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1.
Curr Opin Plant Biol ; 65: 102168, 2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-35016076

RESUMO

Grasses are ubiquitous in our daily lives, with gramineous cereal crops such as maize, rice, and wheat constituting a large proportion of our daily staple food intake. Evolutionary forces, especially over the past ∼20 million years, have shaped grass adaptability, inflorescence architecture, and reproductive success. Here, we provide basic information on grass evolution and inflorescence structures mainly related to two inflorescence types: branched panicle- and spike-type inflorescences, the latter of which has highly modified branching. We summarize and compare known genetic pathways underlying each infloresecence type and discuss how the maize RAMOSA, rice ABERRANT PANICLE ORGANIZATION, and Triticeae COMPOSITUM pathways are regulated. Our analyses might lay the foundation for understanding species-specific gene regulatory networks that could result in improved sink capacities.

2.
Small ; : e2106866, 2022 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-35023615

RESUMO

The continuous, real-time, and concurrent detection of multiple biomarkers in bodily fluids is of high significance for advanced healthcare. While active, semiconductor-based biochemical sensing platforms provide levels of functionality exceeding those of their conventional passive counterparts, the stability of the active biosensors in the liquid environment for continuous operation remains a challenging topic. This work reports the development of a class of flexible and waterproof field-effect transistor arrays for multiplexed biochemical sensing. In this design, monolithic, ultrathin, dense, and low defect nanomembranes consisting of monocrystalline Si and thermally grown SiO2 simultaneously serve as high-performance backplane electronics for signal transduction and stable biofluid barriers with high structural integrity due to the high formation temperature. Coupling the waterproof transistors with various ion-selective membranes through the gate electrode allows for sensitive and selective detection of multiple ions as biomarkers for traumatic brain injury. The study also demonstrates a similar encapsulation structure which enables the design of waterproof amperometric sensors based on this materials strategy and integration scheme. Overall, key advantages in flexibility, stability, and multifunctionality highlight the potential of using such electronic sensing platforms for concurrent, continuous detection of various neurological biomarkers, proving a promising approach for early diagnosis and intervention of chronic diseases.

3.
Biosens Bioelectron ; 195: 113683, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34619484

RESUMO

To understand the physio-pathological state of patients suffering from chronic diseases, scientists and clinicians need sensors to track chemical signals in real-time. However, the lack of stable, safe, and scalable biochemical sensing platforms capable of continuous operation in liquid environments imposes significant challenges in the timely diagnosis, intervention, and treatment of chronic conditions. This work reports a novel strategy for fabricating waterproof and flexible biochemical sensors with active electronic components, which feature a submicron encapsulation layer derived from monocrystalline Si nanomembranes with a high structural integrity due to the high formation temperature (>1000 °C). The ultrathin, yet dense and low-defect encapsulation enables continuous operation of field-effect transistors in biofluids for chemical sensing. The excellent stability in liquid environment and pH sensing performance of such transistors suggest their great potential as the foundation of waterproof and scalable biochemical sensors with active functionalities in the future. The understandings, knowledge base, and demonstrations for pH sensing reported here set the stage for the next generation long-term biosensing with a broad applicability in biomedical research, food science, and advanced healthcare.


Assuntos
Técnicas Biossensoriais , Eletrônica , Humanos , Concentração de Íons de Hidrogênio , Transistores Eletrônicos
5.
Cancer Cell Int ; 21(1): 643, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34861873

RESUMO

BACKGROUND: Human papillomavirus (HPV) E6/E7 mRNA in situ hybridization (HPV E6/E7 RNAscope) appears to be a sensitive and specific technique in detecting transcriptionally active HPV. We aimed to examine the diagnostic utility of this technique in endocervical adenocarcinoma (ECA), to explore the prognostic factors for ECA patients and develop a clinically useful nomogram based on clinicopathological parameters to predict it. METHODS: We retrospectively analyzed 200 patients with ECA who had undergone surgery at Sun Yat-sen University Cancer Center from 2010 and 2014. The diagnostic performance of HPV E6/E7 RNAscope were evaluated by receiver operating characteristic (ROC) curve. A prognostic nomogram model including HPV E6/E7 RNAscope was generated based on multivariate Cox regression analysis, then we compared the predictive accuracy of the prognostic model with FIGO staging and treatment using concordance index (C-index), time-dependent ROC (tdROC), and decision curve analysis (DCA). RESULTS: The sensitivity and specificity of HPV E6/E7 RNAscope for distinguishing HPV-associated adenocarcinoma (HPVA) from non-HPV-associated adenocarcinoma (NHPVA) in the whole cohort were 75.8% and 80%, respectively. According the univariate analysis and multivariate logistic regression analysis, age, lymphovascular invasion (LVI), lymph node involvement (LNI), and HPV E6/E7 RNAscope were valuable predictive factors for OS. These parameters were incorporated into the nomogram model (nomogram A) compared with FIGO stage and treatment. The C-index of nomogram A for predicting OS was 0.825, which was significantly higher than FIGO stage (C-index = 0.653, p = 0.002) and treatment (C-index = 0.578, p < 0.001). CONCLUSIONS:  HPV E6/E7 RNAscope is highly specific for ECA, and the 4-variable nomogram showed more accurate prognostic outcomes in patients with ECA.

6.
Theriogenology ; 180: 53-62, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34952391

RESUMO

Testosterone is an important steroid hormone that is indispensable for male sexual development and the reproductive system. Leydig cells (LCs), where autophagy is extremely active, reside in the testicular interstitium and are the major sites of testosterone production. However, the ultrastructural characteristics and the functional role of autophagy in LCs of livestock remain unknown. In this study, the LCs of the dairy goats were investigated to identify the steroidogenic activity and autophagy levels at different ages of development by light microscopy, immunohistochemistry (IHC), immunofluorescence (IF), and transmission electron microscopy (TEM). Morphological results showed that the steroidogenic activity (3ß-HSD staining) and ultrastructural characteristics of the LCs were changed with increasing age. TEM results demonstrated that the organelles involved in testosterone synthesis, e.g., smooth endoplasmic reticulum, mitochondria, and lipid droplets, were abundantly distributed within the cytoplasm of LCs in pubertal and adult testes. Moreover, autophagy activity was enhanced in the testes at pubertal and adult stages compared with that at the juvenile stage. Several different autophagic vacuoles, including pre-autophagosomes, autophagosomes, and autolysosomes, were observed within the cytoplasm of LCs from pubertal and adult testes. However, immunofluorescent staining and TEM results showed that no typical lipophagic or mitophagic vacuoles were observed in the cytoplasm of LCs. Furthermore, primary LCs from dairy goats were used to study the effect of autophagy on testosterone production. After treatment with 3-methyladenine (3-MA, an autophagy inhibitor), the primary LCs decreased testosterone production. In contrast, treatment with rapamycin (an autophagy activator), enhanced steroidogenesis in LCs. Collectively, these in vivo and in vitro results suggested that autophagy activity is related to steroidogenesis in LCs of dairy goats, which may ultimately influence the spermatogenesis and fertility of these animals.

7.
Front Psychiatry ; 12: 777236, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34955923

RESUMO

Background: Anxiety disorders (ADs) are a group of disorders with a high disability rate and bring a huge social burden. In China, information on future trends in the disability among community ADs patients and its determinants are rare. The objectives of this study are to describe the future trends in the disability among ADs patients living in community and to investigate the determinants of the disability. Methods: Participants diagnosed with 12-month ADs in the China Mental Health Survey (CMHS) were followed up by telephone from April to June 2018 to assess the future trends in the disability in a 5-year interval using the World Health Organization's Disability Assessment Schedule 2.0. The disability rate was reported and its determinants were analyzed by complex sample design multivariate logistic regression. Results: Totally 271 patients were interviewed by telephone and 33 informants finished proxy interviews. The disability rates were 45.9% and 14.3% among ADs patients at baseline and during the follow-up. Patients with general anxiety disorder (GAD) or agoraphobia with/without panic disorder (AGP) had the lower decrease and higher disability during the follow-up than patients with other subtypes. Patients aged in middle age (aged 40-49 years old, OR = 11.12, 95% CI: 4.16-29.72), having disability at baseline (OR = 7.18, 95% CI: 1.37-37.73), having comorbidity with three or more physical diseases (OR = 9.27, 95% CI: 2.48-34.71), and having comorbidity with other mental disorders (OR = 3.97, 95% CI: 1.13-13.96) had higher disability during the follow-up. Conclusions: The disability rate tends to decrease among ADs patients living in communities. Treatment priority should be given for ADs patients with disability and those in middle age. Treatments for the comorbidity of other mental disorders or physical diseases should be considered when treating anxiety.

8.
Nat Commun ; 12(1): 5886, 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34620848

RESUMO

Interlayer spacing is expected to influence the properties of multilayer two-dimensional (2D) materials. However, the ability to non-destructively regulate the interlayer spacing bidirectionally and reversibly is challenging. Here we report the preparation of 2D materials with tunable interlayer spacing by introducing active sites (Ce ions) in 2D materials to capture and immobilize Pt single atoms. The strong chemical interaction between active sites and Pt atoms contributes to the intercalation behavior of Pt atoms in the interlayer of 2D materials and further promotes the formation of chemical bonding between Pt atom and host materials. Taking cerium-embedded molybdenum disulfide (MoS2) as an example, intercalation of Pt atoms enables interlayer distance tuning via an electrochemical protocol, leading to interlayer spacing reversible and linear compression and expansion from 6.546 ± 0.039 Å to 5.792 ± 0.038 Å (~11 %). The electronic property evolution with the interlayer spacing variation is demonstrated by the photoluminescence (PL) spectra, delivering that the well-defined barrier between the multilayer and monolayer layered materials can be artificially designed.

9.
Nanotechnology ; 33(3)2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34627132

RESUMO

As a two-dimensional (2D) layered semiconductor, lead iodide (PbI2) has been widely used in optoelectronics owing to its unique crystal structure and distinctive optical and electrical properties. A comprehensive understanding of its optical performance is essential for further application and progress. Here, we synthesized regularly shaped PbI2platelets using the chemical vapor deposition method. Raman scattering spectroscopy of PbI2platelets was predominantly enhanced when the laser radiated at the edge according to Raman mapping spectroscopy. Combining the outcome of polarized Raman scattering spectroscopy and finite-difference time domain simulation analysis, the Raman enhancement was proven to be the consequence of the enhancement effects inherent to the high refractive index contrast waveguide, which is naturally formed in well-defined PbI2platelets. Because of the enlarged excited area determined by the increased propagation length of the laser in the PbI2platelet formed waveguide, the total Raman enhancements are acquired rather than a localized point enhancement. Finally, the Raman enhancement factor is directly related to the thickness of the PbI2platelet, which further confirms the waveguide-enhanced edge Raman. Our investigation of the optical properties of PbI2platelets offers reference for potential 2D layered-related optoelectronic applications.

11.
Front Microbiol ; 12: 699235, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34690947

RESUMO

Zeaxanthin is vital to human health; thus, its production has received much attention, and it is also an essential precursor for the biosynthesis of other critical carotenoids such as astaxanthin and crocetin. Yarrowia lipolytica is one of the most intensively studied non-conventional yeasts and has been genetically engineered as a cell factory to produce carotenoids such as lycopene and ß-carotene. However, zeaxanthin production by Y. lipolytica has not been well investigated. To fill this gap, ß-carotene biosynthesis pathway has been first constructed in this study by the expression of genes, including crtE, crtB, crtI, and carRP. Three crtZ genes encoding ß-carotene hydroxylase from different organisms were individually introduced into ß-carotene-producing Y. lipolytica to evaluate their performance for producing zeaxanthin. The expression of crtZ from the bacterium Pantoea ananatis (formerly Erwinia uredovora, Eu-crtZ) resulted in the highest zeaxanthin titer and content on the basis of dry cell weight (DCW). After verifying the function of Eu-crtZ for producing zeaxanthin, the high-copy-number integration into the ribosomal DNA of Y. lipolytica led to a 4.02-fold increase in the titer of zeaxanthin and a 721% increase in the content of zeaxanthin. The highest zeaxanthin titer achieved 21.98 ± 1.80 mg/L by the strain grown on a yeast extract peptone dextrose (YPD)-rich medium. In contrast, the highest content of DCW reached 3.20 ± 0.11 mg/g using a synthetic yeast nitrogen base (YNB) medium to culture the cells. Over 18.0 g/L of citric acid was detected in the supernatant of the YPD medium at the end of cultivation. Furthermore, the zeaxanthin-producing strains still accumulated a large amount of lycopene and ß-carotene. The results demonstrated the potential of a cell factory for zeaxanthin biosynthesis and opened up an avenue to engineer this host for the overproduction of carotenoids.

12.
Plant Cell Rep ; 40(12): 2453-2456, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34554293

RESUMO

KEY MESSAGE: Here, we developed a reliable protocol for the fast and efficient gene-edited Anliu sweet orange plants production. The application of in vitro shoot grafting technology significantly reduced the growth cycle of transgenic seedlings, and the survival rate of cleft grafting was more than 90%. In addition, the mutation efficiency of the grafted geneedited sweet orange was significantly improved by short-term heat stress treatments. Thus, the combination strategy of grafting and heat stress treatments provided a reference for the fast and efficient multiplex gene editing of sweet orange.

13.
Nat Commun ; 12(1): 5516, 2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34535678

RESUMO

Understanding the atomic structure and structural instability of organic-inorganic hybrid perovskites is the key to appreciate their remarkable photoelectric properties and understand failure mechanism. Here, using low-dose imaging technique by direct-detection electron-counting camera in a transmission electron microscope, we investigate the atomic structure and decomposition pathway of CH3NH3PbI3 (MAPbI3) at the atomic scale. We successfully image the atomic structure of perovskite in real space under ultra-low electron dose condition, and observe a two-step decomposition process, i.e., initial loss of MA+ followed by the collapse of perovskite structure into 6H-PbI2 with their critical threshold doses also determined. Interestingly, an intermediate phase (MA0.5PbI3) with locally ordered vacancies can robustly exist before perovskite collapses, enlightening strategies for prevention and recovery of perovskite structure during the degradation. Associated with the structure evolution, the bandgap gradually increases from ~1.6 eV to ~2.1 eV. In addition, it is found that C-N bonds can be readily destroyed under irradiation, releasing NH3 and HI and leaving hydrocarbons. These findings enhance our understanding of the photoelectric properties and failure mechanism of MAPbI3, providing potential strategies into material optimization.

14.
Front Plant Sci ; 12: 713890, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34484276

RESUMO

As an important component, 1,000 kernel weight (TKW) plays a significant role in the formation of yield traits of wheat. Kernel size is significantly positively correlated to TKW. Although numerous loci for kernel size in wheat have been reported, our knowledge on loci for kernel area (KA) and kernel circumference (KC) remains limited. In the present study, a recombinant inbred lines (RIL) population containing 371 lines genotyped using the Wheat55K SNP array was used to map quantitative trait loci (QTLs) controlling the KA and KC in multiple environments. A total of 54 and 44 QTLs were mapped by using the biparental population or multienvironment trial module of the inclusive composite interval mapping method, respectively. Twenty-two QTLs were considered major QTLs. BLAST analysis showed that major and stable QTLs QKc.sau-6A.1 (23.12-31.64 cM on 6A) for KC and QKa.sau-6A.2 (66.00-66.57 cM on 6A) for KA were likely novel QTLs, which explained 22.25 and 20.34% of the phenotypic variation on average in the 3 year experiments, respectively. Two Kompetitive allele-specific PCR (KASP) markers, KASP-AX-109894590 and KASP-AX-109380327, were developed and tightly linked to QKc.sau-6A.1 and QKa.sau-6A.2, respectively, and the genetic effects of the different genotypes in the RIL population were successfully confirmed. Furthermore, in the interval where QKa.sau-6A.2 was located on Chinese Spring and T. Turgidum ssp. dicoccoides reference genomes, only 11 genes were found. In addition, digenic epistatic QTLs also showed a significant influence on KC and KA. Altogether, the results revealed the genetic basis of KA and KC and will be useful for the marker-assisted selection of lines with different kernel sizes, laying the foundation for the fine mapping and cloning of the gene(s) underlying the stable QTLs detected in this study.

15.
Biotechnol Biofuels ; 14(1): 176, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488855

RESUMO

BACKGROUND: The efficiency of biological systems as an option for pretreating lignocellulosic biomass has to be improved to make the process practical. Fungal treatment with manganese (Mn) addition for improving lignocellulosic biomass fractionation and enzyme accessibility were investigated in this study. The broad-spectrum effect was tested on two different types of feedstocks with three fungal species. Since the physicochemical and structural properties of biomass were the main changes caused by fungal degradation, detailed characterization of biomass structural features was conducted to understand the mechanism of Mn-enhanced biomass saccharification. RESULTS: The glucose yields of fungal-treated poplar and wheat straw increased by 2.97- and 5.71-fold, respectively, after Mn addition. Particularly, over 90% of glucose yield was achieved in Mn-assisted Pleurotus ostreatus-treated wheat straw. A comparison study using pyrolysis gas chromatography mass spectrometry (Py-GC/MS) and two-dimensional 1H-13C heteronuclear single quantum coherence (2D HSQC) nuclear magnetic resonance (NMR) spectroscopy was conducted to elucidate the role of Mn addition on fungal disruption of the cross-linked structure of whole plant cell wall. The increased Cα-oxidized products was consistent with the enhanced cleavage of the major ß-O-4 ether linkages in poplar and wheat straw lignin or in the wheat straw lignin-carbohydrate complexes (LCCs), which led to the reduced condensation degree in lignin and decreased lignin content in Mn-assisted fungal-treated biomass. The correlation analysis and principal component analysis (PCA) further demonstrated that Mn addition to fungal treatment enhanced bond cleavage in lignin, especially the ß-O-4 ether linkage cleavage played the dominant role in removing the biomass recalcitrance and contributing to the glucose yield enhancement. Meanwhile, enhanced deconstruction of LCCs was important in reducing wheat straw recalcitrance. The findings provided not only mechanistic insights into the Mn-enhanced biomass digestibility by fungus, but also a strategy for improving biological pretreatment efficiency of lignocellulose. CONCLUSION: The mechanism of enhanced saccharification of biomass by Mn-assisted fungal treatment mainly through Cα-oxidative cleavage of ß-O-4 ether linkages further led to the decreased condensation degree in lignin, as a result, biomass recalcitrance was significantly reduced by Mn addition.

16.
Cancer Cell Int ; 21(1): 518, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34583688

RESUMO

BACKGROUND: There is a lack of effective treatments for recurrent or metastatic nasopharyngeal carcinoma (RM-NPC). Furthermore, the response rate of NPC patients to programmed death 1 (PD-1) inhibitors is approximately 20% to 30%. Thus, we aimed to explore reliable and minimally invasive prognostic indicators to predict the efficacy of PD-1 inhibitors combination therapy in RM-NPC. METHODS: The serum markers of 160 RM-NPC patients were measured before and three weeks after the first anti-PD-1 treatment. The least absolute shrinkage and selection operator (LASSO) logistic regression was carried out to select dynamic serum indicators and construct a prediction model. Furthermore, we carried out univariate, multivariate, nomogram and survival analyses to identify independent prognostic factors that were associated with 1-year progression-free survival (PFS). RESULTS: Based on two markers that were screened by Lasso logistic regression, we constructed a risk score prediction model for the prediction of anti-PD-1 efficacy at 8-12 weeks with an AUC of 0.737 in the training cohort and 0.723 in the validation cohort. Risk score and metastases were included in the nomogram, and the Kaplan-Meier survival curves demonstrated that the high-risk group has shorter PFS compared to the low-risk group. The concordance index (C-index) of the nomogram for PFS is higher than that of the TNM stage in the training and validation cohort. CONCLUSION: We proposed a strategy to monitor dynamic changes in the biochemistry markers and emphasized their importance as potential prognostic biomarkers for the treatment of advanced NPC treated with PD-1 inhibitors. Our risk score prediction model was based on the dynamic change of LDH and AST/ALT, which has predictive and prognostic value for NPC patients who were treated with PD-1 inhibitors.

17.
Ther Clin Risk Manag ; 17: 817-822, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34413648

RESUMO

Introduction: Intractable epistaxis refers to deep occult bleeding and uncontrolled persistent bleeding. Effective treatment can only be implemented if the bleeding site is quickly identified and the underlying disease controlled. Objective: The relationship between the bleeding site and the pathogenic factors of intractable epistaxis was analyzed to further strengthen the prevention and treatment of intractable epistaxis by outpatient doctors, family doctors and otolaryngologists. Through accurate search and minimally invasive hemostasis, it helped optimize the treatment plan for intractable epistaxis. Methods: This study retrospectively analyzed the clinical data of 90 patients with intractable epistaxis who were admitted to hospital from January 2016 to December 2017. Chi-square test was used to analyze the relationship between intractable epistaxis site with underlying disease, gender and age. Results: The distribution of intractable epistaxis was associated with hypertension (χ 2=13.76, P=0.017). The incidence of hypertension was the highest in the olfactory sulcus of the middle turbinate region at about 60%. In addition, age was also identified as a factor that affects the distribution of intractable epistaxis (χ 2=21.95, P=0.02). The incidence of intractable epistaxis on the vault of inferiornasal meatus region was highest (63%) in young patients. On the other hand, the olfactory sulcus of the middle turbinate region accounted for the highest incidence in the middle-aged and elderly group (66.7%). There was no obvious relation between the bleeding site of intractable epistaxis with diabetes, cardiovascular disease, chronic sinusitis and allergic rhinitis. Conclusion: The bleeding site of intractable epistaxis is related to hypertension and age. This may improve the identification of the site of intractable epistaxis for timely implementation of treatment and can further strengthen the prevention and treatment of intractable epistaxis in outpatients or family doctors.

18.
Theor Appl Genet ; 134(12): 3895-3909, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34436627

RESUMO

KEY MESSAGE: The genetic architecture of five flag leaf morphology traits was dissected by the functional haplotype-based GWAS and a standard SNP-based GWAS in a diverse population consisting of 197 varieties. Flag leaf morphology (FLM) is a critical factor affecting plant architecture and grain yield in wheat. The genetic architecture of FLM traits has been extensively studied with QTL mapping in bi-parental populations, while few studies exploited genome-wide association studies (GWAS) in diverse populations. In this study, a panel of 197 elite and historical varieties from China was evaluated for five FLM traits including the length (FLL), width (FLW), ratio (FLR), area (FLA) and angle (FLANG) as well as yield in nine environments. Based on the phenotypic correlation between yield and FLL (-0.43), FLA (- 0.32) and FLW (0.11), an empirical FLM index combining the three FLM traits proved to be a good predictor for yield. Two GWAS approaches were applied to dissect the genetic architecture of five FLM traits with a Wheat660K SNP array. The functional haplotype-based GWAS revealed 6, 5 and 7 QTL for FLANG, FLL and FLR, respectively, whereas two QTL for FLW and one for FLR were identified by the standard SNP-based GWAS. Due to co-localization, there were 18 independent QTL and 10 of them were close to known ones. One co-localized QTL on chromosome 5A was associated with FLL, FLANG and FLR. Moreover, both GWAS approaches identified a novel QTL for FLR on chromosome 6B which was not reported in previous studies. This study provides new insights into the relationship between FLM and yield and broadens our understanding of the genetic architecture of FLM traits in wheat.

19.
Trends Biotechnol ; 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34325913

RESUMO

Commercial applications of microalgae for biochemicals and fuels are hampered by their high production costs, and the use of conventional carbon supplies is a key reason. Bicarbonate has been proposed as an alternative carbon source due to its potential advantages in lower carbon supply costs, convenience for photobioreactor development, biomass harvesting, and labor and energy savings. We review recent progress in bicarbonate-based microalgae cultivation, which validated previous assumptions, suggested further advantages, and demonstrated potential to significantly reduce production cost. Future research should focus on improving production efficiency and reducing energy inputs, including optimizing photobioreactor design, comprehensive utilization of natural power, and automation in production systems.

20.
Microorganisms ; 9(5)2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-34063406

RESUMO

Research on enhancing lutein content in microalgae has made significant progress in recent years. However, strategies are needed to address the possible limitations of microalgae as practical lutein producers. The capacity of lutein sequestration may determine the upper limit of cellular lutein content. The preliminary estimation presented in this work suggests that the lutein sequestration capacity of the light-harvesting complex (LHC) of microalgae is most likely below 2% on the basis of dry cell weight (DCW). Due to its nature as a structural pigment, higher lutein content might interfere with the LHC in fulfilling photosynthetic functions. Storing lutein in a lipophilic environment is a mechanism for achieving high lutein content but several critical barriers must be overcome such as lutein degradation and access to lipid droplet to be stored through esterification. Understanding the mechanisms underlying lipid droplet biogenesis in chloroplasts, as well as carotenoid trafficking through chloroplast membranes and carotenoid esterification, may provide insight for new approaches to achieve high lutein contents in algae. In the meantime, building the machinery for esterification and sequestration of lutein and other hydroxyl-carotenoids in model microorganisms, such as yeast, with synthetic biology technology provides a promising option.

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