Table 5 Improvement of lipid content in different species of microalgae with genetic engineering methods
From: Biomass and lipid induction strategies in microalgae for biofuel production and other applications
Microalgae species or strain | Type of modification | Changes in lipid profile in the microalgal cells | Refs. |
|---|---|---|---|
Chlamydomonas reinhardtii | Repression of Major lipid droplet protein (MLDP) gene expression | 40% increase in the average lipid droplet diameter | [197] |
Chlamydomonas reinhardtii | Knockout of citrate synthase gene | TAG level increased up to 169.5% | [198] |
Chlamydomonas reinhardtii | Artificial silencing of Diacylglycerol acyltransferase 2–4 gene (CrDGAT2-4) | 24%-34% increase in lipid content | [199] |
Chlamydomonas reinhardtii (starchless mutant) | Inactivation of Adenosine diphosphoglucose pyrophosphorylase (ADP-glucose pyrophosphorylase) | 10-fold increase in TAG | [200] |
Chlorella minutissima UTEX 2219 | Overexpression of glycerol-3-phosphate aceyltransferease gene, lysophosphatidic acetyltransferase gene and diglyceride acyltransferase | 2-fold increase in lipid content | [201] |
Scenedesmus obliquus (starchless mutant) | Knockdown of competitive pathways genes | Increase in TAG accumulation of up to 51% | [202] |
Phaeodactylum tricornutum | Heterologous gene expression of acyl–acyl carrier protein thioesterases (Acyl-ACP thioesterases) | Increased accumulation of shorter chain length fatty acids | [203] |
Synechocystis sp. | Cyanophycin synthetase gene deletion | Fatty acids secretion into the medium | [204] |
Synechocystis sp. | Phosphotransacetylase gene deletion | Increase in production of fatty acids | [204] |
Phaeodactylum tricornutum | Suppression of TAG lipase gene expression | Increase of the lipid content (0.04 ± 0.01 mg TAG/mg dry weight) | [205] |
Scenedesmus obliquus | Successful expression of diacylglycerol acyl-transferase gene | Enhanced 128% of lipid content. | [190] |
C. reinhardtii | Knock-down of PEPC enzyme with CRISPRi | Enhanced lipid production up to 94% | [191] |
P. tricornutum | Expression of malic enzyme | Enhanced lipid productivity by 2.5 in comparison with wild-type | [192] |
P. tricornutum | Overexpression of glucose-6-phosphate dehydrogenase (G6PD) | Increased production of lipids up to 55.7% of dry weight | [186] |
T. pseudonana | Knock-down of a multifunctional lipase/phospholipase/acetyltransferase enzyme | Mutant strains produced 2.4- to 3.3-fold higher amounts of lipids in comparison with wild-type | [186] |