Roberto Lavecchia

Microalgae and cyanobacteria have emerged as platforms for producing recombinant biologics, vaccine antigens, and bioactive compounds of pharmaceutical interest. However, their translation beyond proof-of-concept remains limited by light-field heterogeneity, gas–liquid mass-transfer constraints, product instability, and matrix complexity, all of which affect recovery, selectivity, and batch comparability. This review synthesizes and organizes published evidence using a process-engineering framework organized around product class, product localization, upstream–downstream coupling, and photobioreactor scale-up. It further considers the role of Quality by Design (QbD), model-informed development, techno-economic assessment (TEA), and life cycle assessment (LCA) in route selection and quality-oriented process development. Across the reported routes, the dominant burden shifts from disruption and clarification in intracellular products to extracellular stability and time-to-capture in secreted products, whereas biomass-based formulations are governed by potency and stabilization consistency, and analog-rich metabolites by profile control and selective fractionation. Current limitations include the scarcity of models that incorporate quality attributes as explicit outputs, the incomplete representation of regulated manufacturing burdens in TEA and LCA, and the lack of minimal, reproducible analytical panels adapted to product class and matrix. By framing these organisms as pharmaceutical process platforms rather than as hosts assessed only by titer, this review provides an engineering basis for scale-up, route prioritization, and controllable manufacturing.

Harvesting and drying are critical post-harvest operations in microalgal biomass processing because they strongly influence biomass conditioning and the subsequent recoverability of major macromolecular fractions. Accordingly, this study evaluated and optimized harvesting and drying conditions to identify processing windows associated with carbohydrate, protein, and lipid responses in Chlorella sp. (UFPS012). An I-optimal design was applied to assess drying temperature (40–60 °C), drying time (18–30 h), equipment (oven vs. food-grade dehydrator), and harvesting method (chemical flocculation vs. electroflotation). Subsequently, temperature and time were optimized using a central composite design while keeping electroflotation and the food-grade dehydrator fixed. The harvesting method was consistently significant across responses, whereas drying factors showed metabolite-dependent effects. During the screening stage, carbohydrates were mainly influenced by drying time and harvesting method, proteins by drying time and equipment, and lipids by drying temperature, equipment, and harvesting method. In the optimization stage, the fitted quadratic models showed high goodness of fit (R² = 0.9778–0.9959), and the desirability function identified a compromise condition at 56.78 °C and 41.28 h. Under these conditions, the model predicted approximately 155.0 mg/L of total carbohydrates, 368.4 mg/L of total proteins, and 15.2 mg/L of total lipids. Process validation showed no significant difference between predicted and observed values for proteins, whereas carbohydrates and lipids differed significantly. In parallel, the moisture ratio approached zero at approximately 2460 min, consistent with the late stage of drying. Overall, electroflotation, coupled with food-grade dehydration, defined a laboratory-scale post-harvest configuration for the simultaneous conditioning of Chlorella biomass for multi-metabolite recovery. Future studies should evaluate specific energy demand, techno-economic feasibility, alternative drying technologies, and other Chlorella-relevant high-value compounds such as carotenoids.

Landfill leachate is a complex pollutant that contains high levels of nitrogenous compounds, heavy metals, and organic contaminants, posing serious environmental risks. This study presents an innovative and sustainable strategy for leachate biotransformation using the microalgae Chlorella sp. (UFPS_016, 017) and the cyanobacteria Oscillatoria sp. (UFPS_004) and Potamosiphon sp. (UFPS_008), integrating circular economy and Blue Economy principles. Strains were cultivated in 5% and 10% leachate under optimized photoperiods, LED illumination, and controlled CO₂ supplementation. The best performance was achieved by Oscillatoria sp. (UFPS_004) with biomass productivity of 0.3923 g L⁻¹ and carbohydrate accumulation up to 64.97% w/w, while Potamosiphon sp. (UFPS_008) achieved the highest PHB content (19.7% w/w). Chlorella sp. strains exhibited greater lipid accumulation, reaching 14.96% w/w, and produced phytohormones (Indole-3-acetic acid) with potential for agricultural applications. 20 L reactors validated scalability, maintaining productivity like that of small-scale systems. This dual-purpose bioprocess simultaneously detoxifies leachate and produces valuable bioproducts, including bioplastics, biofertilizers, and biofuels. The results demonstrate a feasible, low-cost, and eco-efficient biotechnology for landfill leachate management, contributing to waste valorization and environmental sustainability.

This study investigated a phototrophic approach to close nutrient loops by using landfill leachate as a culture medium to produce biomass and polyhydroxybutyrate (PHB) from a thermotolerant strain of Potamosiphon sp. A multi-cycle reuse scheme in which post-culture leachate was partially replenished with fresh leachate and reused in successive cultivation rounds to increase the biomass concentration (g/L) and the intracellular PHB content (% w/w) was tested. Three operational variables were optimized (leachate replenishment percentage, number of reuse cycles, and sanitation method (autoclaving, UV irradiation, or no treatment)) via the Box–Behnken response surface method. Both response variables were modeled with high predictive accuracy (R² = 0.98 for biomass and R² = 1.00 for PHB content). According to the experimental data, leachate replenishment emerged as the key factor influencing nutrient availability—particularly nitrogen and phosphorus—and thus PHB accumulation. The optimized conditions (2.17% v/v fresh leachate, three reuse cycles, and UV sanitation) yielded predicted values of 0.29 g/L biomass and 3.48% w/w PHB. These results demonstrate the feasibility of a controlled multicycle reuse process that integrates effluent treatment and biopolymer synthesis, offering a low-input, circular biotechnological approach for sustainable leachate valorization.

Drying is a critical preprocessing step for stabilizing seaweed biomass and shaping its functional quality for food, nutraceutical, and biorefinery applications. This study evaluated the drying behavior of Saccharina latissima under oven drying (OD), air drying (AD), and freeze drying (FD) by combining thin‐layer kinetic modeling and the analyses of phytochemical composition and antioxidant activity. The three methods exhibited distinct drying behaviors where OD showed rapid moisture removal, reflected by the highest drying constant and effective diffusivity, driven by high vapor pressure gradients and strong internal diffusion. AD proceeded slowly under low‐temperature, low‐convection conditions, exhibited by its slow kinetics and lowest diffusivity. FD followed a two‐stage pattern characterized by fast sublimation during primary drying and slower desorption of bound water during secondary drying. These behaviors were reflected in model performance, with the Lewis model best describing OD, the Page model for AD, and the logarithmic model for FD. These differences corresponded to distinct compositional outcomes, wherein OD yielded the highest total polyphenol and flavonoid contents and antioxidant capacity, while FD preserved moderated levels and AD yielded the lowest. This study establishes process–structure–function relationships linking drying mechanisms with bioactive compound recovery in S. latissima , providing a framework for selecting and optimizing drying strategies in seaweed processing.

The growing concern over plastic pollution and the widespread presence of micro- and nanoplastics has renewed interest in polyhydroxybutyrate (PHB) as a biodegradable alternative; however, its industrial deployment remains constrained by costly recovery operations with a high environmental burden. This study examines how PHB biosynthesis and intracellular organization, physicochemical properties, and the characteristics of the producing microorganism influence the performance of conventional recovery routes, including extraction with organic solvents, alkaline/oxidative chemical digestion, and enzymatic–physical schemes coupled with mechanical disruption. Based on this foundation, quantitative data are analyzed for PHB content in bacteria, mixed microbial cultures, cyanobacteria, and microalgae, along with extraction yields, polymer purity, and solvent recyclability in processes employing chlorine-free solvents, green solvents, and hydrophobic natural deep eutectic solvents (NaDESs) formulated with terpenes and organic acids. The analysis integrates mechanistic perspectives on NaDES–cell and NaDES–PHB interactions with solvent design criteria, biorefinery configurations, and preliminary evidence from technoeconomic and life cycle assessments. The findings identify NaDES as an up-and-coming platform capable of reconciling biopolymer quality with the principles of green chemistry while delineating critical gaps in recovery efficiency, viscosity management, solvent recycling, and pilot-scale validation.

Global dependence on fossil fuels generates severe environmental and socioeconomic impacts, driving the urgent search for sustainable energy alternatives. In response to this global challenge, this research conducts a bibliometric analysis of hydrogen production via biohybrid systems, using publications indexed in Scopus from 2005 to 2025 and analyzed with VOSviewer. The results revealed a significant increase in research output since 2015, driven primarily by interdisciplinary developments in biotechnology, nanotechnology, and bioelectrochemistry, as well as by international sustainability policies. Four main research approaches were identified: bio-assisted photocatalysis, bio-electrochemical systems, dark fermentation, and enhanced artificial photosynthesis with nanomaterials. Despite the progress achieved, significant limitations remain in energy efficiency, operational costs, and the oxygen sensitivity of key enzymes. The study emphasizes that interdisciplinary collaboration is crucial to overcoming these barriers, highlighting priority areas for future research to strengthen the potential of biohybrid hydrogen as a viable and sustainable solution in the global energy transition.

Cyanobacteria are a prolific source of bioactive metabolites with expanding applications in sustainable agriculture and biotechnology. This work explores, for the first time in thermotolerant Colombian isolates, the impact of light spectrum, photoperiod, and irradiance on the co-production of exopolysaccharides (EPS) and indole-3-acetic acid (IAA). Six strains from hot-spring environments were screened under varying blue:red (B:R) LED ratios and full-spectrum illumination. Hapalosiphon sp. UFPS_002 outperformed all others, reaching ~290 mg L⁻¹ EPS and 28 µg mL⁻¹ IAA in the initial screen. Response-surface methodology was then used to optimize light intensity and photoperiod. EPS peaked at 281.4 mg L⁻¹ under a B:R ratio of 1:5 LED, 85 µmol m⁻² s⁻¹, and a 14.5 h light cycle, whereas IAA was maximized at 34.4 µg mL⁻¹ under cool-white LEDs at a similar irradiance. The quadratic models exhibited excellent predictive power (R² > 0.98) and a non-significant lack of fit, confirming the light regime as the dominant driver of metabolite yield. These results demonstrate that precise photonic tuning can selectively steer carbon flux toward either EPS or IAA, providing an energy-efficient strategy to upscale thermotolerant cyanobacteria for climate-resilient biofertilizers, bioplastics precursors, and other high-value bioproducts.

Olive pomace, the solid by-product derived from the olive oil extraction process, is a rich but still underutilized source of bioactive polyphenols. Among the proposed recovery technologies, solvent extraction seems to be the simplest and economically viable method to achieve this purpose. In this study we investigate the recovery of polyphenols from olive pomace by a one-step extraction procedure using aqueous ethanol as solvent, with the aim to model and optimize the proposed process. A central composite rotatable design (CCRD) comprising 2 ⁴ factorial points, eight axial points and six replicates was used to evaluate the effects of temperature (T), extraction time ( E ), liquid-to-solid ratio ( R ) and ethanol concentration in the solvent ( C ) on the extraction yield. The experimental results were correlated by a reduced second-order polynomial model. The statistical analysis of the results showed that all the main factors ( T , E , R , C ) and two binary interactions ( T – E , R – C ) had significant effects on the extraction yield. Under the best conditions ( T = 70 °C, E = 240 min, R = 48 mL/g, C = 50 %) more than 95 % of the extractable polyphenols were recovered. A mechanically stirred batch extractor operating under these conditions was used to produce dry extracts with a polyphenol content of 69.46 mg GAE (gallic acid equivalents) per gram and an antioxidant activity of 32.72 mg TE (Trolox equivalents) per gram. Overall, the results obtained indicate that polyphenol-rich extracts suitable for a variety of food and non-food applications can be easily obtained from olive pomace by subjecting it to the optimized extraction treatment.

Infectious diseases have significantly shaped human history, leading to significant advancements in medical science. The discovery and development of antibiotics represented a critical breakthrough, but the rise of antibiotic-resistant pathogens now presents a serious global health threat. Due to the limitations of current synthetic antimicrobials, such as toxicity and environmental concerns, it is essential to explore alternative solutions. Algae, particularly microalgae and cyanobacteria, have emerged as promising sources of bioactive antimicrobial compounds. This review provides a comprehensive analysis of the antimicrobial properties of algal-derived compounds, including polysaccharides, fatty acids, and phenols, which have shown effectiveness against multi-drug-resistant bacteria. A co-occurrence bibliometric analysis using VOSviewer highlighted five key research clusters: antibiotic resistance, algal extracts, biosynthesis, water treatment, and novel pharmacological compounds. Furthermore, the primary mechanisms of action of these bioactive compounds, such as the inhibition of protein synthesis and cell membrane disruption, were identified, demonstrating their potential against both common and multi-resistant pathogens. Future research should prioritize optimizing algal biomass production, utilizing genetic and metabolic engineering, and creating innovative delivery systems to enhance the efficient production of bioactive compounds.