Recombinant protein production emerged in the early 1980s with the development of genetic engineering tools, which represented a compelling alternative to protein extraction from natural sources. ...Over the years, a high level of heterologous protein was made possible in a variety of hosts ranging from the bacteria
to mammalian cells. Recombinant protein importance is represented by its market size, which reached $1654 million in 2016 and is expected to reach $2850.5 million by 2022. Among the available hosts, yeasts have been used for producing a great variety of proteins applied to chemicals, fuels, food, and pharmaceuticals, being one of the most used hosts for recombinant production nowadays. Historically,
was the dominant yeast host for heterologous protein production. Lately, other yeasts such as
sp.,
, and
have emerged as advantageous hosts. In this review, a comparative analysis is done listing the advantages and disadvantages of using each host regarding the availability of genetic tools, strategies for cultivation in bioreactors, and the main techniques utilized for protein purification. Finally, examples of each host will be discussed regarding the total amount of protein recovered and its bioactivity due to correct folding and glycosylation patterns.
Gold miners working illegally in mines live in poor health conditions related to their strenuous work and precarious housing. Therefore, they are at higher risk for infectious diseases. American ...tegumentary leishmaniasis (ATL) appears to be of great concern to the population living in the Guiana Shield region. Our aim was to describe their demographic characteristics, the clinical features of cutaneous leishmaniasis (CL), and the frequency of Leishmania infection in people working in illegal gold mines in French Guiana. A cross-sectional study was carried out from October to December 2019 in Oiapoque city, Amapá, Brazil. Indeed, many gold miners working in French Guiana are originally from Brazil, and from Oiapoque in particular. A total of 105 participants from 31 different mining sites in French Guiana were recruited. Suspected Leishmania infection was confirmed by the following: detection of kDNA in blood or the lesion site; detection of specific antibodies; or detection of IFN-gamma release after blood incubation with leishmanial antigens (IGRA-Leish). Nine active CL cases, 38 healed ATL (hATL) and 58 cases with no history of ATL (noATL), were identified. Only half of the treated hATL (50.0%; n = 14) reported having been assisted by a health care unit and the others treated themselves. PCR-kDNA for Leishmania was positive in the blood of 100% of CL cases. Curiously, blood PCR-kDNA was positive in 13% of hATL patients and in 15.5% of noATL patients. The IGRA-Leish was positive in 60.5% of hATL and in 37.9% of noATL. In addition to scars suggestive of CL, 71% of hATL had laboratory evidence of Leishmania infection. Restriction fragment polymorphism (RFLP) of the hsp70 gene identified a sympatric circulation of L. (V.) guyanensis (n = 4), L. (V.) braziliensis (n = 1), L. (L.) amazonensis (n = 2), L. (V.) shawi (n = 1) and L. (V.) naiffi/shawi (n = 1). Taking the laboratory techniques and the clinical evaluations together, 76% (n = 80) of the 105 participants had evidence of Leishmania infection. These results suggests that illegal gold miners working in French Guiana are at high risk for infection with different species of Leishmania, but their illegal condition and remoteness make it difficult for them to access health services.
The green synthesis of silver nanoparticles (AgNPs) can be developed using safe and environmentally friendly routes, can replace potentially toxic chemical methods, and can increase the scale of ...production. This study aimed to synthesize AgNPs from aqueous extracts of guarana (Paullinia cupana) leaves and flowers, collected in different seasons of the year, as a source of active biomolecules capable of reducing silver ions (Ag+) and promoting the stabilization of colloidal silver (Ag0). The plant aqueous extracts were characterized regarding their metabolic composition by liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS/MS), phenolic compound content, and antioxidant potential against free radicals. The synthesized AgNPs were characterized by UV/Vis spectrophotometry, dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and scanning electron microscopy coupled to energy-dispersive X-ray spectrometry (EDX). The results demonstrated that the chemical characterization indicated the presence of secondary metabolites of many classes of compounds in the studied aqueous extracts studied, but alkaloids and flavonoids were predominant, which are widely recognized for their antioxidant capabilities. It was possible to notice subtle changes in the properties of the nanostructures depending on parameters such as seasonality and the part of the plant used, with the AgNPs showing surface plasmon resonance bands between 410 and 420 nm using the leaf extract and between 440 and 460 nm when prepared using the flower extract. Overall, the average hydrodynamic diameters of the AgNPs were similar among the samples (61.98 to 101.6 nm). Polydispersity index remained in the range of 0.2 to 0.4, indicating that colloidal stability did not change with storage time. Zeta potential was above −30 mV after one month of analysis, which is adequate for biological applications. TEM images showed AgNPs with diameters between 40.72 to 48.85 nm and particles of different morphologies. EDX indicated silver content by weight between 24.06 and 28.81%. The synthesized AgNPs exhibited antimicrobial efficacy against various pathogenic microorganisms of clinical and environmental interest, with MIC values between 2.12 and 21.25 µg/mL, which is close to those described for MBC values. Therefore, our results revealed the potential use of a native species of plant from Brazilian biodiversity combined with nanotechnology to produce antimicrobial agents.
The prospection of new degrading enzymes of the plant cell wall has been the subject of many studies and is fundamental for industries, due to the great biotechnological importance of achieving a ...more efficient depolymerization conversion from plant polysaccharides to fermentable sugars, which are useful not only for biofuel production but also for various bioproducts. Thus, we explored the shotgun metagenome data of a bacterial community (CB10) isolated from sugarcane bagasse and recovered three metagenome-assembled genomes (MAGs). The genomic distance analyses, along with phylogenetic analysis, revealed the presence of a putative novel
Chitinophaga
species, a
Pandoraea nosoerga
, and
Labrys
sp. isolate. The isolation process for each one of these bacterial lineages from the community was carried out in order to relate them with the MAGs. The recovered draft genomes have reasonable completeness (72.67–100%) and contamination (0.26–2.66%) considering the respective marker lineage for
Chitinophaga
(Bacteroidetes),
Pandoraea
(Burkholderiales), and
Labrys
(Rhizobiales). The
in-vitro
assay detected cellulolytic activity (endoglucanases) only for the isolate
Chitinophaga
, and its genome analysis revealed 319 CAZymes, of which 115 are classified as plant cell wall degrading enzymes, which can act in fractions of hemicellulose and pectin. Our study highlights the potential of this
Chitinophaga
isolate provides several plant-polysaccharide-degrading enzymes.
Hyaluronic acid, or HA, is a rigid and linear biopolymer belonging to the class of the glycosaminoglycans, and composed of repeating units of the monosaccharides glucuronic acid and ...N-acetylglucosamine. HA has multiple important functions in the human body, due to its properties such as bio-compatibility, lubricity and hydrophilicity, it is widely applied in the biomedical, food, health and cosmetic fields. The growing interest in this molecule has motivated the discovery of new ways of obtaining it. Traditionally, HA has been extracted from rooster comb-like animal tissues. However, due to legislation laws HA is now being produced by bacterial fermentation using Streptococcus zooepidemicus, a natural producer of HA, despite it being a pathogenic microorganism. With the expansion of new genetic engineering technologies, the use of organisms that are non-natural producers of HA has also made it possible to obtain such a polymer. Most of the published reviews have focused on HA formulation and its effects on different body tissues, whereas very few of them describe the microbial basis of HA production. Therefore, for the first time this review has compiled the molecular and genetic bases for natural HA production in microorganisms together with the main strategies employed for heterologous production of HA.
Hyaluronic Acid (HA) is a biopolymer composed by the monomers Glucuronic Acid (GlcUA) and N-Acetyl Glucosamine (GlcNAc). It has a broad range of applications in the field of medicine, being marketed ...between USD 1000-5000/kg. Its primary sources include extraction of animal tissue and fermentation using pathogenic bacteria. However, in both cases, extensive purification protocols are required to prevent toxin contamination. In this study, aiming at creating a safe HA producing microorganism, the generally regarded as safe (GRAS) yeast
is utilized. Initially, the
(UDP-Glucose dehydrogenase) gene from
(xl
) is inserted. After that, four strains are constructed harboring different
(HA Synthase) genes, three of humans (hs
, hs
, and hs
) and one with the bacteria
(pm
). Transcript values analysis confirms the presence of
genes only in three strains. HA production is verified by scanning electron microscopy in the strain containing the pmHAS isoform. The pmHAS strain is grown in a 1.3 l bioreactor operating in a batch mode, the maximum HA levels are 1.89 g/L with a molecular weight of 2.097 MDa. This is the first study that reports HA production in
and it has the highest HA titers reported among yeast.
•The chemical weathering intensity in Maritime Antarctica is modeled.•A geophysical survey and lithological characteristics as input data.•Proximal geophysical sensors and terrain attributes are ...combined for modeling.•Use of leave-one-out-cross-validation method in modeling.•Periglacial processes control the distribution of geophysical variables.
The chemical weathering intensity in Antarctica is underestimated. As the chemical weathering intensity increases, hydrological, geochemical and geophysical changes occur in the different environmental spheres and at their interfaces through reactions and energy flows. Thus, once chemical weathering rates are understood and estimated, they can be used to predict and assess changes and trends in different environmental spheres. Few studies on the chemical weathering intensity have been performed in Antarctica. We used radiometric and magnetic properties associated with terrain attributes and the chemical degree of alteration of the igneous rock to model the chemical weathering intensity in Maritime Antarctica by using machine learning. Then, we related the chemical weathering intensity and geophysical variables with periglacial processes. To do this, gamma-spectrometric and magnetic readings were carried out using proximal-field sensors at 91 points located on different lithologies in a representative area of Maritime Antarctica. A qualitative analysis of chemical alteration for the different lithologies was carried out based on field observations and rock properties, and the levels of the chemical weathering degree were established. The geophysical data associated with terrain attributes were used as input data in the modeling of the weathering intensity. Then, the levels of the rock weathering degree were used as the “y” variable in the models. The results indicated that the C5.0 algorithm had the best performance in predicting the weathering intensity, and the most important variables were eTh, 40K, 40K/eTh, 40K/eU, the magnetic susceptibility and terrain attributes. The contents of radionuclides and ferrimagnetic minerals in different lithologies, concomitantly with the intensity at which chemical weathering occurs, determine the contents of these elements. However, the stability and distribution of these elements in a cold periglacial environment are controlled by periglacial processes. The chemical weathering intensity prediction model using gamma-spectrometric and magnetic data matched the in situ estimate of the chemical degree of alteration of the rock. The pyritized andesites showed the highest intensities of weathering, followed by tuffites, diorites, andesitic basalts and basaltic andesites, and the lowest weathering intensity was shown by undifferentiated marine sediments. This work highlighted the suitability of using machine learning techniques and proximal-field sensor data to study the chemical weathering process on different rocks in these important and inhospitable areas of the cryosphere system.
Abstract This systematic review evaluated the potential utility of platelet-rich fibrin (PRF) in bone repair in animals. The question is: can the use of PRF in bone defects in healthy rats induce ...bone repair compared to clot? This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (Prisma). The protocol was registered with Prospero (CRD 42020162319). The literature search involved nine databases, including grey literature. All studies evaluated the bone defects created in rats filled with PRF and clots (control). Biomaterial evaluation was also performed in this study. The risk of bias was assessed using the Systematic Review Center for Laboratory Animal Experimentation (Syrcle) tool for animal studies. A meta-analysis of quantitative data was performed to estimate the effect of PRF on bone repair in rats. Heterogeneity among the studies was assessed using the I2 statistic. The literature search retrieved 685 studies, 10 of which fulfilled the eligibility criteria, and 4 were included in the quantitative assessment. Analysis of the risk of bias revealed that most studies had a high risk of bias in performance and detection. Meta-analysis yielded divergent results and the absence of a statistically significant effect: PRF with control (standardized mean difference 2.54, 95% confidence interval -0.80–5.89; p = 0.14). In general, study heterogeneity was high (I2 ≥ 75.0%). The quality of the studies that influenced the conclusion of the review was based on the PICO, the sources and form of the search, the study selection criteria, the form of evaluation of publication bias, the evaluation of the quality of the studies, and data extraction by two researchers. PRF did not provide significant benefits for bone repair, resulting in unpredictable effects.
Aim of the study
This study aimed to verify the relationship between personality traits and commitment to vaccination against COVID-19.
Subject or material and methods
The sample consisted of 595 ...Brazilian adults aged 18-72 years, who answered the Big Five Inventory 2 Short (BFI-2-S) and a COVID-19 Vaccine Questionnaire.
Results
Higher scores in agreeableness and openness were associated with a higher probability of adhering to the vaccination program, and higher scores in extroversion and lower scores in agreeableness were associated with poor adherence to the vaccination, anti-vaccine movement, and conspiracy beliefs against the vaccine (p ≤ .01).
Discussion
These results show the agreeableness and openness traits seem to be crucial for adherence to the vaccination program.
Conclusions
The findings indicate the importance of acknowledging agreeableness and openness traits as relevant in the adherence to the public policies programs against the COVID-19 pandemic.
Future global climate changes are expected to increase soil organic carbon (SOC) decomposition. However, the combined effect of C inputs, land use changes, and climate on SOC turnover is still ...unclear. Exploring this SOC-climate-land use interaction allows us to understand the SOC stabilization mechanisms and examine whether the soil can act as a source or a sink for CO2. The current study estimates the SOC sequestration potential in the topsoil layer of Danish agricultural lands by 2038, considering the effect of land use change and future climate scenarios using the Rothamsted Carbon (RothC) model. Additionally, we quantified the loss vulnerability of existing and projected SOC based on the soil capacity to stabilize OC. We used the quantile random forest model to estimate the initial SOC stock by 2018, and we simulated the SOC sequestration potential with RothC for a business-as-usual (BAU) scenario and a crop rotation change (LUC) scenario under climate change conditions by 2038. We compared the projected SOC stocks with the carbon saturation deficit. The initial SOC stock ranged from 10 to 181 Mg C ha−1 in different parts of the country. The projections showed a SOC loss of 8.1 Mg C ha−1 for the BAU scenario and 6 Mg C ha−1 after the LUC adoption. This SOC loss was strongly influenced by warmer temperatures and clay content. The proposed crop rotation became a mitigation measure against the negative effect of climate change on SOC accumulation, especially in sandy soils with a high livestock density. A high C accumulation in C-saturated soils suggests an increase in non-complexed SOC, which is vulnerable to being lost into the atmosphere as CO2. With these results, we provide information to prioritize areas where different soil management practices can be adopted to enhance SOC sequestration in stable forms and preserve the labile-existing SOC stocks.
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•First-national map of soil organic carbon sequestration potential for Denmark at 1 km resolution.•Climate change leads up to soil organic carbon loss by 2038 in Danish agroecosystems.•Perennial grasses in rotation with annual crops promote the soil organic carbon sequestration.•Soil organic carbon sequestration strategies must take organic carbon saturation level into account.
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