13 research outputs found

    Utilization of glycerin byproduct derived from soybean oil biodiesel as a carbon source for heterologous protein production in Pichia pastoris

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    AbstractCrude glycerol, also known as glycerin, is the main byproduct of the biodiesel industry. It has been estimated that up to 40,000tons of glycerin will be produced each year by 2020. This study evaluated the value-added use of crude glycerol derived from soybean biodiesel preparation as a carbon source for heterologous protein production using the yeast Pichia pastoris. Eleven glycerin samples were obtained by methanolysis of soybean oil using different acids or bases as catalysts. Cell growth experiments showed that crude glycerol containing either potassium or sodium hydroxide resulted in 1.5–2 times higher final cell densities when compared to glycerol P.A. Finally, crude glycerol containing sodium hydroxide was successfully utilized for constitutive heterologous α-amylase production in P. pastoris. This study demonstrated that crude glycerol without any purification steps may be directly used as carbon source for protein production in P. pastoris

    Selection and testing of epiphytic yeasts to control anthacnose in post-harvest of papaya fruit

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    Anthracnose, caused by Colletotrichum gloeosporioides, is a major post-harvest disease in papaya fruit. The major objectives of the present work were to isolate, select and test the in vitro and in vivo ability of epiphytic microorganisms, isolated from papaya fruit and leaf surfaces, in controlling anthracnose onset after harvest. A total of 75 bacteria, 67 yeasts and 22 mycelial fungi were isolated. Thirty yeast isolates were able to inhibit the mycelial growth of C. gloeosporioide in vitro and seven of those were used in in vivo assays, resulting in the identification of two very effective isolates. Isolate CEN63, identified molecularly as Cryptococcus magnus, was the most effective in controlling the disease and therefore was studied in more detail. The results of the assays with C. magnus provided evidence that when fruit were treated with the antagonists at concentrations of 107 to 108 cells/ml, as early as 24 h, preferentially 48 h, before inoculation with the pathogen, the development of disease was significantly reduced. C. magnus is a potential antagonist for the development of a commercial product. Additional studies on the modes of action of this yeast isolate, as on its ability to interact with fungicides are being conducted to generate solid basis for the development of an environmentally friendly control agen

    Insertion of the LINE-1 element in the C-MYC gene and immunoreactivity of C-MYC, p53, p21 and p27 proteins in different morphological patterns of the canine TVT

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    ABSTRACT The canine transmissible venereal tumor (TVT) affects the external genitalia of dogs by the natural transplant of viable tumor cells. Thus, this research aimed to diagnose and characterize TVT morphological patterns, identify the insertion of the LINE-1 element in C-MYC gene, by means of the polymerase chain reaction (PCR), and evaluate the immunohistochemical expression of C-MYC, p53, p21 and p27 proteins. The relationship between C-MYC and p53 proteins and their interference on the expression of p21 and p27 were also studied. For that, 20 samples of naturally occurring TVT were used, subjected to cytopathological, histopathological and immunohistochemical analysis, and to molecular diagnosis of neoplasia. The increased tissue expression and the correlation among C-MYC, p53, p21 and p27 proteins indicate reduction and/or loss of their functionality in the TVT microenvironment, with consequent apoptotic suppression, maintenance of cell growth and progression of neoplasia

    Culture of bovine ovarian follicle wall sections maintained the highly estrogenic profile under basal and chemically defined conditions

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    Follicle cultures reproduce in vitro the functional features observed in vivo. In a search for an ideal model, we cultured bovine antral follicle wall sections (FWS) in a serum-free defined medium (DM) known to induce 17β-estradiol (E2) production, and in a nondefined medium (NDM) containing serum. Follicles were sectioned and cultured in NDM or DM for 24 or 48 h. Morphological features were determined by light microscopy. Gene expression of steroidogenic enzymes and follicle-stimulating hormone (FSH) receptor were determined by RT-PCR; progesterone (P4) and E2 concentrations in the media were measured by radioimmunoassay. DM, but not NDM, maintained an FWS morphology in vitro that was similar to fresh tissue. DM also induced an increase in the expression of all steroidogenic enzymes, except FSH receptor, but NDM did not. In both DM and NDM, there was a gradual increase in P4 throughout the culture period; however, P4 concentration was significantly higher in NDM. In both media, E2 concentration was increased at 24 h, followed by a decrease at 48 h. The E2:P4 ratio was higher in DM than in NDM. These results suggest that DM maintains morphological structure, upregulates the expression of steroidogenic enzyme genes, and maintains steroid production with a high E2:P4 ratio in FWS cultures

    Cytokine profiles in cyst fluids from ovarian tumors reflect immunosuppressive state of the tumor

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    Contains fulltext : 95782.pdf (publisher's version ) (Closed access)OBJECTIVE: Ovarian tumors, both benign and malignant, often contain cystic lesions. Analysis of cytokine levels of this enclosed fluid may be a pure way to study cytokine expression to gain more insight in tumor-host interaction. METHODS: We analyzed the expression of cytokines in 45 cyst fluids from benign and malignant ovarian tumors and mapped the cytokine profiles for the different histological subgroups. The concentration of interleukin (IL)-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, interferon gamma, tumor necrosis factor alpha, tumor necrosis factor beta, transforming growth factor beta, and C-C motif chemokine 22 was measured. RESULTS: The presence of IL-6 in cyst fluid is correlated with malignancy. IL-8 was also expressed in benign samples, but the levels were significantly higher in malignant cyst fluids. Transforming growth factor beta was only present in latent form in both benign and malignant cyst fluids. C-C motif chemokine 22 was detectable in higher levels in mucinous samples than in serous samples. IL-10 was not expressed in cyst fluid. T helper 1 subtype (TH1: IL-12 and IFN-gamma) and TH2 (IL-4, IL-5) cytokines were similarly expressed in malignant and benign mucinous tumors. However, in the serous group, TH1 and TH2 cytokines were expressed in the benign samples but not in the malignant samples. In the high-grade malignant serous group, we found an inverse relationship between IL-8 levels and overall survival. CONCLUSIONS: Our results suggest that the immunosuppressive state created by ovarian cancer is reflected in the cystic fluid within the tumor. Furthermore, our findings suggest that type 1 and type 2 tumors have a distinct immunological profile and support the dualistic model for ovarian tumorigenesis
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