Probiotic has been widely used in functional food because of numerous advantages for health. MRS broth is commonly used as standard medium in studying lactobacilli. However, in some communities - like muslim and vegetarian society, components in MRS broth/medium become an issue. Beef extract and peptone – animal derived substances as nitrogen sources in the MRS medium should be avoided for the vegetarian. Meanwhile, for the muslim society, all components must be halal-certified including those animal derived ingredients. Therefore, several alternative sources for beef extract and peptone substitution were studied. Combination of alternative nitrogen sources was applied. In order to increase the effect of the alternative nitrogen sources, alternative carbon sources were also included. This is the first report about effects of L. brevis media components on cells growth to expression level of surface layer protein (Slp). Whey, lactose, sucrose, and galactose showed high contribution to L. brevis growth. However, the tested concentration of those substances were not sufficient to obtain equal bacterial growth and Slp expression than that of MRS broth. In addition, yeast extract appeared necessary to maintain cell wall and Slp expression.
Recombinant human epidermal growth factor (rh-EGF) has high value in therapies for h-EGF deficiency-related diseases. The expression of the h-EGF gene was designed by using the pET21b(+) vector and Escherichia coli BL21(DE3) as the expression host. In a previous study, the sequence of a 6xHis tag without any restriction sites was fused to the h-EGF gene, yet it was not possible to obtain a purified and single rh-EGF by this approach. In this study, we modified the rh-EGF expression vector using site-directed mutagenesis (SDM) to remove the sequence of the 6xHis tag. The vector modification was carried out by inserting a stop codon and the EcoRI restriction site, along with deleting the 6xHis tag sequence. The results of PCR showed non-specific bands, while 2-step cycles PCR produced one non-specific band, and 3-step cycles PCR produced two non-specific bands. After purification of the PCR products, the SDM-recombinant plasmids treated for template plasmid-free product were transformed into E. coli DH5a. Even though the transformation efficiency was low, the planned gene mutations including the deletion of the 6xHis tag and insertion of the stop codon and EcoRI restriction site in plasmid pET21b(+) were successfully carried out. When using this modified vector in expression studies, rh-EGF of a similar size to that of the rh-EGF standard and approximately 1 kDa smaller than the rh-EGF-6xHis of the previous study was obtained.
Soy-based beverages offer numerous health benefits, but the presence of lipoxygenases causes an unpleasant off-flavor sensation that hinders acceptability. The addition of a suitable flavoring agent has been shown to enhance the acceptability of soy-based beverages. This study aimed to investigate preferences towards two flavored variants of soy-based beverages: original chocolate made from cocoa powder and vanilla made from vanilla essence. Before comparing the sensory parameters, which included appearance, taste, odor, texture, and overall assessment, the ratio of basic components such as soy and cow milk powder, sugar, and maltodextrin was studied. Fifty-seven untrained panelists evaluated the three flavored variants of soy-based beverages. The chocolate-flavored soy-based beverage received a significantly higher score in taste, odor, texture, and overall assessment (α = 0.05). Hence, adding cocoa powder as a flavoring agent in soy-based beverages effectively improved the sensory attributes.
ABSTRACT. Standard diagnosis of SARS-CoV-2 by nasopharyngeal swab (NPS) and real-time reverse transcriptase-polymerase chain reaction (PCR) requires a sophisticated laboratory, skilled staff, and expensive reagents that are difficult to establish and maintain in isolated, low-resource settings. In the remote setting of tropical Sumba Island, eastern Indonesia, we evaluated alternative sampling with fresh saliva (FS) and testing with colorimetric loop-medicated isothermal amplification (LAMP). Between August 2020 and May 2021, we enrolled 159 patients with suspected SARS-CoV-2 infection, of whom 75 (47%) had a positive PCR on NPS (median cycle threshold [Ct] value: 27.6, interquartile range: 12.5–37.6). PCR on FS had a sensitivity of 72.5% (50/69, 95% confidence interval [CI]: 60.4–82.5) and a specificity of 85.7% (66/77, 95% CI: 75.9–92.6), and positive (PPV) and negative (NPV) predictive values of 82.0% (95% CI: 0.0–90.6) and 77.6% (95% CI: 67.3–86.0), respectively. LAMP on NPS had a sensitivity of 68.0% (51/75, 95% CI: 56.2–78.3) and a specificity of 70.8% (63/84, 95% CI: 58.9–81.0), with PPV 70.8% (95% CI: 58.9-81.0) and NPV 72.4% (95% CI: 61.8–81.5%). LAMP on FS had a sensitivity of 62.3% (43/69, 95% CI: 49.8–73.7%) and a specificity of 72.7% (56/77, 95% CI: 61.4–82.3%), with PPV 67.2% (95% CI: 54.3–78.4) and NPV 68.3% (95% CI: 57.1–78.1%). LAMP sensitivity was higher for NPS and FS specimens with high viral loads (87.1% and 75.0% for Ct value < 26, respectively). Dried saliva on filter paper was stable for 4 days at room temperature. LAMP on either NPS or FS could offer an accessible alternative for SARS-CoV-2 diagnosis in low-resource settings, with potential for optimizing sample collection and processing, and selection of gene targets.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.