Growth dependent silencing and resetting of DGA1 transgene in Nannochloropsis salina

Beacham, Tracey A.; Ali, S. Twareque

doi:10.1016/j.algal.2016.01.005

Cited by 33 publications

(14 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nannochloropsis are one of the most important industrial microalgae of which genomic and transcriptomic resources are available [12, 27], and have been subjected to intense strain developments via transcription factor engineering [38–40] and metabolic engineering [41, 42]. Overall, they show robust growth and high lipid contents [43, 44]; however, their photosynthetic efficiency has been questioned due to the lack of pyrenoids and leaky carbon concentrating mechanisms [14, 15, 45].…”

Section: Discussionmentioning

confidence: 99%

Heterologous synthesis of chlorophyll b in Nannochloropsis salina enhances growth and lipid production by increasing photosynthetic efficiency

Koh

Kang

Jeon

et al. 2019

Biotechnol Biofuels

View full text Add to dashboard Cite

Background Chlorophylls play important roles in photosynthesis, and thus are critical for growth and related metabolic pathways in photosynthetic organisms. They are particularly important in microalgae, emerging as the next generation feedstock for biomass and biofuels. Nannochloropsis are industrial microalgae for these purposes, but are peculiar in that they lack accessory chlorophylls. In addition, the localization of heterologous proteins to the chloroplast of Nannochloropsis has not been fully studied, due to the secondary plastid surrounded by four membranes. This study addressed questions of correct localization and functional benefits of heterologous expression of chlorophyllide a oxygenase from Chlamydomonas (CrCAO) in Nannochloropsis . Results We cloned CrCAO from Chlamydomonas , which catalyzes oxidation of Chl a producing Chl b , and overexpressed it in N. salina to reveal effects of the heterologous Chl b for photosynthesis, growth, and lipid production. For correct localization of CrCAO into the secondary plastid in N. salina , we added the signal-recognition sequence and the transit peptide (cloned from an endogenous chloroplast-localized protein) to the N terminus of CrCAO. We obtained two transformants that expressed CrCAO and produced Chl b . They showed improved growth under medium light (90 μmol/m 2 /s) conditions, and their photosynthetic efficiency was increased compared to WT. They also showed increased expression of certain photosynthetic proteins, accompanied by an increased maximum electron-transfer rate up to 15.8% and quantum yields up to 17%, likely supporting the faster growth. This improved growth resulted in increased biomass production, and more importantly lipid productivity particularly with medium light. Conclusions We demonstrated beneficial effects of heterologous expression of CrCAO in Chl b -less organism N. salina , where the newly produced Chl b enhanced photosynthesis and growth. Accordingly, transformants showed improved production of biomass and lipids, important traits of microalgae from the industrial perspectives. Our transformants are the first Nannochloropsis cells that produced Chl b in the whole evolutionary path. We also succeeded in delivering a heterologous protein into the secondary plastid for the first time in Nannochloropsis . Taken together, our data showed that manipulation of photosynthetic pigments, including Chl b , c...

show abstract

Section: Discussionmentioning

confidence: 99%

Heterologous synthesis of chlorophyll b in Nannochloropsis salina enhances growth and lipid production by increasing photosynthetic efficiency

Koh

Kang

Jeon

et al. 2019

Biotechnol Biofuels

View full text Add to dashboard Cite

show abstract

“…Current genetic engineering strategies to improve microalgal productivity of lipids, which are the precursors for biofuel production, have often resulted in reduced biomass production and/or growth rate. At least to some extent this is because the supply of carbon or energy is insufficient to meet the increased demands of engineered strains (Figure 1) [4][5][6]. Thus, to overcome carbon or energy shortage, further major improvements in microalgal productivities will require extensive rewiring of the upstream metabolic pathways such as carbon fixation, as well as the generation of ATP and reducing power by photosynthesis.…”

Section: Towards Improving Upstream Photosynthetic and Co 2 Fixation Metabolismmentioning

confidence: 99%

Synthetic Biology Approaches To Enhance Microalgal Productivity

Naduthodi

Claassens

D’Adamo

et al. 2021

Trends in Biotechnology

View full text Add to dashboard Cite

“…Moreover, overexpression of DGAT in Nannochloropsis strains has been reported to increase the TAG content between 1.3-to 2.4-fold or to enhance the TFA content (Tracey A. Beacham & Ali, 2016;Iwai et al, 2015;H. Wei et al, 2017;Zienkiewicz et al, 2017).…”

Section: Kennedy Pathwaymentioning

confidence: 99%

Genetic engineering of microalgae for enhanced lipid production

Muñoz

Südfeld

Naduthodi

et al. 2021

Biotechnology Advances

View full text Add to dashboard Cite

Genetic transformation of microalgae remains a challenge due to poor intracellular delivery of exogenous molecules. This limitation is caused by the structure and composition of the cell wall and cell membrane of each species.Moreover, successful delivery of proteins or nucleic acids cannot be assessed by determining transformability since their functionality is not always known in the studied microorganism. We propose a quick and effective screening tool for the prediction and optimization of electroporation settings by monitoring cell permeability and viability using Sytox Green and propidium iodide respectively.We determined voltage settings for the microalgae Chlamydomonas reinhardtii, Chlorella vulgaris, Neochloris oleoabundans and Acutodesmus obliquus. To evaluate the predicted settings, we delivered labelled DNA and proteins into the cells. We demonstrated that high transformation efficiencies can be accomplished when predicted values were applied with functional plasmids.Additionally, we increased transformation efficiencies by testing cell concentrations, light intensities and fragment sizes. This method can be used to determine suitable transformation conditions for non-transformed microalgae species and to increase the insight on established transformation protocols.

show abstract

Growth dependent silencing and resetting of DGA1 transgene in Nannochloropsis salina

Cited by 33 publications

References 40 publications

Heterologous synthesis of chlorophyll b in Nannochloropsis salina enhances growth and lipid production by increasing photosynthetic efficiency

Heterologous synthesis of chlorophyll b in Nannochloropsis salina enhances growth and lipid production by increasing photosynthetic efficiency

Synthetic Biology Approaches To Enhance Microalgal Productivity

Genetic engineering of microalgae for enhanced lipid production

Contact Info

Product

Resources

About