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1.
J Med Chem ; 67(7): 5945-5956, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38504504

RESUMO

Multivalent glycosidase inhibitors based on 1-deoxynojirimycin derivatives against α-glucosidases have been rapidly developed. Nonetheless, the mechanism based on self-assembled multivalent glucosidase inhibitors in living systems needs to be further studied. It remains to be determined whether the self-assembly possesses sufficient stability to endure transit through the small intestine and subsequently bind to the glycosidases located therein. In this paper, two amphiphilic compounds, 1-deoxynojirimycin and α-peptoid conjugates (LP-4DNJ-3C and LP-4DNJ-6C), were designed. Their self-assembling behaviors, multivalent α-glucosidase inhibition effect, and fluorescence imaging on living organs were studied. LP-4DNJ-6C exhibited better multivalent α-glucosidase inhibition activities in vitro. Moreover, the self-assembly of LP-4DNJ-6C could effectively form a complex with Nile red. The complex showed fluorescence quenching effect upon binding with α-glucosidases and exhibited potent fluorescence imaging in the small intestine. This result suggests that a multivalent hypoglycemic effect achieved through self-assembly in the intestine is a viable approach, enabling the rational design of multivalent hypoglycemic drugs.


Assuntos
1-Desoxinojirimicina , Hipoglicemiantes , Hipoglicemiantes/farmacologia , Hipoglicemiantes/metabolismo , 1-Desoxinojirimicina/farmacologia , alfa-Glucosidases/metabolismo , Inibidores Enzimáticos/farmacologia , Glicosídeo Hidrolases , Inibidores de Glicosídeo Hidrolases/farmacologia
2.
Bioresour Technol ; 378: 129013, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37019414

RESUMO

Azo dyes are significant organic pollutants known for their adverse effects on humans and aquatic life. In this study, anthraquinone-2-sulfonate (AQS) immobilized on biochar (BC) was employed as a novel carrier in up-flow anaerobic fixed-bed reactors to induce specific biofilm formation and promote the biotransformation efficiency of azo dyes. Novel carrier-packed reactor 1 (R1) and BC-packed reactor 2 (R2) were used to treat red reactive 2 (RR2) under continuous operation for 175 days. The decolorization rates of R1 and R2 were 96-83% and 91-73%, respectively. The physicochemical characteristics and extracellular polymeric substances (EPS) of the biofilm revealed a more stable structure in R1. Furthermore, the microbial community in R1 interacted more closely with each other and contained more keystone genera. Overall, this study provides a feasible method for improving the biotransformation of azo dyes, thus providing support for practical applications in wastewater treatment projects.


Assuntos
Compostos Azo , Corantes , Humanos , Compostos Azo/química , Anaerobiose , Corantes/química , Biofilmes , Reatores Biológicos
3.
Bioorg Chem ; 132: 106373, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36681043

RESUMO

Synthetic glycoconjugates as chemical probes have been widely developed for the detection of glycosidase enzymes. However, the binding interactions between iminosugar derivatives and glycosidases were limited, especially for the binding interactions between multivalent glycosidase inhibitors and α-glycosidases. In this paper, three naphthalimide-DNJ conjugates were synthesized. Furthermore, the binding interactions and glycosidase inhibition effects of them were investigated. It was found that the strong binding interactions of multivalent glycosidase inhibitors with enzymes were related to the efficient inhibitory activity against glycosidase. Moreover, the lengths of the chain between DNJ moieties and the triazole ring for the naphthalimide-DNJ conjugates influenced the self-assembly properties, binding interactions and glycosidase inhibition activities with multisource glycosidases. Compound 13 with six carbons between the DNJ moiety and triazole ring showed the stronger binding interactions and better glycosidase inhibition activities against α-mannosidase (jack bean) and α-glucosidase (aspergillus niger). In addition, compound 13 showed an effective PBG inhibition effect in mice with 51.18 % decrease in blood glucose at 30 min. This result opens a way for detection of multivalent glycosidase inhibition effect by a fluorescent sensing method.


Assuntos
Inibidores Enzimáticos , Glicosídeo Hidrolases , Camundongos , Animais , Inibidores Enzimáticos/química , Glicosídeo Hidrolases/metabolismo , Naftalimidas/farmacologia , Fluorescência , alfa-Manosidase
4.
Synth Syst Biotechnol ; 8(1): 33-45, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36381963

RESUMO

The current petroleum chemical methods for fumaric acid production can cause heavy pollution and global warming. In this study, the engineered strains of A. pullulans var. aubasidani were found to be suitable for green fumaric acid producer. Removal and complementation of the relevant genes showed only the ornithine-urea cycle (OUC) was involved in high level fumarate biosynthesis which was controlled by the Ca2+ signaling pathway. Removal of both the GOX gene encoding glucose oxidase and the PKS1 gene encoding the polyketide synthase for 3,5-dihydroxydecanoic acid biosynthesis and overexpression of the PYC gene encoding pyruvate carboxylase made the strain e-PYC produce 88.1 ± 4.3 g/L of fumarate at flask level and 93.9 ± 0.8 g/L of fumarate during the fed-batch fermentation. As a yeast-like fungal strain, it was very easy to cultivate A. pullulans var. aubasidani DH177 and their mutants in the bioreactor and to edit its genomic DNAs to enhance fumarate production. It was found that 2 mol of CO2 could be fixed during a maximal theoretical yield of 2 mol of fumarate per mole of glucose consumed in the OUC. Therefore, the OUC-mediated fumarate biosynthesis pathway in A. pullulans var. aubasidani was a green and eco-friendly process for the global sustainable development and carbon neutrality.

5.
Eur J Med Chem ; 241: 114621, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-35931006

RESUMO

Although multivalent glucosidase inhibitors based on iminosugars have shown enhanced inhibition activity, an effective way to improve their hypoglycemic effect in vivo, is still in infancy and needs further development. In this paper, PBI-5DNJ and PBI-6DNJ, with three or four DNJ moieties respectively conjugated at the bay position were synthesized. PBI-6DNJ evidenced stronger π-π stacking interactions and, when self-assembled, a smaller size than that of PBI-5DNJ. It was found that PBI-6DNJ exhibited superior α-glucosidases (from mice) inhibition activity (Ki = 0.14 ± 0.007 µM) in vitro than that (Ki = 0.31 ± 0.01) of PBI-5DNJ and in vivo hypoglycemic effects in mice models. PBI-6DNJ possessed good hypoglycemic effects with the percentages of PBG levels of 40.40 ± 3.33% and 39.23 ± 4.84% at a dose of 2.0 mg/kg after 15 min and 30 min of administration, respectively. In terms of measuring percentage decrease of PBG level per DNJ unit, PBI-6DNJ displayed a 2.1-fold enhancement than miglitol, demonstrating a consistency between in vitro and in vivo experiments. This paves the way to the connection between in vivo hypoglycemic potency and in vitro glucosidase inhibition assay, leading to reliable and simplified assessment of hypoglycemic potency determination, and opening a basic understanding of the design of multivalent glucosidase inhibitors.


Assuntos
Imidas , Perileno , Animais , Inibidores Enzimáticos/farmacologia , Hipoglicemiantes/farmacologia , Camundongos , Perileno/análogos & derivados , alfa-Glucosidases
6.
Environ Res ; 206: 112630, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-34973940

RESUMO

With the acceleration of urbanization, the proportion of surface imperviousness is increasing continuously in cities, resulting in frequent waterlogging disasters. In this context, storm water management, based on the low-impact development (LID) concept, offers an effective measure for the management of urban storm waters. First, the storm water management model (SWMM) was built for a typical cold climate city (Changchun) in China. Next, the two-stage calibrated model was employed to explore the surface runoff and storm sewer control effects of four LID combination plans. Finally, these plans were put through a "cost-benefit" evaluation through an analytic hierarchy process. According to the results, after using four LID plans, the reduction rates of peak runoff exceeded 40% and the problem of overflow load of the storm sewage was significantly mitigated. The infiltration-oriented Plan I proved to be the optimal plan, with the lowest proportions of the overflow nodes and full-load pipe sections in each return period, as well as with maximum overall performance. This study offers technical and conformed methodological support to cold cities for the prevention and control of waterlogging disasters and recycling of rainwater resources.


Assuntos
Chuva , Movimentos da Água , China , Cidades , Clima Frio , Urbanização
7.
Sci Total Environ ; 789: 147761, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34051500

RESUMO

The interactive effects of both biochar (BC) and electrochemistry (EC) can affect nitrogen (N) removal process. However, little is known about how this function in constructed wetland (CW) systems. In this study, an electrochemically (EC) coupled BC-amended saturated subsurface vertical flow constructed wetland (BECW) systems were established to enhance nitrogen (N) removal. Other three CW systems: without BC and EC (CW); with EC only (ECW); and with BC only (BCW) were performed as controls. Results indicated that the total nitrogen (59.88%-93.03%) and nitrate­nitrogen (83.14%-100%) of the BECW system were significantly enhanced (p < 0.05) compared with the control systems. Treated WWTP tail-water could meet Class-IV of the Surface Water Quality Standard (GB3838-2002) in China by the BECW system. The enhanced N removal in the BECW system could be attributed to (1) the autotrophic denitrification process in which H2 and Fe2+ provided by the cathode and anode acted as electron donors; and (2) BC addition acting as substrate could improve the activity, diversity and richness of microorganisms. Microbial community analysis further indicated that high N removal in the BECW system was significantly dependent on the synergy between the heterotrophic and autotrophic denitrifiers, facilitated by BC and EC interaction. Results illustrate that the BECW system is a feasible and eco-sustainable technology for treating low C/N tail-water from WWTPs. This work provides a novel and fundamental understanding of the electrochemically coupled biochar-amended CW system. These results could serve as a theoretical basis for the engineered applications in the deep purification of WWTPs' tail-water.


Assuntos
Nitrogênio , Áreas Alagadas , Carvão Vegetal , China , Desnitrificação , Eletroquímica , Eliminação de Resíduos Líquidos , Águas Residuárias
8.
Microb Cell Fact ; 16(1): 179, 2017 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-29084554

RESUMO

BACKGROUND: 3-Hydroxypropionic acid (3-HP) is an important platform chemical, serving as a precursor for a wide range of industrial applications such as the production of acrylic acid and 1,3-propanediol. Although Escherichia coli or Saccharomyces cerevisiae are the primary industrial microbes for the production of 3-HP, alternative engineered hosts have the potential to generate 3-HP from other carbon feedstocks. Methylobacterium extorquens AM1, a facultative methylotrophic α-proteobacterium, is a model system for assessing the possibility of generating 3-HP from one-carbon feedstock methanol. RESULTS: Here we constructed a malonyl-CoA pathway by heterologously overexpressing the mcr gene to convert methanol into 3-HP in M. extorquens AM1. The engineered strains demonstrated 3-HP production with initial titer of 6.8 mg/l in shake flask cultivation, which was further improved to 69.8 mg/l by increasing the strength of promoter and mcr gene copy number. In vivo metabolic analysis showed a significant decrease of the acetyl-CoA pool size in the strain with the highest 3-HP titer, suggesting the supply of acetyl-CoA is a potential bottleneck for further improvement. Notably, 3-HP was rapidly degraded after the transition from exponential phase to stationary phase. Metabolomics analysis showed the accumulation of intracellular 3-hydroxypropionyl-CoA at stationary phase with the addition of 3-HP into the cultured medium, indicating 3-HP was first converted to its CoA derivatives. In vitro enzymatic assay and ß-alanine pathway dependent 13C-labeling further demonstrated that a reductive route sequentially converted 3-HP-CoA to acrylyl-CoA and propionyl-CoA, with the latter being reassimilated into the ethylmalonyl-CoA pathway. The deletion of the gene META1_4251 encoding a putative acrylyl-CoA reductase led to reduced degradation rate of 3-HP in late stationary phase. CONCLUSIONS: We demonstrated the feasibility of constructing the malonyl-CoA pathway in M. extorquens AM1 to generate 3-HP. Furthermore, we showed that a reductive route coupled with the ethylmalonyl-CoA pathway was the major channel responsible for degradation of the 3-HP during the growth transition. Engineered M. extorquens AM1 represents a good platform for 3-HP production from methanol.


Assuntos
Ácido Láctico/análogos & derivados , Methylobacterium extorquens/metabolismo , Acil Coenzima A/genética , Acil Coenzima A/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Técnicas de Cultura Celular por Lotes , Isótopos de Carbono/química , Isótopos de Carbono/metabolismo , Cromatografia Líquida de Alta Pressão , Coenzima A Ligases/genética , Coenzima A Ligases/metabolismo , Transportadores de Ácidos Dicarboxílicos/deficiência , Transportadores de Ácidos Dicarboxílicos/genética , Engenharia Genética , Marcação por Isótopo , Ácido Láctico/análise , Ácido Láctico/biossíntese , Espectrometria de Massas , Metabolômica , Metanol/metabolismo , Methylobacterium extorquens/genética , Methylobacterium extorquens/crescimento & desenvolvimento , Regiões Promotoras Genéticas
9.
Int J Med Mushrooms ; 18(7): 621-30, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27649730

RESUMO

A new Grifola frondosa mutant, M270, was successfully isolated for high production of exopolysaccharides (EPSs) using cosmic radiation-induced mutagenesis. We found that the mutant M270 had a clearer and thicker EPS layer (~10 µm) adhering to mycelia than those of its parent strain 265 after Congo red staining. In the 20-L batch fermentation for M270, 10.3 g/L of EPS and 17.9 g/L of dry mycelia biomass were obtained after 204 hours of fermentation. Furthermore, a main water-soluble fraction (EP1) in the EPS was purified from M270 and then confirmed to be heteroglycan-protein complex with 91% (w/w) total carbohydrates and 9% (w/w) total proteins. Four kinds of monosaccharide-D-mannose, D-glucosamine, D-glucose, and D-xylose-were detected in EP1 with a molar ratio of 17.6:1.8:100:2.5. The molecular mass of the main component in EP1 was 8.9 kDa. The EPS from M270 significantly inhibited the growth of sarcoma 180 solid tumors in mice. This G. frondosa M270 mutant could serve as a better candidate strain for polysaccharide production.


Assuntos
Polissacarídeos Fúngicos/metabolismo , Grifola/química , Grifola/genética , Animais , Polissacarídeos Fúngicos/genética , Proteínas Fúngicas , Regulação Fúngica da Expressão Gênica , Camundongos , Mutação , Neoplasias Experimentais/tratamento farmacológico , Filogenia , Distribuição Aleatória , Sarcoma 180/tratamento farmacológico , Organismos Livres de Patógenos Específicos
10.
Mar Pollut Bull ; 108(1-2): 62-9, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-27184127

RESUMO

Both the whole cells and protoplasts of Pseudomonas aeruginosa PAO1 and Bacillus cereus, two biofilm-forming bacteria, were disrupted by the lipopeptide 6-2 produced by Bacillus amyloliquefaciens anti-CA. The lipopeptide 6-2 could also effectively inhibit the formation of biofilms and disperse pre-formed biofilms. Live/dead staining of the biofilms grown in the absence or presence of the lipopeptide 6-2 showed that more dead bacterial cells in the presence of the lipopeptide than those in the absence of the lipopeptide and biofilm formation was greatly reduced by the lipopeptide 6-2. Expression of the PslC gene related to exopolysaccharides in P. aeruginosa PAO1 was also inhibited. All these results demonstrated that the lipopeptide 6-2 produced by B. amyloliquefaciens anti-CA had a high activity against biofilm-forming bacteria. The lipopeptide 6-2 also killed the larvae of Balanus amphitrite and inhibit the germination of Laminaria japonica spore and growth of protozoa, all of which were the fouling organisms in marine environments.


Assuntos
Bacillus amyloliquefaciens , Biofilmes , Lipopeptídeos , Pseudomonas aeruginosa
11.
Crit Rev Biotechnol ; 36(1): 99-107, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25025277

RESUMO

l-Malic acid has many uses in food, beverage, pharmaceutical, chemical and medical industries. It can be produced by one-step fermentation, enzymatic transformation of fumaric acid to l-malate and acid hydrolysis of polymalic acid. However, the process for one-step fermentation is preferred as it has many advantages over any other process. The pathways of l-malic acid biosynthesis in microorganisms are partially clear and three metabolic pathways including non-oxidative pathway, oxidative pathway and glyoxylate cycle for the production of l-malic acid from glucose have been identified. Usually, high levels of l-malate are produced under the nitrogen starvation conditions, l-malate, as a calcium salt, is secreted from microbial cells and CaCO3 can play an important role in calcium malate biosynthesis and regulation. However, it is still unclear how it is secreted into the medium. To enhance l-malate biosynthesis and secretion by microbial cells, it is very important to study the mechanisms of l-malic acid biosynthesis and secretion at enzymatic and molecular levels.


Assuntos
Bactérias/metabolismo , Fermentação , Fumarato Hidratase/metabolismo , Malatos/metabolismo , Bactérias/citologia , Indústria Alimentícia , Fumarato Hidratase/química , Glucose/metabolismo , Glioxilatos/metabolismo , Hidrólise , Malatos/química
12.
Crit Rev Biotechnol ; 35(2): 222-34, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24102112

RESUMO

Killer toxins secreted by some yeast strains are the proteins that kill sensitive cells of the same or related yeast genera. In recent years, many new yeast species have been found to be able to produce killer toxins against the pathogenic yeasts, especially Candida albicans. Some of the killer toxins have been purified and characterized, and the genes encoding the killer toxins have been cloned and characterized. Many new targets including different components of cell wall, plasma membrane, tRNA, DNA and others in the sensitive cells for the killer toxin action have been identified so that the new molecular mechanisms of action have been elucidated. However, it is still unknown how some of the newly discovered killer toxins kill the sensitive cells. Studies on the killer phenomenon in yeasts have provided valuable insights into a number of fundamental aspects of eukaryotic cell biology and interactions of different eukaryotic cells. Elucidation of the molecular mechanisms of their action will be helpful to develop the strategies to fight more and more harmful yeasts.


Assuntos
Fatores Matadores de Levedura , Biotecnologia , Candida
13.
Crit Rev Microbiol ; 41(2): 228-37, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25168340

RESUMO

The genus Aureobasidium spp. have been divided into three species, A. pullulans. A. leucospermi and A. proteae, and A. pullulans has been known to have five varieties. However, after analysis of many strains of this yeast isolated from different environments, they do not belong to any of the three species or the five varieties. Although pullulan produced by A. pullulans has been widely used in different fields in industry and different strains of this yeast has been known to produce poly(ß-L-malic acid) (PMA), heavy oils and ß-1,3-glucan, it is still unknown how the black yeast synthesizes and secretes the extracellular polymers at molecular level. In this review article, new biosynthetic pathways of pullulan, PMA and heavy oils, the enzymes and their genes related to their biosynthesis and regulation are proposed. Furthermore, some enzymes and their genes related to pullulan biosynthesis in A. pullulans have been characterized. But it is completely unknown how pullulan is secreted and how PMA, heavy oils and ß-1,3-glucan are synthesized and secreted. Therefore, there is much work to be done about taxonomy and biosynthesis, secretion and regulation of pullulan, PMA, heavy oils and ß-1,3-glucan at molecular levels in Aureobasidium spp.


Assuntos
Ascomicetos/classificação , Ascomicetos/metabolismo , Biopolímeros/metabolismo , Regulação Fúngica da Expressão Gênica , Ascomicetos/genética , Vias Biossintéticas/genética
14.
Mol Biotechnol ; 57(4): 337-47, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25432793

RESUMO

The INU1 gene encoding an exo-inulinase from the marine-derived yeast Candida membranifaciens subsp. flavinogenie W14-3 was cloned and characterized. It had an open reading frame of 1,536 bp long encoding an inulinase. The coding region of it was not interrupted by any intron. The cloned gene encoded 512 amino acid residues of a protein with a putative signal peptide of 23 amino acids and a calculated molecular mass of 57.8 kDa. The protein sequence deduced from the inulinase gene contained the inulinase consensus sequences (WMNDPNGL), (RDP), ECP FS and Q. The protein also had six conserved putative N-glycosylation sites. The deduced inulinase from the yeast strain W14-3 was found to be closely related to that from Candida kutaonensis sp. nov. KRF1, Kluyveromyces marxianus, and Cryptococcus aureus G7a. The inulinase gene with its signal peptide encoding sequence was subcloned into the pMIRSC11 expression vector and expressed in Saccharomyces sp. W0. The recombinant yeast strain W14-3-INU-112 obtained could produce 16.8 U/ml of inulinase activity and 12.5 % (v/v) ethanol from 250 g/l of inulin within 168 h. The monosaccharides were detected after the hydrolysis of inulin with the crude inulinase (the yeast culture). All the results indicated that the cloned gene and the recombinant yeast strain W14-3-INU-112 had potential applications in biotechnology.


Assuntos
Candida/enzimologia , Clonagem Molecular/métodos , Etanol/metabolismo , Proteínas Fúngicas/metabolismo , Glicosídeo Hidrolases/metabolismo , Saccharomyces/genética , Sequência de Aminoácidos , Sequência de Bases , Reatores Biológicos , Candida/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/genética , Modelos Moleculares , Dados de Sequência Molecular , Filogenia , Plasmídeos , Alinhamento de Sequência
15.
Appl Microbiol Biotechnol ; 99(4): 1637-45, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25427679

RESUMO

Yarrowia lipolytica ACA-DC 50109 is an oleaginous yeast. In order to know the function of pyruvate carboxylase (PYC) in lipid biosynthesis, the PYC gene cloned from Pichia guilliermondii Pcla22 was overexpressed in the oleaginous yeast. The lipid contents in the wild-type strain ACA-DC 50109 and the transformants P4, P7, and P103 were 30.2 % (w/w) 36.5 % (w/w), 38.2 % (w/w), and 37.9 % (w/w). However, the amount of the secreted citric acids by strains ACA-DC 50109, P4, P77, and P103 were 0.5, 10.1, 11.5, and 9.4 g/L. In order to reduce the amount of the secreted citric acid, the PYC gene and endogenous ACL1 gene encoding ATP citrate lyase (ACL1) were simultaneously overexpressed in the oleaginous yeast. The lipid contents of the transformants PA19, PA56, PA124 were 44.4 % (w/w), 45.3 % (w/w), and 43.7 % (w/w). At the same time, the amount of the secreted citric acid by the transformants PA19, PA56, and PA124 was reduced to 5.4, 6.2, and 6.3 g/L. The PYC and ACL1 activities and their gene transcriptional levels in all the transformants were greatly enhanced compared to those in their wild-type strain ACA-DC 50109. During 10-L fermentation, lipid content in the transformant PA56 was 49.6 % (w/w) and the amount of secreted citric acid was 2.9 g/L. This meant that PYC and ACL1 can play an important role in accumulation of intracellular lipid of the oleaginous yeast Y. lipolytica ACA-DC 50109.


Assuntos
Metabolismo dos Lipídeos , Pichia/enzimologia , Piruvato Carboxilase/metabolismo , Yarrowia/enzimologia , Yarrowia/metabolismo , Ácido Cítrico , Expressão Gênica , Pichia/genética , Piruvato Carboxilase/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Yarrowia/genética
16.
Appl Microbiol Biotechnol ; 97(20): 8931-9, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23948724

RESUMO

After over 100 strains of Aureobasidium spp isolated from mangrove system were screened for their ability to produce poly(ß-malic acid) (PMA), it was found that Aureobasidium sp. P6 strain among them could produce high level of Ca(2+)-PMA. Fourteen percent glucose and 6.5 % CaCO3 in the medium were the most suitable for Ca(2+)-PMA production. Then, 100.7 g/l of Ca(2+)-PMA was produced using Aureobasidium sp. P6 strain within 168 h at flask level. During 10-l batch fermentation, when the medium contained 12.0 % glucose, 98.7 g/l of Ca(2+)-PMA in the culture and 14.7 g/l of cell dry weight were obtained within 156 h, leaving 0.34 % reducing sugar in the fermented medium. When glucose concentration in the fermentation medium was 14.0 %, 118.3 g/l of Ca(2+)-PMA in the culture and 16.4 g/l of cell dry weight were obtained within 168 h, leaving 0.4 % reducing sugar in the fermented medium. After purification of Ca(2+)-PMA from the culture and acid hydrolysis of the pure Ca(2+)-PMA, analysis of HPLC showed that Aureobasidium sp. P6 strain only produced two main components of Ca(2+)-PMA and minor amount of calcium malate and that the hydrolysate of PMA was mainly composed of calcium malate. This is the first time to report that the novel yeast strain Aureobasidium sp. P6 strain isolated from the mangrove systems can produce such high amount of Ca(2+)-PMA.


Assuntos
Glucose/metabolismo , Malatos/metabolismo , Polímeros/metabolismo , Árvores/microbiologia , Leveduras/isolamento & purificação , Leveduras/metabolismo , China , Meios de Cultura/metabolismo , Fermentação , Dados de Sequência Molecular , Filogenia , Áreas Alagadas , Leveduras/classificação , Leveduras/genética
17.
Bioresour Technol ; 143: 674-7, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23831380

RESUMO

In this study, after screening of 9 fungal strains for their ability to produce calcium malate, it was found that Penicillium sclerotiorum K302 among them could produce high-level of calcium malate. Under the optimal conditions, the titer of calcium malate in the supernatant was 88.6 g/l at flask level. During 10-l fermentation, the titer of 92.0 g/l, the yield of 0.88 g/g of glucose and the productivity of 1.23 g/l/h were reached within 72 h of the fermentation, demonstrating that the titer, yield and productivity of calcium malate by this strain were very high and the fermentation period was very short. After analysis of the partially purified product with HPLC, it was found that the main product was calcium malate. The results showed that P. sclerotiorum K302 obtained in this study was suitable for developing a novel one-step fermentation process for calcium malate production from glucose on large scale.


Assuntos
Cálcio/química , Glucose/metabolismo , Malatos/metabolismo , Penicillium/metabolismo , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Primers do DNA , Fermentação , Malatos/química , Reação em Cadeia da Polimerase
18.
Biochim Biophys Acta ; 1831(4): 675-82, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23274237

RESUMO

In this study, the MIG1 gene in the oleaginous yeast Yarrowia lipolytica ACA-DC 50109 (the parent yeast) was disrupted and the disruptant M25 obtained could grow in yeast nitrogen base-N5000 medium without uracil or the medium with 2-deoxy-D-glucose. It was found that the cells of the disruptant M25 had more lipid bodies than those of its parent yeast. The disruptant M25 contained 48.7% (w/w) of oil based on its cell weight while the parent yeast only contained 36.0% (w/w) of oil. Transcript levels of many genes relevant to lipid biosynthesis in the disruptant M25 were enhanced compared to those of the same genes in the parent yeast. However, transcript level of the MFE1 gene, one of the genes relevant to fatty acid degradation was reduced in the disruptant M25 compared to that of the same gene in the parent yeast. Such changes in gene expression profile may cause the increased lipid biosynthesis in the disruptant M25. Biosynthesis of C18:1 fatty acid in the disruptant M25 was greatly enhanced compared to that in the parent yeast.


Assuntos
Ácidos Graxos/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Metabolismo dos Lipídeos/genética , Yarrowia/genética , Yarrowia/metabolismo
19.
Gene ; 516(2): 255-62, 2013 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-23268348

RESUMO

The INU1 gene (Accession number: JX073660) encoding exo-inulinase from Cryptococcus aureus HYA was cloned and characterized. The gene had an open reading frame (ORF) of 1653 bp long encoding an inulinase. The coding region of the gene was not interrupted by any intron. It encoded 551 amino acid residues of a protein with a putative signal peptide of 23 amino acids and the calculated molecular mass of 59.5 kDa. The protein sequence deduced from the inulinase structural gene contained the inulinase consensus sequences (WMNDPNGL), (RDP), ECP, FS and Q. It also had two conserved putative N-glycosylation sites. The inulinase from C. aureus HYA was found to be closely related to that from Kluyveromyces marxianus and Pichia guilliermondii. The inulinase gene without the signal sequence was subcloned into pPICZaA expression vector and expressed in Pichia pastoris X-33. The expressed fusion protein was analyzed by SDS-PAGE and western blotting and a specific band with molecular mass of about 60 kDa was found. Enzyme activity assay verified the recombinant protein as an inulinase. A maximum inulinase activity of 16.3±0.24 U/ml was obtained from the culture supernatant of P. pastoris X-33 harboring the inulinase gene. The optimal temperature and pH for action of the enzyme were 50 °C and 5.0, respectively. A large amount of monosaccharides were detected after the hydrolysis of inulin with the purified recombinant inulinase.


Assuntos
Cryptococcus/genética , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Catálise , Clonagem Molecular , Cryptococcus/enzimologia , Cryptococcus/metabolismo , Estabilidade Enzimática , Regulação Enzimológica da Expressão Gênica , Genes Fúngicos , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/isolamento & purificação , Modelos Moleculares , Dados de Sequência Molecular , Filogenia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Temperatura , Transfecção
20.
Bioresour Technol ; 124: 77-82, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22989637

RESUMO

In this study, an inulinase-producing yeast strain Pcla22 of Pichia guilliermondii was identified. It was found that the yeast strain Pcla22 could produce higher amount of oil and more lipid bodies in its cells than any other yeast strains tested in this study. Under the optimal conditions, 60.6%(w/w) of lipid based on cell dry weight, 20.4 g/l of the dry cell mass, SCO produced per g of consumed sugar of 0.19 g/g and biomass produced per g of consumed sugar of 0.32 g/g were obtained in the culture of the yeast strain Pcla22 after 96 h of the fed-batch fermentation. Over 79.8% of the fatty acids from the yeast strain Pcla22 grown in the oil production medium containing inulin was C(16:0) and C(18:1), especially C(18:1) (57.9%). The biodiesel obtained from the produced lipid could be burnt well.


Assuntos
Glicosídeo Hidrolases/biossíntese , Lipídeos/biossíntese , Pichia/metabolismo , Biocombustíveis , Biomassa , Divisão Celular , Fermentação , Inulina/metabolismo , Nitrogênio/metabolismo , Filogenia , Pichia/classificação , Pichia/genética , Reação em Cadeia da Polimerase
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