scholarly journals Engineering Yarrowia lipolytica for the Synthesis of Glutathione from Organic By-Products

2020 ◽  
Vol 8 (4) ◽  
pp. 611
Author(s):  
Diem T. H. Do ◽  
Patrick Fickers

Tripeptide glutathione, which plays important roles in many cellular mechanisms, is also a biotechnology-oriented molecule with applications in medicine, food and cosmetic. Here, the engineering of the yeast Yarrowia lipolytica for the production of this metabolite at high titer values from various agro-industrial by-products is reported. The constitutive overexpression of the glutathione biosynthetic genes GSH1 and GSH2 encoding respectively γ-glutamylcysteine synthetase and glutathione synthetase, together with the INU1 gene from Kluyveromyces marxianus encoding inulinase yielded a glutathione titer value and a productivity of 644 nmol/mg protein and 510 µmol/gDCW, respectively. These values were obtained during bioreactor batch cultures in a medium exclusively comprising an extract of Jerusalem artichoke tuber, used as a source of inulin, and ammonium sulfate, used as a nitrogen source.

2017 ◽  
Vol 4 (2) ◽  
Author(s):  
NEHA SINGH ◽  
INDERJEET BHOGAL ◽  
ABHISHEK KUMAR ◽  
PUNIT TYAGI ◽  
GIRIJA SIKARWAR ◽  
...  

Acclimatization is a process that occurs in individual cells to a drastic change in micro and macro environments. When an organism is subjected to a new environment or a change in its normal growing conditions, the cellular mechanisms initiate a warning sign and over a period of time or over generations the acquired, modified traits are being communicated and fixed as a new trait. If there is lack of equilibrium within the cell due to over expression of a single gene or network of associated genes either manmade or due to mutations, the organism or plant tries to fix it by initiating gene regulatory mechanisms. According to our neutral theory of gene expression, always a cell tries to maintain its pH by modifying its cytosol through altered gene expression. In the present investigation, 198 AtMYB genes were analyzed and found to play an intrinsic photosystem linked network of 38 nodes where MYB being regulated by a set of 48 miRNAs. Members of the network have evidence-based link to energy related mechanisms. Altering gene expression to an extent where, the cell may not be able to fix it or a trait, which requires excessive energy loss escorts the organism’s gene regulation by breakdown of the introduced sequence over few generations. Events with constitutive overexpression may suffer poor performance over the years based on gene network prevailing in the crop of interest. Hence, network rewiring with minimal energy expenses is concerned.


Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 88
Author(s):  
Paulina Snopek ◽  
Dorota Nowak ◽  
Bartłomiej Zieniuk ◽  
Agata Fabiszewska

Yarrowia lipolytica is one of the most studied non-conventional forms of yeast, exhibiting a high secretory capacity and producing many industrially important and valuable metabolites. The yeast conceals a great biotechnological potential to synthesize organic acids, sweeteners, microbial oil, or fragrances. The vast majority of bioprocesses are carried out in bioreactors, where suitable culture conditions are provided. In the current study, the effect of agitation speed (200–600 rpm) and air flow rate (0.0375–2.0 dm3/(dm3 × min)) on the biomass yield and lipase activity of Y. lipolytica KKP 379 is analyzed in a growth medium containing waste fish oil. The increase of aeration intensity limited the period of oxygen deficit in the medium. Simultaneously, an increase in lipolytic activity was observed from 2.09 U/cm3 to 14.21 U/cm3; however, an excessive agitation speed likely caused oxidative or shear stresses, and a reduction in lipolytic activity was observed. Moreover, it is confirmed that the synthesis of lipases is related to oxygen consumption, pH, and the yeast growth phase, and appropriate process selection may provide two advantages, namely, the maximum use of the waste carbon source and the production of lipolytic enzymes that are valuable in many industries.


2017 ◽  
Vol 184 (4) ◽  
pp. 1332-1346 ◽  
Author(s):  
Mathiazhakan Kuttiraja ◽  
Ayed Dhouha ◽  
Rajeshwar Dayal Tyagi

1988 ◽  
Vol 254 (2) ◽  
pp. 411-417 ◽  
Author(s):  
Y Kera ◽  
K E Penttilä ◽  
K O Lindros

The zonal distribution of GSH metabolism was investigated by comparing hepatocytes obtained from the periportal (zone 1) or perivenous (zone 3) region by digitonin/collagenase perfusion. Freshly isolated periportal and perivenous cells had similar viability (dye exclusion, lactate dehydrogenase leakage and ATP content) and GSH content (2.4 and 2.7 mumol/g respectively). During incubation, periportal cells slowly accumulated GSH (0.35 mumol/h per g), whereas in perivenous cells a decrease occurred (-0.14 mumol/h per g). Also, in the presence of either L-methionine or L-cysteine (0.5 mM) periportal hepatocytes accumulated GSH much faster (3.5 mumol/h per g) than did perivenous cells (1.9 mumol/h per g). These periportal-perivenous differences were also found in cells from fasted rats. Efflux of GSH was faster from perivenous cells than from periportal cells, but this difference only explained 10-20% of the periportal-perivenous difference in accumulation. Furthermore, periportal cells accumulated GSH to a plateau 26-40% higher than in perivenous cells. There was no significant difference in gamma-glutamylcysteine synthetase or glutathione synthetase activity between the periportal and perivenous cell preparations. The periportal-perivenous difference in GSH accumulation was unaffected by inhibition of gamma-glutamyl transpeptidase or by 5 mM-glutamate or -glutamine, but was slightly diminished by 2 mM-L-methionine. This suggests differences between periportal and perivenous cells in their metabolism and/or transport of (sulphur) amino acids. Our results suggest that a lower GSH replenishment capacity of the hepatocytes from the perivenous region may contribute to the greater vulnerability of this region to xenobiotic damage.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jingbo Li ◽  
Yongshuo Ma ◽  
Nian Liu ◽  
Bekir E. Eser ◽  
Zheng Guo ◽  
...  

AbstractAlka(e)nes are ideal fuel components for aviation, long-distance transport, and shipping. They are typically derived from fossil fuels and accounting for 24% of difficult-to-eliminate greenhouse gas emissions. The synthesis of alka(e)nes in Yarrowia lipolytica from CO2-neutral feedstocks represents an attractive alternative. Here we report that the high-titer synthesis of alka(e)nes in Yarrowia lipolytica harboring a fatty acid photodecarboxylase (CvFAP) is enabled by a discovered pathway. We find that acyl-CoAs, rather than free fatty acids (FFAs), are the preferred substrate for CvFAP. This finding allows us to debottleneck the pathway and optimize fermentation conditions so that we are able to redirect 89% of acyl-CoAs from the synthesis of neutral lipids to alka(e)nes and reach titers of 1.47 g/L from glucose. Two other CO2-derived substrates, wheat straw and acetate, are also demonstrated to be effective in producing alka(e)nes. Overall, our technology could advance net-zero emissions by providing CO2-neutral and energy-dense liquid biofuels.


2003 ◽  
Vol 16 (11) ◽  
pp. 1039-1046 ◽  
Author(s):  
Manuel A. Matamoros ◽  
Maria R. Clemente ◽  
Shusei Sato ◽  
Erika Asamizu ◽  
Satoshi Tabata ◽  
...  

The thiol tripeptides, glutathione (GSH) and homoglu-tathione (hGSH), perform multiple roles in legumes, including protection against toxicity of free radicals and heavy metals. The three genes involved in the synthesis of GSH and hGSH in the model legume, Lotus japonicus, have been fully characterized and appear to be present as single copies in the genome. The γ-glutamylcysteine synthetase (γecs) gene was mapped on the long arm of chromosome 4 (70.0 centimorgans [cM]) and consists of 15 exons, whereas the glutathione synthetase (gshs) and homoglutathione synthetase (hgshs) genes were mapped on the long arm of chromosome 1 (81.3 cM) and found to be arranged in tandem with a separation of approximately 8 kb. Both genes consist of 12 exons of exactly the same size (except exon 1, which is similar). Two types of transcripts were detected for the gshs gene, which putatively encode proteins localized in the plastids and cytosol. Promoter regions contain cis-acting regulatory elements that may be involved in the plant's response to light, hormones, and stress. Determination of transcript levels, enzyme activities, and thiol contents in nodules, roots, and leaves revealed that γecs and hgshs are expressed in all three plant organs, whereas gshs is significantly functional only in nodules. This strongly suggests an important role of GSH in the rhizobia-legume symbiosis.


Genetics ◽  
1997 ◽  
Vol 145 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Biswendu Chaudhuri ◽  
Susham Ingavale ◽  
Anand K Bachhawat

Mutants in the adenine biosynthetic pathway of yeasts (ade1 and ade2 of Saccharomyces cerevisiae, ade6 and ade7 of Schizosaccharomyces pombe) accumulate an intense red pigment in their vacuoles when grown under adenine-limiting conditions. The precise events that determine the formation of the pigment are however, still unknown. We have begun a genetic investigation into the nature and cause of pigmentation of ade6 mutants of S. pombe and have discovered that one of these pigmentation defective mutants, apd1 (adenine pigmentation defective), is a strict glutathione auxotroph. The gene apd1  + was found to encode the first enzyme in glutathione biosynthesis, γ-glutamylcysteine synthetase, gcs1  +. This gene when expressed in the mutant could confer both glutathione prototrophy and the characteristic red pigmentation, and disruption of the gene led to a loss in both phenotypes. Supplementation of glutathione in the medium, however, could only restore growth but not the pigmentation because the cells were unable to achieve sufficient intracellular levels of glutathione. Disruption of the second enzyme in glutathione biosynthesis, glutathione synthetase, gsh2  +, also led to glutathione auxotrophy, but only a partial defect in pigment formation. A reevaluation of the major amino acids previously reported to be present in the pigment indicated that the pigment is probably a glutathione conjugate. The ability of vanadate to inhibit pigment formation indicated that the conjugate was transported into the vacuole through a glutathione-conjugate pump. This was further confirmed using strains of S. cerevisiae bearing disruptions in the recently identified glutathione-conjugate pump, YCF1, where a significant reduction in pigment formation was observed. The pump of S. pombe is distinct from the previously identified vacuolar pump, hmt1p, for transporting cadystin peptides into vacuoles of S. pombe.


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