherein the trace metal preferably is nickel and cobalt (para 0042/last 2 lines); wherein the metal-oxide starting material (metallic ore) is an laterite ore (para 0045) (reading the laterite ore in claim 152); and wherein the metal-oxide reducing bacteria from Shewanellaceae are preferably Shewanella oneidensis MR-1, S. putrefaciens CN-32, or S. loihica PV-4 (reading on the Shewanella species and specific Shewanella strains recited in the claims 147 and 149) (Table 1, paras 0029 and 0030), and the metal-oxide reducing bacteria from Geobacteraceae are preferably Geobacter sulfurreducens PCA or G. metalliresucens GS-15 (Table 2, paras 0031-32). Overall, Gunasekara et al. teach a mixture formed in the step (a), comprising: at least one metal-oxide reducing bacterium (capable of reducing iron), an oxide ore (comprising iron oxides), a substrate mixture (including a reducing agent of lactate, glucose and/or acetate substrate contained in the aqueous medium), a ligand (binding metals in the aqueous medium, see page 8, last 6 lines), and an aqueous phase, which either meet the limitations or are comparable to the mixture components in the step (a) of claim 143. Gunasekara et al. further teach that bio-extraction is carried out in the aqueous medium at a neutral pH ranged from not less than about 5 to not greater than about 9 or 7.5 (para 0087). Regarding the limitation about reducing ferric iron in the ore to ferrous iron, and solubilizing iron, nickel, cobalt, and manganese in an aqueous phase recited in the step (b) of the claim 143, Gunasekara et al. teach reducing ferric iron in the ore to ferrous iron and solubilizing iron, manganese, and trace metal in an aqueous phase, and specifically teach nickel and cobalt are preferred trace metal in their method. Thus, it would have been obvious to solubilize iron, manganese, nickel, and cobalt in the aqueous phase in the method of Gunasekara et al. for recovering nickel, cobalt, and/or manganese.
Gunasekara et al. do not expressively teach that the ligand comprises an organic acid, specifically citric acid, as required by the claims 143, 157, and/or 172.
Tzeferis et al. teach a microbial leaching process for investigating ability of organic acids to solubilize nickel and iron from Greek laterite by, and they reveal that citric acid is the most effective organic acid for nickel extraction from laterites, achieving recoveries of nickel to 60% (abstract, page 357/lines 8-9). Leaching results of Tzeferis et al. demonstrate that citric acid is highly effective at solubilizing both nickel and iron from laterite ore and superior to all other organic acids; specifically, nickel recovery rates with pulp density at 10% and 5% are 34% in one day and 47.23% in 3 days respectively; and even under mild leaching conditions (0.5 M, 30oC) similar to those prevailing during microbial leaching, a nickel recovery rate with pulp density at 10% still reaches a level of 57.5% at Day 40 (see Table 6). Tzeferis et al. further recommend using citric acid for extracting nickel from laterites under the mild conditions of microbial leaching because citric acid can be equally effective or even better than sulphuric acid over longer periods (40-50 d), although citric acid requires more time for effective leaching than equimolar sulphuric acid (page 357/para 2/lines 1-4). Furthermore, Tzeferis et al. teach that leaching by citric acid is accomplished mainly by a complex formation (i.e. forming a complex between metal ions and citric anions), and the formation of the complex occurs at pH 6 and also a pH range of 1.9-4.9 (page 350/para 1/lines 4-6, page 357/para 4/lines 2-5). Tzeferis et al. further teach that citric acid performs better than sulphuric acid for extracting/solubilizing nickel from laterite ore (Kastoria) at the higher pH range (1.9-4.9), while sulphuric acid ceases leaching of the same ore when pH is at a level above 2.0 (page 357/ para 4/lines 3-8 and para 2/lines 1-4, page 350/lines 3-4). Moreover, Tzeferis et al. teach that microbial leaching involves microorganisms and their metabolic products and it has advantages such as lower energy requirements and being more flexible, selective, and less hazardous to the environment compared to conventional leaching processes (page 345/last 5 lines); and Tzeferis et al. specifically indicate that citric acid is a metabolic product of microorganisms (fungus) (page 357, para 2/line 1).
It would have been obvious to one of ordinary skill in the art to modify the microbial leaching process of Gunasekara et al. by further including an organic acid ligand, specifically citric acid, in the mixture/aqueous medium of step (a) for increasing solubilization of metals (e.g. nickel) from laterite ore, thus improving production of the soluble trace metals (e.g. nickel). One of ordinary skill in the art would have been motivated to do so, because it is well known in the art that citric acid improves solubility of metals (e.g. nickel and iron) from oxide ore, specifically laterite ore, and it is the most effective organic acid for nickel extraction from the laterite ore when compared to other organic acids, as supported by Tzeferis et al. In addition, Tzeferis et al. teach that citric acid is effective at leaching/solubilizing nickel under mild leaching conditions similar to those of microbial leaching processes; and although it requires more time for effective leaching than inorganic acid/sulphuric acid, the leaching activity of citric acid can be equally effective or even better than that of sulphuric acid over longer periods. Furthermore, it is well known in the art that a microbial process involved with microorganisms and their metabolites (e.g. citric acid) for leaching ore has the advantages such as lower energy requirements and being more environmentally friendly, flexible, and selective, as supported by Tzeferis et al. One of ordinary skill in the art has a reasonable expectation of success at modifying the method of Gunasekara et al. for improving solubilization of nickel from laterite ore, because both the method of Gunasekara et al. and the method of Tzeferis et al. are directed to leaching nickel from the laterite ore, thus the teachings of Tzeferis about using citric acid as leaching agent for solubilizing nickel are readily applicable to the method of Gunasekara et al. In addition, the method of Gunasekara et al. already solubilizes nickel from the laterite ore, and the addition of citric acid as a leaching agent to the leaching reaction of Gunasekara et al. is expected to further improve solubility of nickel from the laterite ore in view of the fact that citric acid forms a complex with nickel metal, which leads to solubilizing the metal from the ore.
Regarding the pH range recited in Claims 143 and 158, Gunasekara et al. teach that bio-extraction is carried out in the aqueous medium at a neutral pH ranged from not less than about 5 to not greater than about 9 or 7.5. Tzeferis teaches citric acid functions effectively in a pH range of 1.9-4.9 and at pH 6 for forming a complex with and solubilizing nickel, while inorganic acid/sulphuric acid does not leach nickel at pH above 2. The low end of the pH range of 1.9-4.9, e.g. 4.9, as well as pH 6 taught by Tzeferis fall into the pH range of about 5 to about 9 used in the method of Gunasekara. Thus, it would have been obvious to maintain the pH of the mixture and the aqueous phase in the steps (a) and (b) in a range from about 5 to about 9 in the method suggested by Gunasekara et al. and Tzeferis et al. for leaching nickel metal and recovering the metal from ores.
Regarding Claim 144, Gunasekara et al. teach an order of adding the microorganism cells to a suspension of the iron oxide ore (para 0113/lines 8-12), and Gunasekara et al. also teach the iron oxide ore is comprised in M1 aqueous medium, the medium comprising a ligand; a substrate mixture (such as lactate or lactase plus glucose); and an aqueous phase (para 0115: page 8/last 6 lines, page 9/lines 3-4). Thus, it would have been obvious to add the microorganism cells to a suspension/slurry comprising the iron oxide ore, ligand, substrate mixture, and aqueous phase in the method suggested by Gunasekara et al. and Tzeferis et al.
Regarding the claim 145, Gunasekara et al. are silent about whether the bacteria are derived from the ore. However, how the microorganisms are obtained (derived from) is directed to a process of producing the microorganisms. The claimed microorganisms are not limited to the manipulation process of obtaining (deriving) them from ores, only to the structure implied by the manipulation process. Gunasekara et al. teach the iron-oxide reducing bacteria having all the claimed structures (including specific bacteria recited in the dependent claims 147 and 149). In addition, the bacteria of Gunasekara et al. have the same function as those microorganisms in the claimed method with regard to reducing ferric iron and solubilizing ferrous iron, nickel, cobalt, and manganese. Thus, the teachings of Gunasekara et al. meet the additional limitation in the claim 145, in the absence of evidence to the contrary. See MPEP 2113.
Regarding Claim 153, Gunasekara et al. teach that iron in the ore can be 20% by weight or higher (para 0048, last 3 lines), thus rendering the claim to be obvious.
Regarding Claim 154, Gunasekara et al. teach that the ore comprises nickel at an amount of about 1% to about 2%, or about 1-1.5% (paras 0045/lines 2-4, 0047/last 2 lines), thus rendering the claim to be obvious.
Regarding Claim 156, Gunasekara et al. teach that the ore comprises cobalt at an amount of about 0.2-0.25% (para 0047/line 6), thus rendering the claim to be obvious.
Regarding Claim 155, Gunasekara et al. teach that the ore is associated with manganese, as indicated above. Gunasekara et al. further teach that the ore comprises the metal oxide comprising iron oxide, e.g. FeOOH, Fe(OH)3 or Fe2O3 (paras 0027/lines 7-8, 0076/lines 6-8). Thus, the ore of Gunasekara et al. is associated with ferric iron minerals, and ferric iron (oxy)hydroxide.
Regarding Claim 159, Gunasekara et al. teach that the reduction of the iron oxide is carried out under anaerobic (i.e. anoxic) or microaerobic condition (paras 0115/page 9/lines 8-10, 0029/last 5 lines).
Regarding Claim 160, the limitations about releasing specific amounts of trace metals (nickel and cobalt) recited in the claim are directed to the outcome, rather than steps of the claimed method, i.e. the claim is directed to what the method does, not to what the method is. The method suggested by Gunasekara et al. and Tzeferis et al. comprises all the steps recited in the claim. In the absence of evidence to the contrary, it is presumed that methods having substantially the same steps are capable of generating the same outcome. Furthermore, Gunasekara et al. teach an amount from at least about 10% to at least about 95% by weight of the trace metal in the ore is released into the aqueous medium (para 0083); and Tzeferis et al. teach recovering up to 60% nickel from the ore. Thus, combined teachings of Gunasekara et al. and Tzeferis et al. render the claim to be obvious.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention.
Claims 143-145, 147, 149, 151-161 and 172 are rejected under 35 U.S.C. 103 as being unpatentable over Gunasekara et al. (US 2024/0254591, 2024, effective filing date: May 12, 2021, of record) over Tzeferis et al. (Hydrometallurgy, 1994, 36(3): 345-360), as applied to Claims 143-145, 147, 149, 151-160 and 172, further in view of Hallberg et al. (Minerals Engineering, 2011, 24: 620–624, cited in IDS).
The teachings of Gunasekara et al. and Tzeferis et al. are described above.
Regarding Claim 161, Gunasekara et al. and Tzeferis et al. do not expressively teach that the aqueous phase of step (c) is isolated from the mixture by sedimentation of solids.
It would have been obvious to separate or isolate the aqueous solution (aqueous phase) from the mixture by sedimentation of solids and decantation of aqueous liquid phase in the method suggested by Gunasekara et al. and Tzeferis et al. for recovering a leach solution containing nickel and/or cobalt, because it is a common practice in the art to carry out solid-liquid separation through sedimentation of solids, as supported by Hallberg et al., who teach a leaching process for recovering nickel from a laterite ore, (title and abstract), comprising steps of combining an iron-reducing acidophilic bacterium with a substrate mixture comprising sulfur element and citric acid in a aqueous phase/medium; maintaining the mixture to reduce ferric iron in the ore and solubilize ferrous iron, nickel, cobalt, and manganese in the aqueous phase; and separating the aqueous phase of dissolved nickel from the mixture (page 621: methodology sections 2.1 – 2.4, and left col/para 1/line 7- para 2/last line; page 622: section 3.2/lines 1-3; Fig. 2); wherein the remaining undissolved laterite ore is separated by sedimentation (page 621, right col., para 2, line 10).
It is noted that the teachings of Hallberg et al. about contents of iron, nickel, manganese, and cobalt in the ore (see page 621: left col/para 3/lines 1-9; and page 620: right col/lines 1-4) also meet the limitations in the claims 153-156.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention.
Claims 143-145, 147-149, 151-160 and 172 are rejected under 35 U.S.C. 103 as being unpatentable over Gunasekara et al. (US 2024/0254591, 2024, effective filing date: May 12, 2021, of record) over Tzeferis et al. (Hydrometallurgy, 1994, 36(3): 345-360), as applied to Claims 143-145, 147, 149, 151-160 and 172, further in view of Michelson et al. (Environ. Sci. Technol. 2019, 53:3480−3487, of record).
The teachings of Gunasekara et al. and Tzeferis et al. are described above.
Regarding Claim 148, Gunasekara et al. and Tzeferis et al. do not teach the mixture formed in the step (a) comprises an electron shuttle, specifically a flavin. However, Gunasekara et al. further teach that Shewanella bacteria have the ability, through a process called extracellular electron transport (EET), to reduce insoluble iron oxide and they utilize oxidized iron for cellular respiration (in the absence of oxygen) to convert the insoluble iron oxides to soluble metals (e.g., FeCl2) (first half of para 0020).
It would have been obvious to one of ordinary skill in the art to further include a flavin, as an electron shuttle in the EET process, in the mixture/aqueous medium of step (a) in the method suggested by Gunasekara et al. and Tzeferis et al. for facilitating reduction of insoluble iron oxide by Shewanella bacteria (e.g. S. oneidensis MR-1), thus enhancing production of the soluble trace metals, because it is well known in the art that flavin is an important electron shuttle in the EET process, which delivers electron from Shewanella bacteria to insoluble iron oxide for promoting the reduction of iron oxide to soluble metal and generating ATP. In support, Michelson et al. teach that bacteria have evolved mechanisms for transport of respiratory electrons to the outer membrane in a process defined as extracellular electron transport (EET); Shewanella bacteria use a strategy of electron shuttling via redox mediator flavins to generate ATP through reduction of insoluble electron acceptors such as Fe(III) (i.e. ferric iron) to ferrous iron; and electron shuttling of flavins is a dominant pathway for metal oxide reduction by the species S. oneidensis MR-1; and once being reduced, the reduced flavins may transfer electrons as shuttles to a metal oxide (page 3480: left col/lines 7-13, right col/lines 2 and 5 lines; page 3481: left col/lines 1-4). Michelson et al. demonstrate that flavin electron shuttle allows electrons generated from lactate oxidation in S. oneidensis MR-1 to be shuttled to metal oxides (as a physical distant electron acceptor) without direct physical contact between S. oneidensis MR-1 and the metal oxide (abstract, lines 6-9 and 15-16).
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention.
Claims 143-145, 147, 149, 151-160, 162-164, 166-167, 169 and 172 are rejected under 35 U.S.C. 103 as being unpatentable over Gunasekara et al. (US 2024/0254591, 2024, effective filing date: May 12, 2021, of record) over Tzeferis et al. (Hydrometallurgy, 1994, 36(3): 345-360), as applied to Claims 143-145, 147, 149, 151-160 and 172, further in view of Duyvesteyn et al. (US Patent No. 5626648, cited in IDS), Bertuol et al. (Chem. Eng. Technol. 2012, 35(12): 2084–2092, of record), Hay et al. (Journal of Inorganic Biochemistry, 1993, 52:17-25, of record), Hyeung et al. (KR 20090097704 A, 2009, machine-translated English version is of record), and Byrd et al. (US 2006/0030007, 2006, of record), as evidenced by Wołowicz et al. (Chemical Engineering Journal, 2012, 197:493–508, of record) and Luo et al. (US Patent No: 6365147, 2002, of record).
The teachings of Gunasekara et al. and Tzeferis et al. are described above.
Regarding Claims 162-164, 166-167, and 169, Gunasekara et al. and Tzeferis et al. do not teach the steps (d) – (j) recited in the claim 162, specifically comprising: applying a Gly-Gly-His peptide conjugated with a polystyrene bead for selectively binding nickel and/or cobalt from the aqueous phase/leach solution obtained in step (c) to form a conjugate-metal ion complex; isolating the complex and eluting the bound metal(s) from the complex with an acid, subjecting the eluted metal(s) solution to electrowining, and recovering metal(s) from a surface of cathode. However, Gunasekara et al. teach steps for isolating, purifying and recovering trace metals including nickel and/or cobalt, which are comparable to the steps (d) – (j) in the claims. In details, Gunasekara et al. teach processes for selectively separating and recovering the trace metal from the aqueous phase/leach solution and further purifying/recovering the metals, by processes including: absorption of dissolved trace metals, chelating ion exchange, and electrowinning (paras 0099/lines 1-4, and 0103/lines 1-2 and 5-6).
Duyvesteyn et al. teach a similar bioleaching process for recovering nickel from a nickel-containing laterite ore or sulfide oxide ore (abstract), comprising steps: (a) providing at least one microorganism selective to leach the ore in an aqueous solution; (b) combining the microorganism, a substrate mixture (containing sugar, a carbonaceous nutrient), the ore, a ligand (sulfuric acid H2SO4 or citric acid), and an aqueous phase to form a mixture/slurry; (c) maintaining the mixture for a period of time under conditions to dissolute/solubilize the nickel in the aqueous phase; and (d) separating (i.e. isolating) a nickel-containing aqueous solution from a solid leach residue (abstract; Examples 1 and 2: col 5/line 66 – col 6/line18, and col 6/lines 45-66). Duyvesteyn et al. further teach selectively separating and recovering nickel from the nickel-containing aqueous solution (i.e. bioleach solution), which preferably comprises: (I) extracting nickel from the bioleaching solution by a process of absorbing the nickel to a resin specifically selective to nickel absorption, which simultaneously increases nickel concentration, providing sufficient nickel for recovery by downstream electrolysis; (II) eluting the absorbed nickel from the resin by applying a mineral acid; and (III) further applying the eluted nickel solution to electrolysis (i.e. electrowinning) for recovering substantially pure nickel from the eluted nickel (col 5: lines 26-30, 56-61, and 11-12). Duyvesteyn et al. further teach, as an example, using the resin of Dow XFS 4195 and Dow XFS 43084 (col 5: lines 32-34 and 43-48). Wołowicz et al., cited as evidence, teach multiple chelating ion exchange resins and list them in table 1, which shows that Dow XFS 4195 and Dow XFS 43084 have their functional groups conjugated to polystyrene matrix, wherein the polystyrene matrix is in a form of beads (table 1; page 495, right col. Section 3.1, lines 3-4). As such, the absorption resin taught by Duyvesteyn et al. is a conjugate comprising polystyrene beads and Ni-binding functional components, as evidenced by Wołowicz et al.
Bertuol et al. teach an electrowinning process for recovering and purifying nickel and/or cobalt from an aqueous solution or a leaching solution, which contain ions of nickel and/or cobalt, wherein an assembly/circuit comprising a platinum anode and a stainless steel cathode is used for electrowinning of the aqueous/leaching solutions, and after applying electric current to the aqueous or leaching solution in the assembly, metals of nickel and/or cobalt are deposited on the cathode; wherein the deposited metals (Ni and/or Co) are recovered from the cathode for obtaining metals in good purity (abstract; Figs. 1 and 9; Section 2.2 spanning pages 2085 and 2086; page 2091/right col/lines 3-9).
Hay et al. teach that the tripeptide glycylglycyl-L-histine (i.e. Gly-Gly-His peptide, or NH2-GGH peptide) acts as a ligand, and specifically binds a nickel(II) ion or a copper(II) ion and forms a complex between the peptide and the metal ion (nickel or copper ion) (title, abstract), wherein the Gly-Gly-His peptide is commercially available (page 19, lines 3-4).
Byrd et al. teach affinity peptides having specific binding activity for metal ions (e.g. Ni2+, nickel ions) as well as a process of purifying the affinity peptides or proteins thereof through their reversible binding to metal ions on a metal chelate affinity chromatography resin/medium (abstract, paras 0033, 0029, and 0051), wherein the process comprises: contacting the peptides/proteins with the metal chelate affinity chromatography resin to allow them to bind metal ions immobilized on the resin to form a complex between the resin/metal ions and peptides/proteins, washing the complex, and eluting the bound peptides/proteins from the washed complex (para 0033, Example 2), wherein the metal chelate affinity chromatography resin is a nickel ion-bound affinity chromatography resin, and the peptides bound to the nickel ion resin comprise GGH, i.e. Gly-Gly-His (Example 2: para 0210/last 3 lines, and Table 22, see SEQ ID NOs: 97, 88, 268, 323-324, and 326-327); wherein the peptides bound to the resin are eluted from the complex by applying an eluting solution with decreased/low pH (e.g. a low pH or acidic solution) (para 0029, lines 1-2 and 5-6 from bottom). Byrd et al. further teach that the resin/matrix used for immobilizing metal ions for contacting peptides is well known in the art, for example, those in US Patent No: 6365147 (Luo et al.) (para 0070, lines 5-9). Luo et al. disclose that various absorbent matrices may be used for preparing an immobilized metal affinity chromatography matrix, such as polystyrene in the form of beads (col 2/lines 39-43, col 6/line 15). As such, Byrd et al. inherently teach a conjugate/complex comprising a polystyrene resin (bead) and a metal ion (which can be a nickel ion) bound to a peptide (which can be a peptide comprising Gly-Gly-His), as evidenced by Luo et al.
Hyeung et al. teach a fluorescence-labeled peptide that is used as a sensor for selectively binding and detecting metal ions (copper or zinc ion) in a biological sample, wherein the peptide (PG1 or PG2) comprises Gly-Gly-His and is immobilized on PEG-polystyrene resin (abstract; Experimental Example 2: page 10/paras 2-6).
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to modify the method suggested by Gunasekara et al. and Tzeferis et al. for isolating and recovering trace metals (nickel, manganese, and/or cobalt) from the aqueous phase (leach solution) obtained in step (c), by applying a Gly-Gly-His peptide comprised in a conjugate with a polystyrene bead for selectively binding nickel ions from the leach solution to form a conjugate-metal ion complex; isolating the complex and eluting the bound metal/nickel ions from the complex with an acid solution, subjecting the eluted metal ion solution to electrowinning in a circuit, and recovering nickel metal from a surface of cathode, wherein an electric current is applied through the metal ion solution during electrowinning, as taught by Duyvesteyn et al., Bertuol et al., Hay et al., Hyeung et al., and Byrd et al. A person of ordinary skill in the art would have been motivated to do so, because Gunasekara et al. teach isolating and recovering the trace metal by resin absorption and electrowinning; and Duyvesteyn et al. teach that absorbing nickel to resin increases nickel concentration, which facilitates nickel recovery by downstream electrowinning. In addition, polystyrene resin (bead) is commonly used in the art as a support, specifically for immobilizing peptides/functional components having affinity to bind metal ions (e.g. nickel ions), as supported by Duyvesteyn et al., Byrd et al. and/or Hyeung et al. Furthermore, it is well known in the art that a Gly-Gly-His peptide is an effective ligand that selectively binds nickel(II) ions, as supported by Hay et al. It is known in the art that a conjugate comprising polystyrene and a peptide having Gly-Gly-His is effective at binding metal ions, as supported by Hyeung et al. Moreover, it is well known in the art that a binding between metal ions (e.g. nickel ions) and their ligand (an affinity functional group or a Gly-Gly-His peptide) is reversible, and they are readily eluted by an acid solution (with low pH), thus allowing separation of the metal ions from peptide, and recovery of the metal ions, as supported by Duyvesteyn et al. and Byrd et al. With regard to the limitations about electrowinning in the steps (g) – (j), they are well established in the art, as supported by Bertuol et al.
One of ordinary skill in the art has a reasonable expectation of success at modifying the method suggested by Gunasekara et al. and Tzeferis et al. by applying the teachings of Duyvesteyn et al., Bertuol et al., Hay et al., Hyeung et al., and Byrd et al. for absorbing trace metal ions from leach solution by using a Gly-Gly-His peptide on PS beads and further recovering the metal by electrowinning. This is because techniques for metal ion absorption through affinity with Gly-Gly-His peptide and metal recovery through electrowinning have been well established in the art (as supported by the cited prior art), and applying them to the method suggested by Gunasekara et al. and Tzeferis et al. will allow trace metal ions (e.g. nickel ions) in leach solution effectively extracted and recovered.
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention.
Claims 143-`45, 147, 149, 151-160, 162-164, 166-167, 169, and 171-172 are rejected under 35 U.S.C. 103 as being unpatentable over Gunasekara et al. (US 2024/0254591, 2024, effective filing date: May 12, 2021, of record) in view of Tzeferis et al. (Hydrometallurgy, 1994, 36(3): 345-360), Duyvesteyn et al. (US Patent No. 5626648, cited in IDS), Bertuol et al. (Chem. Eng. Technol. 2012, 35(12): 2084–2092, of record), Hay et al. (Journal of Inorganic Biochemistry, 1993, 52:17-25, of record), Hyeung et al. (KR 20090097704 A, 2009, machine-translated English version is of record), and Byrd et al. (US 2006/0030007, 2006, of record), as applied to Claims 143-145, 147, 149, 151-160, 162-164, 166-167, 169 and 172, further in view of Pandey et al. (US 2021/0132062, published on May 6, 2021, of record), as evidenced by Wołowicz et al. (Chemical Engineering Journal, 2012, 197:493–508, of record) and Luo et al. (US Patent No: 6365147, 2002, of record).
The teachings of Gunasekara et al. as modified by Tzeferis et al., Duyvesteyn et al., Bertuol et al., Hay et al., Hyeung et al., and Byrd et al. are described above.
Regarding Claim 171, the modified Gunasekara does not teach the polystyrene bead comprises NH2-PEG groups. However, Hyeung et al. specifically teach the polystyrene resin (bead) immobilized with a Gly-Gly-His peptide is a polystyrene conjugated with PEG (PEG-polystyrene resin).
It would have been obvious to one of ordinary skill in the art to apply a polystyrene resin conjugated with PEG-NH2 (i.e. PEG having NH2-PEG groups) as the PEG-polystyrene bead (resin) in the modified method of Gunasekara et al. for immobilizing the Gly-Gly-His peptide, because it is well known in the art that PEG-NH2 (i.e. PEG having NH2-PEG groups) is well suited for conjugating peptides or proteins. In support, Pandey et al. teach that peptides/polypeptides can be chemically conjugated to carrier particles, and one of functional groups suited for such peptide conjugation is PEG-NH2 (para 0077, lines 1-4).
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention.
Response to Arguments
Applicant's arguments about the claim objection and claim rejections under 35 U.S.C. 112(a) or 112(b) in the response filed on 07/28/2026 (pages 9-12) have been fully considered but they are moot because they have been withdrawn as indicated above.
Applicant's arguments about the claim rejections under 35 U.S.C. 103 in the response filed on 07/28/2026 (pages 13-19) have been fully considered but they are not persuasive for the following reasons.
In response to applicant's arguments based on the combination of Gunasekara with Tzeferis for rendering the claims obvious in the 07/28/2026 response (pages 13-17), Examiner notes that Applicant’s arguments in the previous response to Non-final office action dated 12/03/2025 are not persuasive for the reasons of record (see pages 26-30 of the previous office action dated 01/30/2026). Furthermore, it is noted that the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in anyone or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). As such, the test for obviousness over Gunasekara and Tzeferis is not whether the features of the secondary reference Tzeferis (such as pH ranges and leaching time ranges) may be bodily incorporated into the method of the primary reference Gunasekara. Rather, the test is what the combined teachings of the Gunasekara and Tzeferis would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). For the reasons indicated above in the 103 rejections, in view of the combined teachings of Gunasekara and Tzeferis it would have been obvious to modify the method of Gunasekara by further including citric acid as an organic acid ligand in the aqueous mixture of step (a) for increasing solubilization and improving production of nickel metal from the oxide ore, thus arriving at the claimed invention.
Further in response to Applicant’s arguments based on leaching time and recovering rates of nickel taught by Tzeferis in the 07/28/2026 response (pages 13-17), these arguments are misleading and unpersuasive. Tzeferis demonstrates that citric acid is highly effective at solubilizing nickel and iron from laterite ore and its effect is superior to those of all other organic acids tested for extracting nickel from the ore. The results of Tzeferis show that nickel recovery rates with pulp densities at 10% and 5% reach 34% in one day and 47.23% in 3 days, respectively (see table 3); and even under mild leaching conditions (0.5 M, 30oC) similar to those prevailing during microbial leaching, a nickel recovery rate with pulp density at 10% still reaches a level of 57.5% at Day 40 (Table 6, page 349/para 3/lines 1-6). It is noted that the recovery level of 57.5% is an excellent recovery rate, not a moderate recovery rate, and the time lengths of 40 days (table 6) and even 50 days for low-grade ore (table 7) are reasonable leaching time lengths under standards of microbial leaching, as evidenced by the results of microbial leaching submitted in Applicant’s 1.132 Declaration dated 07/28/2026 (used for supporting the claimed invention is superior to that of the prior art), which shows a recovery level of only ~ 45% can be achieved at Day 38 when the ore at a lower pulp density of 2.5% is combined with Shewanella and citric acid in the reaction (see Experiment 2 and Fig. 2). In this experiment the leaching time length of 38 days is on a level similar to the 40 days taught by Tzeferis, and both the recovery rate 45% and pulp density of 2.5% are significantly lower than 57.5% and 10% taught by Tzeferis, respectively. Examiner points out that lower pulp densities of ore in leaching reactions result in higher recovery rates of nickel and shorter leaching time lengths required for leaching nickel, as evidenced by the table 4 of Tzeferis as well as the differences between results of Experiments 1 and 2 in Applicant’s Declaration). As such, when the pulp density of 10% used by Tzeferis is reduced to a level of 2.5% (same as the level in Experiment 2 of the Declaration) it would be expected that the leaching time can be reduced to a time length significantly lower than 40 days for achieving the same recovery rate. Thus, the kinetics observed in using citric acid to leach nickel are not poor under standards of microbial leaching, rather they are readily compatible to microbial leaching processes with a practical utility. Moreover, Tzeferis recommends using citric acid for extracting nickel from laterite ore under mild conditions of microbial process although it needs a longer leaching time period of 40-50 days, see page 357/para 2: “Citric acid … was the most effective organic solubiliser of nickel from laterite samples. Although citric acid requires more time for effective leaching than equimolar sulphuric acid, it can be equally effective or even better over longer periods ( 40-50 d)” (emphasis added). Thus, in view of Tzeferis, one of ordinary skill in the art would have been motivated to further include the citric acid ligand in the reaction mixture in the method of Gunasekara for increasing solubilization and improving production of nickel metal from the ore.
Further in response to Applicant’s arguments based on acidic pH used in the method of Tzeferis in the 07/28/2026 response (pages 14-17), it is noted that the instant claims (except the claim 158) only define a pH range for forming the mixture in the step (a), but do not recite any limitation to define a pH for carrying out leaching reaction in the step (b). As such, the pH range for the leaching reaction in step (b) of the claimed method is not necessarily maintained at a level of about 5-9. Furthermore, it is noted that the pH range for carrying out leaching reactions in the method suggested by Gunasekara and Tzeferis can be readily modified by routine optimization for achieving a desirable effect for solubilizing nickel from the ore. Gunasekara teaches a neutral pH range from about 5 to about 9. Tzeferis teaches citric acid functions effectively in a pH range of 1.9-4.9 and at pH 6 for forming complex with and solubilizing nickel, while inorganic acid/sulphuric acid does not leach nickel when pH is above 2. The low end of the pH range of 1.9-4.9, e.g. 4.9, as well as pH 6 taught by Tzeferis read on the pH range of about 5 to about 9 in the method of Gunasekara. Thus, the claimed pH range of about 5-9 would have been obvious over the combined teachings of Gunasekara and Tzeferis.
In response to Applicant’s arguments at the end of page 15 of the response, regardless of how old the cited prior art is the teachings of Tzeferis demonstrate that the benefits of citric acid for facilitating solubilization of nickel from oxide ore are well known in the art. Furthermore, the conclusion of obviousness is established based on whether the combined teachings of cited prior art would have suggested to one of ordinary skill in the art the claimed invention before the effective filing date, not based on whether Applicant is aware of any prior art reference that teaches a bioleaching process of using citric acid at a neutral pH as claimed. For the reasons indicated above, the claimed method would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention.
Applicant’s arguments about superior and unexpected results based on Declaration under 37 CFR 1.132 in the 07/28/2026 response (pages 17-19) have been fully considered, but are not persuasive. It is noted that the 37 CFR 1.132 declaration submitted by Dr. Crowe is insufficient to overcome the 103 rejections over Gunasekara et al. in view of Tzeferis et al. and/or other cited prior art. This is because there is no showing that the objective evidence of nonobviousness is commensurate in scope with the claims. See MPEP § 716. In details, the leaching experiments in the 1.132 declaration were performed for specifically recovering nickel from laterite ore under conditions of pH 6-8 with a low pulp density of the ore (0.3-0.7% or 2.5%) for a time period ranged from 3 days to 38 days by using Shewanella bacteria as the leaching bacteria; citric acid, EDTA, or oxalic acid as the organic acid ligand; and laterite ore as the oxide ore. However, these leaching conditions are not recited in the instant claims. The instant claim 1 is directed to a leaching process of recovering any one or more of nickel, manganese, and cobalt from ore, comprising: (a) combining any iron-reducing bacteria of any species/genius, any oxide ore with any pulp density, any organic acid ligand with any amount, and any substrate with any reducing agent in an aqueous phase at pH of about 5-9; and (b) maintaining the mixture for any time range for leaching the ore under a undefined pH range. There is no factual evidence to support a synergetic effect can be achieved when using a combination of any iron-reducing bacteria, any oxide ore at any pulp density, any organic acid ligand at any amount, and any substrate with any reducing agent for any time range in the claimed method. Furthermore, it is known in the art that a synergistic effect can be achieved when two different leaching agents are used together for extracting nickel from oxide ore, as evidenced by Tzeferis (see page 357/para 2/lines 2-4 from bottom). Applicant failed to provide evidence to support that the demonstrated synergistic effect is unexpected in the prior art. Therefore, the evidence provided in the leaching experiments 1-5 and Figures 1-5 in the declaration does not support that the claimed method encompassed by the instant claims can have an unexpected synergistic effect, as stated by Dr. Crowe.
In view of the foregoing, when all of the evidence is considered, the totality of the rebuttal evidence of nonobviousness fails to outweigh the evidence of obviousness.
Overall, The conclusion of the obviousness of the claims 143-145, 147-149, 151-164, 166-167, 169 and 171-172 has been established for all the reasons indicated above.
Conclusion
No claim is in condition for allowance.
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Any inquiry concerning this communication or earlier communications from the examiner should be directed to Qing Xu, Ph.D., whose telephone number is (571) 272-3076. The examiner can normally be reached on Monday-Friday from 9:30 AM to 5:00 PM. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Manjunath N. Rao, can be reached at (571) 272-0939. Any inquiry of a general nature or relating to the status of this application or proceeding should be directed to the receptionist whose telephone number is (571) 272-1600.
/Qing Xu/
Patent Examiner
Art Unit 1656
Prosecution Insights