This review comprehensively examines the various applications of microalgae, focusing on their significant potential in producing biodiesel and hydrogen, serving as sustainable food sources, and their efficacy in treating both municipal and food-related wastewater. While previous studies have mainly focused on specific applications of microalgae, such as biofuel production or wastewater treatment, this review covers these applications comprehensively. It examines the potential for microalgae to be applied in various industrial sectors such as energy, food security, and environmental management. By bridging these different application areas, this review differs from previous studies in providing an integrated and multifaceted view of the industrial applications of microalgae. Since it is essential to increase the productivity of the process to utilize microalgae for various industrial applications, research trends in different microalgae cultivation processes, including the culture system (e.g., open ponds, closed ponds) or environmental conditions (e.g., pH, temperature, light intensity) to improve the productivity of biomass and valuable substances was firstly analyzed. In addition, microalgae cultivation technologies that can maximize the biomass and valuable substances productivity while limiting the potential for contamination that can occur when utilizing these systems have been described to maximize CO reduction. In conclusion, this review has provided a detailed analysis of current research findings and technological innovations, highlighting the important role of microalgae in addressing global challenges related to energy, food supply, and waste management. It has also provided valuable insights into future research directions and potential commercial applications in several bio-related industries, and illustrated how important continued exploration and development in this area is to realize the full potential of microalgae.

The non-pathogenic Mycoplasma pneumoniae engineered chassis (Mycochassis) has demonstrated the ability to express therapeutic molecules in vitro and to be effective for treatment of lung infectious diseases in in vivo mouse models. However, the expression of heterologous molecules, whether secreted or exposed on the bacterial membrane has not been optimized to ensure sufficient secretion and/or exposure levels to exert a maximum in vivo biological effect. Here, we have improved the currently used secretion signal from MPN142 protein. We found that mutations at P1' position of the signal peptide cleavage site do not abrogate secretion but affect it. Increasing hydrophobicity and mutations at the C-terminal of the signal peptide increases secretion. We tested different lipoprotein signal peptides as possible N-terminal protein anchoring motifs on the Mpn cell surface. Unexpectedly we found that these peptides exhibit variable retention and secretion rates of the protein, with some sequences behaving as full secretion motifs. This raises the question of the biological role of the lipobox motif traditionally thought to anchor membrane proteins without a helical transmembrane domain. These results altogether represent a step forward in chassis optimization, offering different sequences for secretion or membrane retention, which could be used to improve Mycochassis as a delivery vector, and broadening its therapeutic possibilities.

2-O-α-D-glucosyl glycerol (2-αGG) is a valuable ingredient in cosmetics, health-care and food fields. Sucrose phosphorylase (SPase) is a favorable choice for biosynthesis of 2-αGG, while its glucosyl-acceptor affinity and thermodynamic feature remain largely unknown, limiting 2-αGG manufacturing.

Hypoxanthine, prevalent in animals and plants, is used in the production of food additives, nucleoside antiviral drugs, and disease diagnosis. Current biological fermentation methods synthesize quantities insufficient to meet industrial demands. Therefore, this study aimed to develop a strain capable of industrial-scale production of hypoxanthine.

Biorefinery using microorganisms to produce biofuels and value-added biochemicals derived from renewable biomass offers a promising alternative to meet our sustainable energy and environmental goals. The ethanologenic strain Zymomonas mobilis is considered as an excellent chassis for constructing microbial cell factories for diverse biochemicals due to its outstanding industrial characteristics in ethanol production, high specific productivity, and Generally Recognized as Safe (GRAS) status. Nonetheless, the restricted substrate range constrains its application.

Depolymerizing polyethylene terephthalate (PET) plastics using enzymes, such as PETase, offers a sustainable chemical recycling route. To enhance degradation, many groups have sought to engineer PETase for faster catalysis on PET and elevated stability. Considerably less effort has been focused toward expressing large quantities of the enzyme, which is necessary for large-scale application and widespread use. In this work, we evaluated several E. coli strains for their potential to produce soluble, folded, and active IsPETase, and moved the production to a benchtop bioreactor. As PETase is known to require disulfide bonds to be functional, we screened several disulfide-bond promoting strains of E. coli to produce IsPETase, FAST-PETase and Hot-PETase.

Lignin is a promising resource for obtaining aromatic materials, however, its heterogeneous structure poses a challenge for effective utilization. One approach to produce homogeneous aromatic materials from lignin involves the application of microbial catabolism, which is gaining attention. This current study focused on constructing a catabolic pathway in Pseudomonas sp. NGC7 to produce vanillate (VA) from aromatic compounds derived from the chemical depolymerization of sulfite lignin.

Since 1982, recombinant insulin has been used as a substitute for pancreatic insulin from animals. However, increasing demand in medical and food industries warrants the development of more efficient production methods. In this study, we aimed to develop a novel and efficient method for insulin production using a yeast secretion system.

Fermentation processes are essential for the production of small molecules, heterologous proteins and other commercially important products. Traditional bioprocess optimisation relies on phenomenological models that focus on macroscale variables like biomass growth and protein yield. However, these models often fail to consider the crucial link between macroscale dynamics and the intracellular activities that drive metabolism and proteins synthesis.

Trichoderma reesei is renowned for its cellulase-producing ability and is used for biofuel production from lignocellulose. In plants and fungi, cellulase production is induced by cellulose and suppressed by glucose; however, whether metformin can enhance cellulase production and mitochondrial function in T. reesei remains unclear. Metformin reduces blood glucose levels by inhibiting hepatic gluconeogenesis; therefore, it is worth investigating whether metformin transmission modulates cellulase biosynthesis in T. reesei.

In microbial cell factories, substrate accessibility to enzyme is a key factor affecting the biosynthesis of natural products. As a robust chassis cells for biofuels and bioproducts, Saccharomyces cerevisiae also encounters the challenge since different enzymes and precursors are typically compartmentalized in different organelles. Such spatial separation could largely limit the efficiency of enzymatic reactions. In this study, the production of the hydrophobic product (vitamin A) was highly improved by metabolic engineering combined with degrading lipid droplets (the primary organelle storing β-carotene) to achieve efficient contact between β-carotene and 15, 15'-β-carotene monooxygenases in Saccharomyces cerevisiae.

To discover effective drugs for treating Influenza (a disease with high annual mortality), large amounts of recombinant neuraminidase (NA) with suitable catalytic activity are needed. However, the functional activity of the full-length form of this enzyme in the bacterial host (as producing cells with a low cost) in a soluble form is limited. Thus, in the present study, a truncated form of the neuraminidase (derived from California H1N1 influenza strain) was designed, then biosynthesized in Escherichia coli BL21 (DE3), Shuffle T7, and SILEX systems. E. coli BL21 (DE3) was selected as a best host for statistical optimization. Using central composite design methodology, neuraminidase expression level was measured at 20 different runs considering most effective factors including; concentration of isopropyl-β-D-thiogalactopyranoside (IPTG), temperature, and induction time.

Uricase is a bio-drug used to reduce urate accumulation in gout disease. Thus, there is a continuous demand for screening soil samples derived from a variety of different sources in order to isolate a strain that possesses a high potential for producing uricase.

Flavonoids are a structurally diverse group of secondary metabolites, predominantly produced by plants, which include a range of compounds with pharmacological importance. Pinocembrin is a key branch point intermediate in the biosynthesis of a wide range of flavonoid subclasses. However, replicating the biosynthesis of these structurally diverse molecules in heterologous microbial cell factories has encountered challenges, in particular the modest pinocembrin titres achieved to date. In this study, we combined genome engineering and enzyme candidate screening to significantly enhance the production of pinocembrin and its derivatives, including chrysin, pinostrobin, pinobanksin, and galangin, in Escherichia coli.

Echinocandin B (ECB) is a key precursor of the antifungal drug anidulafungin and its biosynthesis occurs via ani gene cluster in Aspergillus nidulans NRRL8112. Strain improvement for industrial ECB production has mainly relied on mutation breeding due to the lack of genetic tools.

Carbapenem resistance among bacteria, especially Klebsiella pneumoniae and Acinetobacter baumannii, constitutes a dreadful threat to public health all over the world that requires developing new medications urgently. Carbapenem resistance emerges as a serious problem as this class is used as a last-line option to clear the multidrug-resistant bacteria. Arthrospira maxima (Spirulina) is a well-known cyanobacterium used as a food supplement as it is rich in protein, essential minerals and vitamins and previous studies showed it may have some antimicrobial activity against different organisms. Biosynthesized (green) zinc oxide nanoparticles have been investigated by several researchers as antibacterials because of their safety in health. In this article, previous studies were analyzed to get to a conclusion about their activity as antibacterials.

Elicitation through abiotic stress, including heavy metals, is a new natural product drug discovery technique. In this research, three compounds 1, 2, and 6, were achieved by triggering zinc and nickel on marine Sphingomonas sp. and Streptomyces sp., which were absent in normal culture. Compound 5 was obtained for the first time from marine bacteria. All compounds showed potent antibacterial activity against Staphylococcus aureus and bactericidal effect at 300 µm, but 6 was more active. The potent compound 6 production was further enhanced through response surface methodology by optimizing the condition consisting of nickel 1 mM ions, 20 mg/L sucrose, 30 mg/L salt and culture time 14 days. Under these conditions, the SM-6 production was enhanced with a yield of 6.3 mg/L, which was absent in the normal culture. Further transcriptome analysis of compound 6 unveiled its antibacterial activity on S. aureus by modulating heat shock protein genes, disrupting protein folding and synthesis, and perturbing cellular redox balance, leading to a comprehensive inhibition of normal bacterial growth. In addition, ADMET has shown that all compounds are safe for cardiac and hepatotoxicity. To determine the anti-bacterial mechanism, all compounds were docked with PBP2a and DNA gyrase enzyme, and TLR-4 protein for predicting vaccine construct, and the best docking score was achieved against PBP2a enzyme with the highest score of -10.2 for compound 6. In-silico cloning was carried out to ensure the expression of proteins generated and were cloned using S.aureus as a host. The simulation studies have shown that both SM-6-PBP2a and TLR-4-PBP2a complex are stable with the system. This study presents a new approach to anti-bacterial drug discovery from microorganisms through heavy metals triggering and enhancing the compound production through response surface methodology.

Sphingosine-1-phosphate (S1P) is a multifunctional sphingolipid that has been implicated in regulating cellular activities in mammalian cells. Due to its therapeutic potential, there is a growing interest in developing efficient methods for S1P production. To date, the production of S1P has been achieved through chemical synthesis or blood extraction, but these processes have limitations such as complexity and cost. In this study, we generated an S1P-producing Saccharomyces cerevisiae strain by using metabolic engineering and introducing a heterologous sphingolipid biosynthetic pathway to demonstrate the possibility of microbial S1P production.

Acetate is an important chemical feedstock widely applied in the food, chemical and textile industries. It is now mainly produced from petrochemical materials through chemical processes. Conversion of lignocellulose biomass to acetate by biotechnological pathways is both environmentally beneficial and cost-effective. However, acetate production from carbohydrate in lignocellulose hydrolysate via glycolytic pathways involving pyruvate decarboxylation often suffers from the carbon loss and results in low acetate yield.

Oxygen provision is a bottleneck in conventional aerobic high cell density culturing (HCDC) of bacteria due to the low O solubility in water. An alternative could be denitrification: anaerobic respiration using nitrogen oxides as terminal electron acceptors. Denitrification is attractive because NO is soluble in water, the end-product (N) is harmless, and denitrification is widespread among bacteria, hence suitable organisms for most purposes can be found. The pH must be controlled by injection of an inorganic acid to compensate for the pH increase by NO-consumption, resulting in salt accumulation if feeding the bioreactor with NO salt. We avoid this with our novel pH-stat approach, where the reactor is supplied with 5 M HNO to compensate for the alkalization, thus sustaining NO-concentration at a level determined by the pH setpoint. Here we present the first feasibility study of this method, growing the model strain Paracoccus denitrificans anaerobically to high densities with glucose as the sole C-source and NO as the N-source and electron acceptor.