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Rice false smut caused by the biotrophic fungal pathogen Ustilaginoidea virens has become one of the most important diseases in rice. The large effector repertory in U. virens plays a crucial role in virulence. However, current knowledge of molecular mechanisms how U. virens effectors target rice immune signaling to promote infection is very limited. In this study, we identified and characterized an essential virulence effector, SCRE4 (Secreted Cysteine-Rich Effector 4), in U. virens. SCRE4 was confirmed as a secreted nuclear effector through yeast secretion, translocation assays and protein subcellular localization, as well as up-regulation during infection. The SCRE4 gene deletion attenuated the virulence of U. virens to rice. Consistently, ectopic expression of SCRE4 in rice inhibited chitin-triggered immunity and enhanced susceptibility to false smut, substantiating that SCRE4 is an essential virulence factor. Furthermore, SCRE4 transcriptionally suppressed the expression of OsARF17, an auxin response factor in rice, which positively regulates rice immune responses and resistance against U. virens. Additionally, the immunosuppressive capacity of SCRE4 depended on its nuclear localization. Therefore, we uncovered a virulence strategy in U. virens that transcriptionally suppresses the expression of the immune positive modulator OsARF17 through nucleus-localized effector SCRE4 to facilitate infection.
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Hypocreales , Oryza , Quitina/metabolismo , Cisteína/metabolismo , Hypocreales/metabolismo , Ácidos Indolacéticos/metabolismo , Oryza/genética , Oryza/microbiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Factores de Virulencia/metabolismoRESUMEN
The 2OG-Fe(II) oxygenase (RF) family of enzyme proteins can affect bulliform cells and cause leaf curling. However, there are few studies related to this family in cotton, and there has been no systematic analysis of RF genes. Here, we determined 25 RF genes in the complete genome sequence of upland cotton (Gossypium hirsutum L.) and 11 RF genes in the complete genome sequence of Arabidopsis thaliana. Cotton RF proteins can be divided into three categories. Whole genome/fragment and scattered replication events played an important role in the expansion of the RF gene family. qRT-PCR analysis results showed that RF genes respond to drought stress Pairwise comparison results showed that the expression of RF genes in Shi yuan 321 was higher than that in Kui 85-174. Overall, genome-wide identification approach was used to further analyze the related functions of the RF gene family, which may include the response to drought stress, in cotton. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-021-01065-4.
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BACKGROUND: Neutral/alkaline invertases (N/AINVs) play a crucial role in plant growth, development, and stress response, by irreversibly hydrolyzing sucrose into glucose and fructose. However, research on cotton in this area is limited. This study aims to investigate GhN/AINV23, a neutral/alkaline invertase in cotton, including its characteristics and biological functions. RESULTS: In our study, we analyzed the sequence information, three-dimensional (3D) model, phylogenetic tree, and cis-elements of GhN/AINV23. The localization of GhN/AINV23 was determined to be in the cytoplasm and cell membrane. Quantitative real-time polymerase chain reaction (qRT-PCR) results showed that GhN/AINV23 expression was induced by abscisic acid (ABA), exogenous sucrose and low exogenous glucose, and inhibited by high exogenous glucose. In Arabidopsis, overexpression of GhN/AINV23 promoted vegetative phase change, root development, and drought tolerance. Additionally, the virus-induced gene silencing (VIGS) assay indicated that the inhibition of GhN/AINV23 expression made cotton more susceptible to drought stress, suggesting that GhN/AINV23 positively regulates plant drought tolerance. CONCLUSION: Our research indicates that GhN/AINV23 plays a significant role in plant vegetative phase change, root development, and drought response. These findings provide a valuable foundation for utilizing GhN/AINV23 to improve cotton yield.
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Resistencia a la Sequía , Sequías , Filogenia , Glucosa , SacarosaRESUMEN
Multifunctional biomass-based aerogels with mechanically robust and high fire safety are urgently needed for the development of environmentally-friendly intelligent fire fighting but challenging. Herein, a novel polymethylsilsesquioxane (PMSQ)/cellulose/MXene composite aerogel (PCM) with superior comprehensive performance was fabricated by ice-induced assembly and in-situ mineralization. It exhibited light weight (16.2 mg·cm-3), excellent mechanical resilience, and rapidly recovered after being subjected to the pressure of 9000 times of its own weight. Moreover, PCM demonstrated outstanding thermal insulation, hydrophobicity and sensitive piezoresistive sensing. In addition, benefiting from the synergism of PMSQ and MXene, PCM displayed good flame retardancy and improved thermostability. The limiting oxygen index of PCM was higher than 45.0 %, and it quickly self-extinguished after being removed away from fire. More importantly, the rapid electrical resistance reduction of MXene at high temperature endowed PCM with sensitive fire-warning capability (trigger time was less than 1.8 s), which provided valuable time for people to evacuate and relief. This work provides new insights for the preparation and application of the next-generation high performance biomass-based aerogels.
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Celulosa , Compuestos de Organosilicio , Humanos , BiomasaRESUMEN
Previous phylogenetic analyses of the melanogaster species group have led to conflicting hypotheses concerning their relationship; therefore the addition of new sequence data is necessary to discover the phylogeny of this species group. Here we present new data derived from 17 genes and representing 48 species to reconstruct the phylogeny of the melanogaster group. A variety of statistical tests, as well as maximum likelihood mapping analysis, were performed to estimate data quality, suggesting that all genes had a high degree of contribution to resolve the phylogeny. Individual locus was analyzed using maximum likelihood (ML), and the concatenated dataset (12,988 bp) were analyzed using partitioned maximum likelihood (ML) and Bayesian analyses. Separated analysis produced various phylogenetic relationships, however, phylogenetic topologies from ML and Bayesian analysis based on concatenated dataset, at the subgroup level, were completely identical to each other with high levels of support. Our results recovered three major clades: the ananassae subgroup, followed by the montium subgroup, the melanogaster subgroup and the oriental subgroups form the third monophyletic clade, in which melanogaster (takahashii, suzukii) forms one subclade and ficusphila [eugracilis (elegans, rhopaloa)] forms another. However, more data are necessary to determine the phylogenetic position of Drosophila lucipennis which proved difficult to place.
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Drosophila melanogaster/clasificación , Drosophila melanogaster/genética , Filogenia , Animales , Teorema de Bayes , Proteínas de Drosophila/genética , Evolución Molecular , Genes Mitocondriales , Funciones de Verosimilitud , Modelos Genéticos , ARN Ribosómico 28S/genética , Alineación de SecuenciaRESUMEN
Previous study revealed that the MRP1 gene ortholog DMRP1/CG6214 of Drosophila melanogaster contains 12 exons in the coding region. In the current study, the genes of DMRP1/CG6214 from D. melanogaster and Drosophila virilis were compared, and the result indicated that D. virilis had an extra intron located in exon 2, implying that intron loss or gain might have occurred at this locus. To track the evolution of the extra intron (Intron Z), orthologous nucleotide sequences of 37 arthropod species were cloned or annotated. Based on phylogenetic analysis, we found that Intron Z should present in the common ancestor of arthropod species, more than 420 Ma. In addition, we found that Sophophora subgenus species and mosquito (Culex pipiens) lost Intron Z independently, showing evolutionary convergence.
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Transportadoras de Casetes de Unión a ATP/genética , Culex/genética , Proteínas de Drosophila/genética , Drosophila/genética , Evolución Molecular , Intrones , Animales , Anotación de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Eliminación de SecuenciaRESUMEN
With Alzheimer's disease (AD) becoming a worldwide problem, traditional Chinese medicine (TCM), especially acupuncture, stands out as a complementary therapy because of its feature-"treatment based on syndrome differentiation". This systematic review and network meta-analysis (NMA) confirms the complement effect of acupuncture and explores the best combination of therapy for AD based on the total effect and activity of daily living scale (ADL). We searched relevant randomized controlled trials (RCTs) that applied acupuncture for treating AD. 58 studies with 4334 patients were included in accordance with PRISMA guidelines. The results showed that for the total effect, the order of probability for the effect: acupuncture + western medicine > acupuncture + herbal medicine > acupuncture > acupuncture + western medicine + herbal medicine. For the ADL score, the order of probability for the effect: acupuncture + western medicine > acupuncture > acupuncture + western medicine + herbal medicine > acupuncture + herbal medicine. The combination of acupuncture and medicine has a better clinical effect than acupuncture only in a way. Acupuncture + western medicine has an obvious and exact improvement in the curative effect from both total effect and ADL score, but further higher quality studies, which can detail the classification of these interventions, are still needed to verify it.
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OBJECTIVE: Angelica (A.) sinensis is used as a traditional medical herb for the treatment of neurodegeneration, aging, and inflammation in Asia. A. sinensis optimal formula (AOF) is the best combination in A. sinensis that has been screened to rescue the cognitive ability in ß-amyloid peptide (Aß25-35)-treated Alzheimer's disease (AD) rats. The objective of this study was to investigate the effect of AOF on the learning and memory of AD rats as well as to explore the underlying mechanisms. METHODS: Male Wistar rats were infused with Aß25-35 for AD model induction or saline (negative control). Five groups of AD rats were fed on AOF at 20, 40, or 80 mL/kg every day, donepezil at 0.9 mg/kg every day (positive control), or an equal volume of water (AD model) intragastrically once a day for 4 weeks, while the negative control rats were fed on water. The Morris water maze test was used to evaluate the cognitive function of the rats. The Aß accumulation, cholinergic levels, and antioxidative ability were detected by ELISA. Additionally, the candidate mechanism was determined by gene sequencing and quantitative real-time polymerase chain reaction. RESULTS: The results showed that AOF administration significantly ameliorated Aß25-35-induced memory impairment. AOF decreased the levels of amyloid-ß precursor protein and Aß in the hippocampus, rescued the cholinergic levels, increased the activity of superoxide dismutase, and decreased the malondialdehyde level. In addition, AOF inhibited the expression of IL1b, Mpo, and Prkcg in the hippocampus. CONCLUSION: These experimental findings illustrate that AOF prevents the decrease in cognitive function and Aß deposits in Aß25-35-treated rats via modulating neuroinflammation and oxidative stress, thus highlighting a potential therapeutic avenue to promote the co-administration of formulas that act on different nodes to maximize beneficial effects and minimize negative side effects.
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Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/farmacología , Angelica sinensis , Trastornos de la Memoria/tratamiento farmacológico , Enfermedades Neuroinflamatorias/tratamiento farmacológico , Nootrópicos/farmacología , Estrés Oxidativo/efectos de los fármacos , Preparaciones de Plantas/farmacología , Enfermedad de Alzheimer/inducido químicamente , Enfermedad de Alzheimer/inmunología , Enfermedad de Alzheimer/metabolismo , Animales , Modelos Animales de Enfermedad , Masculino , Trastornos de la Memoria/inducido químicamente , Trastornos de la Memoria/inmunología , Trastornos de la Memoria/metabolismo , Enfermedades Neuroinflamatorias/inducido químicamente , Enfermedades Neuroinflamatorias/inmunología , Enfermedades Neuroinflamatorias/metabolismo , Nootrópicos/administración & dosificación , Preparaciones de Plantas/administración & dosificación , Ratas , Ratas WistarRESUMEN
BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disease, yet there is no effective treatment. Electroacupuncture (EA) is a complementary alternative medicine approach. In clinical and animal studies, EA promotes cognition in AD and vascular dementia. It has been previously reported that cognitive decline in AD might be closely related to reduced glucose intake in the brain. It is worth mentioning that the regions of glucose hypometabolism are usually found to be associated with neuroinflammation. OBJECTIVE: This study is to explore whether the protective mechanism of EA on cognition is related to the regulation of glucose metabolism and neuroinflammation. METHODS: APP/PS1 mice were randomly divided into AD group and the treatment (ADâ+âEA) group. In the ADâ+âEA group, EA was applied on Baihui (GV20) and Yintang (GV29) for 20âmin and then pricked at Shuigou (GV26), once every alternate day for 4 weeks. Morris water maze (MWM) tests were performed to evaluate the effects of EA treatment on cognitive functions. 18F-FDG PET, immunofluorescence, and western blot were used to examine the mechanisms underlying EA effects. RESULTS: From MWM tests, EA treatment significantly improved cognition of APP/PS1 mice. From the 18F-FDG PET, the levels of uptake rate of glucose in frontal lobe were higher than the AD group after EA. From immunofluorescence and western blot, amyloid-ß (Aß) and neuroinflammation were reduced after EA. CONCLUSION: These results suggest that EA may prevent cognitive decline in AD mouse models by enhancing glucose metabolism and inhibiting inflammation-mediated Aß deposition in the frontal lobe.
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Enfermedad de Alzheimer/metabolismo , Encéfalo/metabolismo , Cognición/fisiología , Electroacupuntura/métodos , Glucosa/metabolismo , Mediadores de Inflamación/metabolismo , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/terapia , Precursor de Proteína beta-Amiloide/genética , Animales , Encéfalo/patología , Mediadores de Inflamación/antagonistas & inhibidores , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Proyectos Piloto , Presenilina-1/genéticaRESUMEN
BACKGROUND: Alzheimer's disease (AD) is mainly manifested as a continuous and progressive decline in cognitive ability. Neurofibrillary tangles (NFTs) are pathological hallmarks of AD and due to accumulated phosphorylated Tau. Glycogen synthase kinase-3ß (GSK3ß), as a major Tau kinase and a downstream target of the serine protein kinase B (AKT) signaling pathway, can regulate Tau phosphorylation in AD. Importantly, the AKT/GSK3ß signaling pathway is involved in glucose metabolism, and abnormal glucose metabolism is found in the AD brain. Numerous studies have shown that electroacupuncture (EA), which is thought to be a potential complementary therapeutic approach for AD, can protect cognitive ability to a certain extent. OBJECTIVE: The purpose of this experiment was to investigate whether the protective and beneficial mechanism of EA on cognition was mediated by the AKT/GSK3ß signaling pathway, thereby improving glucose metabolism and Tau phosphorylation in the brain. METHODS: EA was applied to the Baihui (GV20) and Yintang (GV29) acupoints of 6-month-old amyloid precursor protein (APP)/presenilin-1 (PS1) mice for 20 min, and then quickly prick Shuigou (GV26) acupoint. The intervention was performed once every other day for 28 days. The Morris water maze (MWM) test was performed on C57BL/6N (Non-Tg) mice, APP/PS1 (Tg) mice and EA-treated Tg (Tg + EA) mice to evaluate the effect of EA therapy on cognitive function. 18F-FDG positron emission tomography (PET), immunohistochemistry, and western blotting (WB) were used to investigate the possible mechanism underlying the effect of EA on AD. RESULTS: EA treatment significantly improved the cognition of APP/PS1 mice and the glucose uptake rate in the hippocampus. Furthermore, EA inhibited the phosphorylation of Tau (Ser199 and Ser202) proteins by inducing AKT (Ser473) and GSK3ß (Ser9) phosphorylation. CONCLUSION: These results demonstrate that EA intervention protects cognition by enhancing glucose metabolism and inhibiting abnormal phosphorylation of Tau protein in the AD model mice, and the AKT/GSK3ß pathway might play an irreplaceable role in the regulation process.
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This study conducted a national scale survey to assess the levels and distributions of 13 commonly used antibiotics and nine antibiotic resistance genes (ARGs) in the greenhouse and open-field agricultural soils in China. The concentrations of antibiotics in the greenhouse and open-field soils were 428â¯ng/g (nâ¯=â¯51) and 193â¯ng/g (nâ¯=â¯51), respectively. The abundances of ARGs ranged from 1.15â¯×â¯10-7 to 9.78â¯×â¯10-2 copies/16S rRNA copies and from Asunto(s)
Antibacterianos/análisis
, Farmacorresistencia Microbiana/genética
, Suelo/química
, Agricultura
, China
, Contaminación Ambiental/análisis
, Genes Bacterianos
, Efecto Invernadero
, ARN Ribosómico 16S/genética
RESUMEN
Drosophila focal adhesion kinase (Dfak) gene is a single-copy nuclear gene. Previous study revealed that Drosophila melanogaster and Drosophila simulans had lost an intron precisely within the tyrosine kinase (TyK) domain of this gene. However, this did not happen in several other Drosophila species, including Drosophila elegans, Drosophila ficusphila, Drosophila biarmipes, Drosophila jambulina, Drosophila prostipennis, Drosophila takahashii, and Drosophila pseudoobscura. In the current study, homologous sequences of Drosophila sechellia, Drosophila mauritiana, Drosophila yakuba, Drosophila teissieri, Drosophila santomea, and Drosophila erecta were amplified by polymerase chain reaction, and further sequencing analysis indicated that these species were missing a TyK domain intron, indicating they were closely related. The relationship of the D. melanogaster species group was reconstructed using TyK domain nucleotide sequences. The resulting phylogenetic tree revealed that these 8 species were the most related species in the melanogaster group. These results strongly support previously proposed classifications based on morphological and molecular data.
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Drosophila melanogaster/genética , Drosophila/clasificación , Proteína-Tirosina Quinasas de Adhesión Focal/genética , Eliminación de Gen , Intrones , Filogenia , Animales , Drosophila/genética , Drosophila melanogaster/clasificación , Proteína-Tirosina Quinasas de Adhesión Focal/química , Estructura Terciaria de ProteínaRESUMEN
We amplified genomic DNA of the Paramisgurnus dabryanus using the DM degenerate primers and detected a band, approximately 150 bp. After cloned into pMD18-T vector and sequenced, three sequences showed high homology with the DM domain. They were named as PdDmrt1, PdDmrt3, and PdDmrt5. Based on similarities of amino acid sequences of the DM domain, Dmrt gene protein sequences from six vertebrates species were included in a phylogenetic tree. It confirmed the identity of the three PCR products. Our results reveal that Dmrt gene is highly conservative in phylogeny.
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Cipriniformes/genética , Factores de Transcripción/química , Factores de Transcripción/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Secuencia Conservada , Humanos , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-Simple , Estructura Terciaria de Proteína , Análisis de Secuencia de ADNRESUMEN
A national scale survey was conducted to determine an array of inorganic and organic contaminants in agricultural soils from two cultivation modes (greenhouse vs. open field) in 20 provinces across China. The investigated contaminants include organochlorine pesticides (OCPs), phthalate esters (PAEs), polycyclic aromatic hydrocarbons (PAHs), lead (Pb), zinc (Zn), copper (Cu) and cadmium (Cd). The large amounts of agrochemicals used and special cultivation mode in greenhouse caused substantial soil pollution and deterioration of soil quality. Mean concentrations of both OCPs and PAEs in greenhouse soil were approximately 100% higher than those in open field. The pH values were 6.85⯱â¯1.04 and 7.34⯱â¯0.84 for greenhouse and open field, respectively (pâ¯>â¯0.05). The soil microbial community was predicted to be affected by pollution in greenhouse through the PICRUSt analysis of 16s rRNA sequences. The 12 variables including various chemicals and soil properties together explained 15% of the observed variation in the community composition. In the studied variables, PAEs and lead were the primary factors affecting microbial diversity in greenhouse soils, while pH had the greatest impact on the microbial community in open field soils. These findings enhanced our understanding of the environmental impact and contamination management of greenhouses worldwide.
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Agricultura/métodos , Agroquímicos/análisis , Monitoreo del Ambiente/métodos , Contaminación Ambiental/análisis , Microbiota/genética , Plaguicidas/análisis , Ácidos Ftálicos/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes del Suelo/análisis , Cadmio/análisis , China , Cobre/análisis , Contaminación de Medicamentos , Ésteres , Plomo/análisis , ARN Ribosómico 16S , Suelo/química , Zinc/análisisRESUMEN
The interfacial adhesion between polyhydroxyalkanoates (PHAs) and native starch is poor. To improve the interfacial adhesion, PHAs were in-situ grafted onto starch using dicumyl peroxide (DCP) as a free radical initiator. The grafting reaction was carefully characterized and confirmed by gel analysis and Fourier transform infrared spectroscopy (FT-IR). The gel yield of the PHAs/starch/DCP blend increased with the DCP concentration up to 2wt%. Meanwhile, obvious plastic deformation (stretched fibrils) was observed at the interface in the PHAs/starch/DCP blend in comparison with complete interfacial debonding in the PHAs/starch physical blend. The improved interfacial adhesion after grafting was further confirmed by a reduction in adhesion factor (Af) obtained from dynamic mechanical analysis (DMA). The mechanical strength and the crystallization rate of the PHAs were deteriorated after incorporation of starch, and were backed up by the interfacial improvement. A linear relationship between the mechanical properties and the gel yield was discovered. In addition, the PHAs/starch/DCP blend exhibited higher decomposition active energy (Ea) and thus better thermal stability in comparison with the PHAs and the PHAs/starch physical blend. Therefore, this study provides a simple route to utilize low-cost starch as a component in biopolymer blend.
RESUMEN
This study focused on the occurrence and spatial distribution of 13 common antibiotics in the agricultural soils of the Yangtze River Delta (YRD), China. Antibiotics were detected in all the 241 soil samples (i.e., 100% detection rate) with the total concentrations ranging from 4.55 to 2,010 ng/g dry weight. The concentrations of three antibiotic classes decreased in the order: quinolones (mean 48.8 ng/g) > tetracyclines (mean 34.9 ng/g) > sulfonamides (mean 2.35 ng/g). Ciprofloxacin was the prevalent compound with a mean concentration of 27.7 ng/g, followed by oxytetracycline (mean of 18.9 ng/g). A distinct spatial distribution was observed, where high concentrations of antibiotics were detected in the sites adjacent to the livestock and poultry farms. The potential sources of antibiotics in the agricultural soils were the application of manure and wastewater irrigation in this region. Risk assessment for single antibiotic compound indicated that tetracyclines and quinolones could pose a potential risk, in which doxycycline and ciprofloxacin had the most severe ecological effect in the agricultural soils. Antibiotic resistance genes (ARGs), such as tetA, sulI, and qnrS, were detected in 15 analyzed soil samples, and sulI showed significant correlations with quinolones, tetracyclines, copper, and zinc. Further studies on the distribution of other ARGs in agricultural soil at a region-scale are needed for the risk management of extensively used antibiotics and major ARGs.
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Antibacterianos/análisis , Monitoreo del Ambiente , Contaminantes del Suelo/análisis , Agricultura , Animales , China , Farmacorresistencia Microbiana/genética , Granjas , Ganado , Estiércol/análisis , Oxitetraciclina , Quinolonas , Ríos , Suelo , Tetraciclinas , Aguas ResidualesRESUMEN
Based on the traditional knocking-slides and Giemsa-staining methods,this paper firstly analyzed the metaphase chromosomes of five species (D. constricta, D. ohnishii, D. ogumai, D. pseudobaimaii and D. tani) of Drosophila melanogaster species group. The results show that all of the five species share the same chromosomal numbers (2n=8) but with different typical shapes. D. pseudobaimaii and D. tani share the shape 2V, 1R, 1D; D. constricta shows 2V,1R,1D with unclear recognized dot chromosomes; D. ohnishii and D. ogumai share the same chromosomal shapes 2V2R. And that between karyotype and phylogenetic relationships are found to be correspond.
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Drosophila melanogaster/genética , Animales , Cromosomas/química , Cromosomas/genética , Drosophila melanogaster/química , Femenino , Cariotipificación , MasculinoRESUMEN
The widespread distribution of Drosophila simulans in the mainland of China was found recently. Random amplified polymorphic DNA (RAPD) was used to analyzed DNA polymorphisms of 38 Drosophila simulans populations collected from the mainland of China. The origins of D. simulans in China were also discussed. Using 40 arbitary primers (10 bp), we made PCR amplifications under the optimized reaction conditions for RAPD that had been established in our laboratory. Our molecular phylogenetic tree constructed by UPGMA method showed as follows: (1) 38 populations are apparently classified into Northern cluster and Southern cluster, where NJ(Nanjing) can be considered as the boundary according to latitude. The populations in the Northern cluster can be further grouped into two sub-clusters, where BJ(Beijing) can be considered as the boundary according to latitude. The Northeast one consists of 10 populations, including Mohe(MH), Hailaer(HLR), Heihe(HH), Jiamusi(JMS), Haerbin(HRB), Changchun(CC), Shenyang(SY), Dandong(DD), Yanji(YJ), Tumen(TM); the other consists of 12 populations, including Beijing (BJ), Datong(DT), Huhehaote(HHHT), Yinchun(YC), Xinin(XN), Lanzhou(LZ), Taiyuan(TY), Shijiazhuang(SJZ), Yantai (YT), Jinan(JN), Xuzhou(XZ), Lianyungang(LYG). The southern cluster consists of the left 16 populations, including Zhengzhou (ZZ), Wuhan(WH), Shanghai(SH), Nanjing(NJ), Hangzhou(HZ), Chongqing(CQ), Nanchang(NC), Wenzhou(WZ), Changsha (CS), Guiyang(GY), Fuzhou(FZ), Kunming(KM), Xiamen(XM), Guangzhou(GZ), Nanning(NN), Hainan(HN). (2) The genetic distances among populations relate to the collection sites to a great extent, though there are some exceptions. According to the facts that we know, (1) D. simulans is an exotic species; (2) The invasion of D. simulans in the mainland of China took place in recent 30 years or so. (3) The widespread distribution of D. simulans in the mainland of China started in recent 10 years or so. Therefore, the results above might not be due to geographical differentiation, but due to genetic differences of initial founder individual(s) between geographical populations. Some of geographically adjacent populations, however, have common initial founder individual(s), which results in the classification of D. simulans populations according to their geographical relationship. We suggest that there are two possible reasons which result in the genetic differences of initial founder individual(s) between geographical populations, one is the D. simulans in the mainland of China had multiple origins, the other is founder effect and/or bottleneck effect that the D. simulans have experienced in the course of expansion.
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Drosophila/genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Animales , China , Drosophila/clasificación , FilogeniaRESUMEN
Lactic acid is an important platform chemical. Especially with rapid development of poly (lactic acid) industry, the demand for L-lactic acid is continuously increasing. To further reduce the fermentation costs and improve the robustness of strains from industrial point of view, many modern biotechnological approaches have been applied to strain development. In this review, we briefly summarize recent advances in L-lactate fermentation by genetically modified microorganisms, including lactic acid bacteria, yeast, E. coli and Rhizopus species.
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Bacterias/metabolismo , Fermentación , Ácido Láctico/metabolismo , Redes y Vías Metabólicas/genética , Levaduras/metabolismo , Bacterias/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Ingeniería Genética/métodos , Microbiología Industrial/métodos , Estereoisomerismo , Levaduras/genéticaRESUMEN
In this study, a newly isolated alkaliphile Exiguobacterium sp. strain 8-11-1 was used to produce optically pure L-lactate. With an initial glucose concentration of 80 g/L, a high overall L-lactic acid productivity of 8.15 g/L/h was achieved using NaOH as a neutralizing agent. The fed-batch fermentations were carried out under both sterile and nonsterile conditions. Under the nonsterile condition, 125 g/L L-lactic acid was obtained with a high percent yield and average productivity of 98.33% and 3.79 g/L/h, respectively. These values were consistent with the results from sterile condition. No d-isomers of lactic acid were detected, resulting in an optical purity of 100% in both conditions. The high levels of optically pure L-lactic acid produced by Exiguobacterium sp. 8-11-1, combined with the ease of handling and low costs associated with the open fermentation strategy, provide a novel and potentially important approach for L-lactic acid production in the future.