Microalgae-bacteria interactions have recently emerged as a potential approach to enhance microalgal growth and metabolite production. However, successful co-culturing relies on synergistic and metabolically complementary interactions between microalgae and associated microorganisms, which enhance culture stability and productivity. Rather than introducing exogenous bacteria, characterising native host-associated microbiomes represents an ecologically relevant strategy, as these communities may reflect long-standing mutualistic or syntrophic interactions. Despite increasing interest in biofilm-based cultivation, microbial dynamics within microalgal biofilms in bioreactors remain poorly understood compared to planktonic systems. In this study, we investigated bacterial succession in a monoalgal biofilm of the oleaginous benthic diatom Amphora sp. during its exponential growth phase in a porous substrate photobioreactor (PSBR), aiming to identify key bacterial taxa for future co-culturing experiments. The exponential phase was targeted due to its relevance for biomass accumulation and active cellular metabolism underpinning productivity in biofilm-based systems. Non-axenic Amphora sp. was grown in F/2-enriched artificial seawater, and bacterial community dynamics were assessed at Day 0, Day 3 (mid-exponential), and Day 6 (late-exponential) using PacBio Sequel II/IIe 16S rRNA amplicon sequencing. Distinct phase-dependent shifts in bacterial community composition were observed, with Alphaproteobacteria declining over time and concomitant increases in Flavobacteriia and Planctomycetota. Despite these changes, bacterial communities maintained relatively stable evenness, structured around a few pivotal taxa. Marivita , Sulfitobacter , Polaribacter , and Rhodopirellula were identified as key bacterial taxa dynamically associated with the exponential phase of Amphora sp. Overall, this study provides a foundational screening framework to identify native bacterial candidates for co-culturing with mono-microalgal biofilms. • The bioreactor ecology of mono-microalgal biofilms remains poorly understood. • Bacterial dynamics of Amphora biofilm during active growth in a PSBR were studied. • Phase-dependent shifts in bacterial community and predicted functions were observed. • Marivita , Polaribacter , Sulfitobacter and Rhodopirellula were key bacterial taxa.

Applying a single parameter set to describe complex mammalian kinetics often is too simplistic, as it fails to capture sensitive cell-to-environment interactions that may be exploited to optimize production performance. To resolve this time dependency, intra-experimental parameter shifts as part of design of dynamic experiments (DoDE) can be performed to study mammalian growth and production kinetics in fed-batch processes. This enables growth phase-dependent optimization, aligned with cellular requirements. Here, we provide a comprehensive, head-to-head comparison of our phase-dependent optimization approach with intra-experimental shifts of process parameters to a static optimization that retains parameter settings through the entire bioprocess. Showcasing a monoclonal antibody production process development scenario, the study examines growth phase-dependent effects of temperature (T) and dissolved oxygen (DO) together with time-invariant parameters for feed and seeding cell density. While the static optimization suggests settings near the center of the design space, phase-dependent optimization finds an optimum by shifting T and DO between the exponential growth, transition, and production phases. Overall, the phase-wise optimized process gives an experimentally validated ~30% increase in product titer while maintaining comparable product quality. Furthermore, the approach breaks the correlation between product titer and acidic charged variants: both depend on T but at different timeframes. Additionally, DoDE uncovers a crucial interaction between T and DO, with low T and high DO during the exponential growth phase, leading to strong lactate accumulation. The data demonstrate the advantages of phase-dependent optimization enabled by DoDE. The results may serve as a good practice example for follow-up research.

Persistent luminescence nanoparticles (PLNPs) have attracted significant attention in biosensing and bioimaging. However, the variety of PLNPs that can be directly synthesized via bottom-up approaches remains largely limited to ZnGa2O4:Cr, Zn2GeO4:Mn, and their analogs. Herein, we report new spinel-structured CaSc2O4:Tb (CSO) PLNPs synthesized via a straightforward one-step hydrothermal method. The morphology of CSO PLNPs can be precisely tuned from spindle-like to bipyramidal and rod-like structures by adjusting the pH values of the synthesis solution, which in turn directly modulates their persistent luminescence intensity and decay duration. The CSO PLNPs were further functionalized with an azo-bond-containing BHQ-1 quencher to construct CSO-BHQ nanoprobes for profiling bacterial extracellular metabolism by targeting azoreductase (AzoR) activity. As a key enzyme in extracellular bacterial metabolism, AzoR participates in critical processes including azo-antibiotic degradation and bacterial communication, and its secretion level serves as an indicator of metabolic activity. Detecting AzoR secretion across different bacterial growth phases shows that enzyme production peaked during the exponential growth phase, reflecting the most active stage of extracellular metabolism. Moreover, by assessing extracellular metabolic activity with the CSO-BHQ nanoprobes, we can also determine bacterial antibiotic susceptibility. For instance, S. aureus was found to be insensitive to ampicillin but highly susceptible to vancomycin, while E. coli showed the opposite sensitivity profile. This work not only introduces a new class of easily synthesized PLNPs but also highlights their promising utility in tracking bacterial metabolism and rapidly identifying antibiotic susceptibility.

Per- and polyfluoroalkyl substances (PFASs) are persistent contaminants with potential risks to environmental and human health. While perfluorinated compounds are highly recalcitrant, polyfluoroalkyl substances (aka precursors) can undergo biotransformation with fluorotelomer carboxylic acids (FTCAs) commonly observed as intermediates. We evaluated how FTCA structural features impact biotransformation and demonstrate that the soil bacterium Pseudomonas sp. strain 273 defluorinates FTCAs with even numbers of nonfluorinated carbons (n:2 and n:4 FTCAs), but not those with uneven numbers (n:3 and n:5 FTCAs). Growth and transformation occurred with 1:5 FTCA but defluorination of FTCAs containing <5 nonfluorinated carbons was cometabolic and required a primary carbon substrate (e.g., sebacate). Fluoride release started with the onset of growth, increased throughout the exponential growth phase, and extended into the stationary phase. Transformation of n:2 FTCAs yielded inorganic fluoride, the corresponding (n-1):3 FTCAs, perfluorocarboxylic acids (PFCAs) with one less perfluorinated carbon atom (i.e., [n-1] PFCAs), and trace amounts of shorter-chain ([n-2], [n-3]) PFCAs. The detection of 2:2 fluorotelomer unsaturated carboxylic acid, 3-OH-1:3 FTCA, 3-keto-1:3 FTCA, 1:3 FTCA, and trifluoroacetic acid, a maximum defluorination degree of ∼35.9%, and a total fluorine recovery of ∼96.8% support that 2:2 FTCA cometabolism involves β-oxidation pathway enzymes. These findings advance our understanding of bacterial FTCA transformation and defluorination, providing insights into the environmental fate of precursors.

The rapid expansion of lithium-ion battery (LIB) production, driven by the rise of electric vehicles and renewable energy storage, has led to growing concerns about end-of-life management and critical material recovery. In this context, biotechnological processes represent an environmentally sustainable alternative to conventional recycling methods such as pyrometallurgy and hydrometallurgy, offering reduced impacts on both ecosystems and human health. However, the performance of bioleaching systems depends heavily on microbial tolerance to toxic metals released from LIBs. This study focuses on assessing the toxicological effects of Co, a key strategic metal in LIBs, on Acidithiobacillus ferrooxidans, a model organism for bioleaching applications. Experimental findings reveal that Co exhibits greater toxicity than Cu, Cd, Ni, Zn, and As, but is less toxic than Cr. Co concentrations exceeding 5g/L result in a 260% increase in Fe2+ oxidation time and an 80% reduction in the Fe oxidation rate. Additionally, elevated Co levels significantly prolong the exponential growth phase, indicating metabolic stress. A predictive mathematical model was developed and validated to describe bacterial growth and Fe2+ oxidation under varying Co concentrations, achieving a determination coefficient (R2) above 0.95. This model serves as a practical tool for optimizing process parameters in the bio-recycling of LIBs, enabling more efficient and scalable engineering applications. These findings contribute to the advancement of greener technologies for critical raw material recovery and support the integration of bio-based methods into circular economy strategies for battery waste management.

Methyltransferase CclA-dependent control of secondary metabolite gene clusters and stress response in aspergillus nidulans.

Dynamic secretion of Lactobacillus plantarum PO23 (LP-PO23) moonlighting proteins and its regulation of the adherence of LP-PO23 cells.

The central role of YB-1 in messenger ribonucleoprotein particle (mRNP) metabolism and stress-granule biology highlights the importance of defining the determinants of its self-assembly. YB-1 fibrillogenesis has been attributed primarily to the cold shock domain (CSD). Here, we show that the YB-1 fragment spanning residues 1-129 (AP-CSD) form amyloid fibrils under near-physiological ionic strength (0.12-0.15 M KCl). Fibrillization proceeds without a pronounced exponential growth phase and increases approximately linearly over 45-50 h. Far-UV circular dichroism (CD) and attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) indicate no substantial change in overall secondary-structure content during aggregation. In parallel, 1H nuclear magnetic resonance (NMR) spectroscopy reveals the depletion of soluble species, and oriented fiber X-ray diffraction displays the hallmark cross-β reflections at approximately 4.7 Å and 10 Å. The prolonged formation time implies an activation barrier that is unlikely to require global refolding. Instead, it may reflect early association events such as dimerization or other local rearrangements required for primary nucleation, followed by consolidation into stable intermolecular contacts. Aggregation that preserves a largely native-like fold while establishing cross-β order may reduce recognition by cellular quality-control systems that preferentially target globally unfolded or strongly destabilized states. This provides a plausible framework for how YB-1 derived assemblies could persist under stress and during age-associated proteostasis decline.

Lactate is a major byproduct of Chinese hamster ovary (CHO) cell metabolism, typically accumulating during the exponential growth phase and being consumed later during the production phase. Although commonly viewed as a waste product, recent studies suggest that lactate may play a broader role in cellular regulation. To investigate this, we developed a system to modulate intracellular lactate levels by co-expressing lactate oxidase (LOX) and catalase (CAT) in specific cellular compartments, including the cytosol, nucleus, and mitochondria. Using CHO cells secreting a bispecific antibody, this approach enabled assessment of how compartment-specific reduction of intracellular lactate influences cell performance. Reduction of nuclear lactate levels resulted in the most pronounced improvements, including approximately 40% higher viable cell density, 35%-40% increased protein titer, and reduced oxidative stress in fed-batch cultures. In contrast, reduction of mitochondrial lactate levels had minimal impact, indicating that the functional role of lactate is highly dependent on its subcellular localization. Further analysis demonstrated that intracellular lactate reduction was associated with decreased histone acetylation and histone lactylation, a recently described epigenetic modification linked to lactate metabolism. These epigenetic changes correlated with reduced markers of DNA damage and repair activity, suggesting improved genome stability. Overall, our findings indicate that lactate functions as more than a metabolic byproduct and may act as a regulatory metabolite influencing epigenetic state and cellular performance. Targeted modulation of intracellular lactate therefore represents a promising strategy to enhance productivity in CHO cell cultures.

The perception that high water retention time (WRT) inbuildingsincreases microbial and pathogen growth drives costly flushing interventions,which lack a scientific framework to guide effective implementation.Here, we evaluate the effect of WRT from 1 to 21 days in an at-scalebuilding plumbing rig with influent chloramine residuals of <0.2–2.5mg/L as Cl2 and water heater set points of 40 and 60 °C.We found that the classic microbial growth curve consisting of lag,exponential growth, stationary, and decay phases provided a robustexplanation of trends in bulk water total cell counts (TCC) and Legionella pneumophila over a wide range of conditions.We extended this observation to develop a framework to understandhow various controls and operating conditions act to stop (e.g., coldtemperatures, disinfectant) or reset (e.g., pasteurization in waterheaters killing microbes and recycling nutrients) the growth curveas a function of WRT. Bulk water TCC and L. pneumophila reached a consistent peak/plateau at a building WRT of ∼7days before decaying up to 90% at higher WRT. These findings suggestthat recent guidelines recommending weekly flushing of buildings maysometimes be counterproductive and that very high WRT does not necessarilyindicate microbial risk.

RNase PH is a critical exoribonuclease in Escherichia coli that participates in tRNA maturation and RNA degradation. In earlier work, it was observed that levels of RNase PH decreased as much as 90% under conditions of nutrient deprivation, such as induced starvation and prolonged stationary phase, and that its removal was likely due to the degradation of the protein. Here, we examine the mechanisms involved in this regulatory process. We find that the protease Lon is primarily responsible for the removal of RNase PH that occurs in stationary phase and starvation. Conversely, RNase PH remains stable during the exponential phase of growth due to a protective interaction with the chaperonin protein, GroEL. Overproduction of GroEL protects RNase PH even under conditions of nutrient deprivation. Additionally, we find that RNase II activity also is required for the degradation of RNase PH, implying the involvement of an RNA molecule in the overall regulatory process. In mutant strains devoid of RNase II activity, even though retaining RNase II protein, RNase PH levels remain unchanged during nutrient deprivation which leads to excessive rRNA removal and ultimately to loss of viability. These findings provide another example of the complex regulatory mechanisms that underscore the importance of maintaining appropriate RNase levels under varying physiological conditions.IMPORTANCEThis work provides important new information on the regulation of a bacterial ribonuclease as it responds to nutrient deprivation. We find that RNase PH levels decrease up to 90% in late stationary phase and upon carbon starvation. We show that the enzyme is degraded by a protease under the stress conditions but that it is protected during growth by interaction with another protein, the chaperonin GroEL. This interaction does not occur under the stress conditions rendering RNase PH susceptible to degradation by protease Lon. We also find that the activity of another ribonuclease, RNase II, plays a role in the process, and that in the absence of RNase II activity, RNase PH does not decrease in stationary phase leading to cell death due to ribosome degradation. These studies identify a new mechanism of ribonuclease regulation and emphasize the importance of this regulation for cellular homeostasis.

Microbial lipid metabolism can be modulated by non-invasive physical stimuli, offering a sustainable route to tailor functional biomaterials. Here, we report for the first time the frequency-dependent modulation of single cell oils (SCOs) in the oleaginous yeast Rhodotorula sp. and the filamentous fungus Aspergillus flavus through alternating current (AC) electrostimulation during exponential and stationary growth phases. Cultures were exposed to AC frequencies ranging from 100Hz to 1MHz under nitrogen-limited conditions, and lipid yield, fatty acids (FAs) composition, and ultrastructural changes were assessed via gravimetric analysis, GC-MS, FTIR spectroscopy, and TEM imaging. Low-frequency stimulation (100Hz-1kHz) significantly enhanced lipid accumulation (up to 2.7-fold above controls) with enrichment in oleic acid, a monounsaturated fatty acid (MUFA). Mid-frequency exposure (10-100kHz) favored MUFAs accumulation at early stages but later suppressed unsaturation, implying transient desaturase modulation. High-frequency treatment (1MHz) selectively enriched polyunsaturated fatty acids (PUFAs), particularly linoleic acid (ω-6), during prolonged cultivation, linking oxidative stress responses to lipid remodeling. TEM revealed frequency-specific ultrastructural adaptations, including lipid droplet enlargement, membrane invaginations, and autophagic activity. Together, these results demonstrate that AC frequency acts as a tunable "metabolic switch" capable of enhancing both the quantity and quality of microbial lipids. This strategy offers strong potential for scalable production of biofunctional lipids relevant to biofuels, nutraceuticals, biomedical, and advanced biomaterial applications, which aligns with various United Nations Sustainable Development Goals (SDGs) including zero hunger (SDG 2), good health and well-being (SDG 3), and affordable and clean energy (SDG 7).

The microbial production of 1,5-pentanediol (1,5-PDO), a versatile platform chemical with extensive industrial applications, remains limited by suboptimal fermentation titers and incomplete understanding of metabolic bottlenecks. To address these challenges, this study employed comparative transcriptomics to systematically identify novel genetic targets capable of enhancing 1,5-PDO biosynthesis in engineered Escherichia coli. Transcriptomic profiling of the 1,5-PDO-producing strain relative to the parental E. coli W3110, conducted at both exponential (24 h) and stationary (96 h) growth phases, revealed 1384 significantly differentially expressed genes, including 851 upregulated and 533 downregulated genes. From these, 20 candidate metabolic genes associated with 1,5-PDO synthesis were selected for functional validation through plasmid-based overexpression or CRISPR interference (CRISPRi)-mediated repression. Reverse engineering confirmed that overexpression of fecA (encoding an iron(III)-citrate transporter) and deletion of gadA (encoding glutamate decarboxylase) significantly enhanced 1,5-PDO production. Subsequent chromosomal integration of fecA at the neutral ilvG locus and deletion of gadA generated the optimized strain S7, which achieved a 1,5-PDO titer of 1.7 g/L in shake flask cultures, representing a 13.3% increase over the parental strain, with a concomitant 50% improvement in glucose yield (0.18 mol/mol). In fed-batch fermentation at the 5 L bioreactor scale, strain S7 attained a titer of 12.45 g/L and a glucose yield of 0.26 mol/mol, marking a 15.6% enhancement in carbon conversion efficiency relative to the parental strain (0.225 mol/mol), while concurrently improving biomass accumulation by 7.6%. These findings demonstrate that transcriptomics-guided reverse engineering constitutes an effective strategy for elucidating nonobvious metabolic determinants and optimizing microbial cell factories for efficient 1,5-PDO production. The identification of fecA and gadA as beneficial targets provides valuable insights into the metabolic rewiring underlying enhanced 1,5-PDO biosynthesis and establishes a foundation for further strain improvement through systems metabolic engineering.

Sustainable food sanitation and preservation technologies are highly needed to meet the increasing demand for healthy and safe food. In this work, we investigated the effects of a recently developed antimicrobial triple formulation (TF) comprised of a natural polyphenol gallic acid amended with the generally recognized as safe materials hydrogen peroxide and DL-lactic acid, on a gram-positive bacterium Listeria innocua during its exponential and stationary growth phases. Our findings revealed the physiological changes associated with the application of this material, as observed using single-cell flow cytometry, photometric assays, as well as confocal and scanning electron microscopy. Both exponential- and stationary-phase L. innocua cells lost culturability after incubation with TF, but their cellular responses were different. After 30 min of contact with the TF, the nonculturable, stationary-phase cells maintained membrane integrity, membrane potential, stable respiratory electron-transport chains, and high levels of intracellular ATP. These phenotypic features, characteristic of the viable but nonculturable (VBNC) adaptation strategy, appear to be associated with upregulation of the stress-response factor sigB. In contrast, in TF-treated exponential-phase cells, membrane integrity was severely compromised and membrane potential showed hyperpolarization, suggesting sublethal injury accompanied by downregulation of sigB. Furthermore, the TF treatment enhanced the formation of extracellular vesicles in L. innocua and the deposition of extracellular polymeric substances in stationary-phase cells. The overall findings of this work demonstrate that sensitivity of Listeria cells to nature-based antimicrobials depends on their growth phase and, therefore, modulating their growth-phase-associated physiological status may counteract their VBNC defense strategy and improve biocidal efficacy.IMPORTANCEIn this work, we examined the efficacy of our novel, nature-based green sanitizer as a means to improve microbiological food safety without health and environmental risks, using gram-positive Listeria innocua as a model organism. L. innocua serves as a surrogate of the foodborne pathogen L. monocytogenes for evaluating sanitation efficacy and may also be involved in virulence and multidrug resistance transfer between the Listeria species. We demonstrate that the sanitizer effect depends on the physiological state of bacterial cells, which is affected by their growth phase. The treatment caused membrane damage to L. innocua in its exponential phase but induced the viable but nonculturable state during its stationary phase. Thus, this study demonstrates a way to overcome bacterial defense mechanisms and improve sanitizer efficacy by modulating the growth-phase-associated physiological status of targeted bacteria.

Rhizosphere nitrogen-fixing bacteria play a critical role in sustainable crop production by enhancing nitrogen availability and improving soil fertility. This study aimed to isolate and characterize native rhizospheric nitrogen-fixing bacteria (NRNFB) associated with baby maize (Zea mays L.) roots and evaluate their nitrogen-fixing potential. Thirty root samples were collected, and ten bacterial isolates (V1–V10) were obtained using selective media. Morphological, biochemical, and physiological analyses identified strain V3 as the most promising candidate, exhibiting strong growth on nitrogen-free Burk medium and high oxidase, catalase, and urea hydrolysis activities. The strain demonstrated broad environmental tolerance, including salinity up to 4% NaCl, temperatures ranging from 15 to 45 °C, and pH values between 5.0 and 8.0. Molecular identification based on 16S rRNA gene sequencing revealed 100% sequence similarity with Peribacillus simplex LT4 (strain LT4). Nitrogenase activity analysis showed a peak during the exponential growth phase, accompanied by increased nitrogen accumulation in the culture medium, confirming active biological nitrogen fixation. These findings highlight the physiological adaptability and functional efficiency of strain LT4, supporting its potential development as a biofertilizer for sustainable maize production systems.

As primary producers in aquatic ecosystems, microalgae function not only as a natural source of nourishment for several economically important aquatic species but also as reservoirs of bioactive molecules. Microalgae can secrete exosome-like nanoparticles that transport functional biomolecules, such as proteins and nucleic acids, into the extracellular milieu, thereby mediating intercellular signaling and eliciting ecological or biomedical responses. Although plant-derived exosome-like nanoparticles have attracted attention for their utility in drug delivery and dermatology, the functional properties of microalgae-derived nanoparticles-particularly from species extensively applied in aquaculture-remain inadequately characterized. In this study, exosome-like nanovesicles were isolated from Nannochloropsis oculata (N-ELNs), a microalgal species widely used in aquaculture, and their skin-whitening potential was evaluated using the B16-F10 mouse melanoma cell model. The highest N-ELN yield was observed during the adaptation, exponential, and stationary growth phases. Uptake analyses confirmed the efficient internalization of N-ELNs by B16-F10 cells. Cell counting kit-8 assays indicated that N-ELNs exhibited no cytotoxic effects on melanoma cells or normal human dermal fibroblasts (HFF-1). Scratch wound healing assays revealed that N-ELNs exerted no significant effect on cellular migration. In B16-F10 cells, N-ELNs suppressed tyrosinase activity by downregulating Mitf and its downstream genes Tyr and Tyrp1, resulting in a substantial reduction in melanin synthesis (p < 0.05). The inhibitory effects of N-ELNs on melanin production, tyrosinase activity, and gene expression of Tyr, Tyrp1, and Mitf were comparable to those of the positive control, arbutin. Collectively, these findings suggest that N. oculata exhibits promising skin-whitening properties, providing a novel perspective for clinical applications and supporting the high-value utilization of the microalgae aquaculture industry.

Data Literacy, encompassing the necessary skills for working with data, stands as a pivotal competency in the knowledge economy. Despite its prominence, there is currently no unified definition of Data Literacy, along with its constituent skills. This study focuses on Data Literacy in the workplace, particularly in transversal skills applicable to any worker, not exclusively to technicians or specialists, employing two methodologies: (1) bibliometric analysis to assess scientific production, and (2) a systematic literature review using the PRISMA methodology. The results reveal a significant increase in scholarly output on Data Literacy, indicating an exponential growth phase although with a limited number of references concerning the study of transversal skills applicable to all workers. Moreover, they demonstrate the relationship between Data Literacy and other literacies. Finally, we identify the core competencies associated with Data Literacy and propose a definition related to various profiles essential for companies aiming to enhance their data management capabilities or develop training programs to become data-driven enterprises.

Cellvibrio japonicus is a gram-negative, saprophytic bacterium that is a polysaccharide utilization specialist capable of degrading diverse, complex, and recalcitrant polysaccharides. Here, we present transcriptome data sets during exponential growth and stationary phase for C. japonicus using barley β-glucan as the sole carbon source.

The fungal symbiont of leaf-cutter ant Atta mexicana, Leucoagaricus gongylophorus LEU18496 has the capability to produce enzymes such as cellulases, hemicellulases, and ligninases for plant biomass degradation. In this study, the fungus has been cultivated in submerged culture conditions using glucose and cellulose as carbon sources to explore gene expression level and unravel the molecular mechanisms responsible of enzyme production and carbohydrate catabolism. The transcriptomic analysis of L. gongylophorus LEU18496 using RNA-seq data, allowed the examination of the gene expression profiles across different carbon sources and growth phases. During the exponential growth phase on glucose there is a constitutive expression of several CAZymes, including β-glucosidase, pectinase, and endo-β-1,3-glucanase. The transcriptome data showed high expression of the creA repressor gene in the presence of glucose, underscoring its regulatory role in carbohydrate degradation and suggesting a regulatory mechanism governing CAZyme production and secretion when glucose is used as a carbon source. This study offers detailed insights into the pathways of cellulose and glucose catabolism, emphasizing the expression of key components involved in carbohydrate metabolism unravelling the metabolic strategies of L. gongylophorus providing information of the CAZymes and FOLymes production as high-value product suitable for biotechnological applications.

As agriculture faces increasing pressure to reduce pesticide residues and heavy metal accumulation in soils, marine microalgae are emerging as sustainable sources of biopesticides. Among them, Amphidinium carterae produces amphidinols (AMs), polyketide metabolites with strong antifungal activity against crop pathogens. Currently, large-scale AM production remains constrained by a limited understanding of AM biosynthesis across different A. carterae growth phases and by the lack of high-performing industrial strains. In this study, AM production dynamics were investigated in one wild-type (WT) and five mutagenized A. carterae strains. The production of bioactive AM18 and its sulfated inactive form AM19 was monitored through exponential, linear, and early stationary growth phases. The maximum AM productivity occurred between the linear and early stationary phase, with the average values of 5.58 ± 0.4 and 3.58 ± 0.2 µg/mL/day for AM18 and AM19, respectively. The AM18/AM19 ratio consistently decreased with the culture age, indicating that earlier harvesting favors higher proportions of bioactive AMs. UV mutagenesis increased the AM18 cell content by more than twofold and the growth rate by up to 20% in certain mutagenized strains compared to the WT strain, but did not enhance the volumetric AM productivity. Overall, these results identify optimal AM harvesting windows and clarify the potential benefits of mutagenesis strain improvement for industrial AM production improvement.