Trade-offs between biomass productivity and metabolite accumulation constrain microalgae cultivation for high-value biomolecules due to nutrient competition and concurrent metabolic pathways. This study evaluated the independent and combined effects of static magnetic fields (SMF) and polymeric nanofibers on growth performance, biomass composition, and exopolysaccharide (EPS) profiles of Porphyridium purpureum. A process intensification strategy was applied by integrating external physical forcing and structured functional materials to enhance mass transfer and carbon utilization efficiency. Cultivations were conducted under controlled photobioreactor conditions using SMF exposure for 1 h d−1 or 24 h d−1, combined with polyacrylonitrile (PAN) nanofibers or monoethanolamine-functionalized nanofibers (MEA). Intermittent SMF increased maximal biomass concentration by 36% compared to the control, whereas continuous SMF, MEA nanofibers, and combined conditions reduced biomass accumulation by up to 45%. SMF promoted metabolic reallocation toward carbon-rich fractions, increasing released polysaccharides by 83% and lipid content by 38%. Nanofibers strongly enhanced pigment biosynthesis, with β-phycoerythrin reaching 41.3 mg g−1, threefold higher than the control. EPS characterization showed increased purity, uronic acid content, and sulfation depending on treatment. Overall, SMF and nanofibers acted as selective intensification tools, enabling tunable modulation of growth, metabolism, and product formation.
A side-by-side benchmark of these two marine diatoms is provided, offering a data-driven reference for process development and industrial deployment of microalgae-derived fucoxanthin, and high-yield induction methods from the dimensions of nutrient regulation, light optimization, exogenous induction, and strain improvement are summarized.
Man Zhang, Hao-Yu Li, Feichao Du et al.· Marine Drugs· 0 citations
Introduction Siderophore-producing bacteria and their metabolites represent promising components of next-generation biofertilizers, yet their effects on plant physiology and soil microbiome structure remain insufficiently understood. Methods We developed a liquid biofertilizer based on siderophores and siderophore-accompanying metabolites (SSAM) produced by Pseudomonas sp. ANT_H12B and formulated with molasses as an organic carrier. Its effects on sweet basil (Ocimum basilicum L.) were evaluated by assessing plant growth, photosynthetic performance, lipid peroxidation, elemental composition, soil enzyme activities, and bacterial community structure using full-length 16S rRNA nanopore sequencing. Results The combined SSAM+molasses formulation significantly enhanced plant growth, increasing leaf dry biomass by nearly 180%, leaf number by more than 300%, and stem length by approximately 40–50% compared with untreated plants. Improved plant performance was accompanied by enhanced photosynthetic efficiency (Fv/FM) and a marked reduction in oxidative stress, as reflected by nearly 50% lower malondialdehyde (MDA) content compared with the molasses-only treatment. Although elemental analysis revealed no major disturbances in plant nutrient balance among treatments, soil supplementation with the combined formulation strongly affected rhizosphere functioning and microbiome composition. In particular, the SSAM+molasses treatment coincided with approximately 35–50% higher β-glucosidase and dehydrogenase activities and clear shifts in microbial community structure. Discussion These findings suggest that molasses-enriched siderophore metabolites may act as effective biostimulants by promoting plant growth and mitigating oxidative stress, partly through modulation of rhizosphere microbiome structure and function.
M. Musiałowski, A. Bernatowicz, Ł. Kowalewska et al.· Frontiers in Plant Science· 0 citations
The content of extracellular Monascus pigments (eMPs), which has strong functional activity and stability, was improved by adding glycine in previous research. This study systematically elucidated the effects of different glycine concentrations on Monascus purpureus (M. purpureus) S109 eMPs production at both the membrane physiological level and the molecular level of pigment secretion-related gene expression. By measuring the biomass, fatty acid, relative conductivity, fluorescence intensity of tyrosine and tryptophan, membrane potential and ion concentration, coenzyme content, and eMPs content, it was found that 2 g/L glycine could significantly enhance cell membrane fluidity and permeability, and promote the production of eMPs, with their content increasing from 85.82 U/mL to 384.88 U/mL. Under this condition, apart from the negative regulator MrpigI, and the MrpigH directly involved in yellow pigment synthesis, which were down-regulated, all other genes associated with the pigment biosynthesis pathway were significantly up-regulated. Furthermore, the expression of MrpigL and MrpigP genes involved in pigment secretion was significantly up-regulated by 2.8-fold and 10.9-fold, respectively. This study demonstrates that glycine promotes eMPs secretion through modulation of membrane physiological properties and modulation of secretion-related gene expression.
Sixu Lin, Xue Yang, Junyao Wang et al.· Microbial Cell Factories· 0 citations
Cyanophycin granule polypeptide (CGP), also known as multi-L-arginyl-poly(aspartic acid), is a biodegradable biopolymer composed primarily of aspartic acid and arginine. Due to its versatile functional properties, CGP has attracted increasing interest for potential applications in food, medicine, cosmetics, agriculture, and corrosion inhibition. The objective of this study was to biosynthesize a biologically derived corrosion-inhibiting biomaterial using recombinant Escherichia coli BL21(DE3) expressing cyanophycin synthetase (CphA), followed by cost-effective induction strategy. Specifically, this work aimed to establish a high-cell-density cultivation process capable of achieving improved CGP production while reducing dependence on costly inducers such as IPTG. Initial shake-flask experiments demonstrated that lactose induction resulted in higher CGP production and biomass formation compared to IPTG induction. In addition, supplementation with phosphate, ribose, trace elements, yeast extract, and tryptone further improved CGP accumulation. Based on these findings, a high-cell-density fed-batch fermentation strategy using lactose as both inducer and carbon source was developed, maximum gravimetrically recovered crude soluble and insoluble CGP-containing fractions of 35.4 and 17.8 g/L. Product characterization was further supported by FTIR, XRD, MALDI-MS. Furthermore, the recovered CGP-related material was evaluated in preliminary corrosion inhibition experiments under acidic conditions and showed significant reduction in corrosion rates compared with untreated control samples, indicating its potential for future corrosion-protection applications.
S. Kafle, Anirudh Mukunth, Arum Han et al.· Bioprocess and biosystems en...· 0 citations
In vitro data demonstrate enhanced probiotic metabolite production and suggest potential neuroprotective relevance, supporting future confirmatory in vivo investigations.
M. Praveen, Long Yu, Caterina Selva et al.· Food Chemistry· 0 citations
