Expression of alpha- and beta-Tubulin Genes during Growth of Trypanosoma cruzi Epimastigotes

Gonzalez-Pino, M J; Rangel-Aldao, Rafael; Slezynger, Thelma C.

doi:10.1089/104454999315169

Cited by 12 publications

(9 citation statements)

References 27 publications

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“…Although the heterologous XDH (PsXDH) was introduced, there was no significant change in xylitol. This phenomenon may be a result of the protein expression being restricted by the transcriptional level [ 49 ], that is, PsXDH cannot be efficiently expressed in HX-308. Another possibility is that the PsXDH protein successfully expressed in Schizochytrium sp.…”

Section: Discussionmentioning

confidence: 99%

Engineering the xylose metabolism in Schizochytrium sp. to improve the utilization of lignocellulose

Wang

Zhang

Nong

et al. 2022

Biotechnol Biofuels

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Background Schizochytrium sp. is a heterotrophic, oil-producing microorganism that can efficiently produce lipids. However, the industrial production of bulk chemicals using Schizochytrium sp. is still not economically viable due to high-cost culture medium. Replacing glucose with cheap and renewable lignocellulose is a highly promising approach to reduce production costs, but Schizochytrium sp. cannot efficiently metabolize xylose, a major pentose in lignocellulosic biomass. Results In order to improve the utilization of lignocellulose by Schizochytrium sp., we cloned and functionally characterized the genes encoding enzymes involved in the xylose metabolism. The results showed that the endogenous xylose reductase and xylulose kinase genes possess corresponding functional activities. Additionally, attempts were made to construct a strain of Schizochytrium sp. that can effectively use xylose by using genetic engineering techniques to introduce exogenous xylitol dehydrogenase/xylose isomerase; however, the introduction of heterologous xylitol dehydrogenase did not produce a xylose-utilizing engineered strain, whereas the introduction of xylose isomerase did. The results showed that the engineered strain 308-XI with an exogenous xylose isomerase could consume 8.2 g/L xylose over 60 h of cultivation. Xylose consumption was further elevated to 11.1 g/L when heterologous xylose isomerase and xylulose kinase were overexpressed simultaneously. Furthermore, cultivation of 308-XI-XK(S) using lignocellulosic hydrolysates, which contained glucose and xylose, yielded a 22.4 g/L of dry cell weight and 5.3 g/L of total lipid titer, respectively, representing 42.7 and 30.4% increases compared to the wild type. Conclusion This study shows that engineering of Schizochytrium sp. to efficiently utilize xylose is conducive to improve its utilization of lignocellulose, which can reduce the costs of industrial lipid production.

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Section: Discussionmentioning

confidence: 99%

Engineering the xylose metabolism in Schizochytrium sp. to improve the utilization of lignocellulose

Wang

Zhang

Nong

et al. 2022

Biotechnol Biofuels

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“…However, S. cerevisiae was successfully engineered to produce ethanol from xylose by introducing heterologous XR and XDH genes [18]. However, 308-XDH cannot utilize xylose, which may be a result of the protein expression being restricted by the transcriptional level [30], that is, PsXDH cannot be e ciently expressed in HX-308. Another possibility is that the PsXDH protein successfully expressed in Schizochytrium sp.…”

Section: Discussionmentioning

confidence: 99%

Engineering the xylose metabolism in Schizochytrium sp. to improve the utilization of lignocellulose

Wang

Zhang

Nong

et al. 2022

Preprint

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Background: Schizochytrium sp. is a heterotrophic, oil-producing microorganism that can efficiently produce lipids. However, the industrial production of bulk chemicals using Schizochytrium sp. is still not economically viable due to high-cost culture medium. Replacing glucose with cheap and renewable lignocellulose is a highly promising approach to reduce production costs, but Schizochytrium sp. cannot efficiently metabolize xylose, a major component of lignocellulosic biomass.Results: In order to improve the utilization of lignocellulose by Schizochytrium sp., we cloned and functionally characterized the genes encoding enzymes involved in the xylose metabolism. The results showed that the endogenous xylose reductase and xylulose kinase genes possess corresponding functional activities. Additionally, attempts were made to use genetic engineering techniques to introduce exogenous xylitol dehydrogenase/xylose isomerase to construct a strain of Schizochytrium sp. that can efficiently utilize xylose. The results showed that the engineered strain 308-XI with an exogenous xylose isomerase could utilize xylose, consuming 8.2 g/L xylose over 60 h of cultivation. Xylose consumption was further elevated to 11.1 g/L when heterologous xylose isomerase and xylulose kinase were overexpressed simultaneously. Furthermore, culturing 308-XI-XK(S) in a medium with lignocellulosic hydrolysate as the main carbon source resulted in a 22.4 g/L of dry cell weight and 5.3 g/L of total lipid titer, respectively representing 42.7 and 30.4% increases compared to the wild type. Conclusion: This study shows that engineering of Schizochytrium sp. to efficiently utilize xylose is conducive to improve its utilization of lignocellulose, which can reduce the costs of industrial lipid production.

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“…Tikoo et al [1997] have studied DNase I digestion of rat liver nuclei to determine that chromatin that is preferentially digested was enriched with trancriptionally active genes. Our results are important because the differences observed in chromatin behavior during the growth curve of T. cruzi epimastigotes as well as in trypomastigotes might be associated with differences in transcription detected in these developmental stages of the parasite [González‐Pino et al, 1999]. We are currently using specifc genes as probes together with DNase I digestion of chromatin T.cruzi in order to further investigate this matter.…”

Section: Discusionmentioning

confidence: 97%

“…Subsequently, in the hindgut, epimastigotes differentiate into metacyclic trypomastigotes, which can infect mammalian host cells when the excrements of the infected bugs come in contact with the skin of humans [De Souza, 1984]. The complex changes observed during the life cycle of T. cruzi could be the results of adaptative modifications in gene expression [González‐Pino et al, 1999], which might be accompanied by modifications of chromatin structure [Reverol et al, 1997].…”

mentioning

confidence: 99%

Differences in the nuclear chromatin among various stages of the life cycle of Trypanosoma cruzi

Spadiliero

Sánchez

Slezynger

et al. 2002

J of Cellular Biochemistry

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Trypanosoma cruzi is the etiological agent of Chagas. Although the nuclear chromatin of this parasite is organized in the form of nucleosome filaments, its chromatin is physically and enzymatically fragile, and no condensation into chromosomes occurs during mitosis. All previous investigations have been carried out with epimastigote form in its proliferate stage. It is not known whether these differences in chromatin structure are also found in the non-proliferate stationary epimastigote forms and in tissue derived trypomastigotes. Our results confirm that chromatin of logarithmic epimastigotes presents limited compaction when increasing salt concentrations from 1 to 100 mM NaCl, and no 30-nm fibers were formed. Contrary to these results, non-proliferative forms of the parasites showed a pattern of compactation similar to that observed in rat liver chromatin, where solenoids of 30-nm fibers are formed at 100-mM NaCl. In accordance with these results, digestion of the nuclear chromatin with DNase I revealed that the chromatin of logarithmic phase epimastigotes was more accessible to the enzyme. We conclude from these results that structural differences in the chromatin exist not only between T. cruzi and higher eukaryotes but also among various forms of the parasite. The functional significance of these differences are currently under investigation.

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Expression of alpha- and beta-Tubulin Genes during Growth of Trypanosoma cruzi Epimastigotes

Cited by 12 publications

References 27 publications

Engineering the xylose metabolism in Schizochytrium sp. to improve the utilization of lignocellulose

Engineering the xylose metabolism in Schizochytrium sp. to improve the utilization of lignocellulose

Engineering the xylose metabolism in Schizochytrium sp. to improve the utilization of lignocellulose

Differences in the nuclear chromatin among various stages of the life cycle of Trypanosoma cruzi

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