Characterization and immobilization of arylsulfatase on modified magnetic nanoparticles for desulfation of agar.

Carboxyl functioned magnetic nanoparticles (CMNPs) were prepared by a simple co-precipitation method and characterized by Fourier transform infrared spedtroscopy and scanning electron microscope. The prepared CMNPs were used for covalent immobilization of the arylsulfatase which could be applied in desulfation of agar. The optimal immobilizaion conditions were obtained as follows: glutaraldehyde concentration 1.

Preparation and characterization of tannase immobilized onto carboxyl-functionalized superparamagnetic ferroferric oxide nanoparticles.

Tannase from Aspergillus tubingensis was immobilized onto carboxyl-functionalized Fe3O4 nanoparticles (CMNPs), and conditions affecting tannase immobilization were investigated. Successful binding between CMNPs and tannase was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. Vibrating sample magnetometry and X-ray diffraction showed that the CMNPs and immobilized tannase exhibit distinct magnetic responses and superparamagnetic properties.

Characterization of an extracellular biofunctional alginate lyase from marine Microbulbifer sp. ALW1 and antioxidant activity of enzymatic hydrolysates.

A novel alginate-degrading marine bacterium Microbulbifer sp. ALW1 was isolated from rotten brown alga. An extracellular alginate lyase was purified to electrophoretic homogeneity and had a molecular mass of about 26.

[Improving thermal stability of Geobacillus sp. ZH1 carboxylesterase by error-prone PCR].

Objective: This study was aimed to improve the thermal stability of carboxylesterase from Geobacillus sp. ZH1 by directed evolution.

Methods: A library of carboxylesterase mutants was constructed by introducing random mutagenesis using error-prone PCR to screen mutant enzymes with improved thermostability.

Molecular cloning and characterization of a new and highly thermostable esterase from Geobacillus sp. JM6.

A new lipolytic enzyme gene was cloned from a thermophile Geobacillus sp. JM6. The gene contained 750 bp and encoded a 249-amino acid protein.

[Isolation, identification of a κ-carrageenase-producing bacterium and κ-Carrageenase characterization].

Objective: The aim of this study was to screen and identify carrageenase-producing strain from mangrove soil leaf and to characterize produced carrageenase.

Methods: The culture medium with κ-carrageenan as sole carbon source was used to isolate the strain exhibiting carrageenase activity. The isolated strain was identified by morphology observation and 16S rDNA sequencing.

Investigation of sunlight-induced deterioration of aroma of pummelo (Citrus maxima) essential oil.

Deterioration of aromas of pummelo essential oil (EO) induced by sunlight was compared to those induced by heat and oxygen exposure using the techniques of sensory evaluation and GC-MS analysis. The sunlight-exposed EO was found to possess an oily off-flavor odor, which was significantly different from its counterparts induced by oxygen and heat. The strong oily note of the sunlight-exposed EO was attributed to the existence of linalool oxides and limonene oxides, as well as the lack of neral and geranial, for which UV sunlight was revealed to be the critical contributor causing the chemical reactions for the aroma changes.

Molecular cloning and characterization of a thermostable lipase from deep-sea thermophile Geobacillus sp. EPT9.

A gene (1,254 bp) encoding a lipase was identified from a deep-sea hydrothermal field thermophile Geobacillus sp. EPT9. The open reading frame of this gene encoded 417 amino acid residues.

[Isolation, identification and characterization of an agarase-producing marine bacterial strain Stenotrophomonas sp. NTa].

Objective: To identify and characterize a marine bacterial strain producing agarase.

Methods: The agarase-producing bacterium was isolated from coastal sediments in Xiamen using agar as the sole carbon source. The strain was identified by the analyses of 16S rRNA gene sequence, phenotype and biochemical reactions.

Cloning and characterization of a new manganese superoxide dismutase from deep-sea thermophile Geobacillus sp. EPT3.

A new gene encoding a superoxide dismutase (SOD) was identified from a thermophile Geobacillus sp. EPT3 isolated from a deep-sea hydrothermal field in east Pacific. The open reading frame of this gene encoded 437 amino acid residues.

[Identification and characterization of Aspergillus aculeatus JMUdb058 for naringinase production].

Objective: A new naringinase-producing strain, JMUdb058 was identified and characterized.

Methods: The strain was identified by morphological observation and 28S rDNA homogeneous analysis. Naringinase was identified by monitoring the hydrolysis of naringin to prunin and naringenin using a reversed phase High Performance Liquid Chromatography (HPLC).

Development and evaluation of an HPLC method for accurate determinations of enzyme activities of naringinase complex.

An HPLC method that can separate naringin, prunin, and naringenin was used to help accurately measure the activities of naringinase and its subunits (α-L-rhamnosidase and β-D-glucosidase). The activities of the naringinase and β-d-glucosidase were determined through an indirect calculation of the naringenin concentration to avoid interference from its poor solubility. The measured enzymatic activities of the naringinase complex, α-L-rhamnosidase, and β-D-glucosidase were the as same as their theoretical activities when the substrates' (i.

Characterization of a new and thermostable esterase from a metagenomic library.

A new gene encoding an esterase (designated as EstEP16) was identified from a metagenomic library prepared from a sediment sample collected from a deep-sea hydrothermal field in east Pacific. The open reading frame of this gene encoded 249 amino acid residues. It was cloned, overexpressed in Escherichia coli, and the recombinant protein was purified to homogeneity.

Purification and characterization of a naringinase from Aspergillus aculeatus JMUdb058.

A naringinase from Aspergillus aculeatus JMUdb058 was purified, identified, and characterized. This naringinase had a molecular mass (MW) of 348 kDa and contained four subunits with MWs of 100, 95, 84, and 69 kDa. Mass spectrometric analysis revealed that the three larger subunits were β-D-glucosidases and that the smallest subunit was an α-L-rhamnosidase.

Characterization and preparation of Aspergillus niger naringinase for debittering citrus juice.

Unlabelled: Naringinase from Aspergillus niger was prepared and characterized to evaluate its effectiveness in debittering citrus juice. The enzyme was purified to homogeneity by sulfate fractionation and chromatographies on Q-Sepharose, Sephacryl S-200, and S-100 HR columns, and estimated by gel filtration chromatography (GFC) to have a molecular weight (MW) of 131 kDa, of which its subunit was measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be around 65.5 kDa.

[Characterization and evaluation of an astaxanthin over-producing Phaffia rhodozyma].

We evaluated an astaxanthin overproducing Phaffia rhodozyma JMU-MVP14, and developed astaxanthin high-yielding fermentation process. We analyzed several fermentation parameters, i.e.

[Repeated batch and fed-batch process for astaxanthin production by Phaffia rhodozyma].

A comparative study of batch and repeated batch process was carried out for astaxanthin fermentation of Phaffia rhodozyma to develop a more economical method for astaxanthin industrial production. In shaking flask fermentation, the change of biomass and astaxanthin production was studied to compare the five-day cycle with four-day cycle of repeated batch culture of P. rhodozyma.

[Characterization of Cryptococcus sp. Jmudeb008 and regulation of naringinase activity by glucose].

Objective: We identified a new isolated naringinase-producing yeast strain named as Jmudeb008, and analyzed its naringinase-producing ability cultured with different composition and concentration of carbon sources.

Methods: The strain was identified based on conventional phenotypic methods and sequences of the D1/D2 region of 26S rDNA and 5.8S-ITS.

[Technological process of cell disruption for extracting astaxanthin from Phaffia rhodozyma by acid method under autoclave conditions].

Phaffia rhodozyma is one of the organisms for production of astaxanthin, and the key process for extracting intracellular astaxanthin is cell disruption. In this work, cell disruption for extracting astaxanthin from Phaffia rhodozyma was studied with autoclave method at low acid concentration. The optimum disrupting conditions were: autoclave pressure 0.

[Establishment of immunomagnetic capture-fluorescent PCR detection method for Campylobacter jejuni].

In order to develop a rapid method which can check Campylobacter jejuni in animal and poultry foods nicely, an immunomagnetic capture-fluorescent PCR (IMC-FPCR) method was established in this paper. The reported method involves isolation of the target pathogen by immunocapture prior to the fluorescent PCR step, therefore the immunomagnetic-beads for Campylobacter were developed, and two groups of primer/probe, which targeted for the species special sequence of flaA gene and hipO gene for Campylobacter jejuni were designed. The immunomagnetic capture-fluorescent PCR assay amplification of the hipO gene and flaA gene for detection of Campylobacter jejuni was firstly reported in this paper.