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New insights on molecular regulation of biofilm formation in plant-associated bacteria

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Journal of Integrative Plant Biology 2016年第4期58卷 362-372页

作者： Luisa F.Castiblanco George W.Sundin Department of Plant Soil and Microbial Sciences and Center for Microbial Pathogenesis Michigan State University

biofilms are complex bacterial assemblages with a defined three-dimensional architecture, attached to solid surfaces, and surrounded by a self-produced matrix generally composed of exopolysaccharides, proteins, lipids and extracellular DNA. biofilm formation has evolved as an adaptive strategy of bacteria to cope with harsh environmental conditions as well as to establish antagonistic or beneficial interactions with their host. Plant-associated bacteria attach and form biofilms on different tissues including leaves, stems,vasculature, seeds and roots. In this review, we examine the formation of biofilms from the plant-associated bacterial perspective and detail the recently-described mechanisms of genetic regulation used by these organisms to orchestrate biofilm formation on plant surfaces. In addition, we describe plant host signals that bacterial pathogens recognize to activate the transition from a planktonic lifestyle to multicellular behavior.

关键词： Cyclic-di-GMP Erwinia amylovora small RNAs Xanthomonas campestris Xylella fastidiosa

Microbiologically influenced corrosion of titanium caused by aerobic marine bacterium Pseudomonas aeruginosa

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Journal of Materials Science & Technology 2019年第1期35卷 216-222页

作者： M.Saleem Khan Zhong Li Ke Yang Dake Xu Chunguang Yang Dan Liu Yassir Lekbach Enze Zhou Phuri Kalnaowakul Institute of Metal Research Chinese Academy of Sciences University of Chinese Academy of Sciences Corrosion and Protection Division Shenyang National Laboratory for Materials Science Northeastern University laboratory of microbial Biotechnology Faculty of Science and Technology Sidi Mohamed Ben Abdellah University Kasetsart University

Microbiologically influenced corrosion(MIC) is a big threat to the strength and safety of many metallic materials used in different environments throughout the world. The metabolites and bioactivity of the microorganisms cause severe deterioration on the metals. In this study, MIC of pure titanium(Ti) was studied in the presence of a highly corrosive aerobic marine bacterium Pseudomonas aeruginosa. The results obtained from electrochemical test showed that Ti was corrosion resistant in the abiotic culture medium after 14 d, while the increased corrosion current density(i_(corr)) obtained from polarization curves and the decreased charge transfer resistance(R_(ct)) from electrochemical impedance spectroscopy(EIS)indicated the accelerated corrosion of Ti caused by P. aeruginosa biofilm. For further confirmation of the above results, the surface of Ti was investigated using scanning electron microscopy(SEM), confocal laser scanning microscopy(CLSM) and X-ray photoelectron spectroscopy(XPS). According to the XPS results, TiO_2 was formed in both abiotic and biotic conditions, while unstable oxide Ti_2O_3 was detected in the presence of P. aeruginosa, leading to the defects in the passive film and localized corrosion. Pitting corrosion was investigated with the help of CLSM, and the largest pit depth found on Ti surface immersed in P. aeruginosa was 1.2 μm. Ti was not immune to MIC caused by P. aeruginosa.

关键词： Ti Microbiologically influenced corrosion Pseudomonas aeruginosa

The PilZ domain of MrkH represents a nove ）NA binding motif

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Protein & Cell 2016年第10期7卷 766-772页

作者： Feng Wang Qing He Kaixuan Su Fei Gao Yan Huang Zong Lin Deyu Zhu Lichuan Gu State Key laboratory of microbial Technology Shandong University Jinan 250100 China Department of Biotechnology and Biomedicine Yangtze Delta Region Institute of Tsinghua University Jiaxing 314006 China

MrkH is the first characterized c-di-GMP related transcrip- tional regulator which affects type 3 fimbrial expression in response to cellular c-di-GMP level, and thus plays an important role in the biofilm formation of Klebsiella pneu- moniae （Murphy and Clegg, 2012; Wilksch et al., 2011）. However, how MrkH recognizes c-di-GMP and the target DNA sequence remains obscure.

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A bioaugmentation failure caused by phage infection and weak biofilm formation ability

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Journal of Environmental Sciences 2009年第8期21卷 1153-1161页

作者： FU Songzhe FAN Hongxia LIU Shuangjiang LIU Ying LIU Zhipei State Key laboratory of microbial Resources Institute of Microbiology Chinese Academy of Sciences Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100039 China Institute of Oceanology Chinese Academy of Sciences Qingdao 266701 China

Two biological aerated filters （BAF） were setup for ammonia removal treatment of the circulation water in a marine aquaculture. One of the BAFs was bioaugmented with a heterotrophic nitrifying bacterium, Lutimonas sp. H10, where the ammonia removal was not improved and the massive inoculation was even followed by a nitrification breakdown from day 9 to 18. The nitrification was remained stable in control BAF operated under the same conditions. Fluorescent in situ hybridization （FISH） with rRNA-targeted probes and cultivable method revealed that Lutimonas sp. H10 almost disappeared from the bioaugomented BAF within 3 d, and this was mainly due to the infection of a specific phage as revealed by flask experiment, plaque assay and transmission electron observation. Analyses of 16S rRNA gene libraries showed that bacterial groups from two reactors evolved differently and an overgrowth of protozoa was observed in the bioaugmented BAF. Therefore, phage infection and poor biofilm forming ability of the inoculated strain are the main reasons for bioaugmentation failure. In addition, grazing by protozoa of the bacteria might be the reason for the nitrification breakdown in bioaugmented BAF during day 9-18.

关键词： marine culture water circulation ammonia removal Lutimonas sp. HIO nitrification breakdown fluorescent in situhybridization (FISH)

Effect of initial ammonium concentration on a one-stage partial nitrification/anammox biofilm system:Nitrogen removal performance and the microbial community

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Journal of Environmental Sciences 2024年第9期143卷 176-188页

作者： Mengyu Zhou Yun Han Yang Zhuo Fen Yu Gaoyuan Hu Dangcong Peng School of Municipal and Environmental Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Shaanxi Key laboratory of Environmental Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Key laboratory of Northwest Water Resource Environment and EcologyMOEXi’an University of Architecture and TechnologyXi’an 710055China

One-stage partial nitrification coupled with anammox(PN/A)technology effectively reduces the energy consumption of a biological nitrogen removal *** nitrite-oxidizing bacteria(NOB)is essential for this technology to maintain efficient nitrogen removal *** ammonium concentration(IAC)affects the degree of inhibited *** this study,the effect of the IAC on a PN/A biofilm was investigated in a moving bed biofilm *** results showed that nitrogen removal efficiency decreased from 82.49%±1.90%to 64.57%±3.96%after the IAC was reduced from 60 to 20 mg N/L,while the nitrate production ratio increased from 13.87%±0.90%to 26.50%±3.76%.NOB activity increased to1,133.86 mg N/m^(2)/day after the IAC decreased,approximately 4-fold,indicating that the IAC plays an important inhibitory role in *** rate-limiting step in the mature biofilm of the PN/A system is the nitritation process and is not shifted by the *** analysis of the microbial community structure in the biofilm indicates that the IAC was the dominant factor in changes in community *** and *** were the main anammox bacteria,and Nitrosomonas and Nitrospira were the main AOB and NOB,*** did not affect the difference in growth between *** and ***,modulating the IAC promoted the PN/A process with efficient nitrogen removal performance at medium to low ammonium concentrations.

关键词： Biological nitrogen removal Partial nitrification Anammox Ammonium concentration biofilm

Denitrification and microbial community in MBBR using A. donax as carbon source and biofilm carriers for reverse osmosis concentrate treatment

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Journal of Environmental Sciences 2019年第10期31卷 133-143页

作者： Li Li Guokai Yan Haiyan Wang Zhaosheng Chu Zewen Li Yu Ling Tong Wu State Key laboratory of Environmental Criteria And Risk As sessment Chinese Research Academy of Environmental SciencesBeijing 100012China Engineering Center for Environmental Pollution Control Chinese Research Academy of Environmental SciencesBeijing 100012China National Engineering laboratory for Lake Pollution Control and Ecological Restoration Chinese Research Academy of Environmental SciencesBeijing 100012China State Environmental Protection Key laboratory for Lake Pollution Control Chinese Research Academy of Environmental SciencesBeijing 100012China

In this study,raw Arundo donax(***)pieces were applied as carbon source and biofilm carriers for denitrification in a lab-scale moving bed biofilm reactor(MBBR)for the treatment of reverse osmosis concentrate gathered from local wastewater reuse *** stable phase(about 60 days),efficient denitrification performance was obtained with73.2%±19.5%NO3--N average removal and 8.10±3.45 g N/(m3·day)NO3--N average volumetric removal *** balance analysis showed that 4.84 g *** was required to remove 1 g *** real-time PCR analysis results showed that the copy numbers of 16S r-RNA,narG,nirS,nosZ and anammox gene of carrier biofilm and suspended activated sludge in the declination phase(BF2 and AS2)were lower than those of samples in the stable phase(BF1 and AS1),and relatively higher copy numbers of nirS and nirK genes with lower abundance of narG and nosZ genes were ***-throughput sequencing analysis was conducted for BF2 and AS2,and similar dominant phyla and classes with different abundance were *** class Gammaproteobacteria affiliated with the phylum Proteobacteria was the most dominant microbial community in both BF2(52.6%)and AS2(41.7%).The PICRUSt prediction results indicated that 33 predictive specific genes were related to denitrification process,and the relative abundance of 18 predictive specific genes in BF2 were higher than those in AS2.

关键词： Arundo donax carbon source Denitrification MBBR Reverse osmosis concentrate Nitrate removal microbial community High-throughput sequencing

Recombineering enables genome mining of novel siderophores in a non-model Burkholderiales strain

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Engineering Microbiology 2023年第3期3卷 30-36页

作者： Xingyan Wang Haibo Zhou Xiangmei Ren Hanna Chen Lin Zhong Xianping Bai Xiaoying Bian Helmholtz International Lab for Anti-Infectives State Key Laboratory of Microbial TechnologyShandong University-Helmholtz Institute of BiotechnologyShandong UniversityQingdao 266237China

Iron is essential for bacterial survival,and most bacteria capture iron by producing ***-riales bacteria produce various types of bioactive secondary metabolites,such as ornibactin and malleobactin *** this study,the genome analysis of Burkholderiales genomes showed a putative novel siderophore gene cluster crb,which is highly similar to the ornibactin and malleobactin gene clusters but does not have pvdF,a gene encoding a formyltransferase for N-δ-hydroxy-ornithine *** the bacteriophage recom-binase Redγ-Redδβ7029 mediated genome editing system in a non-model Burkholderiales strain Paraburkholderia caribensis CICC 10960 allowed the rapid identification of the products of crb gene cluster,caribactins A-F(1-6).Caribactins contain a special amino acid residue N-δ-hydroxy-N-δ-acetylornithine(haOrn),which differs from the counterpart N-δ-hydroxy-N-δ-formylornithine(hOrn)in ornibactin and malleobactin,owing to the absence of *** inactivation showed that the acetylation of hOrn is catalyzed by CrbK,whose homologs proba-bly not be involved in the biosynthesis of ornibactin and malleobactin,showing possible evolutionary clues of these siderophore biosynthetic pathways from different *** promote biofilm production and en-hance swarming and swimming abilities,suggesting that they may play crucial roles in biofilm *** study also revealed that recombineering has the capability to mine novel secondary metabolites from non-model Burkholderiales species.

关键词： Burkholderiales Recombineering Siderophore Genome mining Caribactins

Exploring biofilm-forming molecular determinants in Listeria monocytogenes by comparative genome-wide and transcriptomic analyses

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Food Science and Human Wellness 2024年

作者： Xinyi Zhang Changzheng Shi Zhaoxin Lu Fanqiang Meng Moutong Chen Xiaomei Bie College of Food Science and Technology， Nanjing Agricultural University Guangdong Provincial Key laboratory of microbial Safety and Health， State Key laboratory of Applied Microbiology Southern China， Institute of Microbiology， Guangdong Academy of Sciences

In the food industry， bacterial cells usually adhere to equipment surfaces， forming biofilms that may cause persistent contamination. This study aimed to identify the key genes responsible for the stronger biofilm-forming capability of the LMB 33426 strain compared to that of the CICC 21662 strain through comparative genomics. Additionally， the expression of genes and related metabolic pathways of LMB 33426 and CICC 21662 strains were analyzed at the transcriptional level by high-throughput sequencing technology to uncover key differentially expressed genes between planktonic and biofilm cells of those two strains. Subsequently， the key genes found to present differences that were uncovered by those genome-wide and transcriptomic analyses were used to construct gene deletion strains. The crystalline violet assay and motility assay showed that GL002291， GL002712 and lmo1438 genes were involved in the regulation of biofilm formation as well as motility. The hydrophobicity and auto-aggregation ability assay results demonstrated an association between the clpB， lmo1438， and lmo0294 genes and bacterial adhesion. However， no significant differences were found regarding this association in the GL002291 and GL002712 genes. This study elucidates some potential regulatory genes associated with biofilm formation in L. monocytogenes， and laying a theoretical foundation for future research.

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Colonization features of marine biofilm-dwelling protozoa in Chinese coastal waters of the Yellow Sea

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Marine Life Science & Technology 2020年第3期2卷 292-301页

作者： Mohammad Nurul Azim Sikder Henglong Xu Alan Warren laboratory of microbial Ecology Ocean University of ChinaQingdao 266003China Institute of Marine Sciences University of ChittagongChittagong 4331Bangladesh Department of Life Sciences Natural History MuseumLondon SW75BDUK

Colonization features of biofilm-dwelling protozoa,especially ciliates,are routinely used as a useful tool for marine *** this review,we summarize some of these features to develop an optimal sampling strategy for using biofilmdwelling protozoa as bioindicators of marine water *** focus on the utility of:(1)diversity in dices to analyze the colonizahon features of biofilm-dwelling protozoa for monitoring marine water quality;(2)MacArthur-Wilson and logistic equation models to determine spatio-temporal variations in colonization dynamics;and(3)homogeneity in taxonomic breadth of biofilm-dwelling protozoa during the process of *** main findings are that:(1)the colonization dynamics of biofilm-dwelling protozoa are similar at depths of 1-5 m in spring and autumn;(2)temporal variability was well fitted to the MacArthur-Wilson and logistic models(P<0.05);and(3)species composition reached an equilibrium after a colonization period of 10-14 days in spring and autumn,but this took less time in the summer and more time in the ***-plotting tests demonstrated spatial variability in homogeneity in taxonomic structure of the ciiiate communities at different depths in the water column,with high levels at 1 m and 2 m and lower levels at 3.5 m and 5 ***,the findings of this review suggest that the colonization dynamics of biofilin-dwelling protozoa may be influenced by different depths and seasons in coastal waters and 1-2 m in spring and autumn may be optimal sampling strategy for bioassessment on large spatial/temporal scales in marine ecosystems.

关键词： Bioassessment Colonization survey Marine ecosystem Periphytic ciliates Taxonomic breadth Seasonal and vertical variations