LasR Might Act as an Intermediate in Overproduction of Phenazines in the Absence of RpoS in Pseudomonas aeruginosa

( Qiuning He ),( Zhibin Feng ),( Yanhua Wang ),( Kewen Wang ),( Kailu Zhang ),( Le Kai ),( Xiuying Hao ),( Zhifen Yu ),( Lijuan Chen ),( Yihe Ge ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.8

As an opportunistic bacterial pathogen, Pseudomonas aeruginosa PAO1 contains two phenazineproducing gene operons, phzA1B1C1D1E1F1G1 (phz1) and phzA2B2C2D2E2F2G2 (phz2), each of which is independently capable of encoding all enzymes for biosynthesizing phenazines, including phenazine-1-carboxylic acid and its derivatives. Other previous study reported that the RpoS-deficient mutant SS24 overproduced pyocyanin, a derivative of phenazine-1- carboxylic acid. However, it is not known how RpoS mediates the expression of two phz operons and regulates pyocyanin biosynthesis in detail. In this study, with deletion of the rpoS gene in the PAΔphz1 mutant and the PAΔphz2 mutant respectively, we demonstrated that RpoS exerted opposite regulatory roles on the expression of the phz1and phz2 operons. We also confirmed that the phz1 operon played a critical role and especially biosynthesized much more phenazines than the phz2 operon when the rpoS gene was knocked out in P. aeruginosa. By constructing the translational reporter fusion vector lasR’-’lacZ and the chromosomal fusion mutant PAΔlasR::lacZ, we verified that RpoS deficiency caused increased expression of lasR, a transcription regulator gene in a first quorum sensing system (las) that activates overexpression of the phz1 operon, suggesting that in the absence of RpoS, LasR might act as an intermediate in overproduction of phenazine biosynthesis mediated by the phz1 operon in P. aeruginosa.

A QEE-Oriented Fair Power Allocation for Two-tier Heterogeneous Networks

( Shiyu Ji ),( Liangrui Tang ),( Yanhua He ),( Shuxian Li ),( Shimo Du ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.5

In future wireless network, user experience and energy efficiency will play more and more important roles in the communication systems compared to their roles at present. Quality of experience (QoE) and Energy Efficiency (EE) become the widely used metrics. In this paper, we study a combinatorial problem of QoE and EE and investigate a fair power allocation in heterogeneous networks. We first design a new metric, QoE-aware EE (QEE) to reflect the relationship of QoE and energy. Then, the concept of Utopia QEE is introduced, which is defined as the achievable maximum QEE in ideal conditions, for each user. Finally, we transform the power allocation process to an optimization of ratio of QEE and Utopia QEE and use invasive weed optimization (IWO) algorithm to solve the optimization problem. Numerical simulation results indicate that the proposed algorithm can get converged and efficiently improve the system energy efficiency and the QoE for each user.

Study of the relationship between variants near CCNL1/LEKR1 and in ADCY5 with low birth weight in a Chinese population

Xuejin Fan,Qi Peng,Yanhua Chen,Zeke Ma,Xiaoguang He,Biying Deng,Hui Huang,Juan Zeng,Chuyun Cheng,Shaoji Liu,Xiaomei Lu 한국유전학회 2015 Genes & Genomics Vol.37 No.12

The aim of this study was to test the impact of variants rs900400 (located near LEKR1 and CCNL1) and rs9883204 (located in ADCY5) on birth weight in a Chinese population. We conducted a case–control study including 156 low-birth- weight infants as the case group and 100 normal-birth-weight infants as the control group. The rs900400 and rs9883204 variants were analyzed by gene sequencing in all the participants. Our results revealed a significant difference in the genotype distribution (v2 = 10.449, p = 0.005) and allele distribution (v2 = 9.277, p = 0.002) of rs900400 between the case group and the control group. The C allele of rs900400 was associated with lower birth weight (OR 1.771 [95 % CI 1.237–2.535]) in the Chinese population. However, the rs9883204 polymorphism was not informative in the Chinese population. Our study shows that the ‘‘birth weightlowering’’ variant rs900400 located near LEKR1 and CCNL1, which is strongly associated with birth weight in European cohorts, appears to have a similar association in Chinese cohorts. However, the rs9883204 variant located in ADCY5 does not appear to be correlated with low birth weight in the same population. Moreover, we found that the variant rs900400 may also be associated with premature birth, thereby supporting the need for further research in this area.

vfr, A Global Regulatory Gene, is Required for Pyrrolnitrin but not for Phenazine-1-carboxylic Acid Biosynthesis in Pseudomonas chlororaphis G05

Xia Wu,Xiaoyan Chi,Yanhua Wang,Kailu Zhang,Le Kai,Qiuning He,Jinxiu Tang,Kewen Wang,Longshuo Sun,Xiuying Hao,Weihai Xie,Yihe Ge 한국식물병리학회 2019 Plant Pathology Journal Vol.35 No.4

In our previous study, pyrrolnitrin produced in Pseudomonas chlororaphis G05 plays more critical role in suppression of mycelial growth of some fungal pathogens that cause plant diseases in agriculture. Although some regulators for pyrrolnitrin biosynthesis were identified, the pyrrolnitrin regulation pathway was not fully constructed. During our screening novel regulator candidates, we obtained a white conjugant G05W02 while transposon mutagenesis was carried out between a fusion mutant G05ΔphzΔprn::lacZ and E. coli S17- 1 (pUT/mini-Tn5Kan). By cloning and sequencing of the transposon-flanking DNA fragment, we found that a vfr gene in the conjugant G05W02 was disrupted with mini-Tn5Kan. In one other previous study on P. fluorescens, however, it was reported that the deletion of the vfr caused increased production of pyrrolnitrin and other antifungal metabolites. To confirm its regulatory function, we constructed the vfr-knockout mutant G05Δvfr and G05ΔphzΔprn::lacZΔvfr. By quantifying β-galactosidase activities, we found that deletion of the vfr decreased the prn operon expression dramatically. Meanwhile, by quantifying pyrrolnitrin production in the mutant G05Δvfr, we found that deficiency of the Vfr caused decreased pyrrolnitrin production. However, production of phenazine-1-carboxylic acid was same to that in the wild-type strain G05. Taken together, Vfr is required for pyrrolnitrin but not for phenazine-1-carboxylic acid biosynthesis in P. chlororaphis G05.

vfr, A Global Regulatory Gene, is Required for Pyrrolnitrin but not for Phenazine-1-carboxylic Acid Biosynthesis in Pseudomonas chlororaphis G05

Wu, Xia,Chi, Xiaoyan,Wang, Yanhua,Zhang, Kailu,Kai, Le,He, Qiuning,Tang, Jinxiu,Wang, Kewen,Sun, Longshuo,Hao, Xiuying,Xie, Weihai,Ge, Yihe The Korean Society of Plant Pathology 2019 Plant Pathology Journal Vol.35 No.4

In our previous study, pyrrolnitrin produced in Pseudomonas chlororaphis G05 plays more critical role in suppression of mycelial growth of some fungal pathogens that cause plant diseases in agriculture. Although some regulators for pyrrolnitrin biosynthesis were identified, the pyrrolnitrin regulation pathway was not fully constructed. During our screening novel regulator candidates, we obtained a white conjugant G05W02 while transposon mutagenesis was carried out between a fusion mutant $G05{\Delta}phz{\Delta}prn::lacZ$ and E. coli S17-1 (pUT/mini-Tn5Kan). By cloning and sequencing of the transposon-flanking DNA fragment, we found that a vfr gene in the conjugant G05W02 was disrupted with mini-Tn5Kan. In one other previous study on P. fluorescens, however, it was reported that the deletion of the vfr caused increased production of pyrrolnitrin and other antifungal metabolites. To confirm its regulatory function, we constructed the vfr-knockout mutant $G05{\Delta}vfr$ and $G05{\Delta}phz{\Delta}prn::lacZ{\Delta}vfr$. By quantifying ${\beta}-galactosidase$ activities, we found that deletion of the vfr decreased the prn operon expression dramatically. Meanwhile, by quantifying pyrrolnitrin production in the mutant $G05{\Delta}vfr$, we found that deficiency of the Vfr caused decreased pyrrolnitrin production. However, production of phenazine-1-carboxylic acid was same to that in the wild-type strain G05. Taken together, Vfr is required for pyrrolnitrin but not for phenazine-1-carboxylic acid biosynthesis in P. chlororaphis G05.

Resource Allocation for Relay-Aided Cooperative Systems Based on Multi-Objective Optimization

( Runze Wu ),( Jiajia Zhu ),( Hailin Hu ),( Yanhua He ),( Liangrui Tang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.5

This paper studies resource allocation schemes for the relay-aided cooperative system consisting of multiple source-destination pairs and decode-forward (DF) relays. Specially, relaying selection, multisubcarrier pairing and assignment, and power allocation are investigated jointly. We consider a combinatorial optimization problem on quality of experience (QoE) and energy consumption based on relay-aided cooperative system. For providing better QoE and lower energy consumption we formulate a multi-objective optimization problem to maximize the total mean opinion score (MOS) value and minimize the total power consumption. To this end, we employ the nondominated sorting genetic algorithm version II (NSGA-II) and obtain sets of Pareto optimal solutions. Specially, two formulas are devised for the optimal solutions of the multi-objective optimization problems with and without a service priority constraint. Moreover, simulation results show that the proposed schemes are superior to the existing ones.