21 results on '"Chengqiang Xia"'
Search Results
2. Cumulative expression of heterologous XlnR regulatory modules and AraRA731V in Penicillium oxalicum enhances saccharification efficiency of corn stover and corn fiber
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Chengqiang Xia, Xiaoyu Qi, and Xin Song
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Filamentous fungi ,XlnR regulatory modules ,Cellulase ,Hemicellulase ,Transcription factor AraR ,Biotechnology ,TP248.13-248.65 ,Fuel ,TP315-360 - Abstract
Abstract Penicillium oxalicum engineered strain DB2 and its mutant strains with multiple regulatory modules were constructed. Mutant strain RE-4-2 with two regulatory modules showed a significant increase in the reducing sugar released from corn stover and corn fiber as well as in the conversion of cellulose than DB2. RE-5-2 with three regulatory modules showed a further increase in reducing sugar released from corn stover and the conversion of cellulose on the basis of RE-4-2. RE-4-2-AraRA731V constructed by overexpressing AraRA731V in RE-4-2 showed an increase of 7.2 times and 1.2 times in arabinofuranosidase and xylosidase activities, respectively. Reducing sugar yield and cellulose conversion of corn stover and corn fiber by RE-4-2-AraRA731V were further increased.
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- 2024
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3. Dietary supplementation of sodium butyrate enhances lactation performance by promoting nutrient digestion and mammary gland development in dairy cows
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Jing Zhang, Lijun Bu, Yapeng Liu, Wenjie Huo, Chengqiang Xia, Caixia Pei, and Qiang Liu
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Sodium butyrate ,Lactation performance ,Nutrient digestion ,Milk fat synthesis ,Mammary gland development ,Animal culture ,SF1-1100 - Abstract
This experiment was to evaluate the influence of sodium butyrate (SB) addition on milk production, ruminal fermentation, nutrient digestion, and the development and metabolism regulation of the mammary gland in dairy cows. Forty Holstein dairy cows averaging 710 ± 18.5 kg body weight, 72.8 ± 3.66 d in milk (DIM), and 41.4 ± 1.42 kg/d milk production were divided into four treatments blocked by DIM and milk production. Treatments were control group, low SB, medium SB, and high SB with 0, 100, 200 and 300 g/d of SB addition per cow, respectively. The study lasted for 105 d. Production of milk, milk protein and lactose quadratically increased (P
- Published
- 2023
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4. Combining manipulation of transcription factors and overexpression of the target genes to enhance lignocellulolytic enzyme production in Penicillium oxalicum
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Liwei Gao, Zhonghai Li, Chengqiang Xia, Yinbo Qu, Meng Liu, Piao Yang, Lele Yu, and Xin Song
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Penicillium oxalicum ,Transcription factor ,Cellulase ,Hemicellulase ,Fuel ,TP315-360 ,Biotechnology ,TP248.13-248.65 - Abstract
Abstract Background Lignocellulolytic enzymes are the main enzymes to saccharify lignocellulose from renewable plant biomass in the bio-based economy. The production of these enzymes is transcriptionally regulated by multiple transcription factors. We previously engineered Penicillium oxalicum for improved cellulase production via manipulation of three genes in the cellulase expression regulatory network. However, the potential of combinational engineering of multiple regulators and their targets at protein abundance and activity levels has not been fully explored. Results Here, we verified that a point mutation XlnRA871V in transcription factor XlnR enhanced the expression of lignocellulolytic enzymes, particularly hemicellulases, in P. oxalicum. Then, overexpression of XlnRA871V with a constitutive PDE_02864 promoter was combined with the overexpression of cellulase transcriptional activator ClrB and deletion of carbon catabolite repressor CreA. The resulted strain RE-7 showed 8.9- and 51.5-fold increased production of cellulase and xylanase relative to the starting strain M12, respectively. Further overexpression of two major cellulase genes cbh1-2 and eg1 enabled an additional 13.0% improvement of cellulase production. In addition, XlnRA871V led to decreased production of β-glucosidase and amylase, which could be attributed to the reduced transcription of corresponding enzyme-encoding genes. Conclusions The results illustrated that combinational manipulation of the involved transcription factors and their target genes was a viable strategy for efficient production of lignocellulolytic enzymes in filamentous fungi. The striking negative effect of XlnRA871V mutation on amylase production was also highlighted.
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- 2017
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5. Alteromonas salexigens sp.nov., isolated from coastal seawater
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Liping Sun, Xinyuan Hu, Qin Wang, Huijing Niu, Caixia Pei, Yi Li, and Chengqiang Xia
- Abstract
A Gram-negative, aerobic, short rod-shaped bacterium, designated ASW11-19T, was isolated from a coastal seawater sample of the Yellow Sea, PR China. Strain ASW11-19T grew optimally at 37°C, 3.0–5.0% (w/v) NaCl and pH 7.5. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain ASW11-19T belonged to the genus Alteromonas and most closely related to Alteromonas profundi 345S023T and Alteromonas fortis 1T (98.4%, both). The draft genome was 3.55 Mb with 3150 protein-coding genes, 18 contigs, and a DNA G + C content was 44.4%. The digital DNA–DNA hybridization and average nucleotide identity values were below the species-delineating thresholds. The major fatty acids were summed featured 3 (C16:1ω7c/C16:1ω6c), summed featured 8 (C18:1ω7c/C18:1ω6c) and C16:0. The sole respiratory quinone was ubiquinone 8. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phospholipid, and two unidentified lipids. Based on these genomic data, phenotypic and chemotaxonomic properties, strain ASW11-19T is considered to represent a novel species of the genus Alteromonas. The name Alteromonas salexigens sp.nov. is proposed for ASW11-19T (= MCCC 1K07239T = KCTC 92247T).
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- 2023
6. Functional analysis of the transcriptional activator XlnR of Penicillium oxalicum
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Zhonghai Li, Guodong Liu, Chengqiang Xia, Liwei Gao, and Xin Song
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Alanine ,chemistry.chemical_classification ,Reporter gene ,Chemistry ,Penicillium ,General Medicine ,Applied Microbiology and Biotechnology ,Yeast ,Amino acid ,Cellulase ,Biochemistry ,Gene expression ,Expression cassette ,Homologous recombination ,Gene ,Transcription Factors ,Biotechnology - Abstract
Aims The aim of this article is to study the functional features of Penicillium oxalicum transcriptional activator XlnR. Methods and results The yeast reporter system was used to identify transcriptional activation domain of XlnR in P. oxalicum. The expression cassette was introduced into the xlnR locus of P. oxalicum by homologous recombination. In this study, several putative structural domains in P. oxalicum XlnR were predicted by bioinformatics analysis, and the transcriptional activation domain (351-694 region) was identified in XlnR relying on reporter gene system in yeast. In addition, the amino acid at XlnR 871 site (alanine) located in the regulatory region could influence the regulatory activity of XlnR directly. When the alanine at XlnR 871 site was replaced by stronger hydrophobic amino acid (e.g. valine or isoleucine), the regulatory activity will be greatly improved, especially for the regulation of hemicellulase genes expression. When alanine at XlnR 871 site was mutated to a hydrophilic amino acid (e.g. aspartic acid or arginine), the regulatory activity of XlnR will be reduced. Conclusions The 351-694 region of P. oxalicum XlnR was identified as transcriptional activation domain, and the regulatory activity of XlnR was greatly influenced by hydrophobicity of amino acid at 871 site of XlnR in P. oxalicum. Significance and impact of the study The results will provide an effective target site to regulate the activity of XlnR and improve cellulase production of P. oxalicum.
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- 2021
7. Effects of guanidinoacetic acid supplementation on lactation performance, nutrient digestion and rumen fermentation in Holstein dairy cows
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Yongjia Liu, Jing Zhang, Cong Wang, Gang Guo, Wenjie Huo, Chengqiang Xia, Lei Chen, Yawei Zhang, Caixia Pei, and Qiang Liu
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Nutrition and Dietetics ,Agronomy and Crop Science ,Food Science ,Biotechnology - Abstract
Considering the high energy demand of lactation and the potential of guanidinoacetic acid (GAA) addition on the increase in creatine supply for cows, the present study investigated the effects of 0, 0.3, 0.6 and 0.9 g kgDM intake was not affected, but milk and milk component yields and feed efficiency increased linearly with increasing GAA addition. The total-tract digestibility of DM, organic matter, neutral detergent fibre, acid detergent fibre and non-fibre carbohydrates increased linearly and that of crude protein increased quadratically with increasing GAA addition. When the addition level of GAA increased, ruminal pH, molar percentages of butyrate, isobutyrate and isovalerate and the acetate-to-propionate ratio decreased linearly, and the total volatile fatty acids concentration and propionate molar percentage also increased linearly, whereas the acetate molar percentage and ammonia-N concentration were unaltered. The activities of fibrolytic enzymes, α-amylase and protease increased linearly. The populations of total bacteria, fungi, Ruminococcus albus, Fibrobacter succinogenes, Ruminococcus flavefaciens, Ruminobacter amylophilus and Prevotella ruminicola increased linearly, whereas protozoa and methanogens decreased linearly with increasing GAA addition. As for the blood metabolites, concentrations of glucose, urea nitrogen and methionine were unchanged, total protein, albumin, creatine and homocysteine increased linearly, and folate decreased linearly with increasing GAA supply.The results of the present study indicate that supplementation of GAA improved milk performance and rumen fermentation in lactating dairy cows. © 2022 Society of Chemical Industry.
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- 2022
8. Comparison of the microbial communities of alpacas and sheep fed diets with three different ratios of corn stalk to concentrate
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Youshe Ren, Huo Wenjie, Qiang Liu, Cai-xia Pei, Chunxiang Zhang, Chengqiang Xia, and Ruimin Chao
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Rumen ,040301 veterinary sciences ,Firmicutes ,Zea mays ,0403 veterinary science ,Animal science ,Food Animals ,Latin square ,RNA, Ribosomal, 16S ,Butyrivibrio ,Animals ,Ovis ,Sheep ,biology ,Microbiota ,0402 animal and dairy science ,Bacteroidetes ,Fusobacteria ,04 agricultural and veterinary sciences ,Armatimonadetes ,biology.organism_classification ,16S ribosomal RNA ,Animal Feed ,040201 dairy & animal science ,Diet ,Fermentation ,Animal Science and Zoology ,Camelids, New World - Abstract
The objective of this study was to investigate the characteristics of ruminal microbial communities of alpacas (Lama pacos) and sheep (Ovis aries) fed three diets with varying ratios of roughage (corn stalk) to concentrate, 3:7 (LS), 5:5 (MS) and 7:3 (HS). Six alpacas (one-year-old and weighing 29.5 ± 7.1 kg) and six sheep (one-year-old and weighing 27.9 ± 2.7 kg) were used in this study, in a replicated 3 × 3 Latin square experiment. Total protozoa concentration was determined under the microscope; total fungi and methanogens were assessed using quantitative polymerase chain reaction and expressed as a percentage of total bacterial 16S rRNA gene copies; bacterial communities were investigated by targeted 16S rRNA gene (V3-V4 region) sequencing. The percentage of fungi was significantly higher in alpacas than in sheep under the LS diet, while the concentration of protozoa was significantly lower in alpacas under HS, MS and LS diets. The alpha diversity including Shannon, Chao l and ACE indices of bacterial communities was higher in alpacas than in sheep, under the LS diet. A total of 299 genera belonging to 22 phyla were observed in the forestomach of alpaca and sheep, with Bacteroidetes and Firmicutes dominating both animal species. Phyla Armatimonadetes and Fusobacteria, as well as 64 genera, were detected only in alpacas, whereas phyla Acidobacteria and Nitrospira, as well as 44 genera, were found only in sheep. The abundance of cellulolytic bacteria, including Butyrivibrio and Pseudobutyrivibrio, was higher in alpacas than in sheep under all three diets. These differences in the forestomach microbial communities partly explained why alpacas displayed a higher poor-quality roughage digestibility, and a lower methane production. Results also revealed that the adverse effects of high-concentrate diets (70%) were lesser in alpacas than in sheep.
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- 2020
9. Lactation Performance Stimulated by Sodium Butyrate Addition Through Promoting Nutrient Digestion and Mammary Gland Development in Dairy Cows
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Jing Zhang, Lijun Bu, Yapeng Liu, Wenjie Huo, Chengqiang Xia, Caixia Pei, and Qiang Liu
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- 2022
10. Effects of guanidinoacetic acid supplementation on lactation performance, nutrient digestion and rumen fermentation in Holstein dairy cows.
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Yongjia Liu, Jing Zhang, Cong Wang, Gang Guo, Wenjie Huo, Chengqiang Xia, Lei Chen, Yawei Zhang, Caixia Pei, and Qiang Liu
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RUMEN fermentation ,DAIRY cattle ,LACTATION ,DIGESTION ,FERMENTATION ,DIETARY supplements ,MILKFAT - Abstract
BACKGROUND: Considering the high energy demand of lactation and the potential of guanidinoacetic acid (GAA) addition on the increase in creatine supply for cows, the present study investigated the effects of 0, 0.3, 0.6 and 0.9 g kg
-1 dry matter (DM) of GAA supplementation on lactation performance, nutrient digestion and ruminal fermentation in dairy cows. The study used 40 mid-lactation multiparous Holstein cows and the study duration was 100 days. RESULTS: DM intake was not affected, but milk and milk component yields and feed efficiency increased linearly with increasing GAA addition. The total-tract digestibility of DM, organic matter, neutral detergent fibre, acid detergent fibre and non-fibre carbohydrates increased linearly and that of crude protein increased quadratically with increasing GAA addition. When the addition level of GAA increased, ruminal pH, molar percentages of butyrate, isobutyrate and isovalerate and the acetate-to-propionate ratio decreased linearly, and the total volatile fatty acids concentration and propionate molar percentage also increased linearly, whereas the acetate molar percentage and ammonia-N concentration were unaltered. The activities of fibrolytic enzymes, α-amylase and protease increased linearly. The populations of total bacteria, fungi, Ruminococcus albus, Fibrobacter succinogenes, Ruminococcus flavefaciens, Ruminobacter amylophilus and Prevotella ruminicola increased linearly, whereas protozoa and methanogens decreased linearly with increasing GAA addition. As for the blood metabolites, concentrations of glucose, urea nitrogen and methionine were unchanged, total protein, albumin, creatine and homocysteine increased linearly, and folate decreased linearly with increasing GAA supply. CONCLUSION: The results of the present study indicate that supplementation of GAA improved milk performance and rumen fermentation in lactating dairy cows. [ABSTRACT FROM AUTHOR]- Published
- 2023
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11. Deletion of the middle region of the transcription factor ClrB in Penicillium oxalicum enables cellulase production in the presence of glucose
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Shiying Li, Guodong Liu, Yanning Xu, Yuqi Qin, Xin Song, Chengqiang Xia, Liwei Gao, Yinbo Qu, and Jiadi Xu
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0301 basic medicine ,chemistry.chemical_classification ,Reporter gene ,030102 biochemistry & molecular biology ,biology ,Chemistry ,Aspergillus niger ,Catabolite repression ,Repressor ,Cell Biology ,Cellulase ,biology.organism_classification ,Biochemistry ,Yeast ,03 medical and health sciences ,030104 developmental biology ,Enzyme ,Transcriptional regulation ,biology.protein ,Molecular Biology - Abstract
Enzymes that degrade lignocellulose to simple sugars are of great interest in research and for biotechnology because of their role in converting plant biomass to fuels and chemicals. The synthesis of cellulolytic enzymes in filamentous fungi is tightly regulated at the transcriptional level, with the transcriptional activator ClrB/CLR-2 playing a critical role in many species. In Penicillium oxalicum, clrB overexpression could not relieve the dependence of cellulase expression on cellulose as an inducer, suggesting that clrB is controlled post-transcriptionally. In this study, using a reporter gene system in yeast, we identified the C-terminal region of ClrB/CLR-2 as a transcriptional activation domain. Expression of clrBID, encoding a ClrB derivative in which the DNA-binding and transcriptional activation domains are fused together to remove the middle region, led to cellulase production in the absence of cellulose in P. oxalicum. Strikingly, the clrBID-expressing strain produced cellulase on carbon sources that normally repress cellulase expression, including glucose and glycerol. Results from deletion of the carbon catabolite repressor gene creA in the clrBID-expressing strain suggested that the effect of clrBID is independent of CreA's repressive function. A similar modification of clrB in Aspergillus niger resulted in the production of a mannanase in glucose medium. Taken together, these results indicate that ClrB suppression under noninducing conditions involves its middle region, suggesting a potential strategy to engineer fungal strains for improved cellulase production on commonly used carbon sources.
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- 2019
12. Introduction of heterologous transcription factors and their target genes into Penicillium oxalicum leads to increased lignocellulolytic enzyme production
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Yanning Xu, Xin Song, Qin Yan, Shiying Li, Liwei Gao, Yinbo Qu, Piao Yang, Zhonghai Li, Yanan Wang, and Chengqiang Xia
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Transcription, Genetic ,Cellulase ,Biology ,Lignin ,Applied Microbiology and Biotechnology ,Neurospora crassa ,03 medical and health sciences ,Gene Expression Regulation, Fungal ,Transcriptional regulation ,Promoter Regions, Genetic ,Gene ,Trichoderma reesei ,030304 developmental biology ,Trichoderma ,Enzyme Gene ,0303 health sciences ,030306 microbiology ,Penicillium ,General Medicine ,biology.organism_classification ,Biochemistry ,Xylanase ,biology.protein ,Heterologous expression ,Genetic Engineering ,Transcription Factors ,Biotechnology - Abstract
Genetic engineering of transcription factors is an efficient strategy to improve lignocellulolytic enzyme production in fungi. In this study, the xylanase transcriptional regulators of Trichoderma reesei (Xyr1) and Neurospora crassa (XLR-1), as well as their constitutively active mutants (Xyr1A824V and XLR-1A828V), were heterologously expressed in Penicillium oxalicum. The two heterologous regulators were identified to be able to activate lignocellulolytic enzyme gene expression in P. oxalicum. Particularly, expression of T. reesei Xyr1 resulted in a higher cellulase production level compared with the expression of native xylanase transcriptional regulator XlnR using the same promoter. Xyr1A824V and XLR-1A828V were found to be able to confer P. oxalicum more enhanced lignocellulolytic abilities than wild-type regulators Xyr1 and XLR-1. Furthermore, introduction of regulatory modules containing Xyr1A824V/XLR-1A828V and their target cellulase genes resulted in greater increases in cellulase production than alone expression of transcriptional regulators. Through the cumulative introduction of three regulatory modules containing regulator mutants and their corresponding target cellulase genes from P. oxalicum, T. reesei, and N. crassa, a 2.8-fold increase in cellulase production was achieved in P. oxalicum.
- Published
- 2019
13. Constitutive Expression of Chimeric Transcription Factors Enables Cellulase Synthesis under Non-Inducing Conditions in Penicillium oxalicum
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Yinbo Qu, Lele Yu, Zhonghai Li, Jiadi Xu, Guodong Liu, Liwei Gao, Chengqiang Xia, and Xin Song
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0301 basic medicine ,Glycoside Hydrolases ,Mutant ,Cellulase ,Biology ,Applied Microbiology and Biotechnology ,Microbiology ,law.invention ,Fungal Proteins ,03 medical and health sciences ,chemistry.chemical_compound ,law ,Inducer ,Cellulose ,Transcription factor ,Penicillium ,General Medicine ,DNA-binding domain ,Recombinant Proteins ,030104 developmental biology ,chemistry ,Biochemistry ,Metabolic Engineering ,Cellulosic ethanol ,Recombinant DNA ,biology.protein ,Molecular Medicine ,Transcription Factors - Abstract
Industrial production of cellulase by filamentous fungi is largely dependent on cellulose, which serves as a natural inducer of cellulase expression. However, insoluble cellulose is unfavorable to submerged fermentation and thus limits the production level of cellulase. Here, the possibility of cellulase production under non-inducing conditions was explored in Penicillium oxalicum by overexpressing two chimeric transcription factors. The chimeric transcription factors contain the DNA binding domain of cellulase transcriptional activator ClrB linked to the C-terminal sequences of XlnRA871V, a constitutively active mutant of hemicellulase transcriptional activator. The obtained recombinant mutants exhibited dramatically improved basal production of cellulase, which was not observed with the overexpression of intact ClrB. When cultivated in a complex cellulosic medium, one of these mutants, OE-CXC-S-1, displayed a 7.3-fold increase in cellulase production (2.8 U/mL) relative to the parent strain. The results demonstrated that the dependence of cellulase synthesis on cellulose could be reduced by the overexpression of artificially designed chimeric transcription factors, and offered a potential strategy to engineer fungal strains for improving cellulase production.
- Published
- 2017
14. MOESM7 of Combining manipulation of transcription factors and overexpression of the target genes to enhance lignocellulolytic enzyme production in Penicillium oxalicum
- Author
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Liwei Gao, Zhonghai Li, Chengqiang Xia, Yinbo Qu, Liu, Meng, Piao Yang, Yu, Lele, and Song, Xin
- Abstract
Additional file 7. Fig. S7 Enzyme activity analysis and phenotype observation of the transformant RE-7-2. FPase (A) and xylanase activities (B) of RE-6 and RE-7-2 strains on wheat bran at 72 h, 96 h and 120 h were determined. Error bars represent the standard deviations. (C) Phenotypic analysis of RE-6 and three parallel transformants (RE-7, RE-7-1 and RE-7-2) on glucose plate after 4 days’ cultivation.
- Published
- 2017
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15. Study on Comparative Histology of Retinas in Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans, Gekko japonicus, and Columba livia
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Yunfei Kong, Qiusheng She, Zhenqiang An, Enxiang Chen, and Chengqiang Xia
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Histology ,Anatomy ,Biology ,biology.organism_classification ,Retina ,Bufo bufo gargarizans ,Cynops orientalis ,Columba livia ,Ctenopharyngodon idella ,Comparative histology ,Gekko japonicus ,Gekko japonicas - Abstract
El objetivo de este estudio fue explorar la relacion entre las estructuras de la retina y su adaptacion al medioambiente en Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans,Gekko japonicus y Columba livia . La medicion del espesor de cada capa de la retina, la capa nuclear y su diametro en los cinco animales, mostro a traves del analisis estadistico que las capas nucleares en todos ellos fueron 4, y sus estructuras se pueden dividir en 10 capas cuando se observan con el microscopio optico. El espesor de la retina de Ctenopharyngodon idella fue 190,49 µm, de Cynops orientalis fue 173,07 µm, de Bufo bufo gargarizans fue 195,06 µm, de Gekko japonicus fue 224,32 µm y de Columba livia fue 174,10 µm. El numero de capas nucleares internas de la retina de Bufo gargarizans, Gekko japonicus y Columba livia fue mayor que sus capas nucleares externas, mientras que las capas nucleares internas de Ctenopharyngodon idella y Cynops orientalis fueron menos que las capas nucleares externas. La capa de conos y bastones de la retina de Cynops orientalis fue mas desarrollada, pero su capa de fibras nerviosas presento una elevada degeneracion, lo que muestra una gran fotosensibilidad, pero una sensibilidad visual baja. En Columba livia, la capa de fibras nerviosas de la retina estuvo muy desarrollada, y de esta manera, su vision. El grado de desarrollo de las diferentes estructuras y funciones de la retina de Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans, Gekko japonicus y Columba livia esta relacionada con sus caracteristicas de comportamiento y el cambio de las condiciones de las vidas acuatica y anfibia en la tierra.
- Published
- 2014
16. Mutation of a Conserved Alanine Residue in Transcription Factor AraR Leads to Hyperproduction of α‐<scp>l</scp>‐Arabinofuranosidases inPenicillium oxalicum
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Yuqi Qin, Guodong Liu, Xin Song, Yinbo Qu, Chengqiang Xia, Yanning Xu, Jiadi Xu, Shiying Li, Jun Liu, and Liwei Gao
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Alanine ,chemistry.chemical_classification ,Glycoside Hydrolases ,biology ,Catabolism ,Chemistry ,Activator (genetics) ,Mutant ,Penicillium ,General Medicine ,biology.organism_classification ,Arabinose ,Applied Microbiology and Biotechnology ,Fungal Proteins ,Enzyme ,Biochemistry ,Mutation ,Molecular Medicine ,Genetic Engineering ,Gene ,Transcription factor ,Transcription Factors - Abstract
α-l-Arabinofuranosidases are important in the degradation of plant polysaccharides and are used in several industrial processes. Although the use of filamentous fungi for the production of α-l-arabinofuranosidases is widely reported, there are few reports on strain engineering for enhanced production of these enzymes by fungi. In this study, the function of transcription factor AraR in l-arabinose release and catabolism by the fungus Penicillium oxalicum (P. oxalicum) is investigated. Also, a mutant of AraR, AraRA731V , is constructed to improve the production of α-l-arabinofuranosidases on the basis of the sequence homology between AraR and the xylanolytic gene activator XlnR. The AraRA731V -overexpressing strain can synthesize α-l-arabinofuranosidase in the absence of an inducer and shows a 54.1-fold increase in α-l-arabinofuranosidase production and a 7.4-fold increase in α-galactosidase production in the medium containing wheat bran. Determination of the transcript abundances of lignocellulolytic enzyme genes reveals significant upregulation of multiple α-l-arabinofuranosidase genes and downregulation of some cellulolytic and xylanolytic enzyme genes in the engineered strain relative to its parent. Taken together, the results suggest the conserved regulatory function of AraR in the family Trichocomaceae and provide a strategy for engineering fungal strains for enhanced α- l-arabinofuranosidase production.
- Published
- 2019
17. Identification and characterization of a long-chain fatty acid transporter in the sophorolipid-producing strain Starmerella bombicola
- Author
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Xin Song, Jiashan Li, Chengqiang Xia, Haizhao Xue, and Xiaoran Fang
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0301 basic medicine ,Coenzyme A ,Mutant ,Biology ,Applied Microbiology and Biotechnology ,Maltose-Binding Proteins ,03 medical and health sciences ,chemistry.chemical_compound ,Affinity chromatography ,Coenzyme A Ligases ,Escherichia coli ,Amino Acid Sequence ,chemistry.chemical_classification ,Fatty Acid Transport Proteins ,Sophorolipid ,Fatty Acids ,Fatty acid ,Biological Transport ,General Medicine ,Recombinant Proteins ,030104 developmental biology ,Enzyme ,chemistry ,Biochemistry ,Saccharomycetales ,Long chain fatty acid ,Glycolipids ,Sequence Alignment ,Biotechnology - Abstract
The sophorolipid-producing strain Starmerella bombicola CGMCC 1576 has a remarkable ability to produce sophorolipids (SLs) under the acidic and lactonic forms with almost equal proportion. In this study, we found the gene encoding for the long-chain acyl-CoA synthetase (ALCS). This enzyme was putatively identified as a membrane-bound long-chain fatty acid transport protein and contributed to the uptake of long-chain fatty acids. Disruption of the alcs gene resulted in an impaired growth of the alcs-deleted mutant in minimal media containing different fatty acids (C12:0, C14:0, C16:0, C18:0, C22:0, and C24:0) as the sole carbon source and led to a dramatic decrease in the uptake of the fluorescent-tagged long-chain fatty acid analogue—boron dipyrromethene difluoride dodecanoic acid (BODIPY-3823). The absence of this alcs gene caused obvious phenotype changes. Compared with the wild-type strain, the yield and compositions of the SLs produced by the gene-deleted mutant of ∆alcs::six showed almost no lactonic form of SLs, and the acidic SLs were composed of medium-chain. The ALCS enzyme was heterologously expressed in Escherichia coli JM109 (DE3) with pMAL-c2x-alcs. The enzyme was purified through a maltose-binding protein (MBP) affinity chromatography column and was confirmed to be homogeneous by SDS-PAGE. The recombinant enzyme could catalyze the formation of the long-chain acyl-CoA when the long-chain fatty acids and the coenzyme A were used as substrates.
- Published
- 2016
18. Identification and characterization of a flavin-containing monooxygenase MoA and its function in a specific sophorolipid molecule metabolism in Starmerella bombicola
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Weiwei Li, Xin Song, Jiashan Li, Hui Li, and Chengqiang Xia
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0301 basic medicine ,Molecular Sequence Data ,Flavin-containing monooxygenase ,Biology ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,Fungal Proteins ,03 medical and health sciences ,Affinity chromatography ,Ascomycota ,medicine ,Amino Acid Sequence ,Escherichia coli ,Phylogeny ,chemistry.chemical_classification ,Fungal protein ,Molecular Structure ,Sophorolipid ,Fatty Acids ,food and beverages ,General Medicine ,Monooxygenase ,Yeast ,030104 developmental biology ,Enzyme ,chemistry ,Biochemistry ,Oxygenases ,lipids (amino acids, peptides, and proteins) ,Sequence Alignment ,Biotechnology - Abstract
The yeast Starmerella bombicola CGMCC 1576 can produce abundant sophorolipids (SLs) including almost equal proportion of acidic and lactonic SLs. In this study, a monooxygenase MoA responsible for the metabolism of a sophorolipid molecule, C18:2 diacetylated acidic sophorolipid (C18:2 DASL), was identified, through genomic analysis, protein modeling, and gene knocking out strategy. The yield and compositions of SLs produced by the deletion mutant ∆moA changed dramatically. In HPLC chromatogram, the UV absorption area of C18:2 DASL (one major acidic sophorolipid component) increased from 9.84 × 10(6) mAU × s to 34.26 × 10(6) mAU × s by an increase of 248.17 % when oleic acid was used as hydrophobic carbon source. Moreover, when linoleic acid was used as hydrophobic carbon source, the content of C18:2 DASL component produced by the overexpressed strain Peno::moA decreased significantly compared with that of wild type and △moA. Furthermore, the MoA enzyme was heterologously expressed in Escherichia coli JM109 (DE3) with a recombinant plasmid named pMAL-c2x-moA, and the purified enzyme was obtained through a maltose-binding protein (MBP) affinity chromatography column. The purified C18:2 DASL and C18:1 DASL were applied to be catalyzed by MoA enzyme, respectively; it turned to be that C18:1 DASL still remained in the MoA reaction system, but C18:2 DASL disappeared.
- Published
- 2015
19. A Research of Peripheral Blood Cells Annually in Bufo Bufo gargarizans
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Chongbin Liu, Zhaohui Xie, Qiusheng She, Yang Jiao, and Chengqiang Xia
- Subjects
Blood cells ,media_common.quotation_subject ,Annual changes ,Art ,Anatomy ,Humanities ,Bufo Bufo gargarizans ,Peripheral blood ,Bufo bufo gargarizans ,media_common - Abstract
Se realizo el presente estudio histologico de las celulas sanguineas de Bufo Bufo gargarizans en diferentes meses del ano: enero, marzo, mayo, julio y octubre. Fueron utilizados metodos de rutina por frotis de sangre con tincion de Wright y observacion in vivo. Encontramos dos tipos principales de celulas de globulos rojos al frotis como tambien en celulas in vivo: mitoticas y amitoticas. Por cuanto amitosis se produce durante todo el ano, sobre todo en el mes de julio, la mitosis hasta el momento se habia observado solamente en julio. Ademas, se encontro una gran cantidad de neutrofilos en los globulos de Bufo Bufo gargarizans. Los nucleos de estas celulas son polimorficos, especialmente en enero y marzo. La concentracion de globulos rojos era mas bajo en mayo y mas alta en enero; la concentracion de las celulas blancas de la sangre fue mayor en octubre y menor en marzo. En cuanto a los granulocitos, eosinofilos estos presentaron una mayor proporcion en julio y octubre, mientras que los neutrofilos y basofilos registraran una mayor proporcion en el mes de julio. Los agranulocitos y las celulas mononucleares alcanzaron el valor mas alto en marzo, y el valor mas bajo en enero. Los linfocitos y el valor maximo fue registrado en mayo, el valor mas bajo fue registrado en julio. No fueron evidentes los cambios morfologicos de trombocitos, lo que podria tener relacion con su estabilidad.
- Published
- 2013
20. Study on Comparative Histology of Retinas in Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans, Gekko japonicus, and Columba livia.
- Author
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Qiusheng She, Zhenqiang An, Chengqiang Xia, Yunfei Kong, and Enxiang Chen
- Subjects
- *
ROCK pigeon , *CTENOPHARYNGODON idella , *MORPHOLOGY , *COMPARATIVE anatomy , *MORPHOGENESIS , *SEGMENTATION (Biology) - Abstract
The objective of this study was to explore the relationship between the retinal structure and its life adaptation to the environment of Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans, Gekko japonicus and Columba livia . Measuring retinal thickness of each layer, the nuclei layer, and the diameter of each nuclear layer of the five animals, the statistical data analysis shows that: the nuclei layers of five animals are all 4, and their structures can be divided to 10 layers when observing with optical microscope. The retinal thickness of Ctenopharyngodon idella was 190.49 mm, Cynops orientalis was 173.07 mm, and the Bufo bufo gargarizans was 195.06 mm, Gekko japonicus was 224.32 mm and Columba livia was 174.10 mm. The number of retinal inner nuclear layers of Bufo bufo gargarizans and Gekko japonicus and Columba livia are more than their outer nuclear layers, on the contrary, retinal inner nuclear layers of Ctenopharyngodon idella and Cynops orientalis are less than their outer nuclear layers. The rod and cone layer of retina of Cynops orientalis were more advanced, but their nerve fiber layer (NFL) degraded highly, revealing a strong photosensitivity but a low visual sensitivity; to Columba livia, their NFL of retina are highly developed, so as their vision. The different structures and functions of the retina of Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans, Gekko japonicus and Columba livia correspond with their behavioral characteristics and the living environment's change from aquatic to amphibious to land. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
21. Deletion of the middle region of the transcription factor ClrB in Penicillium oxalicum enables cellulase production in the presence of glucose.
- Author
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Liwei Gao, Yanning Xu, Xin Song, Shiying Li, Chengqiang Xia, Jiadi Xu, Yuqi Qin, Guodong Liu, and Yinbo Qu
- Subjects
- *
CELLULASE , *TRANSCRIPTION factors , *BIOMASS chemicals , *PENICILLIUM , *GLUCOSE , *PLANT biomass , *LIGNOCELLULOSE - Abstract
Enzymes that degrade lignocellulose to simple sugars are of great interest in research and for biotechnology because of their role in converting plant biomass to fuels and chemicals. The synthesis of cellulolytic enzymes in filamentous fungi is tightly regulated at the transcriptional level, with the transcriptional activator ClrB/CLR-2 playing a critical role in many species. In Penicillium oxalicum, clrB overexpression could not relieve the dependence of cellulase expression on cellulose as an inducer, suggesting that clrB is controlled post-transcriptionally. In this study, using a reporter gene system in yeast, we identified the C-terminal region of ClrB/CLR-2 as a transcriptional activation domain. Expression of clrBID, encoding a ClrB derivative in which the DNA-binding and transcriptional activation domains are fused together to remove the middle region, led to cellulase production in the absence of cellulose in P. oxalicum. Strikingly, the clrBID-expressing strain produced cellulase on carbon sources that normally repress cellulase expression, including glucose and glycerol. Results from deletion of the carbon catabolite repressor gene creA in the clrBID-expressing strain suggested that the effect of clrBID is independent of CreA's repressive function. A similar modification of clrB in Aspergillus niger resulted in the production of a mannanase in glucose medium. Taken together, these results indicate that ClrB suppression under noninducing conditions involves its middle region, suggesting a potential strategy to engineer fungal strains for improved cellulase production on commonly used carbon sources. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
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