arxiv: 2605.12409 · v1 · submitted 2026-05-12 · ⚛️ physics.bio-ph

Recognition: 2 theorem links

· Lean Theorem

Kinetics of Mycoprotein Production from Alternative Carbon Substrates

Mark Taylor, Mason Banks, Miao Guo, Nipon Sarmah, Thomas Vinestock, Yiying He

Pith reviewed 2026-05-13 02:18 UTC · model grok-4.3

classification ⚛️ physics.bio-ph

keywords mycoproteinFusarium venenatumalternative carbon substratesbiokineticsGompertz modelexpired functional drinkbiomass yieldfermentative overflow

0 comments

The pith

Expired functional drink supports the fastest mycoprotein growth and highest biomass yield among tested carbon sources.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper studies the growth kinetics of Fusarium venenatum on sugars and real waste streams to identify better carbon sources for mycoprotein production. It establishes that expired functional drink from beverages drives the highest maximum specific growth rate and biomass titre observed, while showing less fermentative overflow and stronger ethanol reassimilation than a matched synthetic control. Substrate choice shapes carbon allocation, with fast sugars like glucose promoting rapid but low-yield growth plus more byproducts, and slower ones like fructose delivering higher yields. Mixed substrates reveal sequential use but with primary sugars limiting later efficiency, pointing to practical value in repurposing beverage waste for protein output.

Core claim

High-throughput screening of F. venenatum A3/5 on monosaccharides, disaccharides, mixtures, and expired functional drink showed that the beverage waste supported the highest maximum specific growth rate and biomass titre of all conditions, with reduced fermentative overflow and enhanced ethanol reassimilation relative to a compositionally matched synthetic control. Rapidly consumed sugars such as glucose and sucrose produced high growth rates but low biomass yield and high byproduct formation, while fructose and xylose gave slower growth yet higher yield and lower overflow. Galactose and lactose displayed distinct induction-limited dynamics, and all dual-substrate systems exhibited diauxic,

What carries the argument

High-throughput screening of growth on alternative carbon substrates analyzed with modified single- and multiphase Gompertz models, plus comparative metrics on time-series substrate consumption and byproduct profiles to identify carbon allocation strategies.

If this is right

Fast-consumed sugars such as glucose drive high growth rates but lower biomass yield and greater fermentative byproducts.
Slower sugars like fructose and xylose increase biomass yield while decreasing byproduct formation.
In dual-substrate mixtures, primary glucose use reduces the efficiency of secondary sugars relative to their solo performance.
Expired functional drink achieves better overall kinetics and carbon capture than a matched synthetic mix.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

Repurposing beverage waste streams could cut input costs and disposal burdens in mycoprotein manufacturing.
The observed metabolic inheritance effects in mixtures suggest targets for strain adaptation to improve mixed-waste performance.
Insights on carbon allocation may apply to other fungal or microbial processes that valorize food-industry discards.

Load-bearing premise

Differences in growth phenotypes and byproduct formation arise primarily from substrate-specific carbon allocation strategies rather than unmeasured factors like pH drift, oxygen limitation, or batch variability.

What would settle it

A controlled repeat of the expired functional drink versus synthetic control comparison under fixed pH, dissolved oxygen, and identical batch conditions to test whether the superior growth rate, biomass titre, and reduced overflow persist.

read the original abstract

High throughput screening was used to study of the biokinetics of F. venenatum A3/5 cultivation on alternative carbon substrates, including monosaccharides, disaccharides and mixtures relevant to food & beverage, dairy and agricultural waste streams. Expired functional drink from the beverage sector was also assessed as the primary carbon source for mycoprotein production. Growth data was analysed using modified single and multiphase Gompertz models for comparison of maximum specific growth rate and progression milestones across diverse growth regimes. Time-series substrate and byproduct data was analysed using comparative metrics, providing an explanatory basis for the different growth phenotypes observed. Substrate type strongly influenced the apparent carbon allocation strategies, with rapidly consumed sugars such as glucose and sucrose supporting high growth rates, low biomass yield and a high degree of fermentative byproduct formation. Fructose and xylose cultivations led to slower overall growth but higher biomass yield and lower byproduct formation. Galactose and lactose showed distinct dynamics that suggested co-existence of transport and metabolic induction limitations. In all dual-substrate systems, sequential utilisation was observed. However, metabolic inheritance and environmental shift effects were highlighted as potential kinetic limitations. These conditions exhibited stunted diauxic growth and low yield from secondary sugars, with glucose-dominated primary growth significantly reshaping secondary substrate efficiencies relative to their study in silo. The expired functional drink supported highly rapid growth and achieved the highest maximum specific growth rate and biomass titre of all conditions examined, alongside reduced fermentative overflow and enhanced ethanol reassimilation relative to a compositionally matched synthetic control.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

The expired functional drink drives fast growth and high biomass in F. venenatum with less overflow than a synthetic control, but pH and oxygen controls are the key thing to verify before trusting the carbon-allocation story.

read the letter

The paper's core finding is that an expired functional drink supports the highest maximum specific growth rate and biomass titre among the tested conditions, with better ethanol reassimilation and lower fermentative byproducts than a compositionally matched synthetic mix. They screened monosaccharides, disaccharides, and waste-relevant mixtures on F. venenatum using high-throughput methods, then fitted single- and multiphase Gompertz models to extract growth parameters and milestones. Byproduct time series add an explanatory layer for why glucose and sucrose give rapid but low-yield growth while fructose and xylose give slower but higher-yield profiles. Dual-substrate runs show clear sequential use, with some carry-over effects from primary sugar metabolism. The real expired drink is the practical hook here; it moves beyond model sugars to something that could actually come from a waste stream. That part is useful for anyone thinking about circular bioprocesses. The modeling is applied consistently and the qualitative trends line up with known physiology for this organism. The main soft spot is the lack of reported numbers, error bars, or statistical tests in the abstract, which makes it hard to judge effect sizes. The stress-test concern about uncontrolled pH drift or oxygen limitation is reasonable on the evidence given; even small shifts in those variables can flip respiration-fermentation balance in F. venenatum, and the drink medium might differ in buffering or viscosity from the control. If the full methods show no buffering or DO monitoring, that attribution to substrate-specific carbon strategies needs qualification. This is targeted work for bioprocess engineers and mycoprotein groups who want screening data on real waste streams. A reader already working on fungal fermentation or sustainable feedstocks will get concrete comparisons they can build on. It is coherent enough and grounded enough in actual experiments to deserve peer review, though the referees will probably ask for more quantitative tables and clearer control data.

Referee Report

3 major / 2 minor

Summary. The manuscript uses high-throughput screening to examine Fusarium venenatum A3/5 growth kinetics on monosaccharides, disaccharides, and an expired functional drink as carbon sources. Modified single- and multiphase Gompertz models are fitted to compare maximum specific growth rates, biomass titres, and progression milestones, while time-series substrate and byproduct data are used to infer carbon allocation strategies. The central claim is that the expired drink supports the highest μ_max and biomass titre of all conditions, with reduced fermentative overflow and enhanced ethanol reassimilation relative to a compositionally matched synthetic control; substrate type is said to dictate allocation, with glucose/sucrose yielding rapid but low-yield fermentative growth and fructose/xylose yielding slower but higher-yield growth.

Significance. If the quantitative claims hold after addressing controls and data presentation, the work would provide practical value for valorizing beverage waste in mycoprotein production and would illustrate how substrate mixtures reshape diauxic kinetics relative to single-substrate baselines.

major comments (3)

[Abstract] Abstract: the claim that the expired functional drink 'supported highly rapid growth and achieved the highest maximum specific growth rate and biomass titre of all conditions examined' is presented without any numerical values, standard errors, replicate counts, or statistical comparisons; the same section states qualitative trends for all other substrates but supplies no supporting data tables or figures.
[Methods/Results] Methods/Results: no pH profiles, buffering capacity measurements, or dissolved-oxygen time courses are reported for the HTS conditions. Because even modest pH drift or transient hypoxia can shift the respiration/fermentation balance in F. venenatum, the attribution of superior growth metrics and reduced overflow to 'substrate-specific carbon allocation strategies' cannot be isolated from possible confounding by medium-specific buffering or aeration differences.
[Results] Results: growth parameters are derived from modified Gompertz fits, yet no goodness-of-fit statistics (R², RMSE), parameter uncertainties, or raw optical-density time series are shown; without these, it is impossible to assess whether the reported differences in μ_max and biomass titre between the expired drink and the synthetic control exceed experimental variability.

minor comments (2)

[Abstract] Abstract: 'study of the biokinetics' is grammatically incomplete; rephrase for clarity.
[Abstract] Abstract: the phrase 'metabolic inheritance and environmental shift effects' is introduced without definition or mechanistic elaboration, leaving the interpretation of stunted diauxic growth unclear.

Simulated Author's Rebuttal

3 responses · 1 unresolved

We thank the referee for their constructive and detailed comments on our manuscript. We have addressed each major point below, making revisions where feasible to improve clarity, transparency, and robustness of the claims.

read point-by-point responses

Referee: [Abstract] Abstract: the claim that the expired functional drink 'supported highly rapid growth and achieved the highest maximum specific growth rate and biomass titre of all conditions examined' is presented without any numerical values, standard errors, replicate counts, or statistical comparisons; the same section states qualitative trends for all other substrates but supplies no supporting data tables or figures.

Authors: We agree that the abstract would be strengthened by quantitative support. In the revised manuscript, we have added the specific μ_max (with standard error) and biomass titre values for the expired functional drink, along with replicate counts (n=3) and a note on statistical comparisons to the synthetic control. We have also inserted parenthetical references to the relevant figures and tables for the qualitative trends on other substrates. revision: yes
Referee: [Methods/Results] Methods/Results: no pH profiles, buffering capacity measurements, or dissolved-oxygen time courses are reported for the HTS conditions. Because even modest pH drift or transient hypoxia can shift the respiration/fermentation balance in F. venenatum, the attribution of superior growth metrics and reduced overflow to 'substrate-specific carbon allocation strategies' cannot be isolated from possible confounding by medium-specific buffering or aeration differences.

Authors: The experiments were performed in a 96-well microtiter plate format with orbital shaking, which does not permit continuous pH or DO monitoring without specialized instrumentation not available for this study. We have revised the Methods to specify the phosphate buffering system, initial pH of 5.5 for all conditions, and newly added buffering capacity measurements for each medium. A limitations paragraph has been added to the Results/Discussion noting potential pH or oxygen effects while emphasizing that the compositionally matched synthetic control was run under identical physical conditions, supporting our interpretation that substrate composition drives the observed allocation differences. revision: partial
Referee: [Results] Results: growth parameters are derived from modified Gompertz fits, yet no goodness-of-fit statistics (R², RMSE), parameter uncertainties, or raw optical-density time series are shown; without these, it is impossible to assess whether the reported differences in μ_max and biomass titre between the expired drink and the synthetic control exceed experimental variability.

Authors: We have added a supplementary table with R² and RMSE values for every Gompertz fit, together with the standard errors of the estimated parameters. The full raw optical-density time-series datasets have been deposited in a public repository (with DOI referenced in the revised manuscript) to allow independent assessment of fit quality and the statistical significance of differences between the expired drink and synthetic control. revision: yes

standing simulated objections not resolved

Continuous pH profiles and dissolved-oxygen time courses for the individual high-throughput screening conditions, which were not recorded during the experiments owing to the technical constraints of the 96-well plate format.

Circularity Check

0 steps flagged

No circularity: purely empirical comparison of fitted growth parameters

full rationale

The manuscript reports high-throughput experimental growth curves for F. venenatum on defined sugars, mixtures, and an expired beverage, fitted with standard single- and multiphase Gompertz models to extract μ_max and biomass titre. These parameters are then compared directly across conditions, together with measured substrate consumption and byproduct profiles. No derivation, prediction, or first-principles claim is advanced that reduces by construction to the fitted values themselves; the central claims remain descriptive statements about observed phenotypes relative to a matched control. No load-bearing self-citations or ansatz smuggling appear in the provided text. The analysis is therefore self-contained empirical reporting.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 0 invented entities

The central claims rest on the validity of modified Gompertz models for describing multiphase growth and on the assumption that substrate type is the dominant driver of observed phenotypes.

free parameters (1)

Gompertz model parameters (mu_max, lambda, etc.)
Fitted separately to each substrate's growth curve to extract maximum specific growth rate and milestones.

axioms (1)

domain assumption Modified single and multiphase Gompertz models provide accurate and comparable descriptions of growth kinetics across diverse regimes
Invoked to compare maximum specific growth rate and progression milestones.

pith-pipeline@v0.9.0 · 5582 in / 1122 out tokens · 46799 ms · 2026-05-13T02:18:31.025755+00:00 · methodology

discussion (0)

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

IndisputableMonolith/Cost/FunctionalEquation.lean washburn_uniqueness_aczel unclear
Growth data was analysed using modified single and multiphase Gompertz models... Substrate type strongly influenced the apparent carbon allocation strategies...
IndisputableMonolith/Foundation/RealityFromDistinction.lean reality_from_one_distinction unclear
The expired functional drink supported highly rapid growth and achieved the highest maximum specific growth rate...

Reference graph

Works this paper leans on

3 extracted references · 3 canonical work pages

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work page doi:10.1128/aem.56.6.1875-1881.1990 1990
[2]

Avoiding overflow metabolite formation in Komagataella phaffii fermentations to enhance recombinant protein production,

T. Steimann et al., "Avoiding overflow metabolite formation in Komagataella phaffii fermentations to enhance recombinant protein production," (in eng), J Biol Eng, vol. 18, no. 1, p. 54, Oct 3 2024, doi: 10.1186/s13036-024-00453-0. [65] I. M. Helander and T. Mattila‐Sandholm, "Fluorometric assessment of Gram‐negative bacterial permeabilization," Journal o...

work page doi:10.1186/s13036-024-00453-0 2024
[3]

Contribution of citrate metabolism to the growth of Lactococcus lactis CRL264 at low pH,

C. Sánchez et al., "Contribution of citrate metabolism to the growth of Lactococcus lactis CRL264 at low pH," (in eng), Appl Environ Microbiol, vol. 74, no. 4, pp. 1136-44, Feb 2008, doi: 10.1128/aem.01061-07. [80] Z. Wang and J. E. Jablonski, "Targeted and non-targeted detection of lemon juice adulteration by LC-MS and chemometrics," Food Additives & Con...

work page doi:10.1128/aem.01061-07 2008