The GenBank® sequence database, which is an annotated collection of all publicly-available nucleotide and amino acid sequences, contains sequences from approximately 30,000 species of bacteria. While this number may appear impressive, it is instructive to note that a recent estimate suggests that the sea may support as many as 2 million different species of bacteria, and a ton of soil more than double that number (Curtis et al., Proc. Natl. Acad. Sci. USA 99:10494-10499, 2002). Furthermore, only about 13,000 of the bacteria represented in GenBank® have been formally described, and almost all of these lie within 4 of the 40 bacterial divisions (DeLong, Curr. Opin. Microbiol. 4:290-295, 2001). The paucity of knowledge regarding other microbial species is similar or greater. This is at least in part due to the fact that the vast majority of microorganisms from the environment resist cultivation in the laboratory. These so called “uncultivables” represent 99-99.99% of all microbial species in nature (see, e.g., Young, ASM News 63:417-421, 1997).
Microbial diversity is typically examined by amplifying 16S rRNA genes from DNA samples isolated from a specific habitat. The sequences are then compared to each other and to the 16S rRNA sequences from known species. If no close match to an existing 16S rRNA gene sequence is found, then the test sequence is thought to represent a new microorganism and is termed an “uncultured microorganism.” 16S rRNA genes, which are critical for translation, are the genes of choice for these experiments because they are thought to be conserved across vast taxonomic distance, yet show some sequence variation between closely related species. Phylogenetic analyses of 16S rRNA sequences obtained from direct sampling of environments suggest that uncultured microorganisms can be found in nearly every taxon within Bacteria and Archaea, and several groups at the division level have been identified with no known cultivable representatives (see, e.g., Giovannoni et al., Nature 345: 60-63, 1990; and Dojka et al., Appl. Environ. Microbiol. 66:1617-1621, 2000).
The principal reason for this disparity is that few microorganisms from environmental samples grow on nutrient media in Petri dishes. The discrepancy between the microbial total count and plate count is several orders of magnitude. Attempts to improve the recovery of microorganisms from environmental samples by manipulating growth media have been of limited success.
Researchers have used a variety of media in hopes of growing previously uncultivated microorganisms but haven't been able to grow all the organisms from a given environment. Menadione, a synthetic quinone, has been added to media used to grow organisms from the human microbiome but it hasn't been able to grow a significant number of organisms from this environment.
Accordingly, new methods for isolating and growing previously uncultivable microorganisms are desirable. These methods may be useful in identifying microorganisms that are a valuable resource of novel metabolic products useful for pharmaceutical and industrial processes. In addition, these methods may be useful in identifying microorganisms critical for decomposing and recycling nutrients at a global scale.
The present disclosure is directed to the use of quinones as growth factors for previously uncultured microorganisms. The majority of environmental bacteria are uncultured, do not grow in the laboratory on standard growth media, and a considerable part of microorganisms inhabiting humans (the Microbiome) are uncultured as well. Environmental microorganisms are a potential source of valuable secondary metabolites, and uncultured microorganisms from the human microbiome are potential symbionts. Finding growth factors for uncultured microorganisms is therefore of considerable utility. Specifically, the quinone growth factors described in this invention may be used to treat humans with deficiency in certain symbionts. Quinones were found to be essential for growth of uncultured bacteria, but may also be useful to stimulate the growth of desirable cultivable species. Quinones may also be added to growth media for growing uncultured environmental microorganisms for the production of secondary metabolites such as antibiotics.
This is a novel approach as organisms which require an exogenous quinone-type compound have been previously thought to be able to utilize menadione, however the recommended media containing menadione are not capable of growing the organism described here, and this is likely to be the case for other significant bacteria.
In one aspect, the present disclosure is directed to a method for cultivating or isolating a microorganism, the method comprising using one or more quinones as growth factors.
In another aspect, the present disclosure is directed to a method for treating a mammalian species with deficiency in symbionts, the method comprising administering to the mammalian species a therapeutically effective amount of one or more quinones.
These and other embodiments of the invention are further described in the following sections of the application, including the Detailed Description, Examples, and Claims. Still other objects and advantages of the invention will become apparent by those of skill in the art from the disclosure herein, which are simply illustrative and not restrictive. Thus, other embodiments will be recognized by the ordinarily skilled artisan without departing from the spirit and scope of the invention.
In one aspect, the present disclosure is directed to a method for cultivating or isolating a microorganism, the method comprising using one or more quinones as growth factors.
In another aspect, the present disclosure is directed to a method for treating a mammalian species with deficiency in symbionts, the method comprising administering to the mammalian species a therapeutically effective amount of one or more quinones.
In some embodiments, the methods further comprise a helper strain microorganism. In some embodiments, the quinone is produced by the helper strain microorganism. In some embodiments, the quinones are delivered in liposomes.
In some embodiments, the quinones are selected from MK4, MKS, MK6, and 1,4-dihydroxy-2-naphthoate (DHNA).
In some embodiments, the cultivated or isolated microorganism is selected from Flaviramulus sp., Bizinio sp., Porphyromonas sp., and Faecalibacterium sp. In some embodiments, the cultivated or isolated microorganism is from Flaviramulus sp. In some embodiments, the cultivated or isolated microorganism is from Bizinio sp. In some embodiments, the cultivated or isolated microorganism is from Porphyromonas sp. In some embodiments, the cultivated or isolated microorganism is from Faecalibacterium sp.
In some embodiments, the cultivated or isolated microorganism is selected from Flaviramulus sp. KLE1215, Bizinio sp. KLE1402, Bizionia echini, Porphyromonas sp. KLE1280, Porphyromonas catoniae, Porphyromonas gingivalis, Faecalibacterium prausnitzii and Faecalibacterium sp. KLE1255. In some embodiments, the cultivated or isolated microorganism is Flaviramulus sp. KLE1215. In some embodiments, the cultivated or isolated microorganism is Bizinio sp. KLE1402. In some embodiments, the cultivated or isolated microorganism is Bizionia echini. In some embodiments, the cultivated or isolated microorganism is Porphyromonas sp. KLE1280. In some embodiments, the cultivated or isolated microorganism is Porphyromonas catoniae. In some embodiments, the cultivated or isolated microorganism is Porphyromonas gingivalis. In some embodiments, the cultivated or isolated microorganism is Faecalibacterium prausnitzii. In some embodiments, the cultivated or isolated microorganism is Faecalibacterium sp. KLE1255.
In some embodiments, the symbiont is selected from Flaviramulus sp., Bizinio sp., Porphyromonas sp., and Faecalibacterium sp. In some embodiments, the symbiont is from Flaviramulus sp. In some embodiments, the symbiont is from Bizinio sp. In some embodiments, the symbiont is from Porphyromonas sp. In some embodiments, the symbiont is from Faecalibacterium sp.
In some embodiments, the symbiont is selected from Flaviramulus sp. KLE1215, Bizinio sp. KLE1402, Bizionia echini, Porphyromonas sp. KLE1280, Porphyromonas catoniae, Porphyromonas gingivalis, Faecalibacterium prausnitzii and Faecalibacterium sp. KLE1255. In some embodiments, the symbiont is Flaviramulus sp. KLE1215. In some embodiments, the symbiont is Bizinio sp. KLE1402. In some embodiments, the symbiont is Bizionia echini. In some embodiments, the symbiont is Porphyromonas sp. KLE1280. In some embodiments, the symbiont is Porphyromonas catoniae. In some embodiments, the symbiont is Porphyromonas gingivalis. In some embodiments, the symbiont is Faecalibacterium prausnitzii. In some embodiments, the symbiont is Faecalibacterium sp. KLE1255.
In some embodiments, the helper strain microorganism is selected from Escherichia coli, Shewanella oneidensis, Ruegeria lacuscaerulensis, and Micrococcus luteus. In some embodiments, the helper strain microorganism is selected from Escherichia coli, Shewanella oneidensis, and Micrococcus luteus. In some embodiments, the helper strain microorganism is selected from Escherichia coli and Shewanella oneidensis. In some embodiments, the helper strain microorganism is Escherichia coli. In some embodiments, the helper strain microorganism is Shewanella oneidensis. In some embodiments, the helper strain microorganism is Ruegeria lacuscaerulensis. In some embodiments, the helper strain microorganism is Micrococcus luteus.
It will be recognized that one or more features of any embodiments disclosed herein may be combined and/or rearranged within the scope of the invention to produce further embodiments that are also within the scope of the invention.
Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be within the scope of the present invention.
The invention is further described by the following non-limiting Examples.
Examples are provided below to facilitate a more complete understanding of the invention. The following examples illustrate the exemplary modes of making and practicing the invention. However, the scope of the invention is not limited to specific embodiments disclosed in these Examples, which are for purposes of illustration only, since alternative methods can be utilized to obtain similar results.
Isolation of uncultured bacteria of the oral Microbiome: the principal method of isolation was co-culture, placing cultivable bacteria that may produce growth factors on a plate containing uncultured species, and observing organisms that only grow in the presence of helper species.
Serial dilutions of dental plaque from a healthy individual were spread onto Fastidious Anaerobe Agar plates containing 5% sheep blood and 5% pooled human saliva (FBS) and incubated anaerobically. Small colonies growing next to large ones on dense plates were picked and spread onto fresh FBS plates. A helper mix of colonies growing around individual small colonies was spotted on these plates. Isolates were identified that depended for growth on this mix. If E. coli produces a growth factor, its identification can be efficiently performed, since a complete knockout library of this species is available. Testing knockout mutants identifies those that lost their ability to help growth of the uncultured organism, which then leads to the identification of the biosynthetic pathway of the growth factor. One of the isolates, KLE1280, showed dependence on the mix or E. coli. This organism is closely related to Porphyromonas sp. oral taxon 279 (99% similarity by 16S rRNA gene sequencing) (96% similarity to closest type strain Porphyromonas catoniae). In particular, KLE1280 is closely related to Porphyromonas catoniae (96% similarity by 16S rRNA gene sequencing). Medium and large deletion mutants of nonessential genes of E. coli were tested as helpers to determine which knockout did not induce growth of KLE1280. E. coli strain OCL67 showed no induction (
Different quinones (Q), commercially available and/or isolated from E. coli and Micrococcus luteus were tested for induction of growth of KLE1280. The results are shown in Table 2.
The chemical structures of quinones are shown in Table 3.
Menaquinone 4 (MK4) induced growth of KLE1280. One intermediate from the menaquinone biosynthesis pathway, 1,4-dihydroxy-2-naphthoate (DHNA) also showed induction of growth of KLE1280. Different concentrations of MK4 were spotted on media with and without blood (5%) or hemin (10 μg/ml) or hemoglobin (100 μg/ml). MK4 induced growth only in the presence of either of these 3 in the medium. MK4, hemin, hemoglobin or blood alone did not induce growth of KLE1280.
KLE1280 is an anaerobic organism, and quinones apparently serve as electron shuttles between components of anaerobic fermentation and external terminal acceptors. Hemin and hemoglobin apparently serve as terminal acceptors. For anaerobic uncultured microorganisms then, the growth medium should contain a quinone and a suitable electron acceptor such as hemin. The same medium can be used for anaerobic environmental microorganisms. For environmental aerobic microorganisms, a quinone may be sufficient, if its role is to complement an otherwise complete respiratory chain.
Menaquinone biosynthetic pathway of Porphyromonas gingivalis W83, from the National Microbial Pathogen Data Resource is shown in
This isolate grows either poorly or not at all in the absence of exogenous quinone-like compounds. These growth promoting-compounds can be contributed by a laboratory strain of Escherichia coli or other bacteria from the environment, such as Shewanella oneidensis. As shown in
The growth of Flaviramulus sp. KLE1215 is enhanced by the addition of purified quinone-like compounds when they are delivered in liposomes.
This isolate shows complete dependence on exogenous quinones for growth.
An Aerobic Helper-Dependent pair isolated from marine sand biofilm is shown in
Strain KLE1255 was isolated from human feces in co-culture with Escherichia coli. KLE1255 was identified by 16S rRNA gene sequencing as a relative of Faecalibacterium prausnitzii ATCC 27768T. The isolate was isolated on BHI medium supplemented with yeast extract, cysteine and hemin (BHIych) and only grew in close proximity to the E. coli helper.
This invention has allowed growth of a difficult to grow bacterium and can be used to grow other uncultivated bacteria from the environment.
All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. The patent and scientific literature referred to herein establishes knowledge that is available to those skilled in the art. The issued patents, applications, and other publications that are cited herein are hereby incorporated by reference to the same extent as if each was specifically and individually indicated to be incorporated by reference. In the case of inconsistencies, the present disclosure will prevail.
Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, numerous equivalents to the specific substances and procedures described herein. Such equivalents are considered to be within the scope of this invention, and are covered by the following claims.
Although the invention has been described and illustrated in the foregoing illustrative embodiments, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the details of implementation of the invention can be made without departing from the spirit and scope of the invention, which is limited only by the claims that follow. Features of the disclosed embodiments can be combined and rearranged in various ways to obtain additional embodiments within the scope and spirit of the invention.
This application claims priority to U.S. Provisional Patent Application No. 61/489,371, filed May 24, 2011, the contents of which are hereby incorporated by reference in their entireties.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US12/39335 | 5/24/2012 | WO | 00 | 3/6/2014 |
Number | Date | Country | |
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61489371 | May 2011 | US |