Tuberculosis (TB) kills more individuals in the world than any other disease, and a threat made direr by the coverage of drug-resistant strains of Mycobacterium tuberculosis (Mtb). Bacillus ...Calmette-Guérin (BCG) is the single TB vaccine licensed for use in human beings and effectively protects infants and children against severe military and meningeal TB. We applied advanced computational techniques to develop a universal TB vaccine. In the current study, we select the very conserved, experimentally confirmed Mtb antigens, including Rv2608, Rv2684, Rv3804c (Ag85A), and Rv0125 (Mtb32A) to design a novel multi-epitope subunit vaccine. By using the Immune Epitopes Database (IEDB), we predicted different B-cell and T-cell epitopes. An adjuvant (Griselimycin) was also added to vaccine construct to improve its immunogenicity. Bioinformatics tools were used to predict, refined, and validate the 3D structure and then docked with toll-like-receptor (TLR-3) using different servers. The constructed vaccine was used for further processing based on allergenicity, antigenicity, solubility, different physiochemical properties, and molecular docking scores. The in silico immune simulation results showed significant response for immune cells. For successful expression of the vaccine in E. coli, in-silico cloning and codon optimization were performed. This research also sets out a good signal for the design of a peptide-based tuberculosis vaccine. In conclusion, our findings show that the known multi-epitope vaccine may activate humoral and cellular immune responses and maybe a possible tuberculosis vaccine candidate. Therefore, more experimental validations should be exposed to it.
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•Melatonin may alleviate cold-induced membrane lipid peroxidation.•Melatonin treatment increased the ratio of unsaturated to saturated fatty acids.•Melatonin lightened phospholipids ...degradation and gene expression of CaPLD and CaLOX.•Melatonin treatment may activate an antioxidant defense system of bell peppers.•Melatonin treatment may be a reliable method to relieve chilling injury.
Melatonin is a kind of indoleamine that plays an important role against abiotic stress. In the current study, we investigated the effect of exogenous melatonin (100 μM) on bell pepper during storage at 4 °C for 20 d and afterward shelf at 20 °C for 3 d. Melatonin treatment reduced cell structure damage and lightened the increase in chilling injury incidence, membrane permeability, and malonaldehyde (MDA) content under cold stress. The membrane lipid content and the ratio of unsaturated to saturated fatty acids increased by reducing the enzymatic activity and transcripts of phospholipase D (PLD) and lipoxygenase (LOX). Besides, melatonin application also inhibited the transcription of CaNAC1, which is the direct targeted regulator of the CaPLD gene. In addition, peppers treated with melatonin had a higher proline content than untreated peppers. Moreover, melatonin triggered the antioxidation protection system in peppers to resist oxidative damage by up-regulating the transcription level of the CaSOD, CaPOD, CaCAT, and CaAPX genes. Our results show that melatonin treatment may be a reliable method to relieve chilling injury in bell pepper fruit via the alleviation of cold-induced membrane lipid peroxidation and activating an antioxidant defense system.
Cold storage of green bell pepper fruit causes increased production of CaNAC1, which activates CaPLDα4 and results in chilling injury via degradation of membrane phospholipids.
Abstract
Phospholipids ...constitute the main component of biomembranes. During low-temperature storage and transportation of harvested bell peppers (Capsicum annuum), chilling injury participates in their decay. A primary cause of this chilling injury is phospholipid degradation. In this study, three genes encoding phospholipase D (PLD) were identified from bell peppers and their activities were examined under cold stress. Low temperature (4 °C) induced strong accumulation of the CaPLDα4 transcript, suggesting that it is associated with the phenomenon of phospholipid degradation and destruction of cell membranes. Low temperature also significantly induced increased amounts of NAM-ATAF1/2-CUC2 (NAC) domain transcription factors. CaNAC1 was found to interact with the promoter of CaPLD4 in a yeast one-hybrid screen. Electrophoretic mobility shift and ß-glucuronidase reporter assays demonstrated that CaNAC1 binds to the CTGCAG motif in the CaPLDα4 promoter, thereby activating its transcription and controlling phospholipid degradation. The ubiquitination sites of the CaNAC1 protein were characterized by liquid chromatography–tandem mass spectrometry. We conclude that CaNAC1 is a transcriptional activator of CaPLDα4 and suggested that it participates in the degradation of membrane lipids in bell peppers when they are stored at low temperature.
Monascus species produce useful secondary metabolite, Monascus pigments (MPs). They are widely used in food industry as a color intensifier, food additives and nitrite substitute in the meat product. ...MPs are also reported to have the potential for therapeutic use and used as a dye in cosmetic and textile industries. This paper reviews the production, composition, bioactivity, utilization of MPs, the citrinin and methods of eliminating citrinin from MPs were also discussed. MPs possess antioxidant properties, immunosuppressive properties, teratogenicity, and antimicrobial. Notwithstanding all these useful characteristics, it has been discovered that Monascus species co-produce citrinin and current studies on Monascus focus on how to minimize or eliminate citrinin from the useful pigment to improve quality and safety, several methods have been developed, including, detoxification of citrinin, regulation of gene, manipulation of fermentation conditions and use of nanoparticles for production of citrinin free MPs.
Arsenopyrite and pyrite often coexist in metal deposits and tailings, thus simultaneous bioleaching of both sulfides has economic (as well as environmental) significance. Important targets in ...bio-oxidation operations are high solubilization rates and minimized accumulation of Fe(III)/As-bearing secondary products. This study investigated the role of pyrite bioleaching in the enhancement of arsenopyrite dissolution. At a pyrite to arsenopyrite mass ratio of 1:1, 93.6% of As and 93.0% of Fe were solubilized. The results show that pyrite bio-oxidation can promote arsenopyrite dissolution, enhance S0 bio-oxidation, and inhibit the formation of jarosites, tooeleite, and amorphous ferric arsenate. The dry weight of the pyrite & arsenopyrite residue was reduced by 95.1% after bioleaching, compared to the initial load, while only 5% weight loss was observed when pyrite was absent. A biofilm was formed on the arsenopyrite surface in the presence of pyrite, while a dense passivation layer was observed in the absence of pyrite. As(III) (as As2O3) was a dominant As species in the pyrite & arsenopyrite residue. Novel and detailed findings are presented on arsenopyrite bio-dissolution in the presence of pyrite, and the presented approach could contribute to the development of novel cost-effective extractive bioprocesses.
The oxidation of arsenopyrite presents significant environmental hazards, as it can contribute to acid mine drainage generation and arsenic mobilization from sulfidic mine wastes. Bioleaching is a proven cost-effective and environmentally friendly extractive technology, which has been applied for decades in metal recovery from minerals or tailings. In this work, efficient extraction of arsenic from arsenopyrite bioleaching was presented through coupling the process with bio-oxidation of pyrite, resulting in lowered accumulation of hazardous and metastable Fe(III)/As-bearing secondary phases. The results could help improve current biomining operations and/or contribute to the development of novel cost-effective bioprocesses for metal extraction.
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•FeS2 promotes FeAsS bioleaching and inhibits secondary product formation.•Bio-oxidation of FeS2 prior to FeAsS addition further promotes dissolution.•93.6% As and 93.0% Fe were extracted in the assay with a delayed FeAsS supply.•Oxidation layer passivated mineral surface at pH 2, while biofilm formed at pH 1.5.•As2O3 was a major As solid form after FeAsS bioleaching under low pH & high Fe3+.
Biodiesel-derived glycerol is a promising substrate for mixotrophic cultivation of oleaginous microalgae, which can also reduce the cost of microalgal biodiesel. The objective of this study is to ...investigate the potential of using glycerol and glucose as a complex carbon substrate to produce microalgal biomass and biochemical components, such as photosynthetic pigments, lipids, soluble carbohydrates and proteins by Chlorella vulgaris. The results show that C. vulgaris can utilize glycerol as a sole carbon substrate, but its effect is inferior to that of the mixture of glycerol and glucose. The effect of glycerol and glucose could enhance the algal cell growth rate, biomass content and volumetric productivity, and overcome the lower biomass production on glycerol as the sole organic carbon source in mixotrophic culture medium. The utilization of complex organic carbon substrate can stimulate the biosynthesis of lipids and soluble carbohydrates as the raw materials for biodiesel and bioethanol production, and reduce the anabolism of photosynthetic pigments and proteins. This study provides a promising niche for reducing the overall cost of biodiesel and bioethanol production from microalgae as it investigates the by-products of algal biodiesel production and algal cell hydrolysis as possible raw materials (lipids and carbohydrates) and organic carbon substrates (soluble carbohydrates and glycerol) for mixotrophic cultivation of microalgae.
Drug-induced liver injury (DILI) is one of the major safety concerns in drug development. Although various toxicological studies assessing DILI risk have been developed, these methods were not ...sufficient in predicting DILI in humans. Thus, developing new tools and approaches to better predict DILI risk in humans has become an important and urgent task. In this study, we aimed to develop a computational model for assessment of the DILI risk with using a larger scale human dataset and Naïve Bayes classifier. The established Naïve Bayes prediction model was evaluated by 5-fold cross validation and an external test set. For the training set, the overall prediction accuracy of the 5-fold cross validation was 94.0 %. The sensitivity, specificity, positive predictive value and negative predictive value were 97.1, 89.2, 93.5 and 95.1 %, respectively. The test set with the concordance of 72.6 %, sensitivity of 72.5 %, specificity of 72.7 %, positive predictive value of 80.4 %, negative predictive value of 63.2 %. Furthermore, some important molecular descriptors related to DILI risk and some toxic/non-toxic fragments were identified. Thus, we hope the prediction model established here would be employed for the assessment of human DILI risk, and the obtained molecular descriptors and substructures should be taken into consideration in the design of new candidate compounds to help medicinal chemists rationally select the chemicals with the best prospects to be effective and safe.
Bell peppers are valued for their plentiful vitamin C and nutritional content. Pepper fruits are susceptible to cold storage, which leads to chilling injury (CI); however, the crucial metabolic ...product and molecular basis response to cold stress have not been elucidated definitely yet. To comprehensively understand the gene regulation network and CI mechanisms in response to cold stress on a molecular level, we performed high-throughput RNA-Seq analysis to investigate genome-wide expression profiles in bell peppers at different storage temperatures (4 °C and 10 °C). A total of 61.55 Gb of clean data were produced; 3863 differentially expressed genes (DEGs) including 1669 up-regulated and 2194 down-regulated were annotated and classified between the CI group and control. Together, a total of 41 cold-induced transcription factor families comprising 250 transcription factors (TFs) were identified. Notably, numerous DEGs involved in biomembrane stability, dehydration and osmoregulation, and plant hormone signal transduction processes were discovered. The transcriptional level of 20 DEGs was verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Our results present transcriptome profiles of bell peppers in response to cold stress; the data obtained may be useful for the identification of key candidate genes and elucidation of the mechanisms underlying membrane damage during chilling injury.
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•Genome-wide expression profiles of bell peppers at 4 °C and 10 °C were obtained.•3863 differentially expressed genes were identified in response to chilling injury.•41 cold-induced transcription factor families were identified.•The findings reveal how cold stress affects bell pepper biochemistry.
Sanghuangporus
sp., a medicinal and edible homologous macrofungus known as ‘forest gold’, which has good effects on antitumor, hypolipidemia and the treatment of gynecological diseases. However, the ...natural resources of fruiting body are on the verge of depletion due to its long growth cycle and over exploitation. The growth and metabolism of macrofungi are known to depend on the diverse bacterial community. Here, we characterized the diversity and potential function of bacteria inhabiting in the fruiting body of the most widely applied
S. vaninii
using a combination method of high-throughput sequencing with pure culturing for the first time, and tested the biological activities of bacterial isolates, of which Illumina NovaSeq provided a more comprehensive results on the bacterial community structure. Total 33 phyla, 82 classes, 195 orders, 355 families, 601 genera and 679 species were identified in the fruiting body, and our results revealed that the community was predominated by the common Proteobacteria, Gammaproteobacteria, Burkholderiales, Methylophilaceae (partly consistent with pure-culturing findings), and was dominated by the genera of distinctive
Methylotenera
and
Methylomonas
(yet-uncultured taxa). Simultaneously, the functional analysis showed that companion bacteria were involved in the pathways of carbohydrate transport and metabolism, metabolism of terpenoids and polyketides, cell wall/membrane/envelope biogenesis, etc. Hence, it was inferred that bacteria associated with fruiting body may have the potential to adjust the growth, development and active metabolite production of host
S. vaninii
combined with the tested results of indole-3-acetic acid and total antioxidant capacity. Altogether, this report first provided new findings which can be inspiring for further in-depth studies to exploit bioactive microbial resources for increased production of
Sanghuangporus
, as well as to explore the relationship between medicinal macrofungi and their associated endophytes.
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