Teresa Semedo-Lemsaddek, Marta Laranjo, Maria José Saavedra
Industrial microbiology sits at the heart of food safety, fermentation technology, antimicrobial resistance (AMR) surveillance, and sustainable biotechnology, yet leadership in the field remains disproportionately male. Only 26% of full professors in Europe are women, despite women making up the majority of life-science graduates. Portugal offers a particularly telling paradox. Since the 1974 democratic revolution, sustained investment in science has pushed Portuguese women close to parity in doctoral output, and they even hold the majority of principal investigator positions in national competitive funding. Nonetheless, only 24% of Portuguese full professors are women, and a clear vertical “scissors effect” persists, with women’s representation shrinking at each career stage. We argue that this contradiction is highly visible in industrial microbiology, where career advancement depends not just on publications but on access to technology transfer, patenting, and industry-facing leadership roles; specifically, we argue that women’s strong participation in scientific output has not yet been matched by comparable representation in these leadership roles. Drawing on a curated set of studies (2014–2026) led by Portuguese women as first or last author across four thematic areas (traditional fermented food microbiota, starter culture development, biofilm biology, and antimicrobial resistance surveillance under a One Health framework), although field-specific evidence is currently lacking, we advance the hypothesis that the national participation-to-leadership gap also affects Portuguese industrial microbiology. We close with a concrete research and policy agenda: gender-disaggregated bibliometric and patent analyses specific to industrial microbiology, longitudinal tracking of funding and promotion outcomes by gender within this subfield, and systematic evaluation of existing career-support policies. Closing the gender gap in industrial microbiology is not simply a matter of social justice, it is a structural requirement to improve scientific and economic competitiveness.
Microbial α-amylases (EC 3.2.1.1) represent the cornerstone of global industrial starch bioprocessing, valued for their ability to maintain high catalytic velocity and conformational integrity under elevated operating temperatures valued for their ability to maintain catalytic activity under the elevated temperatures characteristic of industrial bioprocessing, with specific poly-extremotolerant variants exhibiting additional resilience across challenging pH regimes, surfactant matrices, and oxidative conditions. This review presents a critical and systematic synthesis of current knowledge on thermostable α-amylases, bridging molecular classification, biosynthesis mechanisms, bioprocess engineering, and downstream applications. We elucidate the contrasting canonical Ca² + -dependent coordination architectures against alternative structural networks that confer a Ca² + -independent biochemical phenotype. The review evaluates diverse microbial reservoirs- spanning thermophilic and hyperthermophilic bacteria, archaea (e.g., Pyrococcales), thermophilic fungi (e.g., Thermomyces lanuginosus), and haloalkaliphilic isolates from geothermal, marine, compost, and agro-waste environments. We critically compare submerged (SmF) and solid-state (SSF) fermentation paradigms across normalized volumetric productivity and downstream recovery metrics, highlighting the statistical transition from empirical one-factor-at-a-time (OFAT) screening to interaction-aware response surface designs (CCD and Box–Behnken). Analytical limitations of standard activity assays (DNS, Nelson–Somogyi, iodine dextrinizing, and synthetic chromophores) and kinetic modeling practices are evaluated, emphasizing non-linear regression over distortive linear transformations. Furthermore, we address core technological controversies and industry trade-offs, including inconsistent characterization practices, particularly the frequent conflation of temperature optima with long-term thermostability and the use of non-standardized conditions for reporting residual activity, thermal half-life, kinetic parameters, and enzyme stability, the high cost of downstream processing, and the narrow taxonomic base of industrially exploited strains, and the translation of bench-scale kinetics to high-dry-solids industrial reactor matrices. Finally, we outline key research bottlenecks and future engineering trajectories—including metagenomic bioprospecting of unculturable extremophiles, machine-learning-assisted structure prediction (characterizationFold), and circular-economy biorefinery integration—poised to define the next generation of industrial biocatalysis.
Vitória G. Navarrete, Vinicius S. Ferreira, Tiago Venâncio, Rafael C. Pulgrossi, Luis Henrique Zanini Branco, Ana T. Lombardi
Vinasse is an organic and nutrient-rich byproduct of the ethanol industry with potential for microalgae cultivation. Although its use is generally limited by the need for dilution, appropriate vinasse pretreatment can improve its suitability as a culture medium, enabling microalgae to thrive. This study investigated the feasibility of cultivating microalgae in 100% previously treated vinasse and evaluated the use of vinasse-grown cultures as inoculum for successive cultivation cycles. Nine microalgal species were evaluated in an initial screening test to determine their tolerance to full-strength treated vinasse. Three species, Chlorolobion braunii, Tetradesmus sp., and Haematococcus pluvialis, were selected for further testing in 6-well plates with 12 mL cultures. Growth rate, cell volume, and the effect of inoculum origin (vinasse vs. synthetic culture medium), were evaluated. Additionally, vinasse was characterized by nuclear magnetic resonance spectroscopy (NMR) before and after algal growth. C. braunii had the best performance in full-strength treated vinasse, achieving the highest growth rate (1.3 d −1), compared to 0.66 d −1 for Tetradesmus sp. and 0.68 d −1 for H. pluvialis. Notably, C. braunii was the only species that showed a higher growth rate in vinasse than in its control, suggesting mixotrophic growth. Mixed effect modeling showed that cell volume increased 1.6 times in vinasse-grown C. braunii (208 μm3) and 6.3 times in Tetradesmus sp. (250 μm3) in comparison to their controls, but H. pluvialis cell volume was maintained (5575 μm3). Compared to the respective controls, when the inoculum was obtained from vinasse, C. braunii presented 3.2 times lower growth rate (0.4 d −1) and larger cells, but no variation in growth response was observed for Tetradesmus sp. cultures (0.67 d −1 growth rate; cell volume 13.2 times larger), while H. pluvialis formed small cysts. NMR results showed that acetate and butyrate were consumed by the microbial consortium. Additionally, H. pluvialis cultures in vinasse released cis-aconitate, a compound that can be related to physiological adjustments in a stressing condition. This study advances the circular economy concept in the ethanol industry by showing that full-strength treated vinasse can serve as a viable culture medium for microalgae, given appropriate species selection.
Bahgat Fayed, Aisha E. Reda, Amira Abood, Shaimaa A. Nour
The pretreatment process of lignocellulosic biomass results in the formation of inhibitory by-products such as furan aldehydes, phenolics, and weak acids that hinder the process of microbial fermentation. Historically, the detoxification process has been regarded as an exercise in waste management, resulting in carbon loss and reduced strength. The current review illustrates how detoxification can be viewed from a new perspective, making it possible to recover carbon and balance redox simultaneously. The results of our analysis indicate that oxidation-based detoxification pathways, and particularly the conversion of furfural into 2-furoic acid by aldehyde hydrogenases followed by entry into the TCA cycle, allow for the recovery of five carbon atoms from each molecule of inhibitor. Our findings revealed the importance of cofactor specificity in the detoxification process: NADPH-dependent reductases negatively affect biosynthesis while their NADH-dependent or bifunctional counterparts allow for the retention of the biosynthetic potential. The modification of aldo-keto reductases to favor NADH along with the combination of detoxification reactions with transhydrogenases and fusion proteins facilitate the process of detoxification without harming product yields. The integration of processes into host organisms is of critical significance acetyl-CoA pathway serves well for lipid synthesis by Yarrowia lipolytica while TCA pathway is beneficial for Pseudomonas spp. The co-utilization of inhibitors with sugars in conditions representative of real hydrolysates offers a win-win situation for carbon recovery when detoxification routes are implemented prior to key metabolic pathways. This approach allows us to regard the inhibitors as auxiliary substrates and develop biorefineries that benefit from the detoxication step in terms of increased product yield. It appears that industrial implementation will require systemic modeling and rational enzyme redesign.
