JBB : Journal of Bioscience and Bioengineering

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Journal of Bioscience and Bioengineering vol.118 cover

 

Journal of Bioscience and Bioengineering – Recent Articles

  • Polygonum cuspidatum extracts as bioactive antioxidaion, anti-tyrosinase, immune stimulation and anticancer agents
    Publication date: Available online 12 October 2014
    Source:Journal of Bioscience and Bioengineering

    Author(s): Chih-Chen Lee , Yen-Ting Chen , Chien-Chih Chiu , Wei-Ting Liao , Yung-Chuan Liu , Hui-Min David Wang

    In our study, it was applied for the technology of supercritical fluid carbon dioxide extraction to achieve biological constitutes from a Taiwan native plant, Polygonum cuspidatum. We developed bioactive effects of P. cuspidatum extracts via multiple examinations that established bio-purposes at a range of dosage ranges. The research of P. cuspidatum extracts indicated that they possessed anti-oxidative properties on radical-scavenging abilities, reducing activities and metal chelating powers in dose-dependant manners. The extracts also had minor in vitro mushroom tyrosinase suppression and decreased cellular tyrosinase activities and melanin production in B16-F10 cells. Immunologically, P. cuspidatum extracts enhanced the release of tumor necrosis factor α (TNF-α) induced by THP-1 macrophage cell line. In addition, the cell proliferation showed anti-proliferation in dose-dependent manner on human skin melanoma cells, A375 and A375.S2, of the extracts suggesting biological constitutes employed the anti-cancer possessions. This is the first statement presenting bioactivities on P. cuspidatum extracts including anti-oxidation, immune stimulation, anti-tyrosinase and anti-melanoma as far as we know.





  • Preparation of melanin from Catharsius molossus L. and preliminary study on its chemical structure
    Publication date: Available online 8 October 2014
    Source:Journal of Bioscience and Bioengineering

    Author(s): Chao Xin , Jia-hua Ma , Cheng-jia Tan , Zhou Yang , Feng Ye , Chan Long , Shuang Ye , Da-bin Hou

    A great deal of melanin was found in the waste alkali liquor produced by extraction of chitin from Catharsius molossus L. Discarding the lye could harm the environment and cause waste of resources. In this paper, melanin from C. molossus L. was recovered through acid precipitation and purified by pepsin and so on. The purity, chemical composition and structure of the prepared melanin were explored by UV-visible absorption spectroscopy, Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, high resolution 13C Cross polarization magic angle spinning nuclear magnetic resonance spectroscopy pyrolysis gas chromatography mass spectrometry, X ray diffraction, X ray fluorescence, matrix-assisted laser desorption/ionization time of flight tandem mass spectrometry, thermal analysis, and so on. The results showed that the purity of the prepared melanin was higher than the commercial standard melanin and it was a kind of nanoaggregates composed of a large quantity of 5,6-dihydroxyindole eumelanin and a small amount of phaeomelanin. In addition, the prepared melanin was irregular in shape and its structure could be divided into three levels: advanced structure maintained by polypeptides, substructure maintained by the ferric ion and microstructure. In particular, the smallest structural unit showed the graphite-like layered structure containing five layers linked by non-covalent bonds and each layer mainly consisted of 5,6-dihydroxyindole and its derivatives, which might be connected to each other through various chemical bonds.





  • Putative endoglucanase PcGH5 from Phanerochaete chrysosporium is a β-xylosidase that cleaves xylans in synergistic action with endo-xylanase
    Publication date: Available online 7 October 2014
    Source:Journal of Bioscience and Bioengineering

    Author(s): Nguyen Duc Huy , Cu Le Nguyen , Jeong-Woo Seo , Dae-Hyuk Kim , Seung-Moon Park

    A predicted endoglucanase gene (PcGH5) was cloned from Phanerochaete chysosporium, and expressed in Pichia pastoris. Although PcGH5 showed similarity with the conserved domains of a cellulase superfamily GH5, a β-glucosidase/6-phospho-β-glucosidase/β-galactosidase superfamily, and an endoglucanase, recombinant PcGH5 exhibited a β-xylosidase activity, rather than endoglucanase activity. Therefore, the predicted gene was named as PcXyl5. Further characterization of recombinant PcXyl5 showed not only catalysis of the hydrolysis of xylo-oligomers to xylose, but also displayed transglycosylation activity using alcohol as a receptor. Optimum pH of rPcXyl5 was found to be 5.5, whereas optimum temperature was 50°C. rPcXyl5 increased reducing sugar release of birchwood xylan, beechwood xylan, and arabinoxylan by 6.4%, 13%, 15.8%, respectively, in synergistic action with endo-xylanase. Interestingly, the late addition of rPcXyl5 into reaction with endo-xylanase resulted in a larger increase of reducing sugar release from pretreated barley straw that addition at the start or by treatment with endo-xylanases alone. The increases observed were 6.3% and 13.8%, respectively, showing a great potential application for hemicellulose saccharification.





  • Lactobacillus plantarum mediated fermentation of Psidium guajava L. fruit extract
    Publication date: Available online 6 October 2014
    Source:Journal of Bioscience and Bioengineering

    Author(s): Ravish Bhat , Lakshminarayana Chikkanayakanahalli Suryanarayana , Karunakara Alageri Chandrashekara , Padma Krishnan , Anil Kush , Puja Ravikumar

    Sixteen hour fermentation of the white flesh raw guava Lucknow 49 cultivar using Lactobacillus plantarum NCIM 2912 was taken up for enhancing the antioxidant potential. The fermented guava product with high antioxidant potential, total phenolic content and short and medium chain fatty acids can be used as functional food.





  • Reorganization of the bacterial and archaeal populations associated with organic loading conditions in a thermophilic anaerobic digester
    Publication date: Available online 5 October 2014
    Source:Journal of Bioscience and Bioengineering

    Author(s): Tomoyuki Hori , Shin Haruta , Daisuke Sasaki , Dai Hanajima , Yoshiyuki Ueno , Atsushi Ogata , Masaharu Ishii , Yasuo Igarashi

    Organic loading conditions are an important factor influencing reactor performances in methanogenic bioreactors. Yet the underlying microbiological basis of the process stability, deterioration, and recovery remains to be understood. Here, structural responses of the bacterial and archaeal populations to the change of organic loading conditions in a thermophilic anaerobic digester were investigated by process analyses and 16S rRNA gene-based molecular approaches. The biogas was produced stably without the accumulation of volatile fatty acids (VFAs) at low organic loading rates (OLRs) in the beginning of reactor operation. Increasing OLR in stages disrupted the stable reactor performance, and high OLR conditions continued the deteriorated performance with slight biogas production and high accumulation of VFAs. Thereafter, the gradual decrease of OLR resulted in the recovery from the deterioration, giving rise to the stable performance again. The stable performances before and after the high OLR conditions conducted were associated with compositionally similar but not identical methanogenic consortia. The bacterial and archaeal populations were synchronously changed at both the transient phases toward the deteriorated performance and in recovery process, during which the dynamic shift of aceticlastic and hydrogenotrophic methanogens including the recently identified Methanomassiliicoccus might contribute to the maintenance of the methanogenic activity. The distinctive bacterial population with a high predominance of Methanobacterium formicicum as archaeal member was found for the deteriorated performance. The results in this study indicate the coordinated reorganization of the bacterial and archaeal populations in response to functional states induced by the change of organic loading conditions in the anaerobic digester.





  • Enhanced cellular content and lactate fraction of the poly(lactate-co-3-hydroxybutyrate) polyester produced in recombinant Escherichia coli by the deletion of σ factor RpoN
    Publication date: Available online 3 October 2014
    Source:Journal of Bioscience and Bioengineering

    Author(s): Ryosuke Kadoya , Yu Kodama , Ken'ichiro Matsumoto , Seiichi Taguchi

    A new approach at the transcriptional level was applied to lactate-based polyester production. Four σ factor disruptants, ΔrpoN, ΔrpoS, ΔfliA and ΔfecI, of Escherichia coli were used as hosts for poly(lactate-co-3-hydroxybutyrate) production from glucose. Among them, ΔrpoN caused dual positive effects of polymer production, enhanced cellular content and lactate fraction.





  • A new aldehyde oxidase catalyzing the conversion of glycolaldehyde to glycolate from Burkholderia sp. AIU 129
    Publication date: Available online 3 October 2014
    Source:Journal of Bioscience and Bioengineering

    Author(s): Miwa Yamada , Keika Adachi , Natsumi Ogawa , Shigenobu Kishino , Jun Ogawa , Michihiko Kataoka , Sakayu Shimizu , Kimiyasu Isobe

    We found a new aldehyde oxidase (ALOD), which catalyzes the conversion of glycolaldehyde to glycolate, from Burkholderia sp. AIU 129. The enzyme further oxidized aliphatic aldehydes, an aromatic aldehyde, and glyoxal, but not glycolate or alcohols. The molecular mass of this enzyme was 130 kDa, and it was composed of three different subunits (αβγ structure), in which the α, β, and γ subunits were 76 kDa, 36 kDa, and 14 kDa, respectively. The N-terminal amino acid sequences of each subunit showed high similarity to those of putative subunits of xanthine dehydrogenase. Metals (copper, iron and molybdenum) and chelating reagents (α,α′-dipyridyl and 8-hydroxyquinoline) inhibited the ALOD activity. The ALOD showed highest activity at pH 6.0 and 50°C. Twenty mM glycolaldehyde was completely converted to glycolate by incubation at 30°C for 3 h, suggesting that the ALOD found in this study would be useful for enzymatic production of glycolate.





  • Cordyceptin induces apoptosis through repressing hTERT expression and inducing extranuclear export of hTERT
    Publication date: Available online 2 October 2014
    Source:Journal of Bioscience and Bioengineering

    Author(s): Kyung-Jun Jang , Gi-Sun Kwon , Jin-Woo Jeong , Cheol-Hong Kim , Hyun-Min Yoon , Gi-Young Kim , Jung-Hyun Shim , Sung-Kwon Moon , Wun-Jae Kim , Yung Hyun Choi

    Cordycepin is an adenosine analog originally extracted from Cordyceps militaris that possesses many pharmacological effects including immune activation and antioxidant and antitumor effects. However, the underlying relationship between apoptosis and telomerase activity in response to cordycepin exposure has not been investigated. In this study, we found that cordycepin-induced apoptosis of human leukemia cells (H937 and THP-1 cells) was associated with inactivation of telomerase and downregulation of human telomerase reverse transcriptase (hTERT) as well as the transcription factors c-Myc and Sp1, which are required for basal transcription from the hTERT gene promoter. Cordycepin also attenuated the activation of phosphoinositide-3-kinase (PI3K)/Akt signaling, thereby reducing phosphorylation and nuclear translocation of hTERT. We further showed that the PI3K inhibitor LY29004 significantly decreased telomerase activity in cordycepin-treated cells and increased cordycepin-induced cell death. These findings demonstrate that cordycepin is cytotoxic to human leukemia cells and suppresses telomerase activity through transcriptional and post-translational suppression of hTERT by inactivating the PI3K/Akt signaling pathway.





  • Synergistic interaction between wavelength of light and concentration of H2O2 in bactericidal activity of photolysis of H2O2
    Publication date: Available online 2 October 2014
    Source:Journal of Bioscience and Bioengineering

    Author(s): Toshihide Toki , Keisuke Nakamura , Michiko Kurauchi , Taro Kanno , Yusuke Katsuda , Hiroyo Ikai , Eisei Hayashi , Hiroshi Egusa , Keiichi Sasaki , Yoshimi Niwano

    The present study aimed to evaluate the interaction between wavelength of light in the range of ultra violet A-visible and concentration of H2O2 in the reaction of photolysis of H2O2 from the point of view of hydroxyl radical (·OH) generation and the bactericidal activity. Light emitting diodes (LEDs) emitting the light at wavelengths of 365, 385, 400 and 465 nm were used at an irradiance of 1000 mW/cm2. H2O2 was used at the final concentrations of 0, 250, 500, and 1000 mM. Quantitative analysis of ·OH generated by the LED irradiation of H2O2 were performed using an electron spin resonance-spin trapping technique. In a bactericidal assay, a bacterial suspension of Staphylococcus aureus prepared in sterile physiological saline was irradiated with the LEDs. The bactericidal activity of each test condition was evaluated by viable counts. When H2O2 was irradiated with the LEDs, ·OH was generated and bacteria were killed dependently on the concentration of H2O2 and the wavelength of LED. The two-way analysis of variance revealed that the wavelength, the H2O2 concentration and their interaction significantly affected the yield of ·OH and the bactericidal activity of the photolysis of H2O2. Therefore, it is suggested that bactericidal activity of photolysis of H2O2 could be enhanced by controlling the wavelength and the concentration of H2O2, which may contributes to shortening the treatment time and/or to reducing the concentration of H2O2.





  • PLE-wu, a new member of piggyBac transposon family from insect, is active in mammalian cells
    Publication date: October 2014
    Source:Journal of Bioscience and Bioengineering, Volume 118, Issue 4

    Author(s): Chunxiao Wu , Shu Wang

    piggyBac, a highly active transposon in insect and mammalian cells, is a very useful tool in genome manipulation. A new piggyBac-like element (PLE), named PLE-wu, was identified from a mutant baculovirus cultured in sf9 insect cells. This new transposon is 2931 bp in length and encodes two active forms of transposase, a 708-amino acid-long transposase and a short 576-residue-long transposase translated from a downstream in-frame initiation codon. PLE-wu has asymmetric terminal structures, containing 6-bp inverted terminal repeats, 32-bp imperfect inverted and direct sub-terminal repeats. Similar to piggyBac, PLE-wu exhibits traceless excision activity in both insect and mammalian cells, restoring the original TTAA target sequence upon excision. It also retains the insertion activity in mammalian cells with a plasmid to chromosome transposition rate about 10-fold higher than random integration. Plasmid rescue assays revealed that the TTAA target sequence was duplicated at the junctions of the insertion site. Deletion of the terminal sequences including the sub-terminal repeats decreased the transposition activity of the 708-residue-long transposase, while the transposition activity of the short form of transposase was not affected. With its low sequence similarity to piggyBac, PLE-wu will contribute to the understanding the mechanism of PLE transposition, as well as design of new transposon systems with higher activity.





  • Characterization of the low-temperature activity of Sulfolobus tokodaii glucose-1-dehydrogenase mutants
    Publication date: October 2014
    Source:Journal of Bioscience and Bioengineering, Volume 118, Issue 4

    Author(s): Taisuke Sugii , Satoshi Akanuma , Sota Yagi , Kazuki Yagyu , Yukiko Shimoda , Akihiko Yamagishi

    Thermophilic enzymes are potentially useful for industrial processes because they are generally more stable than are mesophilic or psychrophilic enzymes. However, a crucial drawback for their use in such processes is that most thermophilic enzymes are nearly inactive at moderate and low temperatures. We have previously proposed that modulation of the coenzyme-binding pocket of thermophilic dehydrogenases can produce mutated proteins with enhanced low-temperature activities. In the current study, we produced and characterized mutants of an NADP-dependent glucose-1-dehydrogenase from the hyperthermophile Sulfolobus tokodaii in which a predicted coenzyme-binding, non-polar residue was replaced by another non-polar residue. Detailed analyses of the kinetic properties of the wild-type enzyme and its mutants showed that one of the mutants (V254I) had improved k cat and k cat/K m values at both 25°C and 80°C. Temperature-induced unfolding experiments showed that the thermal stability of the mutant enzyme was comparable to that of the wild-type enzyme. Calculation of the energetic contribution of the V254I mutation for the dehydrogenase reaction revealed that the mutation destabilizes the enzyme-NADP+-glucose ternary complex and reduces the transition-state energy, thus enhancing catalysis.





  • Novel thrombolytic protease from edible and medicinal plant Aster yomena (Kitam.) Honda with anticoagulant activity: Purification and partial characterization
    Publication date: October 2014
    Source:Journal of Bioscience and Bioengineering, Volume 118, Issue 4

    Author(s): Jun-Hui Choi , Dae-Won Kim , Se-Eun Park , Bong-Suk Choi , Kumar Sapkota , Seung Kim , Sung-Jun Kim

    A thrombolytic protease named kitamase possessing anticoagulant property was purified from edible and medicinal plant Aster yomena (Kitam.) Honda. Kitamase showed a molecular weight of 50 kDa by SDS-PAGE and displayed a strong fibrin zymogram lysis band corresponding to the similar molecular mass. The enzyme was active at high temperatures (50°C). The fibrinolytic activity of kitamase was strongly inhibited by EDTA, EGTA, TPCK and PMSF, inhibited by Zn2+. The Km and V max values for substrate S-2251 were determined as 4.31 mM and 23.81 mM/mg respectively. It dissolved fibrin clot directly and specifically cleaved the α, Aα and γ-γ chains of fibrin and fibrinogen. In addition, kitamase delayed the coagulation time and increased activated partial thromboplastin time and prothrombin time. Kitamase exerted a significant protective effect against collagen and epinephrine induced pulmonary thromboembolism in mice. These results suggest that kitamase may have the property of metallo-protease like enzyme, novel fibrino(geno)lytic enzyme and a potential to be a therapeutic agent for thrombosis.





  • Characterization of α-1,3-glucanase isozyme from Paenibacillus glycanilyticus FH11 in a new subgroup of family 87 α-1,3-glucanase
    Publication date: October 2014
    Source:Journal of Bioscience and Bioengineering, Volume 118, Issue 4

    Author(s): Wasana Suyotha , Shigekazu Yano , Takafumi Itoh , Hiroko Fujimoto , Takao Hibi , Takashi Tachiki , Mamoru Wakayama

    Two α-1,3-glucanase isozymes, designated as α-1,3-glucanase 1 (Agl-FH1) and α-1,3-glucanase 2 (Agl-FH2), were purified from the culture medium of Paenibacillus glycanilyticus FH11. Agl-FH1 and Agl-FH2 exhibited similar characteristics such as optimal pH, pH stability, optimal temperature, thermostability, and molecular masses on SDS-PAGE. However, their hydrolysis products of α-1,3-glucan varied somewhat. Agl-FH1 hydrolyzed α-1,3-glucan into a mixture of maltotriose and maltotetraose, and maltotetraose was the major hydrolysis product of Agl-FH2. N-terminal amino acid sequence analysis and LC–MS/MS analysis of trypsin digested fragments revealed several differences between the amino acid sequences of Agl-FH1 and Agl-FH2. Genes of Agl-FH1 and Agl-FH2 were subcloned into an expression plasmid, and both enzymes were successfully expressed in Escherichia coli. The recombinant Agl-FH1 and Agl-FH2 exhibited the same enzymatic properties as those of each wild-type enzyme, and both of the recombinants showed the activity on the protoplast formation of Schizophyllum commune mycelia. A great diversity was detected in the C-terminal region of family 87 α-1,3-glucanases. Compared with Agl-FH2 which is highly sequence-related to the known α-1,3-glucanases, the C-terminal region of Agl-FH1 has only slight similarity to them (approximately 20% identity). Our analysis revealed that Agl-FH1 was the first member of a new subgroup of family 87 α-1,3-glucanases.





  • Molybdenum-containing membrane-bound formate dehydrogenase isolated from Citrobacter sp. S-77 having high stability against oxygen, pH, and temperature
    Publication date: October 2014
    Source:Journal of Bioscience and Bioengineering, Volume 118, Issue 4

    Author(s): Nga T. Nguyen , Takeshi Yatabe , Ki-Seok Yoon , Seiji Ogo

    Membrane-bound formate dehydrogenase (FDH) was purified to homogeneity from a facultative anaerobic bacterium Citrobacter sp. S-77. The FDH from Citrobacter sp. S-77 (FDHS77) was a monomer with molecular mass of approximately 150 kDa. On SDS-PAGE, the purified FDHS77 showed as three different protein bands with molecular mass of approximately 95, 87, and 32 kDa, respectively. Based on the N-terminal amino acid sequence analysis, the sequence alignments observed for the 87 kDa protein band were identical to that of the large subunit of 95 kDa, indicating that the purified FDHS77 consisted of two subunits; a 95 kDa large subunit and a 32 kDa small subunit. The purified FDHS77 in this purification did not contain a heme b subunit, but the FDHS77 showed significant activity for formate oxidation, determined by the V max of 30.4 U/mg using benzyl viologen as an electron acceptor. The EPR and ICP-MS spectra indicate that the FDHS77 is a molybdenum-containing enzyme, displaying a remarkable O2-stability along with thermostability and pH resistance. This is the first report of the purification and characterization of a FDH from Citrobacter species.





  • Biochemical characterization of Aspergillus oryzae native tannase and the recombinant enzyme expressed in Pichia pastoris
    Publication date: October 2014
    Source:Journal of Bioscience and Bioengineering, Volume 118, Issue 4

    Author(s): Toshiyuki Mizuno , Yoshihito Shiono , Takuya Koseki

    In this study, the biochemical properties of the recombinant tannase from Aspegillus oryzae were compared with those of the native enzyme. Extracellular native tannase was purified from a commercial enzyme source. Recombinant tannase highly expressed in Pichia pastoris was prepared as an active extracellular protein. Purified native and recombinant tannases produced smeared bands with apparent molecular masses of 45–80 kDa and 45–75 kDa, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After N-deglycosylation, the native enzyme yielded molecular masses of 33 kDa and 30 kDa, whereas the recombinant enzyme yielded molecular masses of 34 kDa and 30 kDa. Purified native and recombinant tannases had an optimum pH of 4.0–5.0 and 5.0, respectively, and were stable up to 40°C. After N-deglycosylation, both enzymes exhibited reduced thermostability. Catalytic efficiencies of both purified enzymes were greater with natural substrates, such as (−)-catechin, (−)-epicatechin, and (−)-epigallocatechin gallates, than those with synthetic substrates, such as methyl, ethyl, and propyl gallates. However, there were no activities against the methyl esters of ferulic, p-coumaric, caffeic, and sinapic acids, which indicate feruloyl esterase activity, or the ethyl, propyl, and butyl esters of 4-hydroxybenzoic acid, which indicate paraben hydrolase activity.





  • Antioxidant activities and phenolics of fermented Bletilla formosana with eight plant pathogen fungi
    Publication date: October 2014
    Source:Journal of Bioscience and Bioengineering, Volume 118, Issue 4

    Author(s): Jianwei Dong , Lixing Zhao , Le Cai , Haixian Fang , Xiuhua Chen , Zhongtao Ding

    The tubers of Bletilla formosana were fermented with eight plant pathogen fungi, respectively, and antioxidant activities and total phenolic content (TPC) of the crude extracts of fermented products and non-fermented products were investigated. The antioxidant activities were evaluated in three different test systems [DPPH, ABTS radical-scavenging activity, and ferric reducing-antioxidant power (FRAP)]. It was found that the extract of Helminthosporium maydis fermented B. formosana (FBF) possessed the highest TPC and exhibited a significant antioxidant activity compared with non-fermented product and other fermented products. Correlation analysis between antioxidant activities and TPC was also investigated. The good correlation between antioxidant activities and TPC revealed that the phenolic compounds might be the major contributors for the high antioxidant activities of the fermented B. formosana. Two phenolic compounds, curvularin and dehydrocurvularin, were isolated from H. maydis FBF, which had never been reported from plant of orchidaceae or H. maydis. Curvularin exhibited significant antioxidant activities, and was also present at a high concentration (0.373 mg/mg extract sample), implying an important role for the antioxidant activity of H. maydis FBF. This study suggested that proper fermentation processing could improve TPC and antioxidant activities of B. formosana.





  • Probing of exopolysaccharides with green fluorescence protein-labeled carbohydrate-binding module in Escherichia coli biofilms and flocs induced by bcsB overexpression
    Publication date: October 2014
    Source:Journal of Bioscience and Bioengineering, Volume 118, Issue 4

    Author(s): Minh Hong Nguyen , Yoshihiro Ojima , Makiko Sakka , Kazuo Sakka , Masahito Taya

    Polysaccharides are major structural constituents to develop the three-dimensional architecture of Escherichia coli biofilms. In this study, confocal laser scanning microscopy was applied in combination with a fluorescent probe to analyze the location and arrangement of exopolysaccharide (EPSh) in microcolonies of E. coli K-12 derived strains, formed as biofilms on solid surfaces and flocs in the liquid phase. For this purpose, a novel fluorescent probe was constructed by conjugating a carbohydrate-binding module 3, from Paenibacillus curdlanolyticus, with the green fluorescence protein (GFP-CBM3). The GFP-CBM3 fused protein exhibited strong affinity to microcrystalline cellulose. Moreover, GFP-CBM3 specifically bound to cell-dense microcolonies in the E. coli biofilms, and to their flocs induced by bcsB overexpression. Therefore, the fused protein presents as a novel marker for EPSh produced by E. coli cells. Overexpression of bcsB was associated with abundant EPSh production and enhanced E. coli biofilm formation, which was similarly detectable by GFP-CBM3 probing.





  • Gas chromatography/mass spectrometry based component profiling and quality prediction for Japanese sake
    Publication date: October 2014
    Source:Journal of Bioscience and Bioengineering, Volume 118, Issue 4

    Author(s): Natsuki Mimura , Atsuko Isogai , Kazuhiro Iwashita , Takeshi Bamba , Eiichiro Fukusaki

    Sake is a Japanese traditional alcoholic beverage, which is produced by simultaneous saccharification and alcohol fermentation of polished and steamed rice by Aspergillus oryzae and Saccharomyces cerevisiae. About 300 compounds have been identified in sake, and the contribution of individual components to the sake flavor has been examined at the same time. However, only a few compounds could explain the characteristics alone and most of the attributes still remain unclear. The purpose of this study was to examine the relationship between the component profile and the attributes of sake. Gas chromatography coupled with mass spectrometry (GC/MS)-based non-targeted analysis was employed to obtain the low molecular weight component profile of Japanese sake including both nonvolatile and volatile compounds. Sake attributes and overall quality were assessed by analytical descriptive sensory test and the prediction model of the sensory score from the component profile was constructed by means of orthogonal projections to latent structures (OPLS) regression analysis. Our results showed that 12 sake attributes [ginjo-ka (aroma of premium ginjo sake), grassy/aldehydic odor, sweet aroma/caramel/burnt odor, sulfury odor, sour taste, umami, bitter taste, body, amakara (dryness), aftertaste, pungent/smoothness and appearance] and overall quality were accurately explained by component profiles. In addition, we were able to select statistically significant components according to variable importance on projection (VIP). Our methodology clarified the correlation between sake attribute and 200 low molecular components and presented the importance of each component thus, providing new insights to the flavor study of sake.





  • Chemically pretreating slaughterhouse solid waste to increase the efficiency of anaerobic digestion
    Publication date: October 2014
    Source:Journal of Bioscience and Bioengineering, Volume 118, Issue 4

    Author(s): Cyntia R. Flores-Juarez , Adrián Rodríguez-García , Jesús Cárdenas-Mijangos , Leticia Montoya-Herrera , Luis A. Godinez Mora-Tovar , Erika Bustos-Bustos , Francisco Rodríguez-Valadez , Juan Manríquez-Rocha

    The combined effect of temperature and pretreatment of the substrate on the anaerobic treatment of the organic fraction of slaughterhouse solid waste was studied. The goal of the study was to evaluate the effect of pretreating the waste on the efficiency of anaerobic digestion. The effect was analyzed at two temperature ranges (the psychrophilic and the mesophilic ranges), in order to evaluate the effect of temperature on the performance of the anaerobic digestion process for this residue. The experiments were performed in 6 L batch reactors for 30 days. Two temperature ranges were studied: the psychrophilic range (at room temperature, 18°C average) and the mesophilic range (at 37°C). The waste was pretreated with NaOH before the anaerobic treatment. The result of pretreating with NaOH was a 194% increase in the soluble chemical oxygen demand (COD) with a dose of 0.6 g NaOH per g of volatile suspended solids (VSS). In addition, the soluble chemical oxygen demand/total chemical oxygen demand ratio (sCOD/tCOD) increased from 0.31 to 0.7. For the anaerobic treatment, better results were observed in the mesophilic range, achieving 70.7%, 47% and 47.2% removal efficiencies for tCOD, total solids (TS), and volatile solids (VS), respectively.





  • Production of LYZL6, a novel human c-type lysozyme, in recombinant Pichia pastoris employing high cell density fed-batch fermentation
    Publication date: October 2014
    Source:Journal of Bioscience and Bioengineering, Volume 118, Issue 4

    Author(s): Xiaoyu Zhou , Ying Yu , Jianjun Tao , Long Yu

    Lysozyme acts as an important defensive factor in innate immunity due to its well-recognized bacteriolytic activity. Here we describe the production and performance of human lysozyme-like 6 (LYZL6), a novel human c-type lysozyme homolog. A synthetic codon-optimized cDNA encoding the intact amino acid sequence of LYZL6 was cloned and expressed in Pichia pastoris SMD1168. Bioactive LYZL6 was successfully produced as a single major secreted protein with a molecular weight of 15 kDa, and exhibited bacteriolytic activity against Micrococcus lysodeikticus. The expression conditions were optimized, and the highest expression level of LYZL6 occurred when the recombinant strain was induced with 1.5% methanol under pH 4.5 at 24°C for 96 h. When high cell density fermentation of the recombinant P. pastoris was performed using a fed-batch strategy for totally 125 h in a 30 L fermenter, the dry cell weight and the extracellular lysozyme activity were increased to 116.3 g/L and 2340 U/mL, respectively. The LYZL6 protein concentration was 331 mg/L of fermentation supernatant, and the specific activity of LYZL6 towards M. lysodeikticus was 7069 U/mg. Therefore, we proved that LYZL6 is an antibacterial protein, suggesting a potential application of LYZL6 as an antimicrobial agent, and Pichia expression system for LYZL6 was successful and industrially promising.