Mitigating excessive ammonia nitrogen in chicken farm flushing wastewater by mixing strategy for nutrient removal and lipid accumulation in the green alga Chlorella sorokiniana

Cui, Hongli; Ma, Haotian; Chen, Shuaihang; Yu, Jaecheul; Xu, Wen Jiang; Zhu, Xiaoli; Gujar, A. R.; Ji, Chunli; Xue, Jinai; Zhang, Chunhui; Li, Runzhi

doi:10.1016/j.biortech.2020.122940

Cited by 44 publications

(21 citation statements)

References 46 publications

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“…Total lipids extraction, TAGs separation, and FAs analysis were performed according to previously described procedures [21,[74][75][76]. Briefly, 50 mg of yeast cells, 10 mg of freeze-dried algae cells or 10 mg of dried seeds were used to extract total lipids according to previously reported methods [75].…”

Section: Lipid Extraction and Fatty Acid Analysismentioning

confidence: 99%

Characterization of type-2 diacylglycerol acyltransferases in Haematococcus lacustris reveals their functions and engineering potential in triacylglycerol biosynthesis

Cui

Zhao

et al. 2021

BMC Plant Biol

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Background Haematococcus lacustris is an ideal source of astaxanthin (AST), which is stored in oil bodies containing esterified AST (EAST) and triacylglycerol (TAG). Diacylglycerol acyltransferases (DGATs) catalyze the last step of acyl-CoA-dependent TAG biosynthesis and are also considered as crucial enzymes involved in EAST biosynthesis in H. lacustris. Previous studies have identified four putative DGAT2-encoding genes in H. lacustris, and only HpDGAT2D allowed the recovery of TAG biosynthesis, but the engineering potential of HpDGAT2s in TAG biosynthesis remains ambiguous. Results Five putative DGAT2 genes (HpDGAT2A, HpDGAT2B, HpDGAT2C, HpDGAT2D, and HpDGAT2E) were identified in H. lacustris. Transcription analysis showed that the expression levels of the HpDGAT2A, HpDGAT2D, and HpDGAT2E genes markedly increased under high light and nitrogen deficient conditions with distinct patterns, which led to significant TAG and EAST accumulation. Functional complementation demonstrated that HpDGAT2A, HpDGAT2B, HpDGAT2D, and HpDGAT2E had the capacity to restore TAG synthesis in a TAG-deficient yeast strain (H1246) showing a large difference in enzymatic activity. Fatty acid (FA) profile assays revealed that HpDGAT2A, HpDGAT2D, and HpDGAT2E, but not HpDGAT2B, preferred monounsaturated fatty acyl-CoAs (MUFAs) for TAG synthesis in yeast cells, and showed a preference for polyunsaturated fatty acyl-CoAs (PUFAs) based on their feeding strategy. The heterologous expression of HpDGAT2D in Arabidopsis thaliana and Chlamydomonas reinhardtii significantly increased the TAG content and obviously promoted the MUFAs and PUFAs contents. Conclusions Our study represents systematic work on the characterization of HpDGAT2s by integrating expression patterns, AST/TAG accumulation, functional complementation, and heterologous expression in yeast, plants, and algae. These results (1) update the gene models of HpDGAT2s, (2) prove the TAG biosynthesis capacity of HpDGAT2s, (3) show the strong preference for MUFAs and PUFAs, and (4) offer target genes to modulate TAG biosynthesis by using genetic engineering methods.

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Section: Lipid Extraction and Fatty Acid Analysismentioning

confidence: 99%

Characterization of type-2 diacylglycerol acyltransferases in Haematococcus lacustris reveals their functions and engineering potential in triacylglycerol biosynthesis

Cui

Zhao

et al. 2021

BMC Plant Biol

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“…The lipid extraction and FAs analysis were all performed according to previously described procedures [21,79,80]. Brie y, cellular FAs were extracted by incubating 50 mg of yeast cells or 10 mg freeze-dried algae cells or 10 mg of dried seeds of control and transformed plants in 3 mL of 7.5% (w/v) KOH in methanol for saponi cation at 70 °C for 4 h. Then the pH was adjusted to 2.0 with HCl.…”

Section: Lipid Extraction and Fatty Acids Analysismentioning

confidence: 99%

Characterization of type-2 diacylglycerol acyltransferases in Haematococcus lacustris reveals their functions and engineering potential in triacylglycerol biosynthesis and possible roles in astaxanthin esterification

Cui¹,

Zhao²,

Xu³

et al. 2020

Preprint

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Background: Haematococcus lacustris is an ideal source of astaxanthin (AST) which is stored at oil bodies containing esterified AST (EAST) and triacylglycerol (TAG). Diacylglycerol acyltransferases (DGATs) catalyze the last step of the acyl-CoA-dependent TAG biosynthesis and are also considered as the crucial enzymes involving in EAST biosynthesis in H. lacustris. Previous studies have identified four putative DGAT2 encoding genes in H. lacustris and only the HpDGAT2D allowed the recovery of TAG biosynthesis, but the engineering potential of HpDGAT2s in TAG biosynthesis, especially possible roles in AST esterification, remains ambiguous.Results: Five putative DGAT2 genes (HpDGAT2A, 2B, 2C, 2D, and 2E) were identified in H. lacustris. Transcription analysis showed that the expression levels of HpDGAT2A, 2B, and 2E genes markedly increased under high light and nitrogen deficient conditions with distinct patterns, which led to significant TAG and EAST accumulation. Functional complementation demonstrated HpDGAT2A, 2B, 2D, and 2E had the capability to restore TAG synthesis in a TAG-deficient yeast strain (H1246) with the large difference in enzymatic activity. Fatty acids (FAs) profiles assays revealed that HpDGAT2A, 2D, and 2E except for 2B preferred monounsaturated fatty acyl-CoA (MUFA) for TAG synthesis in yeast cells, and also showed polyunsaturated fatty acyl-CoA (PUFA) preference by feeding strategy. The over-expression of HpDGAT2D in Arabidopsis thaliana and Chlamydomonas reinhardtii significantly increased the TAG content and obviously promoted the MUFA and PUFA contents. Interestingly, molecular docking analysis implied that HpDGAT2s structures contained AST binding sites, which provides strong evidence for AST esterification function in H. lacustris.Conclusions: Our study represents a pioneering work on the characterization of HpDGAT2s by systematically integrating expression pattern, AST/TAG accumulation, functional complementation, molecular docking, and over-expression in yeast, plants, and algae. These results (1) update the gene models of HpDGAT2s, (2) prove TAG biosynthesis capacity of HpDGAT2s, (3) show the strong preference for MUFA and PUFA, (4) offer target genes to modulate TAG biosynthesis by genetic engineering method, and (5) provide new evidence for HpDGAT2s roles in AST esterification.

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“…The lipid extraction and FAs analysis were all performed according to previously described procedures [21,[80][81][82]. Brie y, cellular FAs were extracted by incubating 50 mg of yeast cells or 10 mg freeze-dried algae cells or 10 mg of dried seeds of control and transformed plants in 3 mL of 7.5% (w/v) KOH in methanol for saponi cation at 70 °C for 4 h. Then the pH was adjusted to 2.0 with HCl.…”

Section: Lipid Extraction and Fatty Acids Analysismentioning

confidence: 99%

Characterization of type-2 diacylglycerol acyltransferases in Haematococcus lacustris reveals their functions and engineering potential in triacylglycerol biosynthesis and possible roles in astaxanthin esterification

Cui

Zhao

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Background: Haematococcus lacustris is an ideal source of astaxanthin (AST) which is stored at oil bodies containing esterified AST (EAST) and triacylglycerol (TAG). Diacylglycerol acyltransferases (DGATs) catalyze the last step of the acyl-CoA-dependent TAG biosynthesis and are also considered as the crucial enzymes involving in EAST biosynthesis in H. lacustris. Previous studies have identified four putative DGAT2 encoding genes in H. lacustris and only the HpDGAT2D allowed the recovery of TAG biosynthesis, but the engineering potential of HpDGAT2s in TAG biosynthesis, especially possible roles in AST esterification, remains ambiguous.Results: Five putative DGAT2 genes (HpDGAT2A, HpDGAT2B, HpDGAT2C, HpDGAT2D, and HpDGAT2E) were identified in H. lacustris. Transcription analysis showed that the expression levels of HpDGAT2A, HpDGAT2D, and HpDGAT2E genes markedly increased under high light and nitrogen deficient conditions with distinct patterns, which led to significant TAG and EAST accumulation. Functional complementation demonstrated HpDGAT2A, HpDGAT2B, HpDGAT2D, and HpDGAT2E had the capability to restore TAG synthesis in a TAG-deficient yeast strain (H1246) with the large difference in enzymatic activity. Fatty acids (FAs) profiles assays revealed that HpDGAT2A, HpDGAT2D, and HpDGAT2E except for HpDGAT2B preferred monounsaturated fatty acyl-CoAs (MUFAs) for TAG synthesis in yeast cells, and also showed polyunsaturated fatty acyl-CoAs (PUFAs) preference by feeding strategy. The over-expression of HpDGAT2D in Arabidopsis thaliana and Chlamydomonas reinhardtii significantly increased the TAG content and obviously promoted the MUFAs and PUFAs contents. Interestingly, molecular docking analysis implied that HpDGAT2s structures contained AST binding sites, which provides strong evidence for AST esterification function in H. lacustris.Conclusions: Our study represents a pioneering work on the characterization of HpDGAT2s by systematically integrating expression pattern, AST/TAG accumulation, functional complementation, molecular docking, and over-expression in yeast, plants, and algae. These results (1) update the gene models of HpDGAT2s, (2) prove TAG biosynthesis capacity of HpDGAT2s, (3) show the strong preference for MUFAs and PUFAs, (4) offer target genes to modulate TAG biosynthesis by genetic engineering method, and (5) provide new evidence for HpDGAT2s roles in AST esterification.

show abstract

Mitigating excessive ammonia nitrogen in chicken farm flushing wastewater by mixing strategy for nutrient removal and lipid accumulation in the green alga Chlorella sorokiniana

Cited by 44 publications

References 46 publications

Characterization of type-2 diacylglycerol acyltransferases in Haematococcus lacustris reveals their functions and engineering potential in triacylglycerol biosynthesis

Characterization of type-2 diacylglycerol acyltransferases in Haematococcus lacustris reveals their functions and engineering potential in triacylglycerol biosynthesis

Characterization of type-2 diacylglycerol acyltransferases in Haematococcus lacustris reveals their functions and engineering potential in triacylglycerol biosynthesis and possible roles in astaxanthin esterification

Characterization of type-2 diacylglycerol acyltransferases in Haematococcus lacustris reveals their functions and engineering potential in triacylglycerol biosynthesis and possible roles in astaxanthin esterification

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