DETAILED ACTION
Information Disclosure Statement
The IDS filed 20 July 2026 has been considered.
Specification
The amendment filed 20 July 2026 to the specification has been entered.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-13, 17, 19, 21-28 and 32-36 are rejected under 35 U.S.C. 103 as being unpatentable over Shen (CN 11346553)1 in view of Styriakova (20230339824) and Wang et al. (Applied Surface Science 2020, 512: 1-9).
Regarding claims 1, 33 and 36, Shen teaches a method for leaching rare earth using a microbial community (consortium) (abstract). Shen teaches that more than 4 bacteria can be used (examples 1-3 and 5). 553 teaches the ratios of the bacteria can be 1:1:1:1 (examples 1-3) Shen teaches that Bacillus can be used (acid secreting evidenced by instant spec [0040]) (example 2). Shen teaches that Pseudomonas aeruginosa can be used (example 1). As evidenced by Bonneau, P. aeruginosa is secretes siderophores (title). As evidenced by Chellaiah, P. aeruginosa is heavy metal resistant (abstract). As evidenced by Hassanien, Pseudomonas aeruginosa was able to decrease the rare earth elements concentrations in the liquid by around 50% suggesting the bacteria causes the release and corresponding uptake of rare earth elements (page 814, paragraph 2). Accordingly, Shen teaches incubating a bacterial consortium in the presence of a rare earth metal source comprising a rare earth metal and iron, wherein the bacterial consortium comprises an acid secreting bacterium and a heavy metal resistant bacterium. Shen teaches that an acid is produced and that iron and rare earth metals are leached from the source using the acid. The bacterial consortium is protected from metal using the heavy metal resistant bacterium. It is unclear, however, if Shen teaches sequestering iron using an iron-sequestering molecule secreting bacterium.
Styriakova teaches a process of releasing metallics, metalloids and/or non-metallics from minerals, rocks, wastes, soil, and sediments through bioleaching with a natural consortia of heterotrophic bacteria (Abstract, Claim 16). Products of interest are degraded out of a carrier, which may be a waste including rare earth elements (page 3, paragraph [0030]). Styriakova provides a list of Genera the consortium can be comprised of which includes Acinetobacter spp (e.g., Acinetobacter baumanni) and teaches bacteria in the mineral extracting consortium can secrete butyric acid during the bioleaching event due to the fermentation of an organic source (page 4, paragraph [0048]).
Before the effective filing date of the claimed invention, it would have been obvious to include an iron-sequestering molecule secreting bacterium in the bacterial consortium of Shen. Styriakova indicates that a bacterium secreting butyric acid would be an effective tool in the bioleaching of rare earth metals. Styriakova further discusses the importance of removing iron and iron impurities from a carrier material when obtaining a rare earth metal product via bioleaching. One of ordinary skill would have been motivated to include a butyric-acid secreting bacterium and/or an iron-sequestering molecule secreting bacterium in the bacterial consortium for the extraction of rare earth metals.
Modified Shen still differs from the claimed invention because it is unclear if Shen teaches sequestering the rare earth metal using a rare earth metal sequestering bacterium.
Wang teaches the “separation of bastnaesite from calcite using xanthan gum” (Title) wherein bastnaesite is one of the principal sources of light [rare earth minerals] (REEs) (Introduction, paragraph 1). Wang teaches that xanthan gum “contains numerous hydrophilic (hydroxyl and carboxyl) groups that can be attached to the mineral surface via chelation of certain metal ions” and “[xanthan gum] preferentially interacted with Ca ions on the mineral surface” (page 8, column 1, paragraph 2) to function as “a promising depressant for bastnaesite flotation separation” (page 8, column 2, paragraph 1).
Before the effective filing date of the claimed invention, it would have been obvious to include a rare earth metal sequestering bacterium in the bacterial consortium of Shen. Wang teaches that xanthan gum secreting bacteria are useful because they aid in the sequestration of rare earth metals. More specifically, Wang shows how Xanthomonas spp., such as Xanthomonas campestris pathovar vesicatoria, secretes xanthan gum to create an interface that further aids in the separation and sequestration of rare earth metals from a solution.
With respect to claims 2 and 3, Shen, Styriakova and Wang disclose the combination as described above. The cited references additionally teach that the sequestered rare earth metal may be in an oxide form, a sulfate form, or may be a neodymium. It would have been obvious to use the modified Shen method to sequester essentially any rare earth metal product, including a neodymium, oxides and sulfates.
With respect to claims 4-9, Shen, Styriakova and Wang disclose the combination as described above. It would have been obvious to practice the modified Shen method by incubating the bacterial consortium under conventional culture conditions.
With respect to claims 10-13, Shen, Styriakova and Wang disclose the combination as described above. The cited references disclose the use of a Bacillus microorganism, which is a citric acid secreting bacterium. Styriakova teaches that bacteria in the mineral extracting consortium can secrete butyric acid.
With respect to claims 17 and 19, Shen, Styriakova and Wang disclose the combination as described above. Shen teaches a heavy metal resistant bacterium that resists heavy metal by active transport of metal ions, extracellular sequestration, intracellular sequestration, reduction of metal ions to insoluble metal, an extracellular barrier, or a combination thereof. It would have been obvious to provide an aqueous medium having an optimized heavy metal concentration (e.g., from 10 grams per liter to 50 grams per liter) so as not to overload the bacterium.
With respect to claims 21-23, Shen, Styriakova and Wang disclose the combination as described above. As stated above, Styriakova discloses that the iron-sequestering molecule secreting bacterium may be Acinetobacter baumanni. See paragraphs [0037]-[0041].
With respect to claims 24-28, Shen, Styriakova and Wang disclose the combination as described above. As stated above, Wang teaches a rare earth metal sequestering bacterium configured to secrete xanthan gum. Wang indicates that the bacterium is Xanthomonas vesicatoria, and those of ordinary skill would understand that it is capable of sequestering at least 10 grams of rare earth metal per 1012 bacterial cells. In view of Wang, one of ordinary skill would understand to skim off and filter xanthan gum having rare earth metal bound thereto.
With respect to claim 32, Shen, Styriakova and Wang disclose the combination as described above. The cited references disclose an incubation step performed in an anaerobic environment. For example, it is known that Bacillus can be both aerobic and anaerobic.
With respect to claims 34 and 35, Shen, Styriakova and Wang disclose the combination as described above. The cited references disclose recovering and converting a rare earth metal to an oxide.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Shen (CN 11346553) in view of Styriakova (20230339824) and Wang et al. (Applied Surface Science 2020, 512: 1-9) as applied to claim 13, and further in view of Kopecny et al. (Int J of Syst and Evol Microbio 2003, 53: 201-209).
Modified Shen teaches the use of an acid secreting bacterium within the rare earth metal extracting consortium, but does not teach the use of the butyric acid-secreting Butyrivibrio hungatei.
Styriakova teaches the use of a bacteria secreting butyric acid for the bioleaching of rare earth metals, but fails to disclose the use of Butyrivibrio hungatei in the consortium.
Kopecny teaches of a strain isolated from the rumen of a cow, Butyrivibrio hungatei which are motile, non-spore forming, gram-negative rods that do not grow in the presence of oxygen (page 207, Description of Butyrivibrio hungatei) and when grown in M10 medium with glucose ferments up to 10.8 mM of butyrate (i.e. butyric acid) (page 207, column 2, line 1).
Before the effective filing date of the claimed invention, it would have been obvious to further modify Shen in order to use Butyrivibrio hungatei as a source of the secreted butyric acid. This would have involved a simple substitution of one acid-secreting bacterium for another or, alternatively, the provision of an additional redundant source of butyric acid. One of ordinary skill in the art would have been motivated to include Butyrivibrio hungatei in the consortium to provide high levels of butyric acid to aid in the bioleaching of targeted metals, metalloids, or other targeted minerals with a reasonable expectation of success.
Claims 15 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Shen (CN 11346553) in view of Styriakova (20230339824) and Wang et al. (Applied Surface Science 2020, 512: 1-9) as applied to claim 1, and further in view of Park (US 20210332392).
Modified Shen teaches the use of an organic acid secreting bacterium within the rare earth metal extracting consortium, but does not teach the use of the amino acid fermenting Clostridia venationis.
Park discloses a method for creating a bacterial consortium for facilitating the recovery of rare earth metals. Paragraphs [0079]-[0088] state that Costridium spp. are suitable for expressing rare earth element binding ligands to aid in the separation of metal products from a source.
Before the effective filing date of the claimed invention, it would have been obvious to modify Shen in order to include a Costridium spp., such as Clostridia venationis, within the bacterial consortium. Park teaches that Costridium spp. are readily combined with a wide variety of other bacteria types and are useful for the recovery of rare earth metal products. More specifically, Park teaches in paragraph [0111] that Costridium spp. efficiently bind rare earth and thereby optimize separation and purification.
Claims 18 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Shen (CN 11346553) in view of Styriakova (20230339824) and Wang et al. (Applied Surface Science 2020, 512: 1-9) as applied to claim 1, and further in view of Mergeay et al. (FEMS Microbiol Ecol 2021, 97(2): 1-7).
Modified Shen teaches the use of a heavy metal resistant organism, Pseudomonas aeruginosa, but fails to teach the mechanisms, tolerance levels, and a genera containing pMOL30 plasmid.
Styriakova teaches the use of a heterotrophic consortia of bacteria for the bioleaching of metals, but fails to teach the use of an organism containing the pMOL30 plasmid.
Mergeay teaches the characterization and metal resistance of the Cupriavidus metallidurans CH34, a model organism for metal resistance (Title, summary) wherein the two transferable megaplasmids, pMOL28 and pMOL30, carry a plethora of genes involved in metal resistance (page 2, column 1, paragraph 3). The organism was isolated from a sludge containing 2000 mg/L of zinc (II) (page 1, column 2, last paragraph) and was initially classified in the Pseudomonas genus (page 2, paragraph 2). “pMOL30 encodes resistance to zinc, cadmium, cobalt, lead, mercury, silver, and copper” that uses several mechanisms, including active transport, to reduce the toxicity of the heavy metals (page 2, column 1, last paragraph).
Before the effective filing date of the claimed invention, it would have been obvious prior to combine the teachings of Shen and Styriakova with the teachings of Mergeay to provide an improved and/or alternative source of heavy metal resistance. One of ordinary skill in the art would have been motivated with a reasonable expectation of success to include Cupriavidus metallidurans and/or Burkolderiales (e.g., a bacterium containing a plasmid with at least 99% sequence identity to the pMOL30 plasmid) in the bacterial consortium to help tolerate the high levels of heavy metals that might be within the leachate. The pMOL30 plasmid would confer heavy metal resistance to the consortium via several mechanisms including active transport.
Claims 29-31 are rejected under 35 U.S.C. 103 as being unpatentable over Shen (CN 11346553) in view of Styriakova (20230339824) and Wang et al. (Applied Surface Science 2020, 512: 1-9) as applied to claim 1, and further in view of Desouky et al. (Arabian J Chemistry 2011, 9: S795-S805) and Qin et al. (Microorganisms 2019, 7(3), 78: 1-10).
The cited prior art teaches the use of a rare earth metal sequestering bacterium, Pseudomonas aeruginosa, but fails to teach the mechanism through which the bacteria sequesters the rare earth metals.
Desouky teaches the use of purified siderophores from Pseudomonas aeruginosa for the chelation of rare earth elements such as thorium, uranium, cesium, and yttrium (Abstract) wherein the siderophores were able to complex 68% of uranium and 65% of thorium (page S797, paragraph 3.2; Figures 1-2). Thus, it would have been obvious to one of ordinary skill in the art prior to the effective filing date that when extracting rare earth metals, the Pseudomonas aeruginosa would sequester the rare earth metals through sequestration by a specific binding protein and/or extracellular sequestration.
Qin teaches the characterization of a novel butyric acid-producing strain of Collinsella aerofaciens (Title) wherein the bacterium has the ability to produce several organic acids through fermentation including butyrate, acetic acid, lactic acid, and benzoic acid (page 3, Table 1). It would have been obvious to one of ordinary skill in the art prior to the effective filing date to use the Collinsella aerofaciens in a rare earth metal extracting bacterial consortium. One of ordinary skill in the art would have been motivated with a reasonable expectation of success to include the Collinsella aerofaciens in for its ability to ferment the organic acids to enhance the bioleaching effects of the consortium.
Allowable Subject Matter
Claim 37 is allowed.
Response to Arguments
Applicant's arguments filed 200 July 2026 have been fully considered but they are not persuasive.
Applicant argues that Shen states that the community structure of multiple coexisting microorganisms may be unstable due to trophic and interspecific relationships, and therefore it would not have been obvious to produce the four claimed functional bacterial roles with a reasonable expectation of success. In response, it is believed that this concern raised by Applicant is based on statements made by Chen in the Background section of the reference describing problems associated with earlier work, but is not pertinent to the disclosure and improvements made by Chen. Chen is fundamentally directed to “regulating and controlling microbial community structure” and establishing a stabile microbial consortium that is especially suited for leaching rare earth metals. Shen indicates that it is indeed well within the ability of one of ordinary skill to build a microbial community of varied microorganism types in furtherance of a specified purpose (here, rare earth recovery) according to the specific activity and properties of each identified microorganism (“selecting at least one of the following three groups of microorganisms in each group, performing independent culture, culturing to set concentration, according to the set proportion, mixing the plurality of microorganisms to obtain the microbial community, continuously culturing the microbial community, obtaining microbial community colony suspension”). Each selected microorganism performs a known and predictable function.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/NATHAN A BOWERS/Primary Examiner, Art Unit 1799
1 With additional evidence from Bonneau (Scientific Reports 2020. 10(120): 1-11), Chellaiah (Applied Water Science 2018, 8(154): 1-10) and Hassanien (Wailaki J Sci & Tech 2014; 11(9): 809‐823
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