Production of glutaric acid from 5-aminovaleric acid using Escherichia coli whole cell bio-catalyst overexpressing GabTD from Bacillus subtilis
In this study, as a solution to improve the production of glutaric acid, we introduced gabTD genes from B. subtilis to E. coli for a whole cell biocatalytic approach. This approach enabled us to determine the effect of co-factors on reaction and to achieve a high conversion yield from 5-aminovaleric acid at the optimized reaction condition. Optimization of whole cell reaction by different plasmids, pH, temperature, substrate concentration, and cofactor concentration achieved full conversion with 100 mM of 5-aminovaleric acid to glutaric acid. Nicotinamide adenine dinucleotide phosphate (NAD(P)+) and α-ketoglutaric ...
Source: Enzyme and Microbial Technology - July 11, 2018 Category: Biotechnology Source Type: research

Synergetic effect of Ni2+ and 5-acrylamidobenzoboroxole functional groups anchoring on magnetic nanoparticles for enhanced immobilization of horseradish peroxidase
Publication date: Available online 15 June 2018Source: Enzyme and Microbial TechnologyAuthor(s): Juan Han, Yunfeng Cai, Yun Wang, Lei Gu, Chunmei Li, Yanli Mao, Wenli Zhang, Liang NiAbstractIn this work, a novel Ni2+&AABOB bifunctional core–shell magnetic composite nanoparticles (MNPs), Fe3O4@p(AABOB-co-AIM-Ni2+), were synthesized for the immobilization of horseradish peroxidase (HRP). Two kinds of interaction are simultaneously incorporated to improve the stability and reusability of immobilized HRP: one is the coordination between Ni2+ and amide group in HRP, and the other is the interaction of the wulff-type b...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Biochemical characterization of a thermostable cobalt- or copper-dependent polyphenol oxidase with dye decolorizing ability from Geobacillus sp. JS12
Publication date: Available online 28 June 2018Source: Enzyme and Microbial TechnologyAuthor(s): Soo-Jung Moon, Han-Woo Kim, Sung-Jong JeonAbstractA putative laccase-like gene, GPPO, encoding a protein of 17.2 kDa and belonging to the multicopper oxidase family, was cloned and overexpressed in Escherichia coli cells. The purified recombinant protein GPPO is homodecameric protein with a molecular weight of 171.6 kDa. GPPO was not detected the ultraviolet-visible spectroscopy (UV/Vis) spectrum of typical laccases. Co2+ or Cu2+ was essential for substrate oxidation of GPPO, and the enzyme contained 1 mole of Co or Cu pe...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Role of electron donor in CO2 fixation of chemoautotrophic bacteria and its preconditions: verification in Alcaligenes hydrogenophilus
Publication date: Available online 28 June 2018Source: Enzyme and Microbial TechnologyAuthor(s): Saiwei Zhang, Ya-nan Wang, Lei Wang, Yiu Fai Tsang, Huan Li, Xiaohua FuAbstractAlcaligenes hydrogenophilus was used to verify the role of the electron donor and acceptor in apparent CO2 fixation of chemoautotrophic bacteria. The response mechanisms underlying the apparent CO2 fixation characteristics with different concentrations of electron donor and acceptor were elucidated by analyzing the transcription characteristics of the cbbL gene, cytoskeleton synthesis efficiency and extracellular free organic carbon concentration. Th...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Characterization of an Anaerobic, Thermophilic, Alkaliphilic, High Lignocellulosic Biomass-Degrading Bacterial Community, ISHI-3, Isolated from Biocompost
Publication date: Available online 8 July 2018Source: Enzyme and Microbial TechnologyAuthor(s): Ayumi Shikata, Junjarus Sermsathanaswadi, Thianheng Phakhinee, Sirilak Baramee, Chakrit Tachaapaikoon, Rattiya Waeonukul, Patthra Pason, Khanok Ratanakhanokchai, Akihiko KosugiAbstractThe generation of a complex microbial consortium is a promising approach for efficient biomass decomposition. An anaerobic thermophilic alkaliphilic microbial consortium with efficient degradation ability was screened from bovine manure compost using non-pretreated milling corn stover (CS) and rice straw (RS). A stable microbial consortium ISHI-3 w...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Ruminiclostridium josui Abf62A-Axe6A: A tri-functional xylanolytic enzyme exhibiting α-l-arabinofuranosidase, endoxylanase, and acetylxylan esterase activities
In this study, three Abf62A-Axe6A derivatives were constructed, overexpressed in Escherichia coli, purified, and biochemically characterized: RjAbf62A-Axe6A, containing all four modules but lacking the signal peptide; RjAbf62A-CBM6, containing the GH62 and CBM6 modules; and RjAxe6A, containing only CE6. RjAbf62A-Axe6A was highly active toward arabinoxylan and moderately active toward sugar beet arabinan, and released mainly arabinose. Analysis of the arabinoxylooligosaccharide hydrolysis products revealed that RjAbf62A-Axe6A released α-1,2- and α-1,3-linked arabinofuranose from both singly and doubly substitute...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

N-terminal engineering of overlapping genes in the nitrile hydratase gene cluster improved its activity
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Zhengfei Yang, Xiaolin Pei, Gang Xu, Jianping Wu, Lirong YangAbstractNitrile hydratase which catalyzes the hydration of nitriles to the corresponding amides is operon-encoded. However, when heterologously expressed, genes in the same operon are usually not equally expressed, and the ratio needs to be fine-tuned. A gene cluster of three genes (corresponding to α-subunit, β-subunit and activator) encoding the nitrile hydratase was cloned from Aurantimonas manganoxydans ATCC BAA-1229 and expressed in Escherichia coli. Howeve...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Gene cloning, expression, and X-ray crystallographic analysis of a β-mannanase from Eisenia fetida
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Mitsuhiro Ueda, Yu Hirano, Hiroaki Fukuhara, Yuki Naka, Masami Nakazawa, Tatsuji Sakamoto, Yoshiyuki Ogata, Taro TamadaAbstractThe endo-1,4-β-mannanases (Ef-Man) gene from Eisenia fetida was determined to consist of 1131 bp and encode a 377 amino acid protein. The amino acid sequence showed similarity with the endo-1,4-β-mannanases of Daphnia pulex (62%), Cryptopygus antarcticus (64%), Crassostrea gigas (61%), Mytilus edulis (60%), and Aplysia kurodai (58%). The gene encoding mature Ef-Man was expressed in Pichia pastori...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Re-engineering of an Escherichia coli K-12 strain for the efficient production of recombinant human Interferon Gamma
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Rajat Pandey, Nitin Kumar, Gabriel A. Monteiro, Venkata Dasu Veeranki, D.M.F. PrazeresAbstractThe Escherichia coli phosphoglucose isomerase (pgi) mutant strain GALG20 was developed previously from wild-type K12 strain MG1655 for increased plasmid yield. To investigate the potential effects of the pgi deletion/higher plasmid levels on recombinant human Interferon Gamma (IFN-γ) production, a detailed network of the central metabolic pathway (100 metabolites, 114 reactions) of GALG20 and MG1655 was constructed. Elementary mode an...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

In silico modelling and molecular dynamics simulation studies on L-Asparaginase isolated from bacterial endophyte of Ocimum tenuiflorum
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Madhuri Pola, Satish Babu Rajulapati, Chandrasai Potla Durthi, Rajeswara Reddy Erva, Mayuri BhatiaAbstractBioactive compounds from endophytes have been used to treat various diseases. In the present study, L-Asparaginase producing endophytes were isolated from Ocimum tenuiflorum (Tulasi) from NIT Warangal, Telangana, India to treat Acute Lymphoblastic Leukemia (ALL) in which L-Asparagine (L-Asn) deamination plays a vital role in ALL treatment. 20 (bacteria and fungi) out of 35 endophytes have been screened for L-Asparaginase product...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Carbon-nanotube-caged microbial electrodes for bioelectrocatalysis
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Hong-qi Xia, Kento Sakai, Yuki Kitazumi, Osamu Shirai, Kazuyoshi Takagi, Kenji KanoAbstractA method to stably immobilize microbes on electrodes was developed. Resting cells of Methylobacterium extorquens AM1(MeAM1) were caged within multiwalled carbon nanotubes (MWNTs)by adding the cells to a water dispersion of MWNTs then allowing the resulting mixture to dry on electrodes. The MeAM1-MWCNTs electrode thus obtained displayed excellent activities in the bidirectional bioelectrocatalysis due to formate dehydrogenase(s) in the resting ...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Immobilization of β-galactosidase and α-mannosidase onto magnetic nanoparticles: A strategy for increasing the potentiality of valuable glycomic tools for glycosylation analysis and biological role determination of glycoconjugates
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Ernesto Rodríguez, Karen Francia, Natalie Brossard, Juan J. García Vallejo, Hakan Kalay, Yvette van Kooyk, Teresa Freire, Cecilia GiacominiAbstractGlycans present in biological glycoconjugates have several structural and functional roles. Elucidation of glycan structure and biological function is critical to understand their role in physiological and pathogenic process, enabling the development of diagnostic methods and disease treatment. Immobilized glycosidases are powerful tools for glycan analysis, as they are able...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Synthesis of conjugated linoleic acid-rich triacylglycerols by immobilized mutant lipase with excellent capability and recyclability
In this study, CLA-rich TAG were successfully synthesized by an immobilized mutant lipase (MAS1-H108A)-catalyzed esterification of CLA-rich fatty acids and glycerol under vacuum. MAS1-H108A was first immobilized onto ECR1030 resin. Results showed that the lipase/support ratio of 41 mg/g was suitable for the immobilization and the thermostability of immobilized MAS1-H108A was greatly enhanced. Subsequently, the immobilized MAS1-H108A was employed for the synthesis of CLA-rich TAG and 95.21% TAG with 69.19% CLA was obtained under the optimized conditions. The TAG content (95.21%) obtained by immobilized MAS1-H108A is the r...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

A kinetic spectrophotometric method for the determination of pyridoxal-5′-phosphate based on coenzyme activation of apo-d-phenylglycine aminotransferase
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Juntratip Jomrit, Duangnate Isarangkul, Pijug Summpunn, Suthep WiyakruttaAbstractA new PLP assay method based on the coenzyme activation of apo-d-phenylglycine aminotransferase (apo-d-PhgAT) is reported. The assay process is comprised of two steps. First, PLP present in plasma samples is allowed to reconstitute apo-d-PhgAT, forming active holo-d-PhgAT. In the second step, the enzymatic activity of reconstituted d-PhgAT is determined using d-4-OH-phenylglycine as the amino donor substrate with 4-OH-benzoylformate (OH-BZF) as the reac...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Quorum quenching bacteria encapsulated in PAC-PVA beads for enhanced membrane antifouling properties
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Zhuotong Zeng, Bi Tang, Rong Xiao, Jinhui Huang, Yanling Gu, Yahui Shi, Yi Hu, Jianxin Zhou, Hua Li, Lixiu Shi, Guangming ZengAbstractIn order to improve the antifouling properties of quorum quenching (QQ) bacteria immobilized beads, the mechanical strength and permeability of QQ beads were modified by adding powdered activated carbon (PAC) based on traditional polyvinyl alcohol (PVA)-boric acid method. Optimal PAC concentration was investigated through measuring the mechanical strength, permeability and N-octanoyl-DLhomoserine lact...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Manganese(II) oxidation by the multi-copper oxidase CopA from Brevibacillus panacihumi MK-8
In this study, we identified a new manganese(II) oxidase (CopA) from Brevibacillus panacihumi MK-8. The copA gene was cloned and expressed in Escherichia coli strain BL21(DE3), and the recombinant strain BL21-pET-copA was able to remove 85.87% of Mn(II) from LB medium containing 1 mM Mn(II) after seven days. The optimum Mn(II) oxidase CopA activity was obtained at 37 °C in 10 mM HEPES buffer (pH 8.0) containing 0.4 mM CuCl2. Purified CopA removed 51.98% of manganese(II) under the optimal conditions. The copA gene-deleted strain (MK-8-ΔcopA) barely oxidized manganese, further demonstrating that the copA ge...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

N-terminal domain of the beta-propeller phytase of Pseudomonas sp. FB15 plays a role for retention of low-temperature activity and catalytic efficiency
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Won Je Jang, Jong Min Lee, Hae Dae Park, Yu Bin Choi, In-Soo KongAbstractPseudomonas sp. FB15 producing phytase with a high activity at low temperature was isolated from foreshore soil. The phytase gene was cloned and sequenced. Molecular modeling predictions using its amino acid sequence indicated that it belongs to the group of beta-propeller phytases (BPPs). However, it differs from the conventional structure of BPPs in the number of propeller-shaped domains. Most BPPs have a propeller with six blades that consist of four or five...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Biosynthesis of zinc oxide nanoparticles usingMangifera indica leaves and evaluation of their antioxidant and cytotoxic properties in lung cancer (A549) cells
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): S. Rajeshkumar, S. Venkat Kumar, Arunachalam Ramaiah, Happy Agarwal, T. Lakshmi, Selvaraj Mohana RoopanAbstractGreen synthesis is an eco-friendly approach to nanoparticle production, which eliminates the use of toxic chemicals, high temperatures, and costly equipment needed for traditional physical and chemical synthesis methods. This eco-friendly approach was used in the present study to biosynthesize zinc oxide nanoparticles (ZnO NPs) from Mangifera indica (mango) leaves which were then evaluated for their antioxidant activity and...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Improvement of enzymatic properties of Rhizopus oryzae α-amylase by site-saturation mutagenesis of histidine 286
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Song Li, Qian Yang, Bin Tang, Ana ChenAbstractOptimal pH and ideal functioning temperature for fungal α-amylase can greatly contribute to improving enzyme efficiency in maltose-forming ability. This work aimed to improve the enzymatic properties of Rhizopus oryzae α-amylase by site-saturation mutagenesis of histidine 286. The biochemical properties of selected mutant enzymes were modified to increase their enzymatic efficiencies compared to their wild-type counterparts. For instance, the optimum temperature of mutants H2...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Leu169Trp substitution in MnSOD from Staphylococcus equorum created an active new form of similar resistance to UVC irradiation
In this report, a Leu169Trp substitution was carried out to protect the Tyr168 residue by introducing an amino acid with an aromatic side chain for better photon absorption of the UV light. Interestingly, although the substitution appeared to have a minor effect on enzyme stability and activity upon UVC irradiation, the melting temperature (TM) of the Leu169Trp mutant was different. Unlike the native protein, the TM of the mutant had not changed after UV irradiation. Thus, our effort to extend the resistance to UVC radiation was not successful, but we have discovered a biologically active new form. The present finding prov...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Direct optical density determination of bacterial cultures in microplates for high-throughput screening applications
Publication date: November 2018Source: Enzyme and Microbial Technology, Volume 118Author(s): Annika Meyers, Christoph Furtmann, Joachim JoseAbstractA convenient and most abundantly applied method to determine the growth state of a bacterial cell culture is to determine the optical density (OD) spectrophotometrically. Dilution of the samples, which is necessary to measure within the linear range of the spectrophotometer, is time-consuming and not compatible with high-throughput applications. Here we present a direct approach to estimate the OD at 578 nm (OD578) of bacterial cultures in microplates without the need for sam...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Intermolecular disulfide bonds between unpaired cysteines retard the C-terminal trans-cleavage of Npu DnaE
In this study, we demonstrated that the unpaired cysteine residues in Npu DnaE tend to form disulfide bonds, and contributed to the reduction of the cleavage under non-reducing conditions. This redox trap can be disrupted by site-directed mutation of these unpaired cysteines. The results further indicated that the position 28 and 59 may play certain roles in the correct folding of the active conformation. (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Activating effects on trypsin, α-chymotrypsin, and lipase and inhibitory effects on α-amylase and α-glucosidase as provided by low-molecular-weight compounds in the water extract of the earthworm Eisenia fetida
Publication date: November 2018Source: Enzyme and Microbial Technology, Volume 118Author(s): Katsuhiro Yoshii, Masako Ogasawara, Yoshihiro Yamamoto, Kuniyo InouyeAbstractA fraction (designated as U3EE) with molecular mass under 3 kDa from the water extract of the earthworm Eisenia fetida was prepared and its effects on mammalian digestive enzymes were examined. U3EE itself showed no relevant enzyme activities. However, it increased the activities of trypsin, α-chymotrypsin, and lipase, while decreased those of α-amylase and α-glucosidase. The trypsin activation and α-amylase inhibition were analyz...
Source: Enzyme and Microbial Technology - July 10, 2018 Category: Biotechnology Source Type: research

Characterization of an Anaerobic, Thermophilic, Alkaliphilic, High Lignocellulosic Biomass-Degrading Bacterial Community, ISHI-3, Isolated from Biocompost
Publication date: Available online 8 July 2018Source: Enzyme and Microbial TechnologyAuthor(s): Ayumi Shikata, Junjarus Sermsathanaswadi, Thianheng Phakhinee, Sirilak Baramee, Chakrit Tachaapaikoon, Rattiya Waeonukul, Patthra Pason, Khanok Ratanakhanokchai, Akihiko KosugiAbstractThe generation of a complex microbial consortium is a promising approach for efficient biomass decomposition. An anaerobic thermophilic alkaliphilic microbial consortium with efficient degradation ability was screened from bovine manure compost using non-pretreated milling corn stover (CS) and rice straw (RS). A stable microbial consortium ISHI-3 w...
Source: Enzyme and Microbial Technology - July 9, 2018 Category: Biotechnology Source Type: research

Synergetic effect of Ni2+ and 5-acrylamidobenzoboroxole functional groups anchoring on magnetic nanoparticles for enhanced immobilization of horseradish peroxidase
Publication date: Available online 15 June 2018Source: Enzyme and Microbial TechnologyAuthor(s): Juan Han, Yunfeng Cai, Yun Wang, Lei Gu, Chunmei Li, Yanli Mao, Wenli Zhang, Liang NiAbstractIn this work, a novel Ni2+&AABOB bifunctional core–shell magnetic composite nanoparticles (MNPs), Fe3O4@p(AABOB-co-AIM-Ni2+), were synthesized for the immobilization of horseradish peroxidase (HRP). Two kinds of interaction are simultaneously incorporated to improve the stability and reusability of immobilized HRP: one is the coordination between Ni2+ and amide group in HRP, and the other is the interaction of the wulff-type b...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Biochemical characterization of a thermostable cobalt- or copper-dependent polyphenol oxidase with dye decolorizing ability from Geobacillus sp. JS12
Publication date: Available online 28 June 2018Source: Enzyme and Microbial TechnologyAuthor(s): Soo-Jung Moon, Han-Woo Kim, Sung-Jong JeonAbstractA putative laccase-like gene, GPPO, encoding a protein of 17.2 kDa and belonging to the multicopper oxidase family, was cloned and overexpressed in Escherichia coli cells. The purified recombinant protein GPPO is homodecameric protein with a molecular weight of 171.6 kDa. GPPO was not detected the ultraviolet-visible spectroscopy (UV/Vis) spectrum of typical laccases. Co2+ or Cu2+ was essential for substrate oxidation of GPPO, and the enzyme contained 1 mole of Co or Cu pe...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Role of electron donor in CO2 fixation of chemoautotrophic bacteria and its preconditions: verification in Alcaligenes hydrogenophilus
Publication date: Available online 28 June 2018Source: Enzyme and Microbial TechnologyAuthor(s): Saiwei Zhang, Ya-nan Wang, Lei Wang, Yiu Fai Tsang, Huan Li, Xiaohua FuAbstractAlcaligenes hydrogenophilus was used to verify the role of the electron donor and acceptor in apparent CO2 fixation of chemoautotrophic bacteria. The response mechanisms underlying the apparent CO2 fixation characteristics with different concentrations of electron donor and acceptor were elucidated by analyzing the transcription characteristics of the cbbL gene, cytoskeleton synthesis efficiency and extracellular free organic carbon concentration. Th...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Leu169Trp substitution in MnSOD from Staphylococcus equorum created an active new form of similar resistance to UVC irradiation
In this report, a Leu169Trp substitution was carried out to protect the Tyr168 residue by introducing an amino acid with an aromatic side chain for better photon absorption of the UV light. Interestingly, although the substitution appeared to have a minor effect on enzyme stability and activity upon UVC irradiation, the melting temperature (TM) of the Leu169Trp mutant was different. Unlike the native protein, the TM of the mutant had not changed after UV irradiation. Thus, our effort to extend the resistance to UVC radiation was not successful, but we have discovered a biologically active new form. The present finding prov...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Activating effects on trypsin, α-chymotrypsin, and lipase and inhibitory effects on α-amylase and α-glucosidase as provided by low-molecular-weight compounds in the water extract of the earthworm Eisenia fetida
Publication date: Available online 30 June 2018Source: Enzyme and Microbial TechnologyAuthor(s): Katsuhiro Yoshii, Masako Ogasawara, Yoshihiro Yamamoto, Kuniyo InouyeAbstractA fraction (designated as U3EE) with molecular mass under 3 kDa from the water extract of the earthworm Eisenia fetida was prepared and its effects on mammalian digestive enzymes were examined. U3EE itself showed no relevant enzyme activities. However, it increased the activities of trypsin, α-chymotrypsin, and lipase, while decreased those of α-amylase and α-glucosidase. The trypsin activation and α-amylase inhibition were an...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Intermolecular disulfide bonds between unpaired cysteines retard the C-terminal trans-cleavage of Npu DnaE
Publication date: Available online 3 July 2018Source: Enzyme and Microbial TechnologyAuthor(s): Yanran Xu, Lei Zhang, Buyong Ma, Lifu Hu, Huili Lu, Tonglu Dou, Junsheng Chen, Jianwei Zhu (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Direct optical density determination of bacterial cultures in microplates for high-throughput screening applications
Publication date: Available online 3 July 2018Source: Enzyme and Microbial TechnologyAuthor(s): Annika Meyers, Christoph Furtmann, Joachim JoseAbstractA convenient and most abundantly applied method to determine the growth state of a bacterial cell culture is to determine the optical density (OD) spectrophotometrically. Dilution of the samples, which is necessary to measure within the linear range of the spectrophotometer, is time-consuming and not compatible with high-throughput applications. Here we present a direct approach to estimate the OD at 578 nm (OD578) of bacterial cultures in microplates without the need for ...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Editorial Board
Publication date: September 2018Source: Enzyme and Microbial Technology, Volume 116Author(s): (Source: Enzyme and Microbial Technology)
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Electrochemical synthesis of formic acid from CO2 catalyzed by Shewanella oneidensis MR-1 whole-cell biocatalyst
In this study, Shewanella oneidensis MR-1 (S. oneidensis MR-1), a facultative aerobic bacterium that has been extensively studied for its utility as biofuel cells as well as for the detoxification of heavy metal oxides (i.e., MnO2, uranium), has been applied for the first time as a whole-cell biocatalyst for formic acid synthesis from gaseous CO2 and electrons supplied from an electrode. S. oneidensis MR-1, when aerobically grown in Luria-Bertani (LB) medium, exhibited its ability as a whole-cell biocatalyst for the conversion of CO2 into formic acid with moderate productivity of 0.59 mM h−1 for 24 h. In additi...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Influence of salts and metal nanoparticles on the activity and thermal stability of a recombinant chitinase from Stenotrophomonas maltophilia N4
The objective of this study was to improve thermal stability of the recombinant chitinase by salts and metal nanoparticles (NP). The studied chitinase was thermolabile and largely lost its activity in the first minutes of storage at 50 and 60 °C. The optimum temperature for colloidal chitin hydrolysis by the enzyme was 50 °C. Application of sodium aurothiomalate hydrate and manganese chloride enhanced the activity of the recombinant enzyme. In general, chitinase activity was higher when silver nanoparticles (Ag-NP) were used, but lower for other NP. The thermal stability of chitinase immobilized on Ag-NP and ma...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

One-pot, two-step transaminase and transketolase synthesis of l-gluco-heptulose from l-arabinose
Publication date: September 2018Source: Enzyme and Microbial Technology, Volume 116Author(s): Maria Bawn, Fabiana Subrizi, Gary J. Lye, Tom D. Sheppard, Helen C. Hailes, John M. WardAbstractThe use of biocatalysis for the synthesis of high value added chemical building blocks derived from biomass is becoming an increasingly important application for future sustainable technologies. The synthesis of a higher value chemical from l-arabinose, the predominant monosaccharide obtained from sugar beet pulp, is demonstrated here via a transketolase and transaminase coupled reaction. Thermostable transketolases derived from Deinoco...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

High level extracellular production of recombinant γ-glutamyl transpeptidase from Bacillus licheniformis in Escherichia coli fed-batch culture
Publication date: September 2018Source: Enzyme and Microbial Technology, Volume 116Author(s): Shruti Bindal, Vikas Kumar Dagar, Meenu Saini, Yogender Pal Khasa, Rani GuptaAbstractIncreasing demand of microbial γ-glutamyl transpeptidase (GGT) in food and pharmaceutical sectors raised the need for process development for high level production of the enzyme. In this respect, GGT from Bacillus licheniformis ER15 (SBLGGT) was cloned along with its native secretion signal and expressed in E. coli using different expression vectors. Native signal of the enzyme assistedits extracellular translocationin E. coli.Maximum enzyme...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Immobilized cutinases: Preparation, solvent tolerance and thermal stability
Publication date: September 2018Source: Enzyme and Microbial Technology, Volume 116Author(s): An Su, Abhijit Shirke, Joshua Baik, Yi Zou, Richard GrossAbstractDeveloping active immobilized enzymes and characterization of their use conditions is critically important prior to initiating studies of enzyme selectivity and substrate specificity in organic media. To this end, physical immobilization by hydrophobic interactions was performed with three well-characterized cutinases (Aspergillus oryzae Cutinase (AoC), Humicola insolens Cutinase (HiC), and Thielavia terrestris Cutinase (TtC)) using Lewatit VP OC 1600 as the macropor...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Effect of carbon black functionalization on the analytical performance of a tyrosinase biosensor based on glassy carbon electrode modified with dihexadecylphosphate film
In this study, we describe the use of chemically functionalized CB Vulcan XC 72R for the development of sensitive electrochemical biosensors. The chemical pre-treatment increased the material wettability by raising the concentration of surface oxygenated functional groups verified from elemental analysis and FTIR measurements. In addition, it was observed an enhancement of almost 100-fold on the electron transfer rate constant (k0) related to unfunctionalized CB, confirming a remarkable improvement of the electrocatalytic properties. Finally, we constructed a Tyrosinase (Tyr) biosensor based on functionalized CB and dihexa...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Influence of mediators on laccase catalyzed radical formation in lignin
Publication date: September 2018Source: Enzyme and Microbial Technology, Volume 116Author(s): Line Munk, Mogens Larsen Andersen, Anne S. MeyerAbstractLaccases (EC 1.10.3.2) catalyze oxidation of phenolic groups in lignin to phenoxyl radicals during reduction of O2 to H2O. Here, we examine the influence on this radical formation of mediators which are presumed to act by shuttling electrons between the laccase and the subunits in lignin that the enzyme cannot approach directly. Treatments of three different lignins with laccase-mediator-systems (LMS) including laccases derived from Trametes versicolor and Myceliophthora ther...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Effect of neutral red incorporation on Al-doped ZnO thin films and its bio-electrochemical interaction with NAD+/NADP+ dependent enzymes
Publication date: September 2018Source: Enzyme and Microbial Technology, Volume 116Author(s): Fidal V.T., Chandra T.S.AbstractA new approach to deposition of electroactive ZnO thin films have been carried out, by one-pot chemical bath deposition with Al dopant and incorporation of neutral red as organic mediator. The morphological, structural and functional characterization of the neutral red incorporated, Al-doped ZnO (NR-AZO) film was carried out using electron microscopy, FTIR, XRD and EIS respectively. The incorporated neutral red was found to induce strain in the crystal of AZO proportional to the concentration used i...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Studies on the catalytic behavior of a membrane-bound lipolytic enzyme from the microalgae Nannochloropsis oceanica CCMP1779
Publication date: September 2018Source: Enzyme and Microbial Technology, Volume 116Author(s): Maria G. Savvidou, Alexandra Katsabea, Pavlos Kotidis, Diomi Mamma, Theopisti V. Lymperopoulou, Dimitris Kekos, Fragiskos N. KolisisAbstractThe catalytic behavior of a membrane-bound lipolytic enzyme (MBL-Enzyme) from the microalgae Nannochloropsis oceanica CCMP1779 was investigated. The biocatalyst showed maximum activity at 50 °C and pH 7.0, and was stable at pH 7.0 and temperatures from 40 to 60 °C. Half-lives at 60 °C, 70 °C and 80 °C were found 866.38, 150.67 and 85.57 min respectively. Thermal...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Fast, affordable and eco-friendly enzyme kinetic method for the assay of α-ketoglutaric acid in medical product and sports supplements
Publication date: September 2018Source: Enzyme and Microbial Technology, Volume 116Author(s): Theerasak Rojanarata, Wanida Laiwattanapaisal, Tanasait Ngawhirunpat, Praneet Opanasopit, Kalvalin Worrawethanakul, Takron Chantadee, Thitirat FuangwattanaAbstractA novel kinetic method was developed for the quantitation of α-ketoglutaric acid (AKG) in cardioplegic solution and athletic supplements. The assay relied on an enzymatic transamination of AKG and d-4-hydroxyphenylglycine to form 4-hydroxybenzoylformic acid and l-glutamic acid using d-phenylglycine aminotransferase. Since 4-hydroxybenzoylformic acid absorbed UV str...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Biosynthesis of zinc oxide nanoparticles usingMangifera indica leaves and evaluation of their antioxidant and cytotoxic properties in lung cancer (A549) cells
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): S. Rajeshkumar, S. Venkat Kumar, Arunachalam Ramaiah, Happy Agarwal, T. Lakshmi, Selvaraj Mohana RoopanAbstractGreen synthesis is an eco-friendly approach to nanoparticle production, which eliminates the use of toxic chemicals, high temperatures, and costly equipment needed for traditional physical and chemical synthesis methods. This eco-friendly approach was used in the present study to biosynthesize zinc oxide nanoparticles (ZnO NPs) from Mangifera indica (mango) leaves which were then evaluated for their antioxidant activity and...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Ruminiclostridium josui Abf62A-Axe6A: A tri-functional xylanolytic enzyme exhibiting α-l-arabinofuranosidase, endoxylanase, and acetylxylan esterase activities
In this study, three Abf62A-Axe6A derivatives were constructed, overexpressed in Escherichia coli, purified, and biochemically characterized: RjAbf62A-Axe6A, containing all four modules but lacking the signal peptide; RjAbf62A-CBM6, containing the GH62 and CBM6 modules; and RjAxe6A, containing only CE6. RjAbf62A-Axe6A was highly active toward arabinoxylan and moderately active toward sugar beet arabinan, and released mainly arabinose. Analysis of the arabinoxylooligosaccharide hydrolysis products revealed that RjAbf62A-Axe6A released α-1,2- and α-1,3-linked arabinofuranose from both singly and doubly substitute...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

N-terminal engineering of overlapping genes in the nitrile hydratase gene cluster improved its activity
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Zhengfei Yang, Xiaolin Pei, Gang Xu, Jianping Wu, Lirong YangAbstractNitrile hydratase which catalyzes the hydration of nitriles to the corresponding amides is operon-encoded. However, when heterologously expressed, genes in the same operon are usually not equally expressed, and the ratio needs to be fine-tuned. A gene cluster of three genes (corresponding to α-subunit, β-subunit and activator) encoding the nitrile hydratase was cloned from Aurantimonas manganoxydans ATCC BAA-1229 and expressed in Escherichia coli. Howeve...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Gene cloning, expression, and X-ray crystallographic analysis of a β-mannanase from Eisenia fetida
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Mitsuhiro Ueda, Yu Hirano, Hiroaki Fukuhara, Yuki Naka, Masami Nakazawa, Tatsuji Sakamoto, Yoshiyuki Ogata, Taro TamadaAbstractThe endo-1,4-β-mannanases (Ef-Man) gene from Eisenia fetida was determined to consist of 1131 bp and encode a 377 amino acid protein. The amino acid sequence showed similarity with the endo-1,4-β-mannanases of Daphnia pulex (62%), Cryptopygus antarcticus (64%), Crassostrea gigas (61%), Mytilus edulis (60%), and Aplysia kurodai (58%). The gene encoding mature Ef-Man was expressed in Pichia pastori...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Re-engineering of an Escherichia coli K-12 strain for the efficient production of recombinant human Interferon Gamma
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Rajat Pandey, Nitin Kumar, Gabriel A. Monteiro, Venkata Dasu Veeranki, D.M.F. PrazeresAbstractThe Escherichia coli phosphoglucose isomerase (pgi) mutant strain GALG20 was developed previously from wild-type K12 strain MG1655 for increased plasmid yield. To investigate the potential effects of the pgi deletion/higher plasmid levels on recombinant human Interferon Gamma (IFN-γ) production, a detailed network of the central metabolic pathway (100 metabolites, 114 reactions) of GALG20 and MG1655 was constructed. Elementary mode an...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

In silico modelling and molecular dynamics simulation studies on L-Asparaginase isolated from bacterial endophyte of Ocimum tenuiflorum
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Madhuri Pola, Satish Babu Rajulapati, Chandrasai Potla Durthi, Rajeswara Reddy Erva, Mayuri BhatiaAbstractBioactive compounds from endophytes have been used to treat various diseases. In the present study, L-Asparaginase producing endophytes were isolated from Ocimum tenuiflorum (Tulasi) from NIT Warangal, Telangana, India to treat Acute Lymphoblastic Leukemia (ALL) in which L-Asparagine (L-Asn) deamination plays a vital role in ALL treatment. 20 (bacteria and fungi) out of 35 endophytes have been screened for L-Asparaginase product...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

N-terminal domain of the beta-propeller phytase of Pseudomonas sp. FB15 plays a role for retention of low-temperature activity and catalytic efficiency
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Won Je Jang, Jong Min Lee, Hae Dae Park, Yu Bin Choi, In-Soo KongAbstractPseudomonas sp. FB15 producing phytase with a high activity at low temperature was isolated from foreshore soil. The phytase gene was cloned and sequenced. Molecular modeling predictions using its amino acid sequence indicated that it belongs to the group of beta-propeller phytases (BPPs). However, it differs from the conventional structure of BPPs in the number of propeller-shaped domains. Most BPPs have a propeller with six blades that consist of four or five...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research

Immobilization of β-galactosidase and α-mannosidase onto magnetic nanoparticles: A strategy for increasing the potentiality of valuable glycomic tools for glycosylation analysis and biological role determination of glycoconjugates
Publication date: October 2018Source: Enzyme and Microbial Technology, Volume 117Author(s): Ernesto Rodríguez, Karen Francia, Natalie Brossard, Juan J. García Vallejo, Hakan Kalay, Yvette van Kooyk, Teresa Freire, Cecilia GiacominiAbstractGlycans present in biological glycoconjugates have several structural and functional roles. Elucidation of glycan structure and biological function is critical to understand their role in physiological and pathogenic process, enabling the development of diagnostic methods and disease treatment. Immobilized glycosidases are powerful tools for glycan analysis, as they are able...
Source: Enzyme and Microbial Technology - July 5, 2018 Category: Biotechnology Source Type: research