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Biotechnology Letters

Hiroaki Sakamoto, Tomohiro Komatsu, Koji Yamasaki, Takenori Satomura, Shin-Ichiro Suye
OBJECTIVES: To design and construct a novel bio-anode electrode based on the oxidation of glutamic acid to produce 2-oxoglutarate, generating two electrons from NADH. RESULTS: Efficient enzyme reaction and electron transfer were observed owing to immobilization of the two enzymes using a mixed self-assembled monolayer. The ratio of the immobilized enzymes was an important factor affecting the efficiency of the system; thus, we quantified the amounts of immobilized enzyme using a quartz crystal microbalance to further evaluate the electrochemical reaction...
October 19, 2016: Biotechnology Letters
Ji-Hua Yu, Yang-Yang Li, Mian Xiang, Jian-Quan Zhu, Xin-He Huang, Wan-Jun Wang, Rui Tan, Jia-Yu Zhou, Hai Liao
OBJECTIVES: To clone and characterize a novel bi-functional α-amylase/subtilisin inhibitor (LASI) from the rhizome of Ligusticum chuanxiong, a traditional Chinese medicine. RESULTS: The LASI showed strong homology with members of the Kunitz trypsin inhibitor family. Its putative amino acid sequence has a 40 % identity with that of the α-amylase/subtilisin inhibitor from rice. LASI gene without signal peptide was expressed in E. coli Rosetta. After purification, the recombinant LASI protein was inhibitory against not only α-amylase from porcine pancreas, Helicoverpa armigera, Spodoptera litura and Plutella xylostella, but also subtilisin A, but not against trypsin or chymotrypsin...
October 17, 2016: Biotechnology Letters
Karin Förster-Fromme, Sarah Schneider, Georg A Sprenger, Christoph Albermann
OBJECTIVES: To investigate the translocation of nucleotide-activated sugars from the cytosol across a membrane into the endoplasmatic reticulum or the Golgi apparatus which is an important step in the synthesis of glycoproteins and glycolipids in eukaryotes. RESULTS: The heterologous expression of the recombinant and codon-adapted human GDP-L-fucose antiporter gene SLC35C1 (encoding an N-terminal OmpA-signal sequence) led to a functional transporter protein located in the cytoplasmic membrane of Escherichia coli...
October 13, 2016: Biotechnology Letters
Deqiang Zhu, Jianrong Wu, Xiaobei Zhan, Li Zhu, Zhiyong Zheng, Minjie Gao
OBJECTIVES: N-Acetyl-D-neuraminic acid (Neu5Ac) is often synthesized from exogenous N-acetylglucosamine (GlcNAc) and excess pyruvate. We have previously constructed a recombinant Escherichia coli strain for Neu5Ac production using GlcNAc and intracellular phosphoenolpyruvate (PEP) as substrates (Zhu et al. Biotechnol Lett 38:1-9, 2016). RESULTS: PEP synthesis-related genes, pck and ppsA, were overexpressed within different modes to construct PEP-supply modules, and their effects on Neu5Ac production were investigated...
October 13, 2016: Biotechnology Letters
Jun Kong, Zijie Li, Huijie Zhang, Xiao-Dong Gao, Hideki Nakanishi
OBJECTIVES: To achieve consecutive conversion from creatinine to urea and sarcosine using creatininase and creatinase encapsulated in spores of Saccharomyces cerevisiae. RESULTS: Creatininase encapsulated into the spore wall was produced and its specific activity was 3.4 ± 0.4 U/mg. By deletion of OSW2 gene, which causes a mild spore wall defect, the activity was increased to 10.9 ± 0.5 U/mg. Compared with soluble enzymes, spore-encapsulated creatininase was tolerant to environmental stresses; creatininase encapsulated in osw2∆ spores retained more than 90 % of the activity after treatment by SDS or proteinase K...
October 12, 2016: Biotechnology Letters
Gaoxiang Qi, Lian Xiong, Xiaoqing Lin, Chao Huang, Hailong Li, Xuefang Chen, Xinde Chen
OBJECTIVE: To investigate the inhibiting effect of formic acid on acetone/butanol/ethanol (ABE) fermentation and explain the mechanism of the alleviation in the inhibiting effect under CaCO3 supplementation condition. RESULTS: From the medium containing 50 g sugars l(-1) and 0.5 g formic acid l(-1), only 0.75 g ABE l(-1) was produced when pH was adjusted by KOH and fermentation ended prematurely before the transformation from acidogenesis to solventogenesis. In contrast, 11...
October 6, 2016: Biotechnology Letters
Bing Lin, Xu-Zhong Yang, Xue-Wei Cao, Tao-Zhu Zhang, Fu-Jun Wang, Jian Zhao
OBJECTIVE: To evaluate the anti-tumor effects of trichosanthin after fusion with a cell penetrating peptide, heparin-binding peptide (HBP), derived from human heparin-binding EGF-like growth factor (HB-EGF). RESULTS: The fusion protein of trichosanthin-HBP was expressed in Escherichia coli BL21 and purified by Ni-NTA affinity chromatography. The HBP domain had no influence on the topological inactivation activity and N-glycosidase activity of trichosanthin. Trichosanthin-HBP significantly inhibited the growth of tested cancer cells which are impervious to trichosanthin...
October 6, 2016: Biotechnology Letters
Yujiro Higuchi, Yasunari Eshima, Yibo Huang, Takashi Kinoshita, Wataru Sumiyoshi, Shin-Ichi Nakakita, Kaoru Takegawa
OBJECTIVES: To establish an efficient method of chemoenzymatic modification for making N-linked oligosaccharide chains of glycoproteins structurally homogeneous, which crucially affects their bioactivities. RESULTS: Deglycosylated-RNase B (GlcNAc-RNase B; acceptor), sialylglyco (SG)-oxazoline (donor) and an N180H mutant of Coprinopsis cinerea endo-β-N-acetylglucosaminidase (Endo-CC(N180H)) were employed. pH 7.5 was ideal for both SG-oxazoline's stability and Endo-CC's transglycosylation reaction...
October 6, 2016: Biotechnology Letters
Bijinu Balakrishnan, Si-Hyung Park, Hyung-Jin Kwon
OBJECTIVES: To characterize a biosynthetic gene that is selectively involved in the biosynthesis of yellow or orange components in the azaphilone polyketide pathway of Monascus. RESULTS: A reductive modification is predicted to control the relative levels of reduced (yellow) and oxidized (orange and red) components in the pathway of azaphilone pigment biosynthesis in Monascus. Targeted inactivation of a reductase gene mppE enhanced orange and red pigment production whereas overexpression of the gene promoted yellow pigment production...
October 6, 2016: Biotechnology Letters
Do Young Kim, Chung Wook Chung, Han-Young Cho, Young Ha Rhee, Dong-Ha Shin, Kwang-Hee Son, Ho-Yong Park
OBJECTIVES: To evaluate the biocatalytic characteristics of a new endo-β-1,4-D-mannan-degrading enzyme (ManP) from Paenibacillus sp. strain HY-8, a gut bacterium of the longicorn beetle Moechotypa diphysis. RESULTS: Purified ManP (32 kDa) with an N-terminal amino acid sequence of APSFAVGADFSYVPG displayed the greatest degree of biocatalytic activity toward locust bean gum (LBG) at 55 °C and pH 7.0. The enzyme degraded LBG, guar gum, ivory nut mannan, and mannooligosaccharides (M2-M5), but did not exhibit any hydrolytic activity against structurally unrelated substrates...
October 6, 2016: Biotechnology Letters
Irem Avcilar-Kucukgoze, Zoya Ignatova
The expression of synthetic circuits in host organisms, or chassis, is a key aspect of synthetic biology. Design adjustments made for maximal production may negatively affect the central metabolism and biosynthetic activities of the chassis host. Here, we review recent attempts to modulate synthetic circuit design for optimal production and present models that precisely capture the trade-off between circuit production and chassis growth. We also present emerging concepts for full orthogonalization of synthetic productivity and its decoupling from the endogenous biosynthetic activities of the cell, opening new routes towards robust synthetic circuit expression...
October 4, 2016: Biotechnology Letters
Rachelle Bester, Pieter T Pepler, Dirk J Aldrich, Hans J Maree
OBJECTIVES: To enable analysis and comparisons of different relative quantitation experiments, a web-browser application called Harbin was created that uses a quantile-based scoring system for the comparison of samples at different time points and between experiments. RESULTS: Harbin uses the standard curve method for relative quantitation to calculate concentration ratios (CRs). To evaluate if different datasets can be combined the Harbin quantile bootstrap test is proposed...
October 1, 2016: Biotechnology Letters
Chao Zhao, Yanan Chu, Yanhong Li, Chengfeng Yang, Yuqing Chen, Xumin Wang, Bin Liu
OBJECTIVES: To analyze the microbial diversity and gene content of a thermophilic cellulose-degrading consortium from hot springs in Xiamen, China using 454 pyrosequencing for discovering cellulolytic enzyme resources. RESULTS: A thermophilic cellulose-degrading consortium, XM70 that was isolated from a hot spring, used sugarcane bagasse as sole carbon and energy source. DNA sequencing of the XM70 sample resulted in 349,978 reads with an average read length of 380 bases, accounting for 133,896,867 bases of sequence information...
September 30, 2016: Biotechnology Letters
Xiangrong Dong, Yanping Wang, Fengyuan Yang, Shanshan Zhao, Bing Tian, Tao Li
OBJECTIVES: Lycopene biosynthetic genes from Deinococcus radiodurans were co-expressed in Lactococcus lactis to produce lycopene and improve its tolerance to stress. RESULTS: Lycopene-related genes from D. radiodurans, DR1395 (crtE), DR0862 (crtB), and DR0861 (crtI), were fused in line with S hine-Dalgarno (SD) sequences and co-expressed in L. lactis. The recombinant strain produced 0.36 mg lycopene g(-1) dry cell wt after 48 h fermentation. The survival rate to UV irradiation of the recombinant strain was higher than that of the non-transformed strain...
September 27, 2016: Biotechnology Letters
Songwen Tan, Xuncai Chen, Chunzhi Cui, Yang Hou, Weiguo Li, Hong You
OBJECTIVE: To develop a method to treat saline phenolic wastewater in a biological contact oxidation reactor (BCOR) with immobilized cells of a marine microorganism, Oceanimonas sp., isolated from seawater. RESULTS: Cells were immobilized on fibre carriers in the BCOR. Saline wastewater with phenol at 1.5 g/l and NaCl at 6 % (w/v) was treated. In continuous assays, 99 % removal of phenol was achieved and a kinetic model for the phenol degradation is presented based on Monod's equation...
September 22, 2016: Biotechnology Letters
Abu Yousuf, Maksudur Rahman Khan, M Amirul Islam, Zularisam Ab Wahid, Domenico Pirozzi
Microbial oils are considered as alternative to vegetable oils or animal fats as biodiesel feedstock. Microalgae and oleaginous yeast are the main candidates of microbial oil producers' community. However, biodiesel synthesis from these sources is associated with high cost and process complexity. The traditional transesterification method includes several steps such as biomass drying, cell disruption, oil extraction and solvent recovery. Therefore, direct transesterification or in situ transesterification, which combines all the steps in a single reactor, has been suggested to make the process cost effective...
September 22, 2016: Biotechnology Letters
Roman Akasov, Anastasia Gileva, Daria Zaytseva-Zotova, Sergey Burov, Isabelle Chevalot, Emmanuel Guedon, Elena Markvicheva
OBJECTIVES: To design novel 3D in vitro co-culture models based on the RGD-peptide-induced cell self-assembly technique. RESULTS: Multicellular spheroids from M-3 murine melanoma cells and L-929 murine fibroblasts were obtained directly from monolayer culture by addition of culture medium containing cyclic RGD-peptide. To reach reproducible architecture of co-culture spheroids, two novel 3D in vitro models with well pronounced core-shell structure from tumor spheroids and single mouse fibroblasts were developed based on this approach...
September 22, 2016: Biotechnology Letters
Haiyang Zhang, Zhe Lin, Daoyong Tan, Chunhua Liu, Yali Kuang, Zhu Li
OBJECTIVES: To develop a more effective dissolved air flotation process for harvesting microalgae biomass, a co-flocculation/air flotation (CAF) system was developed that uses an ejector followed by a helix tube flocculation reactor (HTFR) as a co-flocculation device to harvest Chlorella sp. 64.01. RESULTS: The optimal size distribution of micro-bubbles and an air release efficiency of 96 % were obtained when the flow ratio of inlet fluid (raw water) to motive fluid (saturated water) of the ejector was 0...
September 21, 2016: Biotechnology Letters
Min-Ji Kim, Min-Ju Seo, Kyung-Chul Shin, Deok-Kun Oh
OBJECTIVE: To increase the production of 10S-hydroxy-8(E)-octadecenoic acid from oleic acid by whole recombinant Escherichia coli cells expressing Nostoc punctiforme 10S-dioxygenase with the aid of a chaperone. RESULTS: The optimal conditions for 10S-hydroxy-8(E)-octadecenoic acid production by recombinant cells co-expressing chaperone plasmid were pH 9, 35 °C, 15 % (v/v) dimethyl sulfoxide, 40 g cells l(-1), and 10 g oleic acid l(-1). Under these conditions, recombinant cells co-expressing chaperone plasmid produced 7...
September 21, 2016: Biotechnology Letters
Xuexia Zhu, Jingwen Yang, Xingxing Zhang, Lu Zhang, Xiaojun Wang, Yuan Huang, Zhou Yang
OBJECTIVE: To explore the combined effects of temperature and Daphnia-associated infochemicals on colony formation of Scenedesmus obliquus to faciliate harvesting the algal biomass. RESULTS: A three-parameter modified Gaussian model fitted the changes of the number of cells per particle in S. obliquus induced by Daphnia culture filtrate well under any temperature. Decreases in temperature enhanced the induced-colony formation of Scenedesmus. The maximum colony size at 15-25 °C was significantly larger than those at 30-35 °C...
September 21, 2016: Biotechnology Letters
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