rexresearch
Jay KEASLING, et al.
Yeast Biosynthesis of Cannabinoids
Related : THC Synthesis
Patents
https://onezero.medium.com/
Scientists are making THC and CBD without Marijuana
by
Tim McDonnell
New
research paves the way for cannabinoids without cannabis
...In a paper published today (Complete Biosynthesis of
Cannabinoids and their Unnatural Analogues in Yeast) in the
peer-reviewed journal Nature, biochemists at the University of
California, Berkeley report what some cannabis industry experts
are describing as a breakthrough in biosynthetic cannabinoid
production.
By using genetically modified yeast, the Berkeley scientists
were able to convert simple sugars into the active chemical
compounds in marijuana...
The new research from the Berkeley scientists centers on the
identification of a cannabis enzyme that can be transferred into
yeast DNA so that it metabolizes sugar into cannabinoids instead
of alcohol and carbon dioxide.
Jay Keasling, the biochemist at Berkeley who led the
research, says his team tested dozens of options before finding
the right combination of enzyme genes.
Yeast is a good host organism, Keasling says, because its DNA is
thoroughly documented and because it's already in wide use for
other commercial applications like beer-making and wine-making.
"It's as easy as brewing beer," says Keasling
"You feed the yeast sugar, it grows and
replicates, produces the THC, and secretes it outside the cell
so that it's floating in the sugar water that the yeast is
growing in. It comes in high concentrations, and then we purify
it away and you're left with a very pure white powder."
Keasling filed a patent for this method back in 2017, and has
since been hammering down the science and working with a Bay
Area biotech startup, Demetrix, to bring the process from the
lab into commercial production.
Over the next few years, the company hopes to bring the cost of
production below $1,000 per kilogram, far below the cost of
chemically-synthesized cannabinoids (tens of thousands of
dollars per kilogram) or cannabinoids extracted from a plant
(more than $5,000 per kilogram), according to Jeff Ubersax, the
company's CEO.
Biosynthesized cannabinoids aren't yet being produced
commercially by any company.
And some of Demetrix's competitors remain skeptical that
Keasling's approach is much different from what others are
cooking up behind the scenes.
"They're showing how these pieces will all go
together, which is cool, but I don't know that I would describe
it as a breakthrough," says Kevin Chen, CEO of Montreal-based
Hyasynth Bio, which recently received a $7.6 million investment
from the Canadian cannabis distributor OrganiGram to speed up
the rollout of its own biosynthetic cannabinoids.
"Everyone is in the research stage, so it's
hard to say who will have the first product out."
Ronan Levy, chief strategic officer of another Demetrix
competitor, New Mexico-based Trait Biosciences, says his
company's preferred approach is to find ways to induce a
cannabis plant to produce cannabinoids in every one of its
cells, rather than only those in the "tricone" (better known as
the "bud"), where it grows naturally.
"Instead of trying to find other organisms,
why not figure out how to expand on what the plant can do?" he
says. "Yeast is definitely interesting, we just don't think it
makes the most sense."
"So you have a yeast that makes THC. Do you
schedule this yeast?"
It's unclear whether biosynthesized cannabinoids would be
subject to the same legal restrictions as plant-derived
compounds, since federal law applies to the plant and not
necessarily to the cannabinoids in it.
Cannabis researchers are subject to tight restrictions on where
they can procure samples, and the Food and Drug Administration
(FDA) has approved only one CBD-based drug, Epidiolex, for
childhood epilepsy.
"So you have a yeast that makes THC. Do you
schedule this yeast?" says Piomelli, referring to the DEA, Drug
Enforcement Administration's drug classification system.
"We haven't seen the law at work enough to
conclude, case by case, what will work. The legal landscape on
cannabis is so confusing that almost anything goes."
Either way, biosynthesis is poised to change the way we think
about getting high.
"We don't make insulin from animals anymore,
and the plant won't be the way forward for industrial production
of cannabinoids," says Banister.
"If big corporations want to move into the
cannabis space, I think they will be moving in this direction."
https://www.bibliotecapleyades.net/archivos_pdf/complete-biosynthesis-cannabinoids.pdf
Complete
Synthesis of Cannabinoids... in Yeast
X. Luo,
et al.
US2019078168
Generation of Water-Soluble Cannabinoid Compounds in
Yeast and Plant Cell Suspension Cultures and Compositions of
Matter
[ PDF ]

US9822384
Production of Tetrahydrocannabinolic Acid in Yeast
Exemplary embodiments provided herein include
genetically engineering microorganisms, such as yeast or
bacteria, to produce cannabinoids by inserting genes that
produce the appropriate enzymes for the metabolic production of
a desired compound.
WO2019014490
PRODUCTION OF CANNABINOIDS IN YEAST
The
present disclosure relates to the production of cannabinoids in
yeast. In one aspect there is provided a genetically modified
yeast comprising: one or more GPP producing genes and
optionally, one or more GPP pathway genes; two or more
olivetolic acid producing genes; one or more cannabinoid
precursor or cannabinoid producing genes; one or more
Hexanoyl-CoA producing genes, and at least 5% dry weight of
fatty acids or fats.
WO2018200888
MICROORGANISMS
AND METHODS FOR PRODUCING CANNABINOIDS AND CANNABINOID
DERIVATIVES PRODUCTION OF CANNABINOIDS IN YEAST
The present disclosure relates to the production of cannabinoids
in yeast. In one aspect there is provided a genetically modified
yeast comprising: one or more GPP producing genes and
optionally, one or more GPP pathway genes; two or more
olivetolic acid producing genes; one or more cannabinoid
precursor or cannabinoid producing genes; one or more
Hexanoyl-CoA producing genes, and at least 5% dry weight of
fatty acids or fats...
[00133] The present disclosure provides methods, polypeptides,
nucleic acids encoding said polypeptides, and genetically
modified host cells for producing cannabinoids, cannabinoid
precursors, cannabinoid derivatives (e.g., non-naturally
occurring cannabinoids), or cannabinoid precursor derivatives
(e.g., non-naturally occurring cannabinoid precursors). [00134]
Geranyl pyrophosphate:olivetolic acid geranyltransferase (GOT,
Enzyme Commission Number 2.5.1.102) polypeptides play an
important role in the biosynthesis of cannabinoids, but
reconstituting their activity in a genetically modified host
cell has proven challenging, hampering progress in the
production of cannabinoids or cannabinoid derivatives. Herein,
novel genes encoding polypeptides of the disclosure that
catalyze production of cannabigerolic acid (CBGA) from GPP and
olivetolic acid have been identified, isolated, and
characterized. Surprisingly, these polypeptides of the present
disclosure can catalyze production of CBGA from GPP and
olivetolic acid in an amount at least ten times higher than
previously discovered Cannabis polypeptides that catalyze
production of CBGA from GPP and olivetolic acid (see, for
example, U.S. PatentApplication Pub. No. US20120144523 and the
GOT polypeptide, CsPT1, disclosed therein; SEQ ID NO:82 herein).
The new polypeptides of the present disclosure that catalyze
production of CBGA from GPP and olivetolic acid are GOT
polypeptides (e.g., the CsPT4 polypeptide) and can generate
cannabinoids and cannabinoid derivatives in vivo (e.g., within a
genetically modified host cell) and in vitro (e.g., cell-free).
These new GOT polypeptides, as well as nucleic acids encoding
said GOT polypeptides, are useful in the methods and genetically
modified host cells of the disclosure for producing cannabinoids
or cannabinoid derivatives...
[00144] In Cannabis, cannabinoids are produced from the common
metabolite precursors geranylpyrophosphate (GPP) and
hexanoyl-CoA by the action of three polypeptides so far only
identified in Cannabis. Hexanoyl-CoA and malonyl-CoA are
combined to afford a 12-carbon tetraketide intermediate by a TKS
polypeptide. This tetraketide intermediate is then cyclized by
an OAC polypeptide to produce olivetolic acid. Olivetolic acid
is then prenylated with the common isoprenoid precursor GPP by a
GOT polypeptide (e.g., a CsPT4 polypeptide) to produce CBGA, the
cannabinoid also known as the“mother cannabinoid.” Different
synthase polypeptides then convert CBGA into other cannabinoids,
e.g., a THCA synthase polypeptide produces THCA, a CBDA synthase
polypeptide produces CBDA, etc. In the presence of heat or
light, the acidic cannabinoids can undergo decarboxylation,
e.g., THCA producing THC or CBDA producing CBD.
[00145] GPP and hexanoyl-CoA can be generated through several
pathways (see FIGS.1 and 11). One or more nucleic acids encoding
one or more polypeptides having at least one activity of a
polypeptide present in these pathways can be useful in the
methods and genetically modified host cells for the synthesis of
cannabinoids, cannabinoid precursors, cannabinoid derivatives,
or cannabinoid precursor derivatives. [00146] Polypeptides that
generate GPP or are part of a biosynthetic pathway that
generates GPP may be one or more polypeptides having at least
one activity of a polypeptide present in the mevalonate (MEV)
pathway. The term“mevalonate pathway” or“MEV pathway,” as used
herein, may refer to the biosynthetic pathway that converts
acetyl-CoA to isopentenyl pyrophosphate (IPP) and dimethylallyl
pyrophosphate (DMAPP). The mevalonate pathway comprises
polypeptides that catalyze the following steps: (a) condensing
two molecules of acetyl-CoA to generate acetoacetyl-CoA (e.g.,
by action of an acetoacetyl-CoA thiolase polypeptide); (b)
condensing acetoacetyl-CoA with acetyl-CoA to form
hydroxymethylglutaryl-CoA (HMG-CoA) (e.g., by action of a
HMG-CoA synthase (HMGS) polypeptide); (c) converting HMG-CoA to
mevalonate (e.g., by action of a HMG- CoA reductase (HMGR)
polypeptide); (d) phosphorylating mevalonate to mevalonate 5-
phosphate (e.g., by action of a mevalonate kinase (MK)
polypeptide); (e) converting mevalonate 5-phosphate to
mevalonate 5-pyrophosphate (e.g., by action of a
phosphomevalonate kinase (PMK) polypeptide); (f) converting
mevalonate 5-pyrophosphate to isopentenyl pyrophosphate (e.g.,
by action of a mevalonate pyrophosphate decarboxylase (MVD)
polypeptide); and (g) converting isopentenyl pyrophosphate (IPP)
to dimethylallyl pyrophosphate (DMAPP) (e.g., by action of an
isopentenyl pyrophosphate isomerase (IDI) polypeptide) (FIGS.1
and 11). A geranyl diphosphate synthase (GPPS) polypeptide then
acts on IPP and/or DMAPP to generate GPP. Additionally,
polypeptides that generate GPP or are part of a biosynthetic
pathway that generates GPP may be one or more polypeptides
having at least one activity of a polypeptide present in the
deoxyxylulose-5-phosphate (DXP) pathway, instead of those of the
MEV pathway (FIG.1).
[00147] Polypeptides that generate hexanoyl-CoA may include
polypeptides that generate acyl-CoA compounds or acyl-CoA
compound derivatives (e.g., a hexanoyl-CoA synthase (HCS)
polypeptide, an acyl-activating enzyme polypeptide, a fatty
acyl-CoA synthetase polypeptide, or a fatty acyl-CoA ligase
polypeptide). Hexanoyl-CoA may also be generated through
pathways comprising one or more polypeptides that generate
malonyl- CoA, such as an acetyl-CoA carboxylase (ACC)
polypeptide. Additionally, hexanoyl-CoA may be generated with
one or more polypeptides that are part of a biosynthetic pathway
that produces hexanoyl-CoA, including, but not limited to: a
malonyl CoA-acyl carrier protein transacylase (MCT1)
polypeptide, a PaaH1 polypeptide, a Crt polypeptide, a Ter
polypeptide, and a BktB polypeptide; a MCT1 polypeptide, a PhaB
polypeptide, a PhaJ polypeptide, a Ter polypeptide, and a BktB
polypeptide; a short chain fatty acyl-CoA thioesterase (SCFA-TE)
polypeptide; or a fatty acid synthase (FAS) polypeptide (see
FIGS. 1 and 11). Hexanoyl CoA derivatives, acyl-CoA compounds,
or acyl-CoA compound derivatives may also be formed via such
pathways and polypeptides.
[00148] GPP and hexanoyl-CoA may also be generated through
pathways comprising polypeptides that condense two molecules of
acetyl-CoA to generate acetoacetyl-CoA and pyruvate
dehydrogenase complex polypeptides that generate acetyl-CoA from
pyruvate (see FIGS.1 and 11). Hexanoyl CoA derivatives, acyl-CoA
compounds, or acyl-CoA compound derivatives may also be formed
via such pathways.
General
Information
[00149] The practice of the present disclosure will employ,
unless otherwise indicated, conventional techniques of molecular
biology (including recombinant techniques), microbiology, cell
biology, biochemistry, and immunology, which are within the
skill of the art. Such techniques are explained fully in the
literature:“Molecular Cloning: A Laboratory Manual,” second
edition (Sambrook et al., 1989);“Oligonucleotide Synthesis” (M.
J. Gait, ed., 1984);“Animal Cell Culture” (R. I. Freshney, ed.,
1987);“Methods in Enzymology” (Academic Press, Inc.);“Current
Protocols in Molecular Biology” (F. M. Ausubel et al., eds.,
1987, and periodic updates);“PCR: The Polymerase Chain
Reaction,” (Mullis et al., eds., 1994). Singleton et al.,
Dictionary of Microbiology and Molecular Biology 2nd ed., J.
Wiley & Sons (New York, N.Y.1994), and March, Advanced
Organic Chemistry Reactions, Mechanisms and Structure 4th ed.,
John Wiley & Sons (New York, N.Y.1992), provide one skilled
in the art with a general guide to many of the terms used in the
present application.
[00150] “Cannabinoid” or“cannabinoid compound” as used herein
may refer to a member of a class of unique meroterpenoids found
until now only in Cannabis sativa.
Cannabinoids may include, but are not limited to,
cannabichromene (CBC) type (e.g. cannabichromenic acid),
cannabigerol (CBG) type (e.g. cannabigerolic acid), cannabidiol
(CBD) type (e.g. cannabidiolic acid),
?<9>-trans-tetrahydrocannabinol (?<9>-THC) type
(e.g. ?<9>- tetrahydrocannabinolic acid),
?<8>-trans-tetrahydrocannabinol (?<8>-THC) type,
cannabicyclol (CBL) type, cannabielsoin (CBE) type, cannabinol
(CBN) type, cannabinodiol (CBND) type, cannabitriol (CBT) type,
cannabigerolic acid (CBGA), cannabigerolic acid monomethylether
(CBGAM), cannabigerol (CBG), cannabigerol monomethylether
(CBGM), cannabigerovarinic acid (CBGVA), cannabigerovarin
(CBGV), cannabichromenic acid (CBCA), cannabichromene (CBC),
cannabichromevarinic acid (CBCVA), cannabichromevarin (CBCV),
cannabidiolic acid (CBDA), cannabidiol (CBD), cannabidiol
monomethylether (CBDM), cannabidiol-C4(CBD-C4), cannabidivarinic
acid (CBDVA), cannabidivarin (CBDV), cannabidiorcol (CBD-C1),
?<9>–tetrahydrocannabinolic acid A (THCA-A),
?<9>–tetrahydrocannabinolic acid B (THCA-B),
?<9>–tetrahydrocannabinol (THC),
?<9>–tetrahydrocannabinolic acid-C4(THCA-C4),
?<9>–tetrahydrocannabinol-C4(THC-C4),
?<9>–tetrahydrocannabivarinic acid (THCVA),
?<9>–tetrahydrocannabivarin (THCV), ?<9>–
tetrahydrocannabiorcolic acid (THCA-C1),
?<9>–tetrahydrocannabiorcol (THC-C1), ?<7>–cis-
iso-tetrahydrocannabivarin, ?<8>–tetrahydrocannabinolic
acid (?<8>–THCA), ?<8>–tetrahydrocannabinol
(?<8>–THC), cannabicyclolic acid (CBLA), cannabicyclol
(CBL), cannabicyclovarin (CBLV), cannabielsoic acid A (CBEA-A),
cannabielsoic acid B (CBEA- B), cannabielsoin (CBE),
cannabielsoinic acid, cannabicitranic acid, cannabinolic acid
(CBNA), cannabinol (CBN), cannabinol methylether (CBNM),
cannabinol-C4, (CBN-C4), cannabivarin (CBV),
cannabinol-C2(CNB-C2), cannabiorcol (CBN-C1), cannabinodiol
(CBND), cannabinodivarin (CBVD), cannabitriol (CBT),
10-ethyoxy-9-hydroxy-delta-6a- tetrahydrocannabinol,
8,9-dihydroxyl-delta-6a-tetrahydrocannabinol, cannabitriolvarin
(CBTVE), dehydrocannabifuran (DCBF), cannabifuran (CBF),
cannabichromanon (CBCN), cannabicitran (CBT),
10-oxo-delta-6a-tetrahydrocannabinol (OTHC), delta-9-cis-
tetrahydrocannabinol (cis-THC),
3,4,5,6-tetrahydro-7-hydroxy-alpha-alpha-2-trimethyl-9-n-
propyl-2,6-methano-2H-1-benzoxocin-5-methanol (OH-iso-HHCV),
cannabiripsol (CBR), and trihydroxy-delta-9-tetrahydrocannabinol
(triOH-THC).
[00151] “Cannabinoid precursor” as used herein may refer to any
intermediate present in the cannabinoid biosynthetic pathway
before the production of the“mother cannabinoid,” cannabigerolic
acid (CBGA). Cannabinoid precursors may include, but are not
limited to, GPP, olivetolic acid, hexanoyl-CoA, pyruvate,
acetoacetyl-CoA, butyryl-CoA, acetyl-CoA, HMG-CoA, mevalonate,
mevalonate-5-phosphate, mevalonate diphosphate, and malonyl-
CoA...
[00169] As described herein, novel polypeptides for catalyzing
production of cannabigerolic acid from GPP and olivetolic acid
have been identified and characterized. Surprisingly, these new
polypeptides of the present disclosure can catalyze production
of cannabigerolic acid from GPP and olivetolic acid in an amount
at least ten times higher than previously discovered Cannabis
polypeptides that catalyze production of cannabigerolic acid
from GPP and olivetolic acid (see, for example, U.S. Patent
Application Pub. No. US20120144523 and the GOT polypeptide,
CsPT1, disclosed therein; SEQ ID NO:82 herein)...
[00411] Exemplary GPPS heterologous nucleic acids disclosed
herein may include nucleic acids that encode a GPPS polypeptide,
such as, a full-length GPPS polypeptide, a fragment of a GPPS
polypeptide, a variant of a GPPS polypeptide, a truncated GPPS
polypeptide, or a fusion polypeptide that has at least one
activity of a GPPS polypeptide...
[00707] Materials and methods suitable for the maintenance and
growth of the recombinant cells of the disclosure are described
herein, e.g., in the Examples section. Other materials and
methods suitable for the maintenance and growth of cell (e.g.
bacterial or yeast) cultures are well known in the art.
Exemplary techniques can be found in International Publication
No. WO2009/076676, U.S. Patent Application No.12/335,071 (U.S.
Publ. No. 2009/0203102), WO 2010/003007, US Publ.
No.2010/0048964, WO 2009/132220, US Publ. No.2010/0003716,
Manual of Methods for General Bacteriology Gerhardt et al, eds),
American Society for Microbiology, Washington, D.C. (1994) or
Brock in Biotechnology: A Textbook of Industrial Microbiology,
Second Edition (1989) Sinauer Associates, Inc., Sunderland, MA.
[00708] Standard cell culture conditions can be used to culture
the genetically modified host cells disclosed herein (see, for
example, WO 2004/033646 and references cited therein).
[00709] Standard culture conditions and modes of fermentation,
such as batch, fed- batch, or continuous fermentation that can
be used are described in International Publication No. WO
2009/076676, U.S. Patent Application No.12/335,071 (U.S. Publ.
No.
2009/0203102), WO 2010/003007, US Publ. No.2010/0048964, WO
2009/132220, US Publ. No.2010/0003716, the contents of each of
which are incorporated by reference herein in their entireties.
Batch and Fed- Batch fermentations are common and well known in
the art and examples can be found in Brock, Biotechnology: A
Textbook of Industrial
Microbiology, Second Edition (1989) Sinauer Associates, Inc.
Production and Recovery of Produced Cannabinoids, Cannabinoid
Precursors,
Cannabinoid Derivatives or Cannabinoid Precursor Derivatives
SEQ ID
SEQUENCE
SEQ ID NO:20 MIVKPMVRNNICLNAHPQGCKKGVEDQIEYTKKRITAEVKAGAKAPK
Ter: trans-2-enoyl-
NVLVLGCSNGYGLASRITAAFGYGAATIGVSFEKAGSETKYGTPGWY CoA reductase
NNLAFDEAAKREGLYSVTIDGDAFSDEIKAQVIEEAKKKGIKFDLIVYS (Treponema
sp.) LASPVRTDPDTGIMHKSVLKPFGKTFTGKTVDPFTGELKEISAEPANDE
EAAATVKVMGGEDWERWIKQLSKEGLLEEGCITLAYSYIGPEATQAL
YRKGTIGKAKEHLEATAHRLNKENPSIRAFVSVNKGLVTRASAVIPVIP
LYLASLFKVMKEKGNHEGCIEQITRLYAERLYRKDGTIPVDEENRIRID
DWELEEDVQKAVSALMEKVTGENAESLTDLAGYRHDFLASNGFDVE GINYEAEVERFDRI
SEQ ID NO:21 MTREVVVVSGVRTAIGTFGGSLKDVAPAELGALVVREALARAQVSGD
BktB: beta- DVGHVVFGNVIQTEPRDMYLGRVAAVNGGVTINAPALTVNRLCGSGL
ketothiolase QAIVSAAQTILLGDTDVAIGGGAESMSRAPYLAPAARWGARMGDAGL
(Ralstonia sp.) VDMMLGALHDPFHRIHMGVTAENVAKEYDISRAQQDEAALESHRRAS
AAIKAGYFKDQIVPVVSKGRKGDVTFDTDEHVRHDATIDDMTKLRPV
FVKENGTVTAGNASGLNDAAAAVVMMERAEAERRGLKPLARLVSYG
HAGVDPKAMGIGPVPATKIALERAGLQVSDLDVIEANEAFAAQACAV
TKALGLDPAKVNPNGSGISLGHPIGATGALITVKALHELNRVQGRYAL
VTMCIGGGQGIAAIFERI SEQ ID NO:22
MKEVVMIDAARTPIGKYRGSLSPFTAVELGTLVTKGLLDKTKLKKDKI MvaE:
acetyl-CoA DQVIFGNVLQAGNGQNVARQIALNSGLPVDVPAMTINEVCGSGMKAV
acetyltransferase/HM
ILARQLIQLGEAELVIAGGTESMSQAPMLKPYQSETNEYGEPISSMVND G-CoA
reductase GLTDAFSNAHMGLTAEKVATQFSVSREEQDRYALSSQLKAAHAVEAG
(Enterococcus sp.)
VFSEEIIPVKISDEDVLSEDEAVRGNSTLEKLGTLRTVFSEEGTVTAGNA
SPLNDGASVVILASKEYAENNNLPYLATIKEVAEVGIDPSIMGIAPIKAI
QKLTDRSGMNLSTIDLFEINEAFAASSIVVSQELQLDEEKVNIYGGAIAL
GHPIGASGARILTTLAYGLLREQKRYGIASLCIGGGLGLAVLLEANMEQ
THKDVQKKKFYQLTPSERRSQLIEKNVLTQETALIFQEQTLSEELSDHM
IENQVSEVEIPMGIAQNFQINGKKKWIPMATEEPSVIAAASNGAKICGNI
CAETPQRLMRGQIVLSGKSEYQAVINAVNHRKEELILCANESYPSIVKR
GGGVQDISTREFMGSFHAYLSIDFLVDVKDAMGANMINSILESVANKL
REWFPEEEILFSILSNFATESLASACCEIPFERLGRNKEIGEQIAKKIQQA
GEYAKLDPYRAATHNKGIMNGIEAVVAATGNDTRAVSASIHAYAARN
GLYQGLTDWQIKGDKLVGKLTVPLAVATVGGASNILPKAKASLAMLD
IDSAKELAQVIAAVGLAQNLAALRALVTEGIQKGHMGLQARSLAISIG
AIGEEIEQVAKKLREAEKMNQQTAIQILEKIREK SEQ ID NO:23
MKIGIDKLHFATSHLYVDMAELATARQAEPDKYLIGIGQSKMAVIPPS MvaS: HMG-CoA
QDVVTLAANAAAPMLTATDIAAIDLLVVGTESGIDNSKASAIYVAKLL synthase
GLSQRVRTIEMKEACYAATAGVQLAQDHVRVHPDKKALVIGSDVAR (Lactobacillus
YGLNTPGEPTQGGGAVAMLISADPKVLVLGTESSLLSEDVMDFWRPL plantarum)
YHTEALVDGKYSSNIYIDYFQDVFKNYLQTTQTSPDTLTALVFHLPYT
KMGLKALRSVLPLVDAEKQAQWLAHFEHARQLNRQVGNLYTGSLYL
SLLSQLLTDPQLQPGNRLGLFSYGSGAEGEFYTGVIQPDYQTGLDHGLP
QRLARRRRVSVAEYEALFSHQLQWRADDQSVSYADDPHRFVLTGQK NEQRQYLDQQV SEQ
ID NO:24 MKLSTKLCWCGIKGRLRPQKQQQLHNTNLQMTELKKQKTAEQKTRP Erg13:
HMG-CoA QNVGIKGIQIYIPTQCVNQSELEKFDGVSQGKYTIGLGQTNMSFVNDRE
synthase DIYSMSLTVLSKLIKSYNIDTNKIGRLEVGTETLIDKSKSVKSVLMQLFG
(Saccharomyces ENTDVEGIDTLNACYGGTNALFNSLNWIESNAWDGRDAIVVCGDIAIY
cerevisiae) DKGAARPTGGAGTVAMWIGPDAPIVFDSVRASYMEHAYDFYKPDFTS
EYPYVDGHFSLTCYVKALDQVYKSYSKKAISKGLVSDPAGSDALNVL
KYFDYNVFHVPTCKLVTKSYGRLLYNDFRANPQLFPEVDAELATRDY
DESLTDKNIEKTFVNVAKPFHKERVAQSLIVPTNTGNMYTASVYAAFA
SLLNYVGSDDLQGKRVGLFSYGSGLAASLYSCKIVGDVQHIIKELDITN
Recovery
[00925] Whole-cell broth from cultures comprising genetically
modified host cells of the disclosure are extracted with a
suitable organic solvent to afford cannabinoids, cannabinoid
precursors, cannabinoid derivatives, or cannabinoid precursor
derivatives. Suitable organic solvents include, but are not
limited to, hexane, heptane, ethyl acetate, petroleum ether, and
di-ethyl ether, chloroform, and ethyl acetate. The suitable
organic solvent, such as hexane, is added to the whole-cell
broth from fermentations comprising genetically modified host
cells of the disclosure at a 10:1 ratio (10 parts whole-cell
broth– 1 part organic solvent) and stirred for 30 minutes. The
organic fraction is separated and extracted twice with an equal
volume of acidic water (pH 2.5). The organic layer is then
separated and dried in a concentrator (rotary evaporator or thin
film evaporator under reduced pressure) to obtain crude
cannabinoid, cannabinoid precursor, cannabinoid derivative, or
cannabinoid precursor derivative crystals. The crude crystals
may then be heated to 105 °C for 15 minutes followed by 145 °C
for 55 minutes to decarboxylate a crude cannabinoid or
cannabinoid derivative. The crude crystalline product is
re-dissolved and recrystallized in a suitable solvent (e.g.,
n-pentane) and filtered through a 1 µm filter to remove any
insoluble material. The solvent is then removed e.g. by rotary
evaporation, to produce pure crystalline product. In vitro
enzyme assay and cell-free production of cannabinoids or
cannabinoid derivatives
[00926] In some embodiments, genetically modified host cells,
e.g., genetically modified yeast cells, verified to comprise one
or more heterologous nucleic acids encoding a GOT polypeptide
that catalyzes production of cannabigerolic acid from geranyl
pyrophosphate and olivetolic acid in an amount at least ten
times higher than a polypeptide comprising an amino acid
sequence set forth in SEQ ID NO:82 or a polypeptide comprising
an amino acid sequence having at least 65% (e.g., at least 65%,
70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%,
91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%,
99.7%, 99.8%, 99.9%, or 100%) sequence identity to SEQ ID NO:100
or SEQ ID NO:110, are cultured in 96-well microtiter plates
containing 360 µL of YPD (10 g/L yeast extract, 20 g/L Bacto
peptone, 20 g/L dextrose (glucose)) and sealed with a breathable
film seal. Cells are then cultured at 30 °C in a high capacity
microtiter plate incubator shaking at 1000 rpm and 80% humidity
for 3 days until the cultures reach carbon exhaustion. The
growth-saturated cultures are then subcultured into 200 mL of
YPGAL media to an OD600 of 0.2 and incubated with shaking for 20
hours at 30 °C. Cells are then harvested by centrifugation at
3000 x g for 5 minutes at 4 °C. Harvested cells are then
resuspended in 50 mL buffer (50 mM Tris-HCl, 1 mM EDTA, 0.1 M
KCl, pH 7.4, 125 units Benzonase) and then lysed (Emulsiflex C3,
Avestin, INC., 60 bar, 10 min). Cells debris is removed by
centrifugation (10,000 × g, 10 min, 4 °C). Subsequently, the
supernatant is then subjected to ultracentrifugation (150,000 ×
g, 1 h, 4 °C, Beckman Coulter L-90K, TI-70). The resulting
membrane fractions of the GOT polypeptide that catalyzes
production of cannabigerolic acid from geranyl pyrophosphate and
olivetolic acid in an amount at least ten times higher than a
polypeptide comprising an amino acid sequence set forth in SEQ
ID NO:82 or the polypeptide comprising an amino acid sequence
having at least 65% (e.g., at least 65%, 70%, 75%, 80%, 81%,
82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%,
95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, or
100%) sequence identity to SEQ ID NO:100 or SEQ ID NO:110 are
then resuspended in 3.3 mL buffer (10 mM Tris-HCl, 10 mM MgCl2,
pH 8.0, 10% glycerol) and solubilized with a tissue grinder.
Then, 0.02% (v/v) of the respective membrane preparations are
then dissolved in reaction buffer (50 mM Tris-HCl, 10 mM MgCl2,
pH 8.5) and substrate (500 µM olivetolic acid, 500 µM GPP) to a
total volume of 50 µL and incubated for 1 hour at 30 °C. Assays
are then extracted by adding two reaction volumes of ethyl
acetate followed by vortexing and centrifugation. The organic
layer is evaporated for 30 minutes, resuspended in
acetonitrile/H2O/formic acid (80:20:0.05%) and filtered with
Ultrafree® -MC columns (0.22 µm pore size, PVDF membrane
material). Cannabinoids or cannabinoid derivatives are then
detected via LC-MS and/or recovered and purified. Yeast
cultivation in a bioreactor
[00927] Single yeast colonies comprising genetically modified
host cells disclosed herein are grown in 15 mL of Verduyn medium
(originally described by Verduyn et al, Yeast 8(7): 501-17) with
50 mM succinate (pH 5.0) and 2% glucose in a 125 mL flask at 30
°C, with shaking at 200 rpm to an OD600 between 4 to 9. Glycerol
is then added to the culture to a concentration of 20% and 1 mL
vials of the genetically modified host cell suspension are
stored at-80 °C. One to two vials of genetically modified host
cells are thawed and grown in Verduyn medium with 50 mM
succinate (pH 5.0) and 4% sucrose for 24 hours, then
sub-cultured to an OD600 reading of 0.1 in the same media. After
24 hours of growth at 30 °C with shaking, 65 mL of culture is
used to inoculate a 1.3-liter fermenter (Eppendorf DASGIP
Bioreactor) with 585 mL of Verduyn fermentation media containing
20 g/L galactose supplemented with hexanoic acid (2 mM), a
carboxylic acid other than hexanoic acid (2 mM), olivetolic acid
(1 mM), or an olivetolic acid derivative (1 mM). A
poly-alpha-olefin may be added to the fermenter as an extractive
agent. The fermenter is maintained at 30 °C and pH 5.0 with
addition of NH4OH. In an initial batch phase, the fermenter is
aerated at 0.5 volume per volume per minute air (VVM) and
agitation ramped to maintain 30% dissolved oxygen. After the
initial sugar is consumed, the rise in dissolved oxygen triggers
feeding of galactose + hexanoic acid (800 g galactose per liter
+ 9.28 g hexanoic acid per liter) at 10 g galactose per liter
per hour in pulses of 10 g galactose per liter doses
(alternatively, rather than feeding the genetically modified
host cells disclosed herein hexanoic acid, olivetolic acid, an
olivetolic acid derivative, or a carboxylic acid other than
hexanoic acid is fed to the genetically modified host cells).
[00928] Between pulses, the feed rate is lowered to 5 g
galactose per liter per hour. Upon a 10% rise in dissolved
oxygen, the feed rate is resumed at 10 g
L<-1>hour<-1>. As genetically modified host cell
density increases, dissolved oxygen is allowed to reach 0%, and
the pulse dose is increased to 50 g galacose per liter. Oxygen
transfer rate is maintained at rates representative of
full-scale conditions of 100 mM per liter per hour by adjusting
agitation as volume increased. Feed rate is adjusted dynamically
to meet demand using an algorithm that alternates between a high
feed rate and low feed rate. During the low feed rate,
genetically modified host cells should consume galactose and
hexanoic acid, or, alternatively, olivetolic acid, an olivetolic
acid derivative, or a carboxylic acid other than hexanoic acid,
and any overflow metabolites accumulated during the high feed
rate. A rise in dissolved oxygen triggers the high feed rate to
resume. The length of time spent in the low feed rate reflects
the extent to which genetically modified host cells are over- or
under-fed in the prior high feed rate pulse; this information is
then monitored and used to tune the high feed rate up or down,
keeping the low feed rate within a defined range.
[00929] Over time, the feed rate matches sugar and hexanoic
acid, or, alternatively, olivetolic acid, an olivetolic acid
derivative, or a carboxylic acid other than hexanoic acid,
demand from genetically modified host cells. This algorithm
ensures minimal net accumulation of fermentation products other
than cannabinoids, cannabinoid derivatives, cannabinoid
precursors, or cannabinoid precursor derivatives; biomass; and
CO2. In some embodiments, the process continues for 5 to 14
days. In certain such embodiments, accumulated broth is removed
daily and assayed for biomass and cannabinoid, cannabinoid
derivative, cannabinoid precursor, or cannabinoid precursor
derivative concentration. A concentrated solution of NH4H2PO4,
trace metals and vitamins are added periodically to maintain
steady state concentrations. Example 1– Synthesis of Olivetolic
Acid or Derivatives Thereof
[00930] The cannabinoid pathway is composed of four biosynthetic
steps using the precursors hexanoyl-CoA, malonyl-CoA, and
geranyl pyrophosphate (FIG.1, Box 4)...
Polypeptide Function Original host
[00937] Multiple polypeptides in pathway 1b require NADH as a
co-factor. In order to maximize flux through pathway 1b, other
biosynthetic pathways that compete for NADH supply are modified
(FIG.1, Box 2). One target can be the ethanol pathway, mediated
by various alcohol dehydrogenase polypeptides, but may also
include other pathways that consume NADH, such as the glycerol
biosynthesis pathway.
[00938] Another route conceived towards hexanoyl-CoA is
described in pathway 1c: The alfatoxin biosynthetic gene cluster
(iterative type I PKS) encodes a fatty acid synthase- based
mechanism (FasA and FasB) for production of hexanoyl-CoA. In
some embodiments, a heterologous nucleic acid encoding a
thioesterase polypeptide and a heterologous nucleic acid
encoding a CoA ligase polypeptide similar to a C6-tolerant
thioesterase polypeptide (see BMC Biochem.2011 Aug 10;12:44.
doi: 10.1186/1471-2091-12-44) and a heterologous nucleic acid
encoding a HCS polypeptide are expressed to facilitate release
of hexanoyl- ACP and activate free hexanoate to its acyl-CoA
compound. Additionally, various type II PKS biosynthetic
pathways (e.g. benastatin, R1128) contain a FabH-like KSIII
(e.g. BenQ, ZhuH), AT and ACP component, which are crucial for
providing and selecting the rare hexanoate PKS starter unit.
Lastly, the type I PKS pathway for reveromycin biosynthesis
encodes the fatty acyl-CoA ligase RevS polypeptide and the
FabH-like KASIII component RevR polypeptide, which are suggested
to provide hexanoyl-CoA via fatty acid degradation as well as de
novo fatty acid biosynthesis. [00939] To avoid competitive
consumption of hexanoyl-CoA via ß-oxidation, the fatty acid
degradation pathway is engineered to have lowered activity.
Alternatively, yeast are grown in presence of oleic acid to
avoid competition for fatty acids as energy source.
[00940] The pathway of four genes encoding the NADH pathway for
hexanoyl-CoA production, including polypeptides PaaH1, Crt, Ter,
and BktB, was constructed under the control of Gal1, Gal10,
Gal7, and TEF2 promoters, respectively. FIG.4. The whole
cassette was inserted between the upstream and downstream
homology region of ADE2 and was integrated into the genome of S.
cerevisiae using CRISPR/Cas9 to generate yXL001 (using Construct
1/pXL044 as shown in FIG.4). The pathway of four genes encoding
the NADPH pathway (including PhaB, PhaJ, Ter, and BktB
polypeptides) was introduced into to S. cerevisiae in the same
way to generate yXL002 (using Construct 1/pXL072 as shown in
FIG.4). The MCT1 gene under the control of Gal1 promoter flanked
by the 1622b homology region (Construct 2; FIG.4) was introduced
into the genome of yXL001 and yXL002 using CRISPR/Cas9 to
generate yXL003 and yXL004 (FIG.4).
[00941] A cassette encoding TKS and OAC genes under the control
of Gal1 and Gal10 promoters flanked by ACC1 homology region
(Construct 4; FIG.5) was introduced into the genome of yXL003
and yXL004 using CRISPR/Cas9 to generate yXL005 and yXL006. A
heterologous nucleic acid encoding a TKS-OAC fusion polypeptide
under the control of a Gal1 promoter (Construct 5; FIG.5) was
introduced into yXL003 and yXL004 to generate yXL007 and yXL008.
The resulting strains were inoculated into 10 mL YP medium
supplemented with 2% dextrose. After an overnight culture at 30
°C and centrifugation at 3,000 × g for 5 mins, the pellet was
resuspended into YP medium supplemented with 2% galactose. After
two days expression, the culture supernatant was extracted with
equal volume of ethyl acetate, and, after evaporation and
filtration, the samples were analyzed by LC-MS, which showed the
production of a significant amount of olivetolic acid (FIG.9 and
FIG.10).
[00942] CsAAE (Construct 3; FIG.4), TKS, and OAC genes
(Construct 4; FIG.5) were introduced into the genome of S.
cerevisiae using CRISPR/Cas9 to generate yXL009, which can
produce higher level of olivetolic acid in the presence of
exogenously supplied hexanoate (FIG.11).
[00943] In addition, by supplementing the growth medium with
various aliphatic acids, from C4-C10, various olivetolic acid
derivatives can be produced from yXL009 (FIG. 11 and FIG.12).
Some of the olivetolic acid derivatives can be further modified
by biological or chemical means to covalently attach to other
compounds. For example, click chemistry can be performed on the
olivetolic derivative containing alkyne functional group. The
olivetolic derivative is dissolved in biology grade dimethyl
sulfoxide (DMSO) and treated with a DMSO solution of crosslinker
containing an azide group (1.0 equiv.), TBTA (DMSO: tBuOH 1:1),
CuSO45H2O, sodium ascorbate and HEPES-KOH pH: 7.0 (final
HEPES-KOH˜250 mM). The reaction is placed on a water bath at 37
°C for 12 to 16 hours. Liquid chromatograph-mass spectrometry
(LC-MS) analysis of the reaction mixture shows reaction
completion after 16 hours to obtain the further modified
olivetolic acid.
[00944] The GPPS large subunit (GPPSlsu) and small subunit
(GPPSssu) genes from Cannabis sativa under the control of Gal1
and Gal10 promoters flanked by ADE1 homology region (Construct
10; FIG.7) were introduced into yXL008 and yXL009 to generate
yXL010 and yXL011. A cassette encoding a NphB polypeptide and a
THCAS polypeptide under the control of Gal1 and Gal10 promoters
flanked by 1014a homology region
(Construct 12; FIG.8) was introduced into the genome of yXL010
and yXL011 to generate yXL012 and yXL013 using CRISPR/Cas9. The
resulting strains were inoculated into 10 mL YP medium
supplemented with 2% dextrose. After an overnight culture at 30
°C and centrifugation at 3,000 × g for 5 mins, the pellet was
resuspended into YP medium supplemented with 2% galactose. After
two days expression, the culture supernatant was extracted with
equal volume of ethyl acetate, and, after evaporation and
filtration, the samples were analyzed by LC-MS, which showed
that the overexpression of NphB in yXL010 resulted in the
production of cannabigerolic acid (FIGS.14 and 15). In the
presence of a THCAS polypeptide, the cannabigerolic acid was
transformed into THCA or into THC. With yXL013, C4-C10acids were
added to the expression medium, resulting in the production of
cannabigerolic acid derivatives, which were then modified by a
THCAS polypeptide to produce THCA or THC derivatives. Those
derivatives can then be further modified by chemical reactions
(FIG.13). Example 3– Synthesis of Cannabinoid Precursors,
Cannabinoids, or Derivatives of the Foregoing
[00945] To recreate cannabinoid production in microorganisms,
chassis S. cerevisiae strains were developed containing
metabolic pathways for the production of (1) GPP through the
mevalonate (Mva) pathway, (2), olivetolic acid or derivatives,
(3) CBGA or derivatives, and (4) different cannabinoids or
cannabinoid derivatives produced by cannabinoid synthase
polypeptides. Production of GPP
[00946] A GPP-overproducing strain, GTY23, was produced by
overexpressing Mva pathway genes and introducing a repressible
promoter on ERG9. A previously described ERG20 F96W-N127W
mutant, ERG20mut, was added to provide a source of GPP precursor
in the cell (FIG.16). This strain was used to screen GOT
polypeptide candidates.
Production
of Olivetolic Acid or Derivatives Thereof
[00947] Olivetolic acid was produced from sugar by introducing
genes CsTKS and CsOAC, and pathways to produce hexanoyl-CoA.
Pathways for the production of hexanoate and hexanoyl-CoA are
known in the art (e.g., Gajewski et al,“Engineering fungal de
novo fatty acid synthesis for short chain fatty acid
production,” Nature Communications 2017). To produce olivetolic
acid or its derivatives, rather than using hexanoyl-CoA
pathways, a previously reported acyl-CoA ligase polypeptide,
such as a CsAAE1 or CsAAE3 polypeptide, was introduced and
exogenously fed cells hexanoate or a carboxylic acid other than
hexanoate (FIGS.17-19). These pathways allow for the production
of non-naturally occurring cannabinoids.
Production
of CBGA
[00948] The mother cannabinoid CBGA, or derivatives thereof, was
produced by a GOT polypeptide. A C. sativa GOT polypeptide was
identified in the 1990s, yet no report was identified describing
reconstituting GOT polypeptide activity in vivo. Twenty-five
polypeptide variants were screened for in vivo production of
CBGA in strains containing GPP pathways and exogenously fed
olivetolic acid. These genes were all chromosomally integrated
driven by GAL1 promoters and screened for activity in yeast
extract peptone galactose (YPG) media. GC-MS and LC-MS analysis
demonstrated in vivo production of CBGA from a CsPT4t
polypeptide (FIGS 26A-C). The gene sequence of the CsPT4t
polypeptide is referred to as a GOT polypeptide (FIG.20). yL444
was the strain used in the production of CBGA and expresses the
following genotype: CEN.PK2-1D {1114a::GAL1p- CsPT4t-TDH1t;
308a::GAL1p-ERG20(F96W-N127W)-TDH1t; erg9::KanMX_CTR3p- ERG9;
leu2-3,112::His3MX6_GAL1p-ERG19/GAL10p-ERG8;
ura3-52::ura3/GAL1p- MvaS(A110G)/GAL10p-MvaE;
his3_1::hphMX4_GAL1p-ERG12/GAL10p-IDI1; MATa} (FIGS.6 and 20).
LC-MS was carried out as follows (FIGS 26A-C):
Column info: 2015 Kinetex XB-C182.1x100 mm RES6 method 10.6 min
Method info:
0-5.6 mins, 45%-73%B, 0.2 mL/min
5.6-6.2 mins, 73%-97%B, 0.2 mL/min 6.2-11.3 mins, 97%B, 0.3
mL/min
11.3-12.7, 97-45%B, 0.3 mL/min
12.7-15.5, 45%B, 0.3 mL/min
A: H2O+0.05% TFA
Production
of THCA and CBDA
[00949] Cannabinoid synthase genes have been identified from the
Cannabis genome (including but not limited to THCA synthase
(THCAS), CBDA synthase (CBDAS), JP450547, JP454863, JP471546,
JP452622). To produce THCA and CBDA, the corresponding THCA
synthase and CBDA synthase, respectively, were introduced into a
strain producing CBGA containing a heterologous nucleic acid
encoding a CsPT4t polypeptide. The synthases were introduced as
N-terminal truncated polypeptides with polypeptide tags, e.g.,
ProA signal sequence (MIFDGTTMSIAIGLLSTLGIGAEA, from proteinase
A with UniProt accession number F2QUG8) attached and the
transcription of both synthases were under the control of GAL10
promoter. The final plasmid constructs were named as
pESC-ProA-THCAS and pESC-ProA-CBDAS. Both plasmids were
transformed individually into the above-mentioned strain, which
has high CBGA production in the presence of olivetolic acid, to
give strains yXL046 and yXL047 (FIGS.21-25).
[00950] After confirming the transformation by PCR of THCAS or
CBDAS, two colonies from each culture were inoculated into a
defined medium (SC-Leu + 2% Dextrose) and were incubated at 30
°C with shaking at 800 RPM. After two-day growth, the cultures
were back-diluted 1:50 into inducing medium (SC-Leu + 2%
galactose + 1 mM olivetolic acid + CuSO4) and incubated at 30 °C
with shaking at 800 RPM for 4 days. After 4-day incubation,
equal volume of ethyl acetate was added to the expression
cultures and the mixtures were subjected to three rounds of bead
beating. Then the mixtures were then spun down at 5000 RPM and
the organic layers were sent for LC-MS analysis, which showed
the production of THCA and CBGA from the corresponding cultures
(FIGS.27 and 28). Example 4– Generation of a Base Yeast Strain
Capable of High Flux to CBGA with Olivetolic Acid Feeding
[00951] CBGA production strains were created from wild-type
Saccharomyces cerevisiae strain (CEN.PK2) by expressing genes of
the mevalonate pathway polypeptides and a GOT polypeptide under
control of the GAL1 or GAL10 promoter. The S21 strain comprised
the following chromosomally integrated mevalonate pathway genes
from S. cerevisiae: ERG10, ERG13, truncated HMG1 (tHMGR), ERG12,
ERG8, ERG19, and IDI1. The S21 strain additionally comprised the
chromosomally integrated pyruvate decarboxylase (PDC) from
Zymomonas mobilis to increase flux from pyruvate towards
acetyl-CoA.
[00952] To generate additionally strains, a mutant form of
ERG20, ERG20mut, which preferentially generates GPP was added to
the S21 strain with the following chromosomally integrated GOTs
from C. sativa: CsPT1 (S164), a truncated CsPT1 (CsPT1_t75,
S165), or CsPT4 (S29). Constructs used in S29, S164, and S165
are shown in Table 11.
[00953] Yeast colonies verified to contain the expected DNA
assembly comprising one or more heterologous nucleic acids
disclosed herein were picked into 96-well microtiter plates
containing 360 µL of YPD (10 g/L yeast extract, 20 g/L Bacto
peptone, 20 g/L dextrose (glucose)) and sealed with a breathable
film seal. Cells were cultured at 30 °C in a high capacity
microtiter plate incubator shaking at 1000 rpm and 80% humidity
for 3 days until the cultures reached carbon exhaustion. The
growth-saturated cultures were subcultured into fresh plates
containing YPGAL and olivetolic acid (10 g/L yeast extract, 20
g/L Bacto peptone, 20 g/L galactose, 1 g/L glucose and 1 mM
olivetolic acid) by taking 14.4 µL from the saturated cultures
and diluting into 360 µL of fresh media and sealed with a
breathable film seal. Genetically modified host cells in the
production media were cultured at 30 °C in a high capacity
microtiter plate shaker at 1000 rpm and 80% humidity for an
additional 3 days prior to extraction and analysis. Upon
completion, 100 µL of whole cell broth was diluted into 900 µL
of methanol, sealed with a foil seal, and shaken at 1500 rpm for
60 seconds to extract the cannabinoids. After shaking, the plate
was centrifuged at 1000 x g for 60 seconds to remove any solids.
After centrifugation, 12 µL of supernatant was transferred to a
fresh assay plate containing 228 µL of methanol, sealed with a
foil seal, shaken for 60 seconds at 900 rpm, and analyzed by
LC-MS...