Read by QxMD icon Read

Biotechnology Letters

Shinji Takenaka, Jyun Yoshinami, Ampin Kuntiya, Charin Techapun, Noppol Leksawasdi, Phisit Seesuriyachan, Thanongsak Chaiyaso, Masanori Watanabe, Kosei Tanaka, Ken-Ichi Yoshida
OBJECTIVES: A bacterial halotolerant enzyme was characterized to understand the molecular mechanism of salt adaptation and to explore its protein engineering potential. RESULTS: Halotolerant serine protease (Apr_No16) from a newly isolated Bacillus subtilis strain no. 16 was characterized. Multiple alignments with previously reported non-halotolerant proteases, including subtilisin Carlsberg, indicated that Apr_No16 has eight acidic or polar amino acid residues that are replaced by nonpolar amino acids in non-halotolerant proteases...
October 16, 2017: Biotechnology Letters
Jianzhi Zhang, Xi Li
OBJECTIVES: To enhance the efficiency of phenyllactic acid (PLA) production from L-phenylalanine (L-Phe) by introducing a novel artificial pathway into Escherichia coli RESULTS: The production of PLA from L-Phe by recombinant E. coli (ldh-lpox) coexpressing L-phenylalanine oxidase and L-lactate dehydrogenase was studied. The new PLA synthesis pathway was confirmed to be efficient in recombinant E. coli. Subsequently, two different biocatalyst processes were carried out and optimized for PLA production...
October 16, 2017: Biotechnology Letters
Qiao Zhang, Bo Jiang, Tao Zhang, Zhenhua Duan
OBJECTIVE: To explore deactivation kinetics and the effects of some additives on the activity and conformational changes of D-psicose 3-epimerase (DPEase) during its storage. RESULTS: The experimental data of DPEase inactivation during storage at 4-45 °C fitted with the first-order expression model. The inactivation rate constants of DPEase stored at 4, 10, 25, 35 and 45 °C were 0.0076, 0.01, 0.0223, 0.0351 and 0.0605 day, respectively. A regression formula of half-lives as storage temperatures, ln t 1/2 = 4...
October 16, 2017: Biotechnology Letters
Xiaoying Li, Hongxia Song, Zhirong Liu, Yunsheng Bi
OBJECTIVES: To investigate whether miR-1260b can regulate migration and invasion of hepatocellular carcinoma (HCC) by targeting RGS22. RESULTS: miR-1260b was up-regulated in HCC tissues compared with their corresponding non-cancerous tissues. Over-expression of miR-1260b increased migration and invasion of HepG2 and SMMC-7721 cells associated with HCC. Regulator of G-protein signaling 22 (RGS22) was identified as a directly target of miR-1260b and was inhibited by miR-1260b...
October 16, 2017: Biotechnology Letters
Timothy D Leathers, Joseph O Rich, Melinda S Nunnally, Amber M Anderson
OBJECTIVE: To test the inactivation of the antibiotic, virginiamycin, by laccase-induced culture supernatants of Aureobasidium pullulans. RESULTS: Fourteen strains of A. pullulans from phylogenetic clade 7 were tested for laccase production. Three laccase-producing strains from this group and three previously identified strains from clade 5 were compared for inactivation of virginiamycin. Laccase-induced culture supernatants from clade 7 strains were more effective at inactivation of virginiamycin, particularly at 50 °C...
October 16, 2017: Biotechnology Letters
Yanhong Wang, Ranjing Ma, Lu Liu, Lin He, Rui Ban
OBJECTIVES: To construct a Bacillus subtilis strain for improved uridine production. RESULTS: The AAG2846-2848 fragment of the pyrAB gene, encoding carbamoylphosphate synthetase, was deleted in B. subtilis TD246 leading to a 245% increase of uridine production and the conversion from glucose to uridine increased by 10.5%. Overexpression of the pyr operon increased the production of uridine by a further 31% and the conversion rate of glucose to uridine was increased by 18%...
October 16, 2017: Biotechnology Letters
Ran Qiu, Jian Lu
OBJECTIVES: Exogenous phytase improved the activity of hydrolases to decrease the malting time. RESULTS: Treatment with phytase during barley steeping increased activity of hydrolases (α-/β-amylase, proteinase, β-glucanase and xylanase) in green malt. Maximal activity was observed for α-/β-amylase, β-glucanase and xylanase with 0.8 U phytase/g and proteinase with 1.2 U phytase/g. Phytase promoted acrospire growth of green malt and reduced malting process with 0...
October 12, 2017: Biotechnology Letters
Zhangcai Luo, Jing Miao, Wei Luo, Guoying Li, Yao Du, Xiaobin Yu
OBJECTIVE: To explore an efficient use of crude glycerol for the production of a highly thermostable β-mannanase (ReTMan26) by Pichia pastoris X33. RESULTS: Cell growth was significantly inhibited by 4 and 6% (w/v) crude glycerol in 250 ml shake-flasks and in 5 l bioreactor batch cultures, respectively, but not affected by pure glycerol at the same concentrations. For further study, the impact of various impurities in crude glycerol on the cell growth of, and ReTMan26 production by, Pichia pastoris was investigated...
October 12, 2017: Biotechnology Letters
Kristína Markošová, Andrea Camattari, Michal Rosenberg, Anton Glieder, Nicholas J Turner, Martin Rebroš
OBJECTIVE: To clone monoamine oxidase N, that catalyses the selective oxidative deamination or deracemisation of amines into imines, in Pichia pastoris and prove the importance of choosing the proper expression system for its recombinant production. RESULTS: Monoamine oxidase, originating from Aspergillus niger and subjected to directed evolution (MAO-N D5), was cloned and expressed in Pichia pastoris CBS7435 Mut(S) strain for the first time. Various transformants were screened at microscale level...
October 10, 2017: Biotechnology Letters
Qiufang Chen, Qingfei Liang, Weixia Zhuang, Jun Zhou, Bingyu Zhang, Pu Xu, Yang Ju, Yasuyuki Morita, Qing Luo, Guanbin Song
OBJECTIVES: To investigate the impact of secreted factors of rat bone marrow mesenchymal stem cells (MSCs) on the proliferation and migration of tenocytes and provide evidence for the development of MSC-based therapeutic methods of tendon injury. RESULTS: Rat bone marrow mesenchymal stem cell-derived conditioned medium (MSC-CM) promoted the proliferation of tenocytes within 24 h and decreased the percentage of tenocytes in G1 phase. MSC-CM activated the extracellular signal-regulated kinase1/2 (ERK1/2) signal molecules, while the ERK1/2 inhibitor PD98059 abrogated the MSC-CM-induced proliferation of tenocytes, decreased the fraction of tenocytes in the G1 phase and elevated p-ERK1/2 expression...
October 10, 2017: Biotechnology Letters
Xiao Shen, Danijel Dojcinovic, Lucia Baldi, David L Hacker, Immanuel F Luescher, Florian M Wurm
OBJECTIVES: To investigate the effects of operational process conditions on expression of MHC class II protein from a stable Drosophila S2 cell line. RESULTS: When the Drosophila S2 cells were grown in vented orbitally shaken TubeSpin bioreactor 600 containers, cell growth was improved three-fold and the yield of recombinant major histocompatibility (MHC) class II protein (HLA-DR12xHis) increased four-fold over the levels observed for the same cells cultivated in roller bottles (RB) without vented caps...
October 9, 2017: Biotechnology Letters
Jianhua He, Lili Dong, Kang Xu, Yuna Qian, Chunli Wang, Yongqiang Sha, Juila Li Zhong, Wanqian Liu, Yonggang Lv, Yang Song, Li Yang
OBJECTIVE: To evaluate the effects of mechano growth factor E peptide (MGF) on the invasive properties of melanoma cells. RESULTS: Melanoma cells (GLL19) were treated with 10, 20 and 30 ng MGF/ml for 24 h. Their invasive properties were investigated by transwell assay. Cytoskeleton reorganization was assessed via staining with phalloidin-FITC; lysyl oxidase (LOX) family gene expression was tested by qRT-PCR, and western blotting was used to detect expression of the matrix metalloproteinases (MMPs) and endoplasmic reticulum (ER) stress...
October 6, 2017: Biotechnology Letters
Jing Wu, Qiuling Luo, Jia Liu, Xiulai Chen, Liming Liu
OBJECTIVES: To enhance acid tolerance of Candida glabrata for pyruvate production by engineering AMP metabolism. RESULTS: The physiological function of AMP deaminase in AMP metabolism from C. glabrata was investigated by deleting or overexpresseing the corresponding gene, CgAMD1. At pH 4, CgAMD1 overexpression resulted in 59 and 51% increases in biomass and cell viability compared to those of wild type strain, respectively. In addition, the intracellular ATP level of strain Cgamd1Δ/CgAMD1 was down-regulated by 22%, which led to a 94% increase in pyruvate production...
October 5, 2017: Biotechnology Letters
Shiwei Zhang, Qiding Zhong, Daobing Wang, Zhanbin Huang, Guohui Li
OBJECTIVES: To determine the origin of (15)N-labeled phenylalanine in microbial metabolic flux analysis using (15)N as a tracer, a method for measuring phenylalanine δ(15)N using HPLC coupled with elemental analysis-isotope ratio mass spectrometry (EA-IRMS) was developed. RESULTS: The original source of the (15)N-labeled phenylalanine was determined using this new method that consists of three steps: optimization of the HPLC conditions, evaluation of the isotope fractionation effects, and evaluation of the effect of pre-processing on the phenylalanine nitrogen stable isotope...
October 5, 2017: Biotechnology Letters
Ye Li, Zhiqing Wang, Patrick C Cirino
OBJECTIVE: To isolate and characterize the kinetics of variants of E. coli β-glucuronidase (GUS) having altered substrate specificity. RESULTS: Two small combinatorial libraries of E. coli GUS variants were constructed and screened for improved activities towards the substrate p-nitrophenyl-β-D-galactoside (pNP-gal). Nine of the most active variants were purified and their kinetic parameters were determined. These variants show up to 134-fold improved kcat/KM value towards pNP-gal compared to wild-type GUS, up to 9 × 10(8)-fold shift in specificity from p-nitrophenyl-β-D-glucuronide (pNP-glu) to pNP-gal compared to wild-type, and 10(3)-fold increase in specificity shift compared to a previously evolved GUS variant...
October 4, 2017: Biotechnology Letters
Zikang Xie, Jianda Xu, Libo Peng, Yi Gao, Hong Zhao, Yuxing Qu
OBJECTIVES: To investigate the roles of miR-149 in the progression of human osteosarcoma (OS). RESULTS: miR-149 level was upregulated in tissues from OS patients more than in normal subjects. Cell proliferation and apoptosis assays revealed that miR-149 increased cell proliferation and inhibited cell apoptosis in OS cell line (MG63). An increase of Bcl-2 gene expression and a decrease of cleaved-caspase-3, and cleaved-PARP expression were observed in MG63 cells with transfection of miR-149...
September 27, 2017: Biotechnology Letters
Wenhua Li, Yuwen Chen, Yuwen Sheng, Zeyu Xie, Yaxiong Tang
OBJECTIVE: To synthesize and determine the antitumor activity of 10-chlorocanthin-6-one in ovarian cancer HO8910PM cells. RESULTS: Among the synthesized canthin-6-one analogs, 10-chlorocanthin-6-one was the most cytotoxic (IC50 = 4.9 μM), as demonstrated by a dose-dependent cytotoxicity assay. Moreover, 10-chlorocanthin-6-one induced apoptosis through the activation of poly(ADP-ribose) polymerase and caspase-3 cleavage, upregulation of Bcl-2, and downregulation of Bim, x-linked inhibitor of apoptosis protein (XIAP), and survivin in HO8910PM cells...
September 25, 2017: Biotechnology Letters
Evdoxia Gourbatsi, Jane F Povey, C Mark Smales
OBJECTIVES: There are a number of blockbuster monoclonal antibodies on the market used for the treatment of a variety of diseases. Although the formulation of many antibodies is achieved in 'platform' formulations, some are so difficult to formulate that it can result in an inability to develop a finished drug product. Further, a large number of antibody-inspired or-based molecules are now being developed and assessed for biotherapeutic purposes and less is understood around the required active protein drug concentrations, excipients and additives required in final product formulations...
September 23, 2017: Biotechnology Letters
José S Fernández-Reyes, J Viridiana García-Meza
OBJECTIVES: To develop a bioelectrochemical system (BES) to couple the biooxidation of chalcopyrite (CuFeS2), bioelectrogenesis, and the cathodic Cu(2+) reduction, bioanodes of acidophilic (pH < 2) and aerobic chemolithoautotrophic bacteria Acidithiobacillus thiooxidans (sulfur oxidizing) and Leptospirillum sp. (Fe(2+) oxidizing) were used. RESULTS: CuFeS2 biooxidation increases the charge transfer from the media due to the bioleaching of Cu and Fe. The biofilm on a graphite bar endows a more electropositive (anodic) character to the bioelectrode...
September 22, 2017: Biotechnology Letters
Nicola McGillicuddy, Patrick Floris, Simone Albrecht, Jonathan Bones
Raw materials, in particular cell culture media, represent a significant source of variability to biopharmaceutical manufacturing processes that can detrimentally affect cellular growth, viability and specific productivity or alter the quality profile of the expressed therapeutic protein. The continual expansion of the biopharmaceutical industry is creating an increasing demand on the production and supply chain consistency for cell culture media, especially as companies embrace intensive continuous processing...
September 22, 2017: Biotechnology Letters
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"