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3-hydroxypropionate is the conjugate base formed when the carboxyl group of 3-hydroxypropionic acid loses a proton. Its structure isThe primary ChEBI record gives formula ${\mathrm{C}}_3{\mathrm{H}}_5{\mathrm{O}}_3$, net charge $-1$ and the systematic name 3-hydroxypropanoate. The terminal hydroxyl group remains present; the acid-to-base change occurs at the carboxyl group, not by moving that hydroxyl or removing the carbon skeleton.^[ref]

The acid–base pair can be represented asIn a dilute-solution approximation with activity coefficients treated as equal, the Henderson-Hasselbalch equation givesAt a pH one unit above the relevant $\mathrm{p}{K}_a$, the ratio is $10:1$, so about $10/11$ of the acid-plus-conjugate-base pool is anionic in that model. This is an illustrative equilibrium calculation; no numerical $\mathrm{p}{K}_a$ for this compound is being supplied.

Speciation and total amount answer different analytical questions. If no other reactions occur, changing pH can redistribute $[\mathrm{HA}]$ and $[{\mathrm{A}}^{-}]$ while preserving their sum. A negatively charged 3-hydroxypropionate ion in a bulk solution is accompanied by compensating positive charge elsewhere; it is not the same molecular species as the neutral acid or a complete named salt.

The record’s average mass of $89.070g/mol$ applies to the anion’s composition. Reporting a concentration as acid equivalents instead uses the acid’s reference mass, while reporting a particular salt requires the salt’s complete composition. This distinction matters when comparing metabolic engineering measurements that use an acid name for a total analytical product pool.^[ref]

3-hydroxypropionic acid is a three-carbon beta-hydroxy acid with structureIts carboxyl group carbon is numbered 1; the additional hydroxyl group is on carbon 3. The primary ChEBI record identifies the systematic name 3-hydroxypropanoic acid, formula ${\mathrm{C}}_3{\mathrm{H}}_6{\mathrm{O}}_3$ and average molecular mass $90.078g/mol$. The acid and its conjugate base, 3-hydroxypropionate, are distinguished chemical species.^[ref]

Moving the hydroxyl group by one carbon gives the different connectivity of lactic acid, $\mathrm{C}{\mathrm{H}}_3\mathrm{CH}(\mathrm{OH})\mathrm{COOH}$. The two acids have the same molecular formula but are constitutional isomers. Molecular mass alone cannot decide which one a sample contains. The terminal alcohol and the carboxyl group also provide different sites for chemical transformation; the compound’s name specifies the initial structure rather than guaranteeing one reaction pathway.

An experimentally demonstrated motivation is production as a chemical building block by metabolic engineering. In the 2016 primary study by Chan Woo Song and colleagues, engineered Escherichia coli produced $31.1g/L$ of 3-hydroxypropionic acid in fed-batch culture. The study screened enzyme combinations and altered the strain, so the observation concerns a particular engineered production system rather than a universal property of the species.^[ref]

Using the record’s molecular mass, that mass concentration corresponds to approximatelyof acid equivalents. This conversion is an original calculation, not a separate measurement. Product concentration alone gives neither production rate without a time interval nor mass yield without substrate consumption. Chemical identity, accumulated amount and process performance remain different experimental questions.

Primary curated chemical record: www.ebi.ac.uk/chebi/CHEBI:33404 . CHEBI:33404, 3-hydroxypropionic acid; CAS 503-66-2. Definition, structure and formula identify a terminal hydroxy group on propionic acid, with formula C3H6O3 and SMILES O=C(O)CCO. The ontology classifies the compound as a 3-hydroxy monocarboxylic acid, CHEBI:35969; the Names section gives 3-hydroxypropanoic acid. Last Modified is 24 January 2023; no publication date or individual authorship is inferred.

The same CHEBI:33404 record, www.ebi.ac.uk/chebi/CHEBI:33404 , gives Average Mass 90.078 and lists the conjugate-base relation to 3-hydroxypropionate, CHEBI:16510, in the Ontology section. These support the species distinction and the mass-to-molar concentration conversion in 3-hydroxypropionic acid.

A beta-hydroxy acid is a carboxylic acid with a hydroxyl group on the beta carbon: the carbon two carbon–carbon bonds away from the carboxyl group carbon. For a simple chain numbered from the carboxyl carbon as carbon 1, the beta carbon is carbon 3. The hydroxyl within the carboxyl group itself does not establish the additional hydroxy substitution.

The small example 3-hydroxypropionic acid has structureStarting at the carboxyl carbon, the adjacent $\mathrm{C}{\mathrm{H}}_2$ is alpha and the terminal $\mathrm{C}{\mathrm{H}}_2\mathrm{OH}$ is beta. The primary ChEBI record gives the systematic name 3-hydroxypropanoic acid, formula ${\mathrm{C}}_3{\mathrm{H}}_6{\mathrm{O}}_3$ and its classification as a 3-hydroxy monocarboxylic acid.^[ref]

An alpha-hydroxy acid instead places the additional hydroxyl group one carbon closer to the carboxyl group. Thus lactic acid, $\mathrm{C}{\mathrm{H}}_3\mathrm{CH}(\mathrm{OH})\mathrm{COOH}$, and 3-hydroxypropionic acid, $\mathrm{HOC}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{COOH}$, have the same molecular formula but different atom connectivity. They are constitutional isomers; counting oxygen atoms or measuring molecular mass alone cannot distinguish them. The distinction is structural, not a statement about acidity or biological activity.^[ref]

The two functional groups also describe different possible transformations. Removing the carboxyl proton forms a carboxylate while preserving the beta-hydroxy carbon skeleton. Converting the hydroxyl group to a carbonyl changes the hydroxy-acid functionality. Which transformation occurs depends on reagents and conditions; the class name alone supplies no reaction rate or treatment claim. Tracking positions relative to the carboxyl group makes such structural changes easier to compare.

Chan Woo Song is the first-listed author of the 2016 primary paper on producing 3-hydroxypropionic acid and malonic acid through an engineered bacterial pathway. Its verified byline and chemical/biomolecular engineering affiliation identify a concrete contribution to metabolic engineering.^[ref]

The product pair illustrates why chemical identity is part of evaluating a biological production system. 3-hydroxypropionic acid has a terminal alcohol group, whereas malonic acid has a carboxyl group at each end of its three-carbon skeleton. The two products are not interchangeable merely because both contain three carbon atoms. Route selection must account for the chemical transformation as well as carbon bookkeeping.

An original analytical illustration considers a culture in which a signal rises after a strain modification. That observation alone does not establish more of the intended product: the signal could include another compound or change with recovery. Product-specific identification and an amount measurement address different parts of the claim. Song’s documented publication belongs to this experimental connection between pathway construction and chemical output; the byline does not specify which individual author performed each step.

In Jin Cho is a verified coauthor of the 2016 primary paper on engineered Escherichia coli production of 3-hydroxypropionic acid and malonic acid, documenting a contribution to metabolic engineering.^[ref]

KAIST’s dated 2017 institutional news also identifies Cho’s research on biological conversion of p-xylene to terephthalic acid with engineered Escherichia coli. That is a distinct chemical-production problem: converting the two methyl substituents of the aromatic starting material into carboxyl groups while retaining the ring skeleton.^[ref]

An experimental assessment of such a conversion must distinguish consumption of starting material from formation of the intended product. Disappearance of a substrate can also reflect competing reactions or losses. Measuring both substrate and product, with a specified chemical identity and balance, tests the conversion more directly than measuring growth alone.

These publications connect Cho with engineering biological transformations and evaluating their chemical output. They do not establish a separate biography from a matching name alone, nor do they assign every step of the collaborative work to one researcher.

Je Woong Kim is a verified coauthor of the 2016 primary study on metabolic engineering of Escherichia coli for production of 3-hydroxypropionic acid and malonic acid. The paper’s affiliation places this published work in chemical and biomolecular engineering; it does not by itself establish a current position or an individual experimental role.^[ref]

A useful scientific question in that research area is how pathway output is measured across cultures. For an original example, product concentration $2g/L$ in $0.10\mathrm{L}$ corresponds to $0.20\mathrm{g}$, while $1g/L$ in $0.50\mathrm{L}$ corresponds to $0.50\mathrm{g}$. The more concentrated culture contains less total product. Comparing production systems therefore requires stating whether the quantity is concentration, accumulated mass, a time-dependent rate or a yield relative to consumed substrate.

This measurement distinction explains why chemical engineering analysis accompanies pathway construction. Genetic changes, culture conditions and the chosen normalization jointly determine what an experimental comparison establishes. Kim’s documented coauthorship supplies the research connection; the illustrative arithmetic is explanatory and is not attributed to a particular experiment or author task.

Metabolic engineering deliberately modifies a biological system’s reaction pathways and regulation to change its chemical production or other metabolic behavior. Altering an enzyme, its expression or the availability of a precursor can redirect metabolic flux. The desired outcome is a measured cellular or process phenotype, not merely a changed gene sequence.

A stoichiometric matrix provides one useful bookkeeping model. If $\mathbf{x}$ contains intracellular metabolite amounts per volume, $S$ encodes reaction stoichiometry and $\mathbf{v}$ contains reaction rates, a simplified balance isA steady intracellular state imposes $S\mathbf{v}=0$. This condition conserves the represented species but generally does not determine a unique flux vector. Enzyme capacities, substrate supply and other biological constraints are additional information.

An original two-branch example consumes a common precursor through product and competing routes. At steady state, $v_{\mathrm{in}}=v_P+v_B$. Reducing the capacity of the competing route need not increase $v_P$ by the same amount: precursor supply can fall, another route can increase, or the precursor can accumulate until regulation changes. A pathway diagram by itself cannot establish a production gain.

A concrete primary experiment is the 2016 work by Chan Woo Song, Je Woong Kim, In Jin Cho and Sang Yup Lee. Engineered Escherichia coli strains were screened and modified to produce 3-hydroxypropionic acid or malonic acid; the abstract reports $31.1g/L$ and $3.60g/L$ respectively in fed-batch cultures. The two results concern different engineered product routes, rather than simultaneous outputs guaranteed for every strain.^[ref]

Evaluation therefore compares controlled strains, product identity, accumulated amount, substrate consumption and time. A higher final product concentration does not alone prove a higher yield or production rate. Metabolic engineering connects molecular changes with reaction-network balances and chemical engineering measurements of the actual production process.

Sang Yup Lee is a chemical engineer whose research includes metabolic engineering, systems biology and synthetic biology. KAIST’s institutional profile identifies him with its Department of Chemical and Biomolecular Engineering and describes research on engineered microbial production systems.^[ref]

A concrete publication is the 2016 primary study coauthored with Chan Woo Song, Je Woong Kim and In Jin Cho on engineered Escherichia coli production of 3-hydroxypropionic acid and malonic acid. The project connects modification of metabolic pathways with measured chemical production, rather than treating expression of a gene as proof of successful manufacture.^[ref]

The engineering distinction is between a possible biochemical route and a functioning production process. A route can satisfy a reaction-network balance while being limited by enzyme capacity, cellular resource demands or transport. Testing product identity, amount and production conditions therefore complements genetic design. This connection between molecular interventions and measurable process behavior is central to the documented research area.