scholarly journals Characterization and expression of AMP-forming Acetyl-CoA Synthetase from Dunaliella tertiolecta and its response to nitrogen starvation stress

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ming-Hua Liang ◽  
Xiao-Ying Qv ◽  
Hong-Hao Jin ◽  
Jian-Guo Jiang
Keyword(s):  
Nitrogen Starvation ◽  
Dunaliella Tertiolecta ◽  
Starvation Stress ◽  
Acetyl Coa

scholarly journals Engineering cytoplasmic acetyl-CoA synthesis decouples lipid production from nitrogen starvation in the oleaginous yeast Rhodosporidium azoricum

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Silvia Donzella ◽  
Daniela Cucchetti ◽  
Claudia Capusoni ◽  
Aurora Rizzi ◽  
Silvia Galafassi ◽  
...  
Keyword(s):  
Lipid Content ◽  
Nitrogen Starvation ◽  
Neutral Lipids ◽  
Lipid Production ◽  
Industrial Process ◽  
Wild Type ◽  
Lipid Concentration ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Engineered Strain

Abstract Background Oleaginous yeasts are able to accumulate very high levels of neutral lipids especially under condition of excess of carbon and nitrogen limitation (medium with high C/N ratio). This makes necessary the use of two-steps processes in order to achieve high level of biomass and lipid. To simplify the process, the decoupling of lipid synthesis from nitrogen starvation, by establishing a cytosolic acetyl-CoA formation pathway alternative to the one catalysed by ATP-citrate lyase, can be useful. Results In this work, we introduced a new cytoplasmic route for acetyl-CoA (AcCoA) formation in Rhodosporidium azoricum by overexpressing genes encoding for homologous phosphoketolase (Xfpk) and heterologous phosphotransacetylase (Pta). The engineered strain PTAPK4 exhibits higher lipid content and produces higher lipid concentration than the wild type strain when it was cultivated in media containing different C/N ratios. In a bioreactor process performed on glucose/xylose mixture, to simulate an industrial process for lipid production from lignocellulosic materials, we obtained an increase of 89% in final lipid concentration by the engineered strain in comparison to the wild type. This indicates that the transformed strain can produce higher cellular biomass with a high lipid content than the wild type. The transformed strain furthermore evidenced the advantage over the wild type in performing this process, being the lipid yields 0.13 and 0.05, respectively. Conclusion Our results show that the overexpression of homologous Xfpk and heterologous Pta activities in R. azoricum creates a new cytosolic AcCoA supply that decouples lipid production from nitrogen starvation. This metabolic modification allows improving lipid production in cultural conditions that can be suitable for the development of industrial bioprocesses using lignocellulosic hydrolysates.

scholarly journals Effects of Light Intensity and Nitrogen Starvation on Glycerolipid, Glycerophospholipid, and Carotenoid Composition in Dunaliella tertiolecta Culture

PLoS ONE ◽  
2013 ◽  
Vol 8 (9) ◽  
pp. e72415 ◽  
Author(s):  
So-Hyun Kim ◽  
Kwang-Hyeon Liu ◽  
Seok-Young Lee ◽  
Seong-Joo Hong ◽  
Byung-Kwan Cho ◽  
...  
Keyword(s):  
Light Intensity ◽  
Nitrogen Starvation ◽  
Dunaliella Tertiolecta ◽  
Carotenoid Composition

scholarly journals Woronin Body Function in Magnaporthe grisea Is Essential for Efficient Pathogenesis and for Survival during Nitrogen Starvation Stress

2004 ◽  
Vol 16 (6) ◽  
pp. 1564-1574 ◽  
Author(s):  
Shanthi Soundararajan ◽  
Gregory Jedd ◽  
Xiaolei Li ◽  
Marilou Ramos-Pamploña ◽  
Nam H. Chua ◽  
...  
Keyword(s):  
Magnaporthe Grisea ◽  
Nitrogen Starvation ◽  
Starvation Stress ◽  
Body Function ◽  
Woronin Body

scholarly journals Comparative transcriptome analysis of two Cercospora sojina strains reveals differences in virulence under nitrogen starvation stress

2020 ◽  
Author(s):  
Xin Gu ◽  
Shuai Yang ◽  
Xiaohe Yang ◽  
Liangliang Yao ◽  
Xuedong Gao ◽  
...  
Keyword(s):  
Transcriptome Analysis ◽  
Gene Networks ◽  
Nitrogen Starvation ◽  
Cellulose Degradation ◽  
Virulent Strain ◽  
Expression Patterns ◽  
Lignocellulose Degradation ◽  
Starvation Stress ◽  
Cercospora Sojina ◽  
Highly Virulent

Abstract Background: Cercospora sojina is a fungal pathogen that causes frogeye leaf spot in soybean-producing regions, leading to severe yield losses worldwide. It exhibits variations in virulence due to race differentiation between strains. However, the candidate virulence-related genes are unknown because the infection process is slow, making it difficult to collect transcriptome samples. Methods: In this study, virulence-related differentially expressed genes (DEGs) were obtained from the highly virulent Race15 strain and mildly virulent Race1 strain under nitrogen starvation stress, which mimics the physiology of the pathogen during infection. Weighted gene co-expression network analysis (WGCNA) was then used to find co-expressed gene modules and assess the relationship between gene networks and phenotypes. Results: Upon comparison of the transcriptomic differences in virulence between the strains, a total of 378 and 124 DEGs were upregulated, while 294 and 220 were downregulated in Race 1 and Race 15, respectively. Annotation of these DEGs revealed that many were associated with virulence differences, including scytalone dehydratase, 1,3,8-trihydroxynaphthalene reductase, and β-1,3-glucanase. In addition, two modules highly correlated with the highly virulent strain Race 15 and 36 virulence-related DEGs were found to contain mostly β-1,4-glucanase, β-1,4-xylanas, and cellobiose dehydrogenase. Conclusions: These important nitrogen starvation-responsive DEGs are frequently involved in the synthesis of melanin, polyphosphate storage in the vacuole, lignocellulose degradation, and cellulose degradation during fungal development and differentiation. Transcriptome analysis indicated unique gene expression patterns, providing further insight into pathogenesis.

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