Microbial Biotechnology Research Articles

Advanced methanotrophic bioreactor design for efficient bioremediation of hydrogen sulfide (H₂S) And Volatile Organic Compounds (Vocs): Integrating genetic engineering and industrial scalability

The convergence of advanced microbial biotechnology and metabolic engineering has facilitated groundbreaking advancements in bioremediation. This study presents the engineered Methylomicrobium buryatense strain 5GB1C-RO1, optimized for the simultaneous removal of hydrogen sulfide (H₂S) and volatile organic compounds (VOCs) within a two-stage methanotrophic bioreactor system. Through precise CRISPR/Cas9-mediated genome editing, critical metabolic pathways for sulfide oxidation (SQR, FCCAB, SOXABXYZ) and VOC degradation (alkB, adhP, todC1C2BA) were integrated, achieving catalytic efficiencies exceeding 3.2 × 10⁷ M⁻¹s⁻¹ and substrate conversion rates above 450 nmol min⁻¹ mg⁻¹ protein. The strain demonstrates exceptional robustness under industrial conditions, maintaining 95% pollutant removal efficiency at H₂S concentrations up to 1000 ppm and VOC concentrations exceeding 500 ppm. The innovative bioreactor system incorporates enhanced gas-liquid mass transfer mechanisms, achieving mass transfer coefficients (kLa) exceeding 300 h⁻¹ and enabling stable operation for over 1000 continuous hours. Experimental results confirm the system's capacity for pollutant mineralization, generating methane-rich biogas (>95% CH₄) and high-protein microbial biomass (>85%), which are valuable for energy and agricultural applications. This integrated bioremediation approach not only reduces reliance on chemical scrubbing and flaring but also supports circular economy principles by transforming waste gases into renewable resources. The technology provides a scalable, sustainable, and cost-effective solution to mitigate industrial emissions while addressing environmental and regulatory challenges. The findings highlight the potential of combining advanced genetic engineering with innovative bioreactor design to redefine industrial pollutant management and resource recovery.

Seed bacterization with siderophore-producing bacteria: a strategy to enhance growth and alkaloid content in Catharanthus roseus.

Catharanthus roseus is a medicinal plant widely known for producing monoterpenoid indole alkaloids (MIAs), including therapeutic compounds such as vinblastine and vincristine, which are crucial for cancer treatment. However, the naturally low concentration of these alkaloids in plant tissues poses a significant challenge for large-scale production. This study explores the application of siderophore-producing bacteria for seed bacterization of Catharanthus roseus to enhance the production of MIAs, including vindoline, catharanthine, and vinblastine. Utilizing High-Performance Liquid Chromatography (HPLC), we observed a significant increase in the concentration of these alkaloids in bacterized plants compared to controls. FTIR spectra of treated plants showed strong correlations with standard alkaloid mixtures, confirming higher alkaloid accumulation. Our findings demonstrate that bacterial siderophores play a vital role in optimizing iron uptake, which is crucial for secondary metabolite biosynthesis. This research highlights the potential of using microbial biotechnology to improve the yield of valuable pharmaceutical compounds in medicinal plants. Enhancing the biosynthetic pathways of MIAs offers a sustainable and efficient strategy for boosting the production of key therapeutic alkaloids in Catharanthus roseus, paving the way for advanced biotechnological applications in plant-based drug production.

Root microbes can improve plant tolerance to insect damage: A systematic review and meta-analysis.

To limit damage from insect herbivores, plants rely on a blend of defensive mechanisms that includes partnerships with beneficial microbes, particularly those inhabiting roots. While ample evidence exists for microbially mediated resistance responses that directly target insects through changing phytotoxin and volatile profiles, we know surprisingly little about the microbial underpinnings of plant tolerance. Tolerance defenses counteract insect damage via shifts in plant physiology that reallocate resources to fuel compensatory growth, improve photosynthetic efficiency, and reduce oxidative stress. Despite being a powerful mitigator of insect damage, tolerance remains an understudied realm of plant defenses. Here, we propose a novel conceptual framework that can be broadly applied across study systems to characterize microbial impacts on expression of tolerance defenses. We conducted a systematic review of studies quantifying the impact of rhizosphere microbial inoculants on plant tolerance to herbivory based on several measures-biomass, oxidative stress mitigation, or photosynthesis. We identified 40 studies, most of which focused on chewing herbivores (n = 31) and plant growth parameters (e.g., biomass). Next, we performed a meta-analysis investigating the impact of microbial inoculants on plant tolerance to herbivory, which was measured via differences in plant biomass, and compared across key microbe, insect, and plant traits. Thirty-five papers comprising 113 observations were included in this meta-analysis, with effect sizes (Hedges' d) ranging from -4.67 (susceptible) to 18.38 (overcompensation). Overall, microbial inoculants significantly reduce the cost of herbivory via plant growth promotion, with overcompensation and compensation comprising 25% of observations of microbial-mediated tolerance. The grand mean effect size 0.99 [0.49; 1.49] indicates that the addition of a microbial inoculant increased plant biomass by ~1 SD under herbivore stress, thus improving tolerance. This effect was influenced most by microbial attributes, including functional guild and total soil community diversity. Overall, results highlight the need for additional investigation of microbially mediated plant tolerance, particularly in sap-feeding insects and across a more comprehensive range of tolerance mechanisms. Such attention would round out our current understanding of anti-herbivore plant defenses, offer insight into the underlying mechanisms that promote resilience to insect stress, and inform the application of microbial biotechnology to support sustainable agricultural practices.

Harnessing PGPRs from Asparagus officinalis to Increase the Growth and Yield of Zea mays L

Microbial biotechnology employs techniques that rely on the natural interactions that occur in ecosystems. Bacteria, including rhizobacteria, play an important role in plant growth, providing crops with an alternative that can mitigate the negative effects of abiotic stress, such as those caused by saline environments, and increase the excessive use of chemical fertilizers. The present study examined the promoting potential of bacterial isolates obtained from the rhizospheric soil and roots of the Asparagus officinalis cultivar UF-157 F2 in Viru, la Libertad, Peru. This region has high soil salinity levels. Seventeen strains were isolated, four of which are major potential plant growth–promoting traits, and were characterized based on their morphological and molecular characteristics. These salt-tolerant bacteria were screened for phosphate solubilization, indole acetic acid, deaminase activity, and molecular characterization by 16S rDNA sequencing. Fifteen samples were from saline soils of A. officinalis plants in the northern coastal desert of San Jose, Lambayeque, Peru. The bacterial isolates were screened in a range of salt tolerances from 3 to 6%. Isolates 05, 08, 09, and 11 presented maximum salt tolerance, ammonium quantification, phosphate solubilization, and IAA production. The four isolates were identified by sequencing the amplified 16S rRNA gene and were found to be Enterobacter sp. 05 (OQ885483), Enterobacter sp. 08 (OQ885484), Pseudomonas sp. 09 (OR398704) and Klebsiella sp. 11 (OR398705). These microorganisms promoted the germination of Zea mays L. plants, increased the germination rates in the treatments with chemical fertilizers at 100% and 50%, and the PGPRs increased the height and length of the roots 40 days after planting. The beneficial effects of salt-tolerant PGPR isolates isolated from saline environments may lead to new species that can be used to overcome the detrimental effects of salt stress on plants. The biochemical response and inoculation of the three isolates prove the potential of these strains as sources of products to develop new compounds, confirming their potential as biofertilizers for saline environments.

Penitentiaries: Bringing microbiological literacy to the fringes of society.

This report highlights a science outreach effort for prisons launched by the Spanish National Research Council (CSIC) in collaboration with the NGO Solidarios para el Desarrollo. The Microbiology-focused part of the initiativeaims at educating inmates on some basic facts, in order to raise awareness about microorganisms and their impact on daily life. The outline of the talks, inspired by the International Initiative for Microbial Literacy, aims to encourage this collective to move from passive listeners into active participants, helping them understand that Earth is a microbial planet, and that their bodies harbour vast microbiomes that affect their health and social interactions. The talks introduce Microbiology using simple metaphors and emphasize the role of beneficial microorganisms. By explaining the power of microscopes, inmates are shown the hidden microbial world that surrounds them, sparking interest and curiosity. The talks also cover microbial biotechnology, using examples such as bioplastics, anti-cavity bacteria, and skin microorganisms designed for acne prevention. Overall, this outreach initiative seeks to provide inmates with valuable scientific knowledge, fostering curiosity and critical thinking. Despite the challenges of delivering such content in a prison setting, the initiative demonstrates that even marginalized groups can benefit from microbiological literacy, helping them to both endure their terms and eventually reintegrate into society.

PRODUKSI MEDIA TANAM ORGANIK DAN BRIKET ARANG TERBARUKAN SEBAGAI HASIL KONVERSI LIMBAH BAGLOG JAMUR TIRAM

ABSTRACT Much baglog waste is produced as a by-product of oyster mushroom cultivation activities carried out by some farmers in Cinanggung village which has not been processed and utilized optimally, thus having a negative impact on the environment. The community service team from the Microbial Biotechnology scientific group, School of Biological Sciences and Technology (KK BM, SITH) Bandung Institute of Technology (ITB) held a community service program in the form of training for the people of Cinanggung Village, Tanjungsari sub-district, Sumedang district, on how to process baglog waste into planting media. organic and renewable charcoal briquettes, and using them as a medium for growing vegetables in the home garden as an effort to increase food security in household capacity. There were 24 participants in this training, involving members of oyster mushroom farming groups and housewives. The training program is preceded by an understanding of the management of cultivated waste, followed by processing the waste into useful products. This training is a manifestation of the concern of SITH ITB lecturers for the residents of the villages around Mount Geulis. The processing of mushroom baglog waste into a plant growing medium and renewable energy in the form of charcoal briquettes is expected to improve the lives of the people of Cinanggung village through the use of plant growing media to support vegetable growing activities in polybags for the yard, at least to be used for family needs to support family food security. It is hoped that this program will make farmers more prosperous and make government programs related to community food security a success, starting from family food security. Keywords: Waste, baglog, oyster mushrooms, fertilizer, briquettes

Whole-genome sequence of Metarhizium anisopliae JEF-157 against Asian tiger mosquito larvae (Aedes albopictus).

Metarhizium anisopliae JEF-157, one of the biological control agents, was obtained from the Insect Microbial Biotechnology Laboratory at Jeonbuk National University. Herein, we report the whole genome of JEF-157, which has pathogenicity against Asian tiger mosquito larvae. The genome has 13,725 genes with a length of 17,719,696 bp.

INSECTS AS SOURCE OF ACTINOBACTERIA

Actinobacteria, a group of Gram-positive, filamentous bacteria known for their extensive production of bioactive compounds, are widely recognized for their role in microbial ecology and biotechnology. Insects, particularly those with specialized diets or complex social structures, have evolved intricate symbiotic relationships with Actinobacteria, which provide crucial benefits to their hosts. This paper examines the interactions between insects and Actinobacteria, focusing on the protective roles these bacteria offer to their insect hosts, their ecological significance, and their potential applications.

Molecular Genetic Characteristics of the Mutant Strain B-162/2 of the Bacteria <i>Pseudomonas chlororaphis</i> subsp. <i>aurantiaca</i>

The production of microorganisms that produce biologically active compounds for agriculture, the chemical, veterinary and pharmaceutical industries as well as for environmental protection continues to be an important direction of microbial biotechnology. One of the most effective approaches to the production of producers is chemical mutagenesis, which, in combination with the right breeding strategy, makes it possible to obtain highly productive strains. A significant disadvantage of chemical mutagenesis is the large number of induced mutations in the genomes of mutant strains, which makes it difficult to identify genes and, accordingly, biosynthetic pathways involved in the production of a given compound. The solution to this problem is modern technologies of genome sequencing and analysis, which make it possible to identify new genes and unknown biochemical pathways involved in the formation of biologically active compounds. The aim of the work was to analyse the genome of the mutant strain B-162/2 of the bacterium Pseudomonas chlororaphis subsp. aurantiaca, which is capable of increased production of biologically active compounds of the phenazine series and is resistant to hydrogen peroxide. When analysing the genome of strain B-162/2 in full size, 6482 coding sequences and 64 coding RNA sequences were identified. Comparison of the genome of the B-162/2 strain with the genome of the wild type B-162 allowed the identification of 39 mutations, 5 of which are localised in intergenic regions, and 34 affected coding sequences. Of the mutations detected, 14 led to a radical amino acid substitution in the proteins and 2 led to the formation of premature stop codons (methyl group sensor and MFS-type transporter). Several substitutions with high values of the Grantham coefficient were found, which could possibly lead to a change in the activity of the proteins concerned. The presence of three regions with phage genes in the genome of the B-162/2 strain was detected.

The Role of Biotechnology in Shaping the Future of Modern Agriculture

Biotechnology stands as a cornerstone in the evolution of modern agriculture, offering an array of innovative solutions poised to revolutionize crop productivity, enhance nutritional quality, and foster environmental sustainability. This comprehensive review delves into the multifaceted role of biotechnology in shaping the future landscape of agriculture, encompassing diverse realms such as genetic engineering, molecular breeding, and microbial biotechnology. Spanning from crop improvement to pest and disease management, soil health, and sustainable agriculture practices, the applications of biotechnology in agriculture are far-reaching and profound. Genetic engineering emerges as a powerful tool in the arsenal of agricultural biotechnology, facilitating the precise manipulation of plant genomes to confer desirable traits such as increased yield, enhanced nutritional content, and resistance to biotic and abiotic stresses. Molecular breeding techniques complement this approach, leveraging advances in genomics and bioinformatics to expedite the breeding process and develop high-performing crop varieties tailored to specific agroecological contexts, microbial biotechnology emerges as a pivotal force in sustainable agriculture, harnessing the power of beneficial microorganisms to improve soil fertility, enhance nutrient uptake, and suppress plant pathogens. From biofertilizers and biopesticides to bioremediation and phytoremediation, microbial-based solutions hold immense potential in mitigating environmental degradation and promoting agroecosystem resilience, the widespread adoption of biotechnology in agriculture is not devoid of societal, economic, and ethical considerations. Regarding food safety, environmental impact, and socio-economic equity underscore the need for rigorous regulatory frameworks and robust risk assessment protocols to ensure the responsible deployment of biotechnological innovations, public perceptions and fostering dialogue between stakeholders are essential for building trust and garnering support for biotechnology in agriculture. Education, transparency, and stakeholder engagement are paramount in navigating the complex terrain of biotechnology governance and fostering an enabling environment for innovation, the current state and future prospects of biotechnology in agriculture, this review endeavors to inform policymakers, researchers, and stakeholders about the transformative potential of biotechnology to address pressing global challenges such as food security, climate change, and environmental sustainability. Embracing the opportunities afforded by biotechnology holds the key to unlocking a more resilient, equitable, and sustainable agricultural future.

Studying the Antimicrobial Effects of Silver Nanoparticles Coated with Alginate Biosynthesized by Dulcicalothrix alborzica

Introduction: Nowadays, Cyanobacteria are one of the important candidates in the green biosynthesis of nanoparticles. Considering the detrimental effects of chemically synthesized nanoparticles, the aim of this study was the biosynthesis and antimicrobial activity of nanoparticles by aquatic cyanobacterium. Methods: Silver nanoparticles (AgNPs) were biosynthesized using three different approaches: wet biomass, boiling, and extracellular polysaccharides (EPS). Alginate coating was employed to enhance the nanoparticles' stability. Characterization of the nanoparticles was performed using UV-vis spectroscopy, Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and zeta potential measurements. The antimicrobial properties of the nanoparticles were evaluated against fish pathogenic bacteria and fungi. Statistical analyzes were performed with SPSS version 16 software, and the significant difference between the means was performed with one-way analysis of variance with 95% confidence limits and Tukey's test, and the results were drawn as a graph with Excel software. Results: The UV-vis spectroscopy results confirmed the synthesis of AgNPs in all three methods. FTIR analysis revealed similar spectra for all three methods, indicating comparable purity and production of similar compounds. Electron microscope images showed the sphericity of nanoparticles prepared by boiling method, and the average diameter of uncoated and alginate coated nanoparticles was 38 and 180.04 nm, respectively. Zeta potential analysis indicated a positive surface charge on the nanoparticles. The highest zone of inhibition was observed for AgNPs synthesized by the boiling method and coated with alginate. Similar results were obtained for the antifungal activity, with Saprolegnia exhibiting higher sensitivity to the synthesized nanoparticles compared to the other species studied. Conclusion: The novel strain Dulcicalothrix alborzica demonstrated potential as a potent producer of AgNPs with unique properties and promising applications in microbial biotechnology.

From pollutants to products: Microbial cell factories driving sustainable biomanufacturing and environmental conservation

Microbial cell factories are emerging as powerful tools in addressing pressing environmental challenges and promoting sustainable biomanufacturing. This paper highlights the key role of engineered microorganisms in mitigating pollution, converting waste and pollutants into valuable products, and reducing reliance on fossil fuels. Through advancements in metabolic engineering, gene editing technologies, and synthetic biology, microbial cell factories are being optimized to enhance their efficiency in breaking down pollutants and producing renewable chemicals, such as biofuels, bioplastics, and specialty chemicals. These processes contribute to environmental conservation, waste valorization, and the establishment of a circular economy.The study focuses on overcoming key barriers in microbial biotechnology, such as limited scalability, process inefficiency, and economic viability, by employing strategies like metabolic pathway optimization, enzyme overexpression, and tolerance enhancement. These strategies are applied to various microbial species, demonstrating how their metabolic capabilities can be fine-tuned for industrial applications. Detailed case studies illustrate successful implementations, such as the conversion of lignocellulosic biomass, CO2, and industrial waste into high-value products, underscoring the practical impact of microbial cell factories in diverse sectors, including energy, materials, and chemicals.Furthermore, this research addresses the challenges faced by microbial cell factories in industrial-scale operations, such as maintaining genetic stability and optimizing growth conditions, and offers insight into emerging technological solutions to these obstacles. By providing a comprehensive overview of recent developments and identifying future research directions, this paper offers actionable recommendations for unlocking the full potential of microbial biotechnology. These efforts aim to further integrate microbial processes into industrial systems, contributing to a more sustainable and resilient global economy, with the ultimate goal of fostering a circular bioeconomy.

Omic-driven strategies to unveil microbiome potential for biodegradation of plastics: a review.

Plastic waste accumulation has lately been identified as the leading and pervasive environmental concern, harming all living beings, natural habitats, and the global market. Given this issue, developing ecologically friendly solutions, such as biodegradation instead of standard disposal, is critical. To effectively address and develop better strategies, it is critical to understand the inter-relationship between microorganisms and plastic, the role of genes and enzymes involved in this process. However, the complex nature of microbial communities and the diverse mechanisms involved in plastic biodegradation have hindered the development of efficient plastic waste degradation strategies. Omics-driven approaches, encompassing genomics, transcriptomics and proteomics have revolutionized our understanding of microbial ecology and biotechnology. Therefore, this review explores the application of omics technologies in plastic degradation studies and discusses the key findings, challenges, and future prospects of omics-based approaches in identifying novel plastic-degrading microorganisms, enzymes, and metabolic pathways. The integration of omics technologies with advanced molecular technologies such as the recombinant DNA technology and synthetic biology would guide in the optimization of microbial consortia and engineering the microbial systems for enhanced plastic biodegradation under various environmental conditions.

Multi-omics framework to reveal the molecular determinants of fermentation performance in wine yeast populations

BackgroundConnecting the composition and function of industrial microbiomes is a major aspiration in microbial biotechnology. Here, we address this question in wine fermentation, a model system where the diversity and functioning of fermenting yeast species are determinant of the flavor and quality of the resulting wines.ResultsFirst, we surveyed yeast communities associated with grape musts collected across wine appellations, revealing the importance of environmental (i.e., biogeography) and anthropic factors (i.e., farming system) in shaping community composition and structure. Then, we assayed the fermenting yeast communities in synthetic grape must under common winemaking conditions. The dominating yeast species defines the fermentation performance and metabolite profile of the resulting wines, and it is determined by the initial fungal community composition rather than the imposed fermentation conditions. Yeast dominance also had a more pronounced impact on wine meta-transcriptome than fermentation conditions. We unveiled yeast-specific transcriptomic profiles, leveraging different molecular functioning strategies in wine fermentation environments. We further studied the orthologs responsible for metabolite production, revealing modules associated with the dominance of specific yeast species. This emphasizes the unique contributions of yeast species to wine flavor, here summarized in an array of orthologs that defines the individual contribution of yeast species to wine ecosystem functioning.ConclusionsOur study bridges the gap between yeast community composition and wine metabolite production, providing insights to harness diverse yeast functionalities with the final aim to producing tailored high-quality wines.74dL8hDE5Rym1TqBfqxSSDVideo

Artificial intelligence-based prediction of pathogen emergence and evolution in the world of synthetic biology.

The emergence of new techniques in both microbial biotechnology and artificial intelligence (AI) is opening up a completely new field for monitoring and sometimes even controlling the evolution of pathogens. However, the now famous generative AI extracts and reorganizes prior knowledge from large datasets, making it poorly suited to making predictions in an unreliable future. In contrast, an unfamiliar perspective can help us identify key issues related to the emergence of new technologies, such as those arising from synthetic biology, whilst revisiting old views of AI or including generative AI as a generator of abduction as a resource. This could enable us to identify dangerous situations that are bound to emerge in the not-too-distant future, and prepare ourselves to anticipate when and where they will occur. Here, we emphasize the fact that amongst the many causes of pathogen outbreaks, often driven by the explosion of the human population, laboratory accidents are a major cause of epidemics. This review, limited to animal pathogens, concludes with a discussion of potential epidemic origins based on unusual organisms or associations of organisms that have rarely been highlighted or studied.

Heterologous expression of the Oenococcus oeni two-component signal transduction response regulator in the Lactiplantibacillus plantarum WCFS1 strain enhances acid stress tolerance

BackgroundOenococcus oeni is a commercial wine-fermenting bacterial strain, owing to its high efficiency of malolactic fermentation and stress tolerance. The present study explored the function of key genes in O. oeni to enhance stress resistance by heterologous expression of these genes in another species.ResultsThe orf00404 gene that encodes a two-component signal transduction response regulator in O. oeni was heterologously expressed in Lactiplantibacillus plantarum WCFS1. The expression of orf00404 significantly enhanced the growth rate of the recombinant strain under acid stress. At 60 h, 72 h, and 108 h of culture at pH 4.0, the recombinant strain had 1562, 641, and 748 differentially expressed genes compared to the control strain, respectively. At all three time points, 20 genes were upregulated in the recombinant strain, including the lamA-D operon-coding genes of the quorum-sensing two component signal transduction system and the spx5 RNA polymerase-binding protein coding gene, which may help adaptation to acid stress. In addition, 47 genes were downregulated in the recombinant strain at all three time points, including the hsp1 heat shock protein-coding gene, the trxA1 thioredoxin-coding gene, and the dinP, mutY, umuC, and uvrB DNA damage repair-related protein-coding genes, potentially indicating that the recombinant strain was less susceptible to stress and had less DNA damage than the control strain in acid stress conditions. The recombinant strain had higher membrane fluidity, permeability, and integrity at an early stage of logarithmic growth (72 h), suggesting that it had a more complete and active cell membrane state at this stage. The intracellular ATP content was significantly reduced in the recombinant strain at the beginning of logarithmic growth (60 h), implying that the recombinant strain consumed more energy at this stage to resist acid stress and growth.ConclusionsThese results indicated that the recombinant strain enhances acid stress tolerance by regulating a gene expression pattern, increasing ATP consumption, and enhancing cell membrane fluidity, membrane permeability, and membrane integrity at specific growth stages. Thus, the recombinant strain may have potential application in the microbial biotechnology industry.

Advances in the microbial synthesis of active ingredients in cosmetics

With the rapid development of the medical beauty industry, functional skin care products become increasingly popular. The functions of cosmetics mainly depend on the active ingredients, which are mainly proteins, peptides, polysaccharides, phenolic acids, terpenes, vitamins, and amino acids. These active ingredients endow cosmetics with skin repairing, moistening, whitening, UV protecting, and anti-aging effects. They are mainly obtained through biological extraction and chemical synthesis. In recent years, with the development of biomanufacturing, microbial synthesis of active ingredients in cosmetics has been widely studied and applied. This article reviews the research progresses in the production of natural products including collagens, peptides, hyaluronic acid, polyphenols, terpenes, and vitamins by microbial synthetic biotechnology. Moreover, this article highlighted the synthetic pathways, metabolic regulation, and prospects of the natural products, providing a reference for subsequent microbial synthesis of active ingredients in cosmetics.

Isolation and characterization of a Halomonas species for non-axenic growth-associated production of bio-polyesters from sustainable feedstocks.

The urgent need for renewable replacements for synthetic materials may be addressed through microbial biotechnology. To simplify the large-scale implementation of such bio-processes, robust cell factories that can utilize sustainable and widely available feedstocks are pivotal. To this end, non-axenic growth-associated production could reduce operational costs and enhance biomass productivity, thereby improving commercial competitiveness. Another major cost factor is downstream processing, especially in the case of intracellular products, such as bio-polyesters. Simplified cell-lysis strategies could also further improve economic viability.

Advances in Microbial Biotechnology for Sustainable Alternatives to Petroleum-Based Plastics: A Comprehensive Review of Polyhydroxyalkanoate Production.

The industrial production of polyhydroxyalkanoates (PHAs) faces several limitations that hinder their competitiveness against traditional plastics, mainly due to high production costs and complex recovery processes. Innovations in microbial biotechnology offer promising solutions to overcome these challenges. The modification of the biosynthetic pathways is one of the main tactics; allowing for direct carbon flux toward PHA formation, increasing polymer accumulation and improving polymer properties. Additionally, techniques have been implemented to expand the range of renewable substrates used in PHA production. These feedstocks are inexpensive and plentiful but require costly and energy-intensive pretreatment. By removing the need for pretreatment and enabling the direct use of these raw materials, microbial biotechnology aims to reduce production costs. Furthermore, improving downstream processes to facilitate the separation of biomass from culture broth and the recovery of PHAs is critical. Genetic modifications that alter cell morphology and allow PHA secretion directly into the culture medium simplify the extraction and purification process, significantly reducing operating costs. These advances in microbial biotechnology not only enhance the efficient and sustainable production of PHAs, but also position these biopolymers as a viable and competitive alternative to petroleum-based plastics, contributing to a circular economy and reducing the dependence on fossil resources.

Induction of bacterial expression at the mRNA level by light.

Vital organismal processes, including development, differentiationand adaptation, involve altered gene expression. Although expression is frequently controlled at the transcriptional stage, various regulation mechanisms operate at downstream levels. Here, we leverage the photoreceptor NmPAL to optogenetically induce RNA refolding and the translation of bacterial mRNAs. Blue-light-triggered NmPAL binding disrupts a cis-repressed mRNA state, thereby relieves obstruction of translation initiation, and upregulates gene expression. Iterative probing and optimization of the circuit, dubbed riboptoregulator, enhanced induction to 30-fold. Given action at the mRNA level, the riboptoregulator can differentially regulate individual structural genes within polycistronic operons. Moreover, it is orthogonal to and can be wed with other gene-regulatory circuits for nuanced and more stringent gene-expression control. We thus advance the pAurora2 circuit that combines transcriptional and translational mechanisms to optogenetically increase bacterial gene expression by>1000-fold. The riboptoregulator strategy stands to upgrade numerous regulatory circuits and widely applies to expression control in microbial biotechnology, synthetic biologyand materials science.