1
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Einhaus A, Baier T, Kruse O. Molecular design of microalgae as sustainable cell factories. Trends Biotechnol 2024; 42:728-738. [PMID: 38092627 DOI: 10.1016/j.tibtech.2023.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/17/2023] [Accepted: 11/17/2023] [Indexed: 06/09/2024]
Abstract
Microalgae are regarded as sustainable and potent chassis for biotechnology. Their capacity for efficient photosynthesis fuels dynamic growth independent from organic carbon sources and converts atmospheric CO2 directly into various valuable hydrocarbon-based metabolites. However, approaches to gene expression and metabolic regulation have been inferior to those in more established heterotrophs (e.g., prokaryotes or yeast) since the genetic tools and insights in expression regulation have been distinctly less advanced. In recent years, however, these tools and their efficiency have dramatically improved. Various examples have demonstrated new trends in microalgal biotechnology and the potential of microalgae for the transition towards a sustainable bioeconomy.
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Affiliation(s)
- Alexander Einhaus
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Thomas Baier
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Olaf Kruse
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany.
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2
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Kerckhofs E, Schubert D. Conserved functions of chromatin regulators in basal Archaeplastida. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 118:1301-1311. [PMID: 37680033 DOI: 10.1111/tpj.16446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 08/15/2023] [Accepted: 08/18/2023] [Indexed: 09/09/2023]
Abstract
Chromatin is a dynamic network that regulates genome organization and gene expression. Different types of chromatin regulators are highly conserved among Archaeplastida, including unicellular algae, while some chromatin genes are only present in land plant genomes. Here, we review recent advances in understanding the function of conserved chromatin factors in basal land plants and algae. We focus on the role of Polycomb-group genes which mediate H3K27me3-based silencing and play a role in balancing gene dosage and regulating haploid-to-diploid transitions by tissue-specific repression of the transcription factors KNOX and BELL in many representatives of the green lineage. Moreover, H3K27me3 predominantly occupies repetitive elements which can lead to their silencing in a unicellular alga and basal land plants, while it covers mostly protein-coding genes in higher land plants. In addition, we discuss the role of nuclear matrix constituent proteins as putative functional lamin analogs that are highly conserved among land plants and might have an ancestral function in stress response regulation. In summary, our review highlights the importance of studying chromatin regulation in a wide range of organisms in the Archaeplastida.
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Affiliation(s)
- Elise Kerckhofs
- Epigenetics of Plants, Institute for Biology, Freie Universität Berlin, Berlin, Germany
| | - Daniel Schubert
- Epigenetics of Plants, Institute for Biology, Freie Universität Berlin, Berlin, Germany
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3
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Khunnonkwao P, Thitiprasert S, Jaiaue P, Khumrangsee K, Cheirsilp B, Thongchul N. The outlooks and key challenges in renewable biomass feedstock utilization for value-added platform chemical via bioprocesses. Heliyon 2024; 10:e30830. [PMID: 38770303 PMCID: PMC11103475 DOI: 10.1016/j.heliyon.2024.e30830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 05/04/2024] [Accepted: 05/06/2024] [Indexed: 05/22/2024] Open
Abstract
The conversion of renewable biomass feedstock into value-added products via bioprocessing platforms has become attractive because of environmental and health concerns. Process performance and cost competitiveness are major factors in the bioprocess design to produce desirable products from biomass feedstock. Proper pretreatment allows delignification and hemicellulose removal from the liquid fraction, allowing cellulose to be readily hydrolyzed to monomeric sugars. Several industrial products are produced via sugar fermentation using either naturally isolated or genetically modified microbes. Microbial platforms play an important role in the synthesis of several products, including drop-in chemicals, as-in products, and novel compounds. The key elements in developing a fermentation platform are medium formulation, sterilization, and active cells for inoculation. Downstream bioproduct recovery may seem like a straightforward chemical process, but is more complex, wherein cost competitiveness versus recovery performance becomes a challenge. This review summarizes the prospects for utilizing renewable biomass for bioprocessing.
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Affiliation(s)
- Panwana Khunnonkwao
- Institute of Biotechnology and Genetic Engineering, Chulalongkorn University, Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand
- Center of Excellence in Bioconversion and Bioseparation for Platform Chemical Production, Chulalongkorn University, Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand
| | - Sitanan Thitiprasert
- Institute of Biotechnology and Genetic Engineering, Chulalongkorn University, Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand
- Center of Excellence in Bioconversion and Bioseparation for Platform Chemical Production, Chulalongkorn University, Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand
| | - Phetcharat Jaiaue
- Center of Excellence in Bioconversion and Bioseparation for Platform Chemical Production, Chulalongkorn University, Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand
- Program in Biotechnology, Faculty of Science, Chulalongkorn University, Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand
| | - Katsaya Khumrangsee
- Institute of Biotechnology and Genetic Engineering, Chulalongkorn University, Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand
- Center of Excellence in Bioconversion and Bioseparation for Platform Chemical Production, Chulalongkorn University, Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand
| | - Benjamas Cheirsilp
- Center of Excellence in Innovative Biotechnology for Sustainable Utilization of Bioresources, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Nuttha Thongchul
- Institute of Biotechnology and Genetic Engineering, Chulalongkorn University, Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand
- Center of Excellence in Bioconversion and Bioseparation for Platform Chemical Production, Chulalongkorn University, Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330, Thailand
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4
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Li Y, Kim EJ, Voshall A, Moriyama EN, Cerutti H. Small RNAs >26 nt in length associate with AGO1 and are upregulated by nutrient deprivation in the alga Chlamydomonas. THE PLANT CELL 2023; 35:1868-1887. [PMID: 36945744 DOI: 10.1093/plcell/koad093] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/14/2023] [Accepted: 02/17/2023] [Indexed: 05/30/2023]
Abstract
Small RNAs (sRNAs) associate with ARGONAUTE (AGO) proteins forming effector complexes with key roles in gene regulation and defense responses against molecular parasites. In multicellular eukaryotes, extensive duplication and diversification of RNA interference (RNAi) components have resulted in intricate pathways for epigenetic control of gene expression. The unicellular alga Chlamydomonas reinhardtii also has a complex RNAi machinery, including 3 AGOs and 3 DICER-like proteins. However, little is known about the biogenesis and function of most endogenous sRNAs. We demonstrate here that Chlamydomonas contains uncommonly long (>26 nt) sRNAs that associate preferentially with AGO1. Somewhat reminiscent of animal PIWI-interacting RNAs, these >26 nt sRNAs are derived from moderately repetitive genomic clusters and their biogenesis is DICER-independent. Interestingly, the sequences generating these >26-nt sRNAs have been conserved and amplified in several Chlamydomonas species. Moreover, expression of these longer sRNAs increases substantially under nitrogen or sulfur deprivation, concurrently with the downregulation of predicted target transcripts. We hypothesize that the transposon-like sequences from which >26-nt sRNAs are produced might have been ancestrally targeted for silencing by the RNAi machinery but, during evolution, certain sRNAs might have fortuitously acquired endogenous target genes and become integrated into gene regulatory networks.
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Affiliation(s)
- Yingshan Li
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Nebraska-Lincoln, NE 68588-0666, USA
| | - Eun-Jeong Kim
- Department of Life Science, Chung-Ang University, Seoul 06974, Korea
| | - Adam Voshall
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Nebraska-Lincoln, NE 68588-0666, USA
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Etsuko N Moriyama
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Nebraska-Lincoln, NE 68588-0666, USA
| | - Heriberto Cerutti
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Nebraska-Lincoln, NE 68588-0666, USA
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5
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Zadabbas Shahabadi H, Akbarzadeh A, Ofoghi H, Kadkhodaei S. Site-specific gene knock-in and bacterial phytase gene expression in Chlamydomonas reinhardtii via Cas9 RNP-mediated HDR. FRONTIERS IN PLANT SCIENCE 2023; 14:1150436. [PMID: 37275253 PMCID: PMC10235511 DOI: 10.3389/fpls.2023.1150436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 03/28/2023] [Indexed: 06/07/2023]
Abstract
In the present study, we applied the HDR (homology-directed DNA repair) CRISPR-Cas9-mediated knock-in system to accurately insert an optimized foreign bacterial phytase gene at a specific site of the nitrate reductase (NR) gene (exon 2) to achieve homologous recombination with the stability of the transgene and reduce insertion site effects or gene silencing. To this end, we successfully knocked-in the targeted NR gene of Chlamydomonas reinhardtii using the bacterial phytase gene cassette through direct delivery of the CRISPR/Cas9 system as the ribonucleoprotein (RNP) complex consisting of Cas9 protein and the specific single guide RNAs (sgRNAs). The NR insertion site editing was confirmed by PCR and sequencing of the transgene positive clones. Moreover, 24 clones with correct editing were obtained, where the phytase gene cassette was located in exon 2 of the NR gene, and the editing efficiency was determined to be 14.81%. Additionally, site-specific gene expression was analyzed and confirmed using RT-qPCR. Cultivation of the positive knocked-in colonies on the selective media during 10 generations indicated the stability of the correct editing without gene silencing or negative insertion site effects. Our results demonstrated that CRISPR-Cas9-mediated knock-in could be applied for nuclear expression of the heterologous gene of interest, and also confirmed its efficacy as an effective tool for site-specific gene knock-in, avoiding nuclear positional effects and gene silencing in C. reinhardtii. These findings could also provide a new perspective on the advantageous application of RNP-CRISPR/Cas9 gene-editing to accelerate the commercial production of complex recombinant proteins in the food-grade organism "C. reinhardtii".
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Affiliation(s)
- Hassan Zadabbas Shahabadi
- Department of Fisheries, Faculty of Marine Science and Technology, University of Hormozgan, Bandar Abbas, Iran
- Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran
- Agricultural Biotechnology Research Institute of Iran (ABRII), Isfahan Branch, Agricultural Research, Education and Extension Organization (AREEO), Isfahan, Iran
| | - Arash Akbarzadeh
- Department of Fisheries, Faculty of Marine Science and Technology, University of Hormozgan, Bandar Abbas, Iran
| | - Hamideh Ofoghi
- Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran
| | - Saeid Kadkhodaei
- Agricultural Biotechnology Research Institute of Iran (ABRII), Isfahan Branch, Agricultural Research, Education and Extension Organization (AREEO), Isfahan, Iran
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6
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Li Y. Algal epigenetics: insights from DNA methylation in a symbiotic dinoflagellate. JOURNAL OF PHYCOLOGY 2023; 59:289-291. [PMID: 36468447 DOI: 10.1111/jpy.13090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Affiliation(s)
- Yantao Li
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science and University of Maryland, 701 E. Pratt St., Baltimore, Maryland, 21202, USA
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7
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Lee TM, Lin JY, Tsai TH, Yang RY, Ng IS. Clustered regularly interspaced short palindromic repeats (CRISPR) technology and genetic engineering strategies for microalgae towards carbon neutrality: A critical review. BIORESOURCE TECHNOLOGY 2023; 368:128350. [PMID: 36414139 DOI: 10.1016/j.biortech.2022.128350] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
Carbon dioxide is the major greenhouse gas and regards as the critical issue of global warming and climate changes. The inconspicuous microalgae are responsible for 40% of carbon fixation among all photosynthetic plants along with a higher photosynthetic efficiency and convert the carbon into lipids, protein, pigments, and bioactive compounds. Genetic approach and metabolic engineering are applied to accelerate the growth rate and biomass of microalgae, hence achieve the mission of carbon neutrality. Meanwhile, CRISPR/Cas9 is efficiently to enhance the productivity of high-value compounds in microalgae for it is easier operation, more affordable and is able to regulate multiple genes simultaneously. The genetic engineering strategies provide the multidisciplinary concept to evolute and increase the CO2 fixation rate through Calvin-Benson-Bassham cycle. Therefore, the technologies, bioinformatics tools, systematic engineering approaches for carbon neutrality and circular economy are summarized and leading one step closer to the decarbonization society in this review.
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Affiliation(s)
- Tse-Min Lee
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - Jia-Yi Lin
- Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
| | - Tsung-Han Tsai
- Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
| | - Ru-Yin Yang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - I-Son Ng
- Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
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8
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Nishshanka GKSH, Anthonio RADP, Nimarshana PHV, Ariyadasa TU, Chang JS. Marine microalgae as sustainable feedstock for multi-product biorefineries. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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9
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Huang D, Liu W, Hu Q, Li H, Wang C. The Histone Acetyltransferase HpGCN5 Involved in the Regulation of Abiotic Stress Responses and Astaxanthin Accumulation in Haematococcus pluvialis. FRONTIERS IN PLANT SCIENCE 2022; 13:903764. [PMID: 35668806 PMCID: PMC9163953 DOI: 10.3389/fpls.2022.903764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
The histone acetyltransferases (HATs), together with histone deacetylases, regulate the gene transcription related to various biological processes, including stress responses in eukaryotes. This study found a member of HATs (HpGCN5) from a transcriptome of the economically important microalgae Haematococcus pluvialis. Its expression pattern responding to multiple abiotic stresses and its correlation with transcription factors and genes involved in triacylglycerols and astaxanthin biosynthesis under stress conditions were evaluated, aiming to discover its potential biological function. The isolated HpGCN5 was 1,712 bp in length encoding 415 amino acids. The signature domains of Acetyltransf_1 and BROMO were presented, as the GCN5 gene from Arabidopsis and Saccharomyces cerevisiae, confirming that HpGCN5 belongs to the GCN5 subfamily of the GNAT superfamily. The phylogenetic analysis revealed that HpGCN5 is grouped with GNAT genes from algae and is closer to that from higher plants, compared with yeast, animal, fungus, and bacteria. It was predicted that HpGCN5 is composed of 10 exons and contains multiple stress-related cis-elements in the promoter region, revealing its potential role in stress regulation. Real-time quantitative PCR revealed that HpGCN5 responds to high light and high salt stresses in similar behavior, evidenced by their down-regulation exposing to stresses. Differently, HpGCN5 expression was significantly induced by SA and Nitrogen-depletion stresses at the early stage but was dropped back after then. The correlation network analysis suggested that HpGCN5 has a strong correlation with major genes and a transcription factor involved in astaxanthin biosynthesis. Besides, the correlation was only found between HpGCN5 and a few genes involved in triacylglycerols biosynthesis. Therefore, this study proposed that HpGCN5 might play a role in the regulation of astaxanthin biosynthesis. This study firstly examined the role of HATs in stress regulation and results will enrich our understanding of the role of HATs in microalgae.
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Affiliation(s)
- Danqiong Huang
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Wenfu Liu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Qunju Hu
- Marine Resources Big Data Center of South China Sea, Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang, China
| | - Hui Li
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Chaogang Wang
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
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10
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Leung C, Grulois D, Chevin LM. Plasticity across levels: relating epigenomic, transcriptomic, and phenotypic responses to osmotic stress in a halotolerant microalga. Mol Ecol 2022; 31:4672-4687. [PMID: 35593517 PMCID: PMC9543585 DOI: 10.1111/mec.16542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 05/12/2022] [Indexed: 12/01/2022]
Abstract
Phenotypic plasticity, the ability of a given genotype to produce alternative phenotypes in response to its environment of development, is an important mechanism for coping with variable environments. While the mechanisms underlying phenotypic plasticity are diverse, their relative contributions need to be investigated quantitatively to better understand the evolvability of plasticity across biological levels. This requires relating plastic responses of the epigenome, transcriptome, and organismal phenotype, and investigating how they vary with the genotype. Here we carried out this approach for responses to osmotic stress in Dunaliella salina, a green microalga that is a model organism for salinity tolerance. We compared two strains that show markedly different demographic responses to osmotic stress, and showed that these phenotypic responses involve strain‐ and environment‐specific variation in gene expression levels, but a relative low—albeit significant—effect of strain × environment interaction. We also found an important genotype effect on the genome‐wide methylation pattern, but little contribution from environmental conditions to the latter. However, we did detect a significant marginal effect of epigenetic variation on gene expression, beyond the influence of genetic differences on epigenetic state, and we showed that hypomethylated regions are correlated with higher gene expression. Our results indicate that epigenetic mechanisms are either not involved in the rapid plastic response to environmental change in this species, or involve only few changes in trans that are sufficient to trigger concerted changes in the expression of many genes, and phenotypic responses by multiple traits.
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Affiliation(s)
- Christelle Leung
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - Daphné Grulois
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, Montpellier, France
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11
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Tan FHP, Nadir N, Sudesh K. Microalgal Biomass as Feedstock for Bacterial Production of PHA: Advances and Future Prospects. Front Bioeng Biotechnol 2022; 10:879476. [PMID: 35646848 PMCID: PMC9133917 DOI: 10.3389/fbioe.2022.879476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 04/06/2022] [Indexed: 11/13/2022] Open
Abstract
The search for biodegradable plastics has become the focus in combating the global plastic pollution crisis. Polyhydroxyalkanoates (PHAs) are renewable substitutes to petroleum-based plastics with the ability to completely mineralize in soil, compost, and marine environments. The preferred choice of PHA synthesis is from bacteria or archaea. However, microbial production of PHAs faces a major drawback due to high production costs attributed to the high price of organic substrates as compared to synthetic plastics. As such, microalgal biomass presents a low-cost solution as feedstock for PHA synthesis. Photoautotrophic microalgae are ubiquitous in our ecosystem and thrive from utilizing easily accessible light, carbon dioxide and inorganic nutrients. Biomass production from microalgae offers advantages that include high yields, effective carbon dioxide capture, efficient treatment of effluents and the usage of infertile land. Nevertheless, the success of large-scale PHA synthesis using microalgal biomass faces constraints that encompass the entire flow of the microalgal biomass production, i.e., from molecular aspects of the microalgae to cultivation conditions to harvesting and drying microalgal biomass along with the conversion of the biomass into PHA. This review discusses approaches such as optimization of growth conditions, improvement of the microalgal biomass manufacturing technologies as well as the genetic engineering of both microalgae and PHA-producing bacteria with the purpose of refining PHA production from microalgal biomass.
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Affiliation(s)
| | | | - Kumar Sudesh
- School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
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12
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Geng Y, Cui D, Yang L, Xiong Z, Pavlostathis SG, Shao P, Zhang Y, Luo X, Luo S. Resourceful treatment of harsh high-nitrogen rare earth element tailings (REEs) wastewater by carbonate activated Chlorococcum sp. microalgae. JOURNAL OF HAZARDOUS MATERIALS 2022; 423:127000. [PMID: 34461547 DOI: 10.1016/j.jhazmat.2021.127000] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/01/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
The discharge of rare earth element (REE) tailings wastewater results in serious ecological deterioration and health risk, due to high ammonia nitrogen, and strong acidity. The low C/N ratio makes it recalcitrant to biodegradation. Recently it has been shown that microalgal technology has a promising potential for the simultaneous harsh wastewater treatment and resource recovery. However, the low nitrogen removal rate and less biomass of microalgae restricted its development. In this work, Chlorococcum sp. was successfully isolated from the rare earth mine effluent. The microalgae was capable of enhancing nitrogen contaminants removal from REEs wastewater due to the carbonate addition, which simulated the activity increase of carbonic anhydrase (CA). The total inorganic nitrogen (TIN) removal rate reached 4.45 mg/L h-1, which compared to other microalgal species, the nitrogen removal rate and biomass yield were 7.8- and 4.9-fold higher, respectively. Notably, high lipid contents (mainly triglycerides, 43.85% of dry weight) and a high biomass yield were obtained. Meanwhile, the microalgae had an excellent settleability attributed to higher extracellular polymeric substance (EPS) formation, leading to easier resource harvest. These results were further confirmed in a continuous-flow photobioreactor with a stable operation for more than 30 days, indicating its potential for application.
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Affiliation(s)
- Yanni Geng
- National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource Utilization, Nanchang Hangkong University, Nanchang 330063, PR China; Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Dan Cui
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, PR China
| | - Liming Yang
- National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource Utilization, Nanchang Hangkong University, Nanchang 330063, PR China; Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China.
| | - Zhensheng Xiong
- National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource Utilization, Nanchang Hangkong University, Nanchang 330063, PR China; Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Spyros G Pavlostathis
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0512, USA
| | - Penghui Shao
- National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource Utilization, Nanchang Hangkong University, Nanchang 330063, PR China; Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Yakun Zhang
- National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource Utilization, Nanchang Hangkong University, Nanchang 330063, PR China; Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Xubiao Luo
- National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource Utilization, Nanchang Hangkong University, Nanchang 330063, PR China; Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China.
| | - Shenglian Luo
- National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource Utilization, Nanchang Hangkong University, Nanchang 330063, PR China; Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China
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13
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Agrobacterium tumefaciens-Mediated Nuclear Transformation of a Biotechnologically Important Microalga- Euglena gracilis. Int J Mol Sci 2021; 22:ijms22126299. [PMID: 34208268 PMCID: PMC8230907 DOI: 10.3390/ijms22126299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/07/2021] [Accepted: 06/09/2021] [Indexed: 12/30/2022] Open
Abstract
Euglena gracilis (E. gracilis) is an attractive organism due to its evolutionary history and substantial potential to produce biochemicals of commercial importance. This study describes the establishment of an optimized protocol for the genetic transformation of E. gracilis mediated by Agrobacterium (A. tumefaciens). E. gracilis was found to be highly sensitive to hygromycin and zeocin, thus offering a set of resistance marker genes for the selection of transformants. A. tumefaciens-mediated transformation (ATMT) yielded hygromycin-resistant cells. However, hygromycin-resistant cells hosting the gus gene (encoding β-glucuronidase (GUS)) were found to be GUS-negative, indicating that the gus gene had explicitly been silenced. To circumvent transgene silencing, GUS was expressed from the nuclear genome as transcriptional fusions with the hygromycin resistance gene (hptII) (encoding hygromycin phosphotransferase II) with the foot and mouth disease virus (FMDV)-derived 2A self-cleaving sequence placed between the coding sequences. ATMT of Euglena with the hptII-2A–gus gene yielded hygromycin-resistant, GUS-positive cells. The transformation was verified by PCR amplification of the T-DNA region genes, determination of GUS activity, and indirect immunofluorescence assays. Cocultivation factors optimization revealed that a higher number of transformants was obtained when A. tumefaciens LBA4404 (A600 = 1.0) and E. gracilis (A750 = 2.0) cultures were cocultured for 48 h at 19 °C in an organic medium (pH 6.5) containing 50 µM acetosyringone. Transformation efficiency of 8.26 ± 4.9% was achieved under the optimized cocultivation parameters. The molecular toolkits and method presented here can be used to bioengineer E. gracilis for producing high-value products and fundamental studies.
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Bhattacharjya R, Tiwari A, Marella TK, Bansal H, Srivastava S. New paradigm in diatom omics and genetic manipulation. BIORESOURCE TECHNOLOGY 2021; 325:124708. [PMID: 33487514 DOI: 10.1016/j.biortech.2021.124708] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
Diatoms are one of the most heterogeneous eukaryotic plankton known for regulating earth's biogeochemical cycles and maintaining the marine ecosystems ever since the late Eocene epoch. The advent of multidisciplinary omics approach has both epitomized and revolutionized the nature of their chimeric genetic toolkit, ecophysiology, and metabolic adaptability as well as their interaction with other communities. In addition, advanced functional annotation of transcriptomic and proteomic data using cutting edge bioinformatics tools together with high-resolution genome-scale mathematical modeling has effectively proven as the catapult in solving genetic bottlenecks in microbial as well as diatom exploration. In this review, a corroborative summation of the robust work done in manipulating, engineering, and sequencing of the diatom genomes besides underpinning the holistic application of omics in transcription and translation has been discussed in order to shrewd their multifarious novel potential in the field of biotechnology and provide an insight into their dynamic evolutionary relevance.
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Affiliation(s)
- Raya Bhattacharjya
- Diatom Research Laboratory, Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh 201313, India
| | - Archana Tiwari
- Diatom Research Laboratory, Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh 201313, India.
| | - Thomas Kiran Marella
- Algae Biomass Energy System Development Research Center (ABES), Tennodai, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Hina Bansal
- Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh 201313, India
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Bacova R, Kolackova M, Klejdus B, Adam V, Huska D. Epigenetic mechanisms leading to genetic flexibility during abiotic stress responses in microalgae: A review. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101999] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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16
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George J, Kahlke T, Abbriano RM, Kuzhiumparambil U, Ralph PJ, Fabris M. Metabolic Engineering Strategies in Diatoms Reveal Unique Phenotypes and Genetic Configurations With Implications for Algal Genetics and Synthetic Biology. Front Bioeng Biotechnol 2020; 8:513. [PMID: 32582656 PMCID: PMC7290003 DOI: 10.3389/fbioe.2020.00513] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 04/30/2020] [Indexed: 12/23/2022] Open
Abstract
Diatoms are photosynthetic microeukaryotes that dominate phytoplankton populations and have increasing applicability in biotechnology. Uncovering their complex biology and elevating strains to commercial standards depends heavily on robust genetic engineering tools. However, engineering microalgal genomes predominantly relies on random integration of transgenes into nuclear DNA, often resulting in detrimental “position-effects” such as transgene silencing, integration into transcriptionally-inactive regions, and endogenous sequence disruption. With the recent development of extrachromosomal transgene expression via independent episomes, it is timely to investigate both strategies at the phenotypic and genomic level. Here, we engineered the model diatom Phaeodactylum tricornutum to produce the high-value heterologous monoterpenoid geraniol, which, besides applications as fragrance and insect repellent, is a key intermediate of high-value pharmaceuticals. Using high-throughput phenotyping we confirmed the suitability of episomes for synthetic biology applications and identified superior geraniol-yielding strains following random integration. We used third generation long-read sequencing technology to generate a complete analysis of all transgene integration events including their genomic locations and arrangements associated with high-performing strains at a genome-wide scale with subchromosomal detail, never before reported in any microalga. This revealed very large, highly concatenated insertion islands, offering profound implications on diatom functional genetics and next generation genome editing technologies, and is key for developing more precise genome engineering approaches in diatoms, including possible genomic safe harbour locations to support high transgene expression for targeted integration approaches. Furthermore, we have demonstrated that exogenous DNA is not integrated inadvertently into the nuclear genome of extrachromosomal-expression clones, an important characterisation of this novel engineering approach that paves the road to synthetic biology applications.
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Affiliation(s)
- Jestin George
- University of Technology Sydney, Climate Change Cluster, Faculty of Science, Ultimo, NSW, Australia
| | - Tim Kahlke
- University of Technology Sydney, Climate Change Cluster, Faculty of Science, Ultimo, NSW, Australia
| | - Raffaela M Abbriano
- University of Technology Sydney, Climate Change Cluster, Faculty of Science, Ultimo, NSW, Australia
| | | | - Peter J Ralph
- University of Technology Sydney, Climate Change Cluster, Faculty of Science, Ultimo, NSW, Australia
| | - Michele Fabris
- University of Technology Sydney, Climate Change Cluster, Faculty of Science, Ultimo, NSW, Australia.,CSIRO Synthetic Biology Future Science Platform, Brisbane, QLD, Australia
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18
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Bacova R, Klejdus B, Ryant P, Cernei N, Adam V, Huska D. The effects of 5-azacytidine and cadmium on global 5-methylcytosine content and secondary metabolites in the freshwater microalgae Chlamydomonas reinhardtii and Scenedesmus quadricauda. JOURNAL OF PHYCOLOGY 2019; 55:329-342. [PMID: 30506677 DOI: 10.1111/jpy.12819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 10/22/2018] [Indexed: 06/09/2023]
Abstract
Epigenetic changes are important mechanisms in the regulation of chromatin structure and gene expression. Cytosine methylation is one of the major epigenetic modifications, mediated by DNA methyltransferases, which transfer methyl groups from S-adenosyl-L-methionine (SAM) to the fifth carbon of cytosine. Various external environmental conditions can change the global hypo/hypermethylation pattern of DNA. These alterations may affect the organism's response to stress conditions. In this study, for the first time, we investigated the effects of 5-azacytidine, a DNA methyltransferase inhibitor, and cadmium, a toxic metal and environmental pollutant, on the growth, biosynthesis of secondary metabolites (phenols, flavonoids, carotenoids), SAM, S-adenosylhomocysteine, 5'-methylthioadenosine and global 5-methylcytosine (5-mC) in the green microalgae Chlamydomonas reinhardtii and Scenedesmus quadricauda. The studied species showed major differences in 5-mC content, secondary metabolite content, and antioxidant activity. Cadmium increased GSH (glutathione) content in C. reinhardtii by 60% whereas 5-azacytidine did not affect GSH. The biosynthesis of GSH in S. quadricauda in response to the stressors was the opposite. Global 5-mC content of C. reinhardtii was 1%-1.5%, and the content in S. quadricauda was 3.5%. Amount of some investigated methionine cycle metabolites (SAM, S-adenosyl homocysteine [SAH], methionine) in S. quadricauda distinctly exceeded C. reinhardtii as well. However, chlorophylls a and b, carotenoids, total phenolic content, total flavonoid content and, antioxidant activity were significantly higher in C. reinhardtii than S. quadricauda. Therefore, in further studies it would be advisable to verify whether methylation of cytosine affects the expression of genes encoding certain secondary metabolites.
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Affiliation(s)
- Romana Bacova
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic
| | - Borivoj Klejdus
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic
- Central European Institute of Technology, Mendel University in Brno, Zemedelska 1, CZ-613 00, Brno, Czech Republic
| | - Pavel Ryant
- Department of Agrochemistry, Soil Science, Microbiology and Plant Nutrition, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic
| | - Natalia Cernei
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Purkyňova 656/123, Brno, Czech Republic
| | - Vojtech Adam
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Purkyňova 656/123, Brno, Czech Republic
| | - Dalibor Huska
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Purkyňova 656/123, Brno, Czech Republic
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A novel salt-inducible CrGPDH3 promoter of the microalga Chlamydomonas reinhardtii for transgene overexpression. Appl Microbiol Biotechnol 2019; 103:3487-3499. [DOI: 10.1007/s00253-019-09733-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/25/2019] [Accepted: 02/28/2019] [Indexed: 01/02/2023]
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20
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Navarro FJ, Baulcombe DC. miRNA-Mediated Regulation of Synthetic Gene Circuits in the Green Alga Chlamydomonas reinhardtii. ACS Synth Biol 2019; 8:358-370. [PMID: 30624905 DOI: 10.1021/acssynbio.8b00393] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
MicroRNAs (miRNAs), small RNA molecules of 20-24 nts, have many features that make them useful tools for gene expression regulation-small size, flexible design, target predictability, and action at a late stage of the gene expression pipeline. In addition, their role in fine-tuning gene expression can be harnessed to increase robustness of synthetic gene networks. In this work, we apply a synthetic biology approach to characterize miRNA-mediated gene expression regulation in the unicellular green alga Chlamydomonas reinhardtii. This characterization is then used to build tools based on miRNAs, such as synthetic miRNAs, miRNA-responsive 3'UTRs, miRNA decoys, and self-regulatory loops. These tools will facilitate the engineering of gene expression for new applications and improved traits in this alga.
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Affiliation(s)
- Francisco J. Navarro
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
| | - David C. Baulcombe
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
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Hovde BT, Hanschen ER, Steadman Tyler CR, Lo CC, Kunde Y, Davenport K, Daligault H, Msanne J, Canny S, Eyun SI, Riethoven JJM, Polle J, Starkenburg SR. Genomic characterization reveals significant divergence within Chlorella sorokiniana (Chlorellales, Trebouxiophyceae). ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.09.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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22
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Jeon S, Lim JM, Lee HG, Shin SE, Kang NK, Park YI, Oh HM, Jeong WJ, Jeong BR, Chang YK. Current status and perspectives of genome editing technology for microalgae. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:267. [PMID: 29163669 PMCID: PMC5686953 DOI: 10.1186/s13068-017-0957-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 11/04/2017] [Indexed: 05/25/2023]
Abstract
Genome editing techniques are critical for manipulating genes not only to investigate their functions in biology but also to improve traits for genetic engineering in biotechnology. Genome editing has been greatly facilitated by engineered nucleases, dubbed molecular scissors, including zinc-finger nuclease (ZFN), TAL effector endonuclease (TALEN) and clustered regularly interspaced palindromic sequences (CRISPR)/Cas9. In particular, CRISPR/Cas9 has revolutionized genome editing fields with its simplicity, efficiency and accuracy compared to previous nucleases. CRISPR/Cas9-induced genome editing is being used in numerous organisms including microalgae. Microalgae have been subjected to extensive genetic and biological engineering due to their great potential as sustainable biofuel and chemical feedstocks. However, progress in microalgal engineering is slow mainly due to a lack of a proper transformation toolbox, and the same problem also applies to genome editing techniques. Given these problems, there are a few reports on successful genome editing in microalgae. It is, thus, time to consider the problems and solutions of genome editing in microalgae as well as further applications of this exciting technology for other scientific and engineering purposes.
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Affiliation(s)
- Seungjib Jeon
- Advanced Biomass Research and Development Center (ABC), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Jong-Min Lim
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Hyung-Gwan Lee
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Sung-Eun Shin
- LG Chem, 188 Munji-ro, Yuseong-gu, Daejeon, 34122 Republic of Korea
| | - Nam Kyu Kang
- Advanced Biomass Research and Development Center (ABC), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Youn-Il Park
- Department of Biological Sciences, Chungnam National University, Daejeon, 34134 Republic of Korea
| | - Hee-Mock Oh
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Won-Joong Jeong
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Byeong-ryool Jeong
- Advanced Biomass Research and Development Center (ABC), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Yong Keun Chang
- Advanced Biomass Research and Development Center (ABC), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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Yamasaki T. Isolation and Characterization of ARGONAUTE Mutants in Chlamydomonas. Methods Mol Biol 2017; 1640:159-172. [PMID: 28608341 DOI: 10.1007/978-1-4939-7165-7_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Random insertional mutagenesis and subsequent reverse genetic screening allow the isolation of mutants of interest. Here I describe the protocol for generating a tag insertion line and subsequent PCR-based screening for ARGONAUTE mutants as an example of a reverse genetic screen for the unicellular green alga Chlamydomonas reinhardtii.
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Affiliation(s)
- Tomohito Yamasaki
- Science Department, Natural Science Cluster, Kochi University, Kochi, 780-8520, Japan.
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24
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Mikulski P, Komarynets O, Fachinelli F, Weber AP, Schubert D. Characterization of the Polycomb-Group Mark H3K27me3 in Unicellular Algae. FRONTIERS IN PLANT SCIENCE 2017; 8:607. [PMID: 28484477 PMCID: PMC5405695 DOI: 10.3389/fpls.2017.00607] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 04/04/2017] [Indexed: 05/03/2023]
Abstract
Polycomb Group (PcG) proteins mediate chromatin repression in plants and animals by catalyzing H3K27 methylation and H2AK118/119 mono-ubiquitination through the activity of the Polycomb repressive complex 2 (PRC2) and PRC1, respectively. PcG proteins were extensively studied in higher plants, but their function and target genes in unicellular branches of the green lineage remain largely unknown. To shed light on PcG function and modus operandi in a broad evolutionary context, we demonstrate phylogenetic relationship of core PRC1 and PRC2 proteins and H3K27me3 biochemical presence in several unicellular algae of different phylogenetic subclades. We focus then on one of the species, the model red alga Cyanidioschizon merolae, and show that H3K27me3 occupies both, genes and repetitive elements, and mediates the strength of repression depending on the differential occupancy over gene bodies. Furthermore, we report that H3K27me3 in C. merolae is enriched in telomeric and subtelomeric regions of the chromosomes and has unique preferential binding toward intein-containing genes involved in protein splicing. Thus, our study gives important insight for Polycomb-mediated repression in lower eukaryotes, uncovering a previously unknown link between H3K27me3 targets and protein splicing.
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Affiliation(s)
- Pawel Mikulski
- Institute of Biology, Free University of BerlinBerlin, Germany
- Institute of Genetics, Heinrich-Heine-Universität DüsseldorfDüsseldorf, Germany
| | - Olga Komarynets
- Institute of Genetics, Heinrich-Heine-Universität DüsseldorfDüsseldorf, Germany
- Faculty of Medicine, University of GenevaGeneva, Switzerland
| | - Fabio Fachinelli
- Institute of Plant Biochemistry, Heinrich-Heine-Universität DüsseldorfDüsseldorf, Germany
| | - Andreas P.M. Weber
- Institute of Plant Biochemistry, Heinrich-Heine-Universität DüsseldorfDüsseldorf, Germany
| | - Daniel Schubert
- Institute of Biology, Free University of BerlinBerlin, Germany
- Institute of Genetics, Heinrich-Heine-Universität DüsseldorfDüsseldorf, Germany
- *Correspondence: Daniel Schubert,
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The Potential for Microalgae as Bioreactors to Produce Pharmaceuticals. Int J Mol Sci 2016; 17:ijms17060962. [PMID: 27322258 PMCID: PMC4926494 DOI: 10.3390/ijms17060962] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 05/25/2016] [Accepted: 06/08/2016] [Indexed: 01/12/2023] Open
Abstract
As photosynthetic organisms, microalgae can efficiently convert solar energy into biomass. Microalgae are currently used as an important source of valuable natural biologically active molecules, such as carotenoids, chlorophyll, long-chain polyunsaturated fatty acids, phycobiliproteins, carotenoids and enzymes. Significant advances have been achieved in microalgae biotechnology over the last decade, and the use of microalgae as bioreactors for expressing recombinant proteins is receiving increased interest. Compared with the bioreactor systems that are currently in use, microalgae may be an attractive alternative for the production of pharmaceuticals, recombinant proteins and other valuable products. Products synthesized via the genetic engineering of microalgae include vaccines, antibodies, enzymes, blood-clotting factors, immune regulators, growth factors, hormones, and other valuable products, such as the anticancer agent Taxol. In this paper, we briefly compare the currently used bioreactor systems, summarize the progress in genetic engineering of microalgae, and discuss the potential for microalgae as bioreactors to produce pharmaceuticals.
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DesAutels L. Natural selection and mechanistic regularity. STUDIES IN HISTORY AND PHILOSOPHY OF BIOLOGICAL AND BIOMEDICAL SCIENCES 2016; 57:13-23. [PMID: 26921876 DOI: 10.1016/j.shpsc.2016.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 01/19/2016] [Accepted: 01/22/2016] [Indexed: 06/05/2023]
Abstract
In this article, I address the question of whether natural selection operates regularly enough to qualify as a mechanism of the sort characterized by Machamer, Darden, and Craver (2000). Contrary to an influential critique by Skipper and Millstein (2005), I argue that natural selection can be seen to be regular enough to qualify as an MDC mechanism just fine-as long as we pay careful attention to some important distinctions regarding mechanistic regularity and abstraction. Specifically, I suggest that when we distinguish between process vs. product regularity, mechanism-internal vs. mechanism-external sources of irregularity, and abstract vs. concrete regularity, we can see that natural selection is only irregular in senses that are unthreatening to its status as an MDC mechanism.
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Affiliation(s)
- Lane DesAutels
- Program for the History and Philosophy of Science, University of Notre Dame, 436 Geddes Hall, Notre Dame, IN 46556, USA.
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Guihéneuf F, Khan A, Tran LSP. Genetic Engineering: A Promising Tool to Engender Physiological, Biochemical, and Molecular Stress Resilience in Green Microalgae. FRONTIERS IN PLANT SCIENCE 2016; 7:400. [PMID: 27066043 PMCID: PMC4815356 DOI: 10.3389/fpls.2016.00400] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 03/14/2016] [Indexed: 05/03/2023]
Abstract
As we march into the 21st century, the prevailing scenario of depleting energy resources, global warming and ever increasing issues of human health and food security will quadruple. In this context, genetic and metabolic engineering of green microalgae complete the quest toward a continuum of environmentally clean fuel and food production. Evolutionarily related, but unlike land plants, microalgae need nominal land or water, and are best described as unicellular autotrophs using light energy to fix atmospheric carbon dioxide (CO2) into algal biomass, mitigating fossil CO2 pollution in the process. Remarkably, a feature innate to most microalgae is synthesis and accumulation of lipids (60-65% of dry weight), carbohydrates and secondary metabolites like pigments and vitamins, especially when grown under abiotic stress conditions. Particularly fruitful, such an application of abiotic stress factors such as nitrogen starvation, salinity, heat shock, etc., can be used in a biorefinery concept for production of multiple valuable products. The focus of this mini-review underlies metabolic reorientation practices and tolerance mechanisms as applied to green microalgae under specific stress stimuli for a sustainable pollution-free future. Moreover, we entail current progress on genetic engineering as a promising tool to grasp adaptive processes for improving strains with potential biotechnological interests.
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Affiliation(s)
- Freddy Guihéneuf
- Botany and Plant Science, School of Natural Sciences, Ryan Institute, National University of Ireland GalwayGalway, Ireland
| | - Asif Khan
- Research Group Germline Biology, Centre for Organismal Studies (COS), Heidelberg UniversityHeidelberg, Germany
| | - Lam-Son P. Tran
- Plant Abiotic Stress Research Group & Faculty of Applied Sciences, Ton Duc Thang UniversityHo Chi Minh City, Vietnam
- Signaling Pathway Research Unit, RIKEN Center for Sustainable Resource ScienceTsurumi, Japan
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Yamasaki T, Kim EJ, Cerutti H, Ohama T. Argonaute3 is a key player in miRNA-mediated target cleavage and translational repression in Chlamydomonas. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 85:258-268. [PMID: 26686836 DOI: 10.1111/tpj.13107] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Revised: 11/27/2015] [Accepted: 12/07/2015] [Indexed: 06/05/2023]
Abstract
MicroRNAs (miRNAs) play important roles in diverse biological processes in eukaryotes, generally through degradation and/or inhibition of the translation of target mRNAs. MicroRNAs are loaded into Argonaute (AGO) proteins to form the RNA-induced silencing complex (RISC) and used as guides to identify complementary transcripts. The distinct functions and features, such as associated small RNA classes and modes of silencing, of individual AGO paralogs have been well documented in multicellular eukaryotes. However, this aspect of miRNA function remains poorly understood in the unicellular green alga Chlamydomonas reinhardtii, which contains three AGO paralogs. In this study, we isolated AGO2 and AGO3 insertional mutants and confirmed that AGO3 is more abundantly expressed than AGO2. MicroRNA-directed target transcript cleavage and translational repression were impaired in the AGO3 mutant background, indicating that AGO3 can mediate both modes of silencing. In contrast, although the AGO2 mutant is not a null, the involvement of AGO2 in miRNA-directed silencing appears to be more limited. Our results strongly suggest that miRNA-mediated post-transcriptional gene silencing relies primarily on AGO3 in Chlamydomonas.
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Affiliation(s)
- Tomohito Yamasaki
- Department of Environmental Systems Engineering, Kochi University of Technology (KUT), 185 Miyanokuchi, Tosayamada, Kami, Kochi, 782-8502, Japan
| | - Eun-Jeong Kim
- School of Biological Science and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Heriberto Cerutti
- School of Biological Science and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Takeshi Ohama
- Department of Environmental Systems Engineering, Kochi University of Technology (KUT), 185 Miyanokuchi, Tosayamada, Kami, Kochi, 782-8502, Japan
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29
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Zhang H, Xia R, Meyers BC, Walbot V. Evolution, functions, and mysteries of plant ARGONAUTE proteins. CURRENT OPINION IN PLANT BIOLOGY 2015; 27:84-90. [PMID: 26190741 DOI: 10.1016/j.pbi.2015.06.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 06/09/2015] [Accepted: 06/15/2015] [Indexed: 05/05/2023]
Abstract
ARGONAUTE (AGO) proteins bind small RNAs (sRNAs) to form RNA-induced silencing complexes for transcriptional and post-transcriptional gene silencing. Genomes of primitive plants encode only a few AGO proteins. The Arabidopsis thaliana genome encodes ten AGO proteins, designated AGO1 to AGO10. Most early studies focused on these ten proteins and their interacting sRNAs. AGOs in other flowering plant species have duplicated and diverged from this set, presumably corresponding to new, diverged or specific functions. Among these, the grass-specific AGO18 family has been discovered and implicated as playing important roles during plant reproduction and viral defense. This review covers our current knowledge about functions and features of AGO proteins in both eudicots and monocots and compares their similarities and differences. On the basis of these features, we propose a new nomenclature for some plant AGOs.
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Affiliation(s)
- Han Zhang
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
| | - Rui Xia
- Department of Plant and Soil Sciences and Delaware Biotechnology Institute, University of Delaware, Newark, DE 19716, USA
| | - Blake C Meyers
- Department of Plant and Soil Sciences and Delaware Biotechnology Institute, University of Delaware, Newark, DE 19716, USA
| | - Virginia Walbot
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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