Characterization and Cofactor Binding Mechanism of a Novel NAD(P)H-Dependent Aldehyde Reductase from Klebsiella pneumoniae DSM2026

( Cheng Wei Ma ),( Le Zhang ),( Jian Ying Dai ),( Zhi Long Xiu ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.12

During the fermentative production of 1,3-propanediol under high substrate concentrations, accumulation of intracellular 3-hydroxypropionaldehyde will cause premature cessation of cell growth and glycerol consumption. Discovery of oxidoreductases that can convert 3- hydroxypropionaldehyde to 1,3-propanediol using NADPH as cofactor could serve as a solution to this problem. In this paper, the yqhD gene from Klebsiella pneumoniae DSM2026, which was found encoding an aldehyde reductase (KpAR), was cloned and characterized. KpAR showed broad substrate specificity under physiological direction, whereas no catalytic activity was detected in the oxidation direction, and both NADPH and NADH can be utilized as cofactors. The cofactor binding mechanism was then investigated employing homology modeling and molecular dynamics simulations. Hydrogen-bond analysis showed that the hydrogen-bond interactions between KpAR and NADPH are much stronger than that for NADH. Free-energy decomposition dedicated that residues Gly37 to Val41 contribute most to the cofactor preference through polar interactions. In conclusion, this work provides a novel aldehyde reductase that has potential applications in the development of novel genetically engineered strains in the 1,3-propanediol industry, and gives a better understanding of the mechanisms involved in cofactor binding.

Distinctive Endophytic Fungal Assemblage in Stems of Wild Rice (Oryza granulata) in China with Special Reference to Two Species of Muscodor (Xylariaceae)

Zhi-lin Yuan,Zhen-zhu Su,Li-juan Mao,Yang-qing Peng,Guan-mei Yang,Fu-cheng Lin,Chu-long Zhang 한국미생물학회 2011 The journal of microbiology Vol.49 No.1

Ecological niches in the rhizosphere and phyllosphere of grasses capable of sustaining endophytes have been extensively studied. In contrast, little information regarding the identity and functions of endophytic fungi in stems is available. In this study, we investigated the taxonomic affinities, diversity, and host specificities of culturable endophytes in stems of wild rice (Oryza granulata) in China. Seventy-four isolates were recovered. Low recovery rate (11.7%) indicated that there were relatively few sites for fungal infection. Identification using morphology, morphospecies sorting, and molecular techniques resulted in classification into 50 taxa, 36 of which were recovered only once. Nucleotide sequence similarity analysis indicated that 30% of the total taxa recovered were highly divergent from known species and thus may represent lineages new to science. Most of the taxa were classified as members of the classes Sordariomycetes or Dothideomycetes (mainly in Pleosporales). The presence of Arthrinium and Magnaporthaceae species, most often associated with poaceous plants, suggested a degree of host specificity. A polyphasic approach was employed to identify two Muscodor taxa based on (i) ITS and RPB2 phylogenies, (ii) volatile compounds produced, and (iii)an in vitro bioassay of antifungal activity. This to our knowledge is only the second report regarding the isolation of Muscodor spp. in China. Therefore, we hypothesize that wild plants represent a huge reservoir of unknown fungi. The prevalence, novelty, and species-specificity of unique isolates necessitate a reevaluation of their contribution to ecosystem function and fungal biodiversity.

Simultaneous Information and Power Transfer for Multi-antenna Primary-Secondary Cooperation in Cognitive Radio Networks

Zhi Hui Liu,Wen Jun Xu,Sheng Yu Li,Cheng Zhi Long,Jia Ru Lin 한국전자통신연구원 2016 ETRI Journal Vol.38 No.5

In this paper, cognitive radio and simultaneous wireless information and power transfer (SWIPT) are effectively combined to design a spectrum-efficient and energy-efficient transmission paradigm. Specifically, a novel SWIPT-based primary-secondary cooperation model is proposed to increase the transmission rate of energy/spectrum constrained users. In the proposed model, a multi-antenna secondary user conducts simultaneous energy harvesting and information forwarding by means of power splitting (PS), and tries to maximize its own transmission rate under the premise of successfully assisting the data delivery of the primary user. After the problem formulation, joint power splitting and beamforming optimization algorithms for decode-and-forward and amplify-and-forward modes are presented, in which we obtain the optimal PS factor and beamforming vectors using a golden search method and dual methods. Simulation results show that the proposed SWIPTbased primary-secondary cooperation schemes can obtain a much higher level of performance than that of non-SWIPT cooperation and non-cooperation schemes.

Bioactivity of essential oil of Litsea cubeba from China and its main compounds against two stored product insects

Kai Yang,Cheng FangWang,Chun Xue You,Zhu Feng Geng,Rui Qi Sun,Shan Shan Guo,Shu Shan Du,Zhi Long Liu,Zhi Wei Deng 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.3

During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oilof Litsea cubeba fruits was found to possess strong contact toxicity against the cigarette beetle Lasiodermaserricorne adults and the booklouse Liposcelis bostrychophila, with LD50 values of 27.33 μg/adult and71.56 μg/cm2, respectively, and also showed strong fumigant toxicity against the two stored product insectswith LC50 values of 22.97 and 0.73 mg/L, respectively. The essential oil obtained by hydrodistillation wasinvestigated by GC MS. The main components of the essential oil were identified to be E-citral (geranial)(27.49%), Z-citral (neral) (23.57%) and D-limonene (18.82%) followed by β-thujene (3.34%), β-pinene (2.85%), α-pinene (2.57%), 6-methyl-5-hepten-2-one (2.40%) and linalool (2.36%). Citral (Z/E-citral), D-limonene, β-pinene,α-pinene and linalool were separated and purified by silica gel column chromatography and preparative thinlayer chromatography, and further identified by means of physicochemical and spectrometric analysis. Citral andlinalool showed strong contact toxicity against L. serricorne and L. bostrychophila (LD50 = 11.76, 12.74 μg/adultand 20.15, 99.97 μg/cm2, respectively) and fumigant toxicity against L. serricorne and L. bostrychophila (16.54,18.04 mg/L air and 0.14, 0.71 mg/L air, respectively). Otherwise, citral, D-limonene and linalool were strongly repellentagainst the cigarette beetle L. serricorne as the essential oil whereas β-pinene and α-pinene exhibited weakerrepellency against the cigarette beetle compared with the positive control, DEET. Moreover, except α-pinene andlinalool, the other three compounds as well as the essential oil exhibited comparable repellency against thebooklouse relative to DEET.

Efficacy and Safety of Autologous Fibroblast (FB) Seeded Biodegradable Scaffold for Rabbit Penile Girth Enlargement

( Yi Guang Wu ),( Zhe Jin ),( Zhong Cheng Xin ),( Wei Dong Song ),( Jing Peng ),( Zhi Chao Zhang ),( Bing Gao ),( Ze Long Kim ) 한국조직공학·재생의학회 2007 조직공학과 재생의학 Vol.4 No.4

The purpose of this experiment is to construct an in vitro model of rabbit penis enlargement using tissue engineering method, and to investigate the efficacy and safety of autologous fibroblast cell seeded to biodegradable scaffold and also to provide a new perspective of clinical application. We observed the growth of GFP transgenic fibroblast cell from SD mouse after transplantation with the biodegradable scaffold by fluorescence microscope. At the second hand, 160 male New Zealand rabbits were divided into four groups; Group A for control; Group B for acellular matrix implanted; Group C for scaffold implanted only; Group D for autologous cultured fibroblast seeded scaffold. Rabbit scrotal skin (4×4 mm) was detached under general anesthesia, and fibroblast (FB) was cultured and proliferated for 2weeks. Cultured cells were seeded into the scaffold and inserted on the between buck`s and dartos fascia of rabbit penis. To assess the efficacy and safety of the cells, we observed for 4months. The FB of rabbit were successfully cultured and confirmed by immunohistochemistry method. In the results of group D, dermal cell seeding group, the penile girth was significantly increased to 22.3% compared to other groups (Group A 0.3%, Group B 12.7%, Group C 14.6% and Group D 22.3%). We checked the results in 2~4 months later. We observed that moderate penile girth increase was gained using the biodegradable scaffold without other side-effects. Therefore, we carefully suggest a new guidance for penile augmentation by the tissue engineering method.

Dynamics of Microbial Community Structure, Function and Assembly Mechanism with Increasing Stand Age of Slash Pine (Pinus elliottii) Plantations in Houtian Sandy Area, South China

Zhang Xiaoyang,Xiong Si-Yi,Wu Xiukun,Zeng Bei-Bei,Mo Yang-Mei,Deng Zhi-Cheng,Wei Qi,Gao Yang,Cui Licao,Liu Jianping,Long Haozhi 한국미생물학회 2023 The journal of microbiology Vol.61 No.11

Establishing slash pine plantations is the primary method for restoring sandification land in the Houtian area of South China. However, the microbial variation pattern with increasing stand age remains unclear. In this study, we investigated microbial community structure and function in bare sandy land and four stand age gradients, exploring ecological processes that determine their assembly. We did not observe a significant increase in the absolute abundance of bacteria or fungi with stand age. Bacterial communities were dominated by Chloroflexi, Actinobacteria, Proteobacteria, and Acidobacteria; the relative abundance of Chloroflexi significantly declined while Proteobacteria and Acidobacteria significantly increased with stand age. Fungal communities showed succession at the genus level, with Pisolithus most abundant in soils of younger stands (1- and 6-year-old). Turnover of fungal communities was primarily driven by stochastic processes; both deterministic and stochastic processes influenced the assembly of bacterial communities, with the relative importance of stochastic processes gradually increasing with stand age. Bacterial and fungal communities showed the strongest correlation with the diameter at breast height, followed by soil available phosphorus and water content. Notably, there was a significant increase in the relative abundance of functional groups involved in nitrogen fixation and uptake as stand age increased. Overall, this study highlights the important effects of slash pine stand age on microbial communities in sandy lands and suggests attention to the nitrogen and phosphorus requirements of slash pine plantations in the later stages of sandy management.