Chlamydomonas reinhardtii-expressed multimer of ToAMP4 inhibits the growth of bacteria of both Gram-positive and Gram-negative

Harnessing the potential of microalgae for the production of monoclonal antibodies and other recombinant proteins

Monoclonal antibodies (mAbs) have become indispensable tools in various fields, from research to therapeutics, diagnostics, and industries. However, their production, primarily in mammalian cell culture systems, is cost-intensive and resource-demanding. Microalgae, diverse photosynthetic microorganisms, are gaining attention as a favorable option for manufacturing mAbs and various other recombinant proteins. This review explores the potential of microalgae as a robust expression system for biomanufacturing high-value proteins. It also highlights the diversity of microalgae species suitable for recombinant protein. Nuclear and chloroplast genomes of some microalgae have been engineered to express mAbs and other valuable proteins. Codon optimization, vector construction, and other genetic engineering techniques have significantly improved recombinant protein expression in microalgae. These accomplishments demonstrate the potential of microalgae for biopharmaceutical manufacturing. Microalgal biotechnology holds promise for revolutionizing the production of mAbs and other therapeutic proteins, offering a sustainable and cost-effective solution to address critical healthcare needs.

Secretory Expression and Application of Antilipopolysaccharide Factor 3 in Chlamydomonas reinhardtii

Anti-lipopolysaccharide factor is a class of antimicrobial peptides with lipopolysaccharide-binding structural domains, which has a broad antimicrobial spectrum, high antimicrobial activities, and broad application prospects in terms of the aquaculture industry. However, the low yield of natural antimicrobial peptides and their poor expression activity in bacteria and yeast have hindered their exploration and utilization. Therefore, in this study, the extracellular expression system of Chlamydomonas reinhardtii, by fusing the target gene with the signal peptide, was used to express anti-lipopolysaccharide factor 3 (ALFPm3) from Penaeus monodon in order to obtain highly active ALFPm3. Transgenic C. reinhardtii T-JiA2, T-JiA3, T-JiA5, and T-JiA6, were verified using DNA-PCR, RT-PCR, and immunoblot. Additionally, the IBP1-ALFPm3 fusion protein could be detected not only within the cells but also in the culture supernatant. Moreover, the extracellular secretion containing ALFPm3 was collected from algal cultures, and then its bacterial inhibitory activity was analyzed. The results showed that the extracts from T-JiA3 had an inhibition rate of 97% against four common aquaculture pathogenic bacteria, including Vibrio harveyi, Vibrio anguillarum, Vibrio alginolyticus, and Vibrio parahaemolyticus. The highest inhibition rate of 116.18% was observed in the test against V. anguillarum. Finally, the minimum inhibition concentration (MIC) of the extracts from T-JiA3 to V. harveyi, V. anguillarum, V. alginolyticus, and V. parahaemolyticus were 0.11 μg/μL, 0.088 μg/μL, 0.11 μg/μL, and 0.011 μg/μL, respectively. This study supports the foundation of the expression of highly active anti-lipopolysaccharide factors using the extracellular expression system in C. reinhardtii, providing new ideas for the expression of highly active antimicrobial peptides.

Antimicrobial peptides derived from microalgae for combating antibiotic resistance: Current status and prospects

Microalgae are photosynthetic cell factories that produce a spectrum of bioactive compounds extensively used for various applications. Owing to the increase in antibiotic resistance among microbial pathogens, there is a significant thrust for identifying new treatment strategies, and antimicrobial peptides (AMPs) generation is one such method. These AMPs have multiple roles and are active against bacteria, fungi, and viruses. Such peptides synthesized in microalgae have a significant role in medical application, managing aquaculture-associated diseases, and the food industry. To increase their effectiveness and novel peptides, genetically modified microalgae are used as cell factories. With the advancement of new technologies like the CRISPR-Cas system, new avenues are opened for developing novel AMPs using microalgae. This review gives us insight into the various AMPs produced by microalgae and multiple technologies involved in creating such therapeutically essential molecules.

Chlamydomonas reinhardtii: A Factory of Nutraceutical and Food Supplements for Human Health

Chlamydomonas reinhardtii (C. reinhardtii) is one of the most well-studied microalgae organisms that revealed important information for the photosynthetic and metabolic processes of plants and eukaryotes. Numerous extensive studies have also underpinned its great potential as a biochemical factory, capable of producing various highly desired molecules with a direct impact on human health and longevity. Polysaccharides, lipids, functional proteins, pigments, hormones, vaccines, and antibodies are among the valuable biomolecules that are produced spontaneously or under well-defined conditions by C. reinhardtii and can be directly linked to human nutrition and diet. The aim of this review is to highlight the recent advances in the field focusing on the most relevant applications related to the production of important biomolecules for human health that are also linked with human nutrition and diet. The limitations and challenges are critically discussed along with the potential future applications of C. reinhardtii biomass and processed products in the field of nutraceuticals and food supplements. The increasing need for high-value and low-cost biomolecules produced in an environmentally and economy sustainable manner also underline the important role of C. reinhardtii.

Production of recombinant and therapeutic proteins in microalgae

Microalgae is emerging as a promising platform for the production of recombinant proteins of therapeutic importance. Since microalgae are safe for oral consumption and some microalgal species can form extracellular vesicles, they can potentially be used as edible vaccines or drug-delivery vehicles in addition to their status as naturally rich sources of nutraceutical bioproducts. This article focuses on recent advances in the field of recombinant protein production in microalgae, and developments toward the use of microalgae as a vehicle for drug delivery.

Current Status and Perspective on the Use of Viral-Based Vectors in Eukaryotic Microalgae

During the last two decades, microalgae have attracted increasing interest, both commercially and scientifically. Commercial potential involves utilizing valuable natural compounds, including carotenoids, polysaccharides, and polyunsaturated fatty acids, which are widely applicable in food, biofuel, and pharmaceutical industries. Conversely, scientific potential focuses on bioreactors for producing recombinant proteins and developing viable technologies to significantly increase the yield and harvest periods. Here, viral-based vectors and transient expression strategies have significantly contributed to improving plant biotechnology. We present an updated outlook covering microalgal biotechnology for pharmaceutical application, transformation techniques for generating recombinant proteins, and genetic engineering tactics for viral-based vector construction. Challenges in industrial application are also discussed.

Antibacterial activity of antimicrobial peptide gcDefb1 against foodborne pathogenic bacteria and its application in pork storage

Pork and its products are preferably contaminated by bacteria; thus, it is essential to develop low-cost, high-efficiency and biologically safe preservatives to prevent the growth of bacteria during storage. In the current study, grass carp β-defensin 1 (gcDefb1) was produced and purified from Pichia pastoris through the heterologous expression method. The in vitro antimicrobial assay demonstrated that yeast-derived gcDefb1 possesses a broad antibacterial spectrum, including both Gram-positive and -negative bacteria, and the MIC values against Escherichia coli ATCC 25,922 were as low as 30 μg/mL and showed no cytotoxicity or hemolytic activity. The bactericidal rate of gcDefb1 was less than 60 min by disrupting the cell membranes, and it inhibited the formation of bacterial biofilms. Moreover, gcDefb1 was used as a biopreservative for pork storage, indicating that the physicochemical and sensory qualities were improved. This study provides an efficient method to prepare and utilize gcDefb1 as a novel biopreservative.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01060-9.

Antimicrobial property of Pichia pastoris-derived natto peptide against foodborne bacteria and its preservative potential to maintain pork quality during refrigerated storage

Pork spoilage caused by foodborne bacteria contamination always leads to substantial economic loss in the meat industry. The toxicity and drug resistance of chemical preservatives have raised public concerns about their safety and stability. In this study, natto peptide from Pichia pastoris was prepared using DNA recombinant technology. It showed an excellent antibacterial effect against Gram-positive and -negative bacteria, with minimum inhibitory concentrations (MICs) ranging from 6 to 30 μg/ml. Of note, natto peptide exhibited low cytotoxicity and hemolytic activity. The application of natto peptide on pork during refrigerated storage dramatically decreased the growth of Staphylococcus spp., Escherichia spp., and Pseudomonas spp. The bactericidal properties remained in force when natto peptide was used in pork models contaminated with artificial bacteria. Moreover, the application of natto peptide (90 μg/ml) inhibited the increase in pH variation and drip loss, decreased the generation of total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARS), and maintained a high sensory quality score during pork storage. These results implied that P. pastoris-derived natto peptide could extend the storage time of pork, and it has the potential to be a promising antiseptic biopreservative to replace chemical preservatives.

Production of an invertebrate lysozyme of Scylla paramamosain in E.coli and evaluation of its antibacterial, antioxidant and anti-inflammatory effects

Lysozymes, which are secreted in many organisms, including invertebrates, mammals, plants, bacteria and fungus, exhibit antimicrobial, antiviral, antioxidant, and anti-inflammatory activities. Splys-i is an invertebrate-type (i-type) lysozyme isolated from Scylla paramamosain in 2017 and is involved in immune defense against bacteria. However, the antibacterial, antioxidant, and anti-inflammatory activities of Splys-i remain to be elucidated. In the current study, the expression parameters (including IPTG concentration, induction temperature, and induction duration) of Splys-i in Escherichia coli were optimized to achieve high-level yield through shake-flask cultivation with approximately 120 mg of Splys-i obtained from 1 L of LB medium. The purified Splys-i displayed low cytotoxicity to RAW264.7 macrophage cells and low hemolytic activity against erythrocytes of mouse, rat, and rabbit, respectively, and exhibited potent antibacterial activity against both Gram-positive and -negative bacteria with minimum concentrations ranging from 15 to 90 μg/mL. The antibacterial property of Splys-i was also unaffected when treated with various temperature, pHs, and salinity, respectively, and Splys-i showed resistance to proteinase digestion. Radical-scavenging rate assay (including ABTS⁺, DPPH, hydroyl free radical, and superoxide anion) indicated that Splys-i was an efficient antioxidant. Splys-i also exerted anti-inflammatory effect through the inhibition of IκBα and NF-κB(P65) phosphorylation, thereby reducing the secretion of pro-inflammatory cytokines. All these results suggested that Splys-i can be prepared from E. coli with potent biological property.