Optimization of recombinant Zea mays transglutaminase production and its influence on the functional properties of yogurt

Hongbo Li,Yanhua Cui,Lanwei Zhang,Lili Zhang,Hui Liu,Jinghua Yu 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.3

The requirements for the production of optimized Zea mays transglutaminase (TGZo) using Pichia pastoris GS115 (pPIC9K-tgzo) were optimized in this study. Plackett–Burman design was used to screen variables that significantly influence TGZo production. Oleic acid, methanol, and loading volume were identified as the most significant parameters. Central composite design was employed to determine the optimal level of these three parameters for TGZo production. Results showed that 1078 mU/mL of TGZo activity and 7.6 mg/L of TGZo production were obtained under conditions of 0.07% oleic acid, 1.31% methanol, and 7.36% loading volume. To explore the functional characteristics of TGZo, it was used in yogurt. It was found that the addition of TGZo could produce yogurt with stronger acid gel and higher consistency, cohesiveness, index of viscosity, and apparent viscosity than the untreated product. Therefore, TGZo can be used as a substitute for microbial transglutaminase in the yogurt, even in the food industry.

Heterologous Expression and Purification of Zea mays Transglutaminase in Pichia pastoris

Hongbo Li,Yanhua Cui,Lanwei Zhang,Huaxi Yi,Xue Han,Yuehua Jiao,Ming Du,Rongbo Fan,Shuang Zhang 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.5

Transglutaminases (TGases) are a family ofenzymes that catalyze the cross-linking of proteins and arewidely used in the food industry to improve the texture ofdairy, meat, and bread products. Zea mays transglutaminase(TGZ) is a new type of TGase with a wide potential. TGZwas expressed in the yeast Pichia pastoris under an alcoholoxidase promoter. Maximal expression of recombinantTGZ was achieved by inducing recombinant GS115(pPIC9K-tgz) in BMMY medium using 1.5% methanol for96 h. Secreted TGZ was initially separated using Superdex200 resin and further purified on cation exchange resin. The activity of TGZ following purification was 0.32 U/mgof protein. The polymerization effect of TGZ on caseincatalyzed by recombinant TGZ was slightly lower than theeffect of microbial transglutaminase (MTG). TGZ is a newpotential additive for the food industry.

Seasonal Agricultural Products Distribution and Traceability System Based on the RFID Internet of Things

Zhang Hongbo,Gao Wei 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.11

Based on the big data and complexity in the identification process of IOT radio frequency, this article puts forward an optimal algorithm for Adaptive Gaussian Traversal Harmony Search IOT radio frequency identification, which aim at solving the problems of high computational complexity and low identification accuracy of traditional algorithm. At first, the network optimization design is carried out based on Harmony Search (HS) algorithm, and in order to solve the problems of standard HS in optimization accuracy, computational complexity and other aspects, control parameters are introduced into the algorithm improvisation process on the basis of traverse characteristics of Gaussian function, so that the pertinence of preliminary and later searches are improved, and meanwhile, theoretical analysis on parameters selection is described; Secondly, the optimization model of IOT radio frequency identification is studied and improved adaptive optimization objectives are put forward to achieve equilibrium optimization of performance indicators; at last, test results are compared to prove the suggested algorithm having high computational accuracy and faster computational speed.

Chirality detection of amino acid enantiomers by organic electrochemical transistor

Zhang, Lijun,Wang, Guiheng,Xiong, Can,Zheng, Lei,He, Jianbo,Ding, Yunsheng,Lu, Hongbo,Zhang, Guobing,Cho, Kilwon,Qiu, Longzhen Elsevier 2018 Biosensors & bioelectronics Vol.105 No.-

<P><B>Abstract</B></P> <P>Chiral recognition of α-amino acids is attracting increasing interest due to the importance of α-amino acids in protein metabolism as well as in food products and pharmaceuticals. Organic electrochemical transistors (OECTs) with gate electrodes modified with molecularly imprinted polymer (MIP) films were fabricated and successfully used as highly selective and sensitive chiral recognition biosensors for <SMALL>D/L</SMALL>-tryptophan (<SMALL>D</SMALL> <SMALL>/</SMALL> <SMALL>L</SMALL>-Trp) and <SMALL>D/L</SMALL>-tyrosine (<SMALL>D</SMALL> <SMALL>/</SMALL> <SMALL>L</SMALL>-Tyr). The MIP films, which can specifically recognize and has an electrocatalytic effect on the oxidation of Trp and Tyr, together with the amplification function of an OECT, provide a highly sensitive and selective OECT biosensor. The sensor showed a linear response range for <SMALL>L</SMALL>-Trp and <SMALL>L</SMALL>-Tyr from 300 nM to 10 μM with a sensitivity of 3.19 and 3.64 μA/μM, respectivity. And the detection limit for <SMALL>L</SMALL>-Trp and <SMALL>L</SMALL>-Tyr is of 2 nM and 30 nM (S/N > 3). The selectivity factors of <SMALL>L</SMALL>-Trp, <SMALL>D</SMALL>-Trp, <SMALL>L</SMALL>-Tyr and <SMALL>D</SMALL>-Tyr to their enantiomers are 11.6, 3.5, 14.5 and 2.6, respectively. This method can pave the way for widespread applications of OECT-based sensors in chiral material identification.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An novel chiral recognition MIP-OECT sensor was developed. </LI> <LI> The MIP films showed good performance of selective and electro-catalytic oxidation for Trp and Tyr. </LI> <LI> The MIP films together with the amplification function of an OECT afforded a highly sensitive, selective sensor for chirality detection of amino acid enantiomers. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Asymmetrical SPWM‑based control scheme for BESS‑integrated UPQC with hybrid connected configuration

Zhenqiang Zhang,Jianjun Zhao,Shen Liu,Hongbo Wang,Nan Wang,Peng Zhang,Yue Yu,Peng Xu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.10

The unified power quality conditioner (UPQC) integrated with the battery energy storage system not only mitigates the power quality problems on the grid side and load side but also supplies active power to the load or the grid. The wide voltage variation of the battery and the high efficiency of the whole system can be achieved with the hybrid connected configuration, i.e., the battery is connected simultaneously to the series and shunt converters of the UPQC directly and indirectly through the dc–dc converter. However, the control and modulation strategies are the major challenges for this configuration. This study proposes a control scheme based on asymmetrical sinusoidal pulse width modulation (SPWM) to realize high-efficiency active power delivery, thereby addressing the issue above. The mechanism of the modulation scheme to regulate active power is revealed, and the voltage variation of the battery is considered. The modified SPWM strategy features easy implementation and a low computation burden. The effectiveness of the system with the proposed control and modulation schemes is verified by both simulation and experimental results.

How Do Microbial Metabolism and New Microbial Legacy Mediate Soil Carbon and Nitrogen Cycling?

Xudong Zhang,Hongbo He,Yeye Wu,Wei Zhang 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Spatial Distribution and Influencing Factor of Soil Moisture in Typical Depression Area of Karst Region

Jiguang Zhang,Yirong Su,Hongsong Chen,Xiangli Kong,Wei Zhang,Jiuquan Zhang,Hongbo Liang 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Wood Defects Recognition Based on Fuzzy BP Neural Network

Hongbo Mu,Mingming Zhang,Dawei Qi,Shuyue Guan,Haiming Ni 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.5

Firstly, we applied the X-ray non-destructive testing technology to detect wood defects for getting the images. After graying the images, we calculated their GLCMS(Gray Level Co-occurrence Matrixes), then we normalized GLCMS to obtain the joint probabilities of GLCMS. The feature vectors of images, which included 13 eigenvalues of images were calculated and extracted by the joint probability of GLCMS. The fuzzy BP neural network(abbreviated as FBP) was designed by combining fuzzy mathematics and BP neural network . And the FBP neural network was regarded as the membership function of feature vectors, the outputs of the network was regarded as the degree of membership to the feature vectors in each category. We use the maximum degree of membership method for the pattern recognition of feature vectors, so the automatic identification and classification for feature vectors were achieved , and then the automatic identification of wood defects was realized. By simulated study and training many times, the results shown that the average recognition success rate of the network was more than 90%, and some FBP networks had an extremely high recognition success rate to training samples and test samples.

An efficient process for co-production of γ-aminobutyric acid and probiotic Bacillus subtilis cells

Hongbo Wang,Jinge Huang,Lei Sun,Fuchao Xu,Wei Zhang,Jixun Zhan 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.1

This study was to establish an integrated processfor the co-production of c-aminobutyric acid (GABA) andlive probiotics. Six probiotic bacteria were screened andBacillus subtilis ATCC 6051 showed the highest GABAproducingcapacity. The optimal temperature and initial pHvalue for GABA production in B. subtilis were found to be30 C and 8.0, respectively. A variety of carbon andnitrogen sources were tested, and potato starch and peptonewere the preferred carbon and nitrogen sources for GABAproduction, respectively. The concentrations of carbonsource, nitrogen source and substrate (sodium L-glutamate)were then optimized using the response surface methodology. The GABA titer and concentration of viable cells ofB. subtilis reached 19.74 g/L and 6.0 9 108 cfu/mL at120 h. The GABA titer represents the highest production ofGABA in B. subtilis. This work thus demonstrates a highlyefficient co-production process for GABA and probiotic B. subtilis cells.

DC-Link Active Power Filter for High-Power Single-Phase PWM Converters

Hongbo Li,Kai Zhang,Hui Zhao 전력전자학회 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.3

Single phase converters suffer from ripple power pulsating at twice the line frequency. The ripple power is usually absorbed by a bulky capacitor bank and/or a dedicative LC resonant link, resulting in a low power density and a high cost. An alternative solution is using a dc link active power filter (APF) to direct the pulsating power into another energy-storage component. The main dc link filter capacitor can then be reduced substantially. Based on a mainstream dc APF topology, this paper proposed a new control strategy incorporating both dual-loop control and repetitive control. The circuit parameter design is also re-examined from a control point of view. The proposed APF scheme has better control performance, and is more suited for high power applications since it works in CCM and with a low switching frequency.