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Tetraselmis subcordiformis, a unicellular marine green alga, is used widely in aquaculture as an initial feeding for fish, bivalve mollusks, penaeid shrimp larvae, and rotifers because of its rich content of amino acids and fatty acids. A stable nuclear transformation system using the herbicide phosphinothricin (PPT) as a selective reagent was established previously. In this research, the recombinant expression in T. subcordiformis was investigated by particle bombardment with the rt-PA gene that encodes the recombinant human tissue-type plasminogen activator (Reteplase), which is a thrombolytic agent for acute myocardial infarction treatment. Transgenic algal strains were selected by their resistance to PPT, and expression of rt-PA was validated by PCR, Southern blotting, and Western blotting, and bioactivity of rt-PA was confirmed by the fibrin agarose plate assay for bioactivity. The results showed that rt-PA was integrated into the genome of T. subcordiformis, and the expression product was bioactive, indicating proper post-transcriptional modification of rt-PA in T. subcordiformis. This report contributes to efforts that take advantage of marine microalgae as cell factories to prepare recombinant drugs and in establishing a characteristic pathway of oral administration in aquaculture.
Chunhui Wu; Caiyun Zheng; Jinxia Wang; Peng Jiang. Recombinant Expression of Thrombolytic Agent Reteplase in Marine Microalga Tetraselmis subcordiformis (Chlorodendrales, Chlorophyta). Marine Drugs 2021, 19, 315 .
AMA StyleChunhui Wu, Caiyun Zheng, Jinxia Wang, Peng Jiang. Recombinant Expression of Thrombolytic Agent Reteplase in Marine Microalga Tetraselmis subcordiformis (Chlorodendrales, Chlorophyta). Marine Drugs. 2021; 19 (6):315.
Chicago/Turabian StyleChunhui Wu; Caiyun Zheng; Jinxia Wang; Peng Jiang. 2021. "Recombinant Expression of Thrombolytic Agent Reteplase in Marine Microalga Tetraselmis subcordiformis (Chlorodendrales, Chlorophyta)." Marine Drugs 19, no. 6: 315.
Green tides, dominated by Ulva, are on the rise worldwide, and invasive Ulva spp. tend to bloom in new habitats. Over the last decade, green tides have caused serious problems in all marine regions of China, especially the Yellow Sea, but there has been no study emphasizing alien species or new records of Ulva in China. In this study, based on a molecular investigation spanning over 10 years, we found six new records of Ulva in China and analysed their distribution patterns. Three northern temperate species – Ulva simplex, U. splitiana and U. partita – were also distributed in temperate marine areas in China. Meanwhile, three subtropical species – U. meridionalis, U. tepida and U. chaugulii – were found to be dominant in the green tides in the South China Sea, and have also successfully exploited temperate areas, especially U. meridionalis which has a wide distribution in China. U. meridionalis has an unusual morphology distinct from the other three types reported in Ulva: along the middle of the longitudinal axis, both sides of the thallus are connected, forming a thin sheet in the middle with bilateral tubular structures, like a bow-tie in transverse view. We found a rapid Ulva bioinvasion and we provide fundamental new data for the future monitoring and risk assessment of green tides in China.
Wei Feng Xie; Chun Hui Wu; Jin Zhao; Xu Yin Lin; Peng Jiang. New records of Ulva spp. (Ulvophyceae, Chlorophyta) in China, with special reference to an unusual morphology of U. meridionalis forming green tides. European Journal of Phycology 2020, 55, 412 -425.
AMA StyleWei Feng Xie, Chun Hui Wu, Jin Zhao, Xu Yin Lin, Peng Jiang. New records of Ulva spp. (Ulvophyceae, Chlorophyta) in China, with special reference to an unusual morphology of U. meridionalis forming green tides. European Journal of Phycology. 2020; 55 (4):412-425.
Chicago/Turabian StyleWei Feng Xie; Chun Hui Wu; Jin Zhao; Xu Yin Lin; Peng Jiang. 2020. "New records of Ulva spp. (Ulvophyceae, Chlorophyta) in China, with special reference to an unusual morphology of U. meridionalis forming green tides." European Journal of Phycology 55, no. 4: 412-425.
Recombinant phycobiliprotein can be used as fluorescent label in immunofluorescence assay. In this study, pathway for phycocyanin beta subunit (CpcB) carrying noncognate chromophore phycoerythrobilin (PEB) and phycourobilin (PUB) was constructed in Escherichia coli. Lyase CpcS and CpcT could catalyze attachment of PEB to Cys84-CpcB and Cys155-CpcB, respectively. However, PEB was attached only to Cys84-CpcB when both CpcS and CpcT were present in E. coli. A dual plasmid expression system was used to control the expression of lyases and the attachment order of PEB to CpcB. The production of PEB-Cys155-CpcB was achieved by L-arabinose-induced expression of CpcS, CpcB, Ho1, and PebS, and then the attachment of PEB to Cys84-CpcB was achieved by IPTG-induced expression of CpcS. The doubly chromophorylated CpcB absorbed light maximally at 497.5 nm and 557.0 nm and fluoresced maximally at 507.5 nm and 566.5 nm. An amount of light energy absorbed by PUB-Cys155-CpcB is transferred to PEB-Cys84-CpcB in doubly chromophorylated CpcB, conferring a large stokes shift of 69 nm for this fluorescent protein. There are interactions between chromophores of CpcB which possibly together with the help of lyases lead to isomerization of PEB-Cys155-CpcB to PUB-Cys155-CpcB.
Huaxin Chen; Caiyun Zheng; Peng Jiang; Gengsheng Ji. Biosynthesis of a Phycocyanin Beta Subunit with Two Noncognate Chromophores in Escherichia coli. Applied Biochemistry and Biotechnology 2019, 191, 763 -771.
AMA StyleHuaxin Chen, Caiyun Zheng, Peng Jiang, Gengsheng Ji. Biosynthesis of a Phycocyanin Beta Subunit with Two Noncognate Chromophores in Escherichia coli. Applied Biochemistry and Biotechnology. 2019; 191 (2):763-771.
Chicago/Turabian StyleHuaxin Chen; Caiyun Zheng; Peng Jiang; Gengsheng Ji. 2019. "Biosynthesis of a Phycocyanin Beta Subunit with Two Noncognate Chromophores in Escherichia coli." Applied Biochemistry and Biotechnology 191, no. 2: 763-771.
Normal intestinal flora is widely involved in many functions of the host: nutritional metabolism; maintenance of intestinal microecological balance; regulation of intestinal endocrine function and nerve signal transduction; promotion of intestinal immune system development and maturation; inhibition of pathogenic bacteria growth and colonization, reduction of its invasion to intestinal mucosa, and so on. In recent years, more and more studies have shown that intestinal flora is closely related to the occurrence, development, and treatment of various tumors. It is indicated that recombinant phycoerythrin (RPE) has significant anti-tumor and immunomodulatory effects. However, little is known about the mechanism of the effect of oral (or intragastric) administration of RPE on gut microbiota in tumor-bearing animals. In this study, using high-throughput 16S rDNA sequencing, we examined the response of gut microbiota in H22-bearing mice to dietary RPE supplementation. The results showed that the abundance of beneficial bacteria in the mice intestinal flora decreased and that of the detrimental flora increased after inoculation with tumor cells (H22); following treatment with dietary RPE, the abundance of beneficial bacteria in the intestinal flora significantly increased and that of detrimental bacteria decreased. In this study, for the first time, it was demonstrated that dietary RPE could modulate the gut microbiota of the H22 bearing mice by increasing the abundance of beneficial bacteria and decreasing that of detrimental bacteria among intestinal bacteria, providing evidence for the mechanism by which bioactive proteins affect intestinal nutrition and disease resistance in animals.
Hongtao Qi; Ying Liu; Xin Qi; Hui Liang; Huaxin Chen; Peng Jiang; Dongfeng Wang. Dietary Recombinant Phycoerythrin Modulates the Gut Microbiota of H22 Tumor-Bearing Mice. Marine Drugs 2019, 17, 665 .
AMA StyleHongtao Qi, Ying Liu, Xin Qi, Hui Liang, Huaxin Chen, Peng Jiang, Dongfeng Wang. Dietary Recombinant Phycoerythrin Modulates the Gut Microbiota of H22 Tumor-Bearing Mice. Marine Drugs. 2019; 17 (12):665.
Chicago/Turabian StyleHongtao Qi; Ying Liu; Xin Qi; Hui Liang; Huaxin Chen; Peng Jiang; Dongfeng Wang. 2019. "Dietary Recombinant Phycoerythrin Modulates the Gut Microbiota of H22 Tumor-Bearing Mice." Marine Drugs 17, no. 12: 665.
Brown algae have convergently evolved plant-like body plans and reproductive cycles, which in plants are controlled by differential DNA methylation. This contribution provides the first single-base methylome profiles of haploid gametophytes and diploid sporophytes of a multicellular alga. Although only c. 1.4% of cytosines in Saccharina japonica were methylated mainly at CHH sites and characterized by 5-methylcytosine (5mC), there were significant differences between life-cycle stages. DNA methyltransferase 2 (DNMT2), known to efficiently catalyze tRNA methylation, is assumed to methylate the genome of S. japonica in the structural context of tRNAs as the genome does not encode any other DNA methyltransferases. Circular and long noncoding RNA genes were the most strongly methylated regulatory elements in S. japonica. Differential expression of genes was negatively correlated with DNA methylation with the highest methylation levels measured in both haploid gametophytes. Hypomethylated and highly expressed genes in diploid sporophytes included genes involved in morphogenesis and halogen metabolism. The data herein provide evidence that cytosine methylation, although occurring at a low level, is significantly contributing to the formation of different life-cycle stages, tissue differentiation and metabolism in brown algae.
Xiao Fan; Wentao Han; Linhong Teng; Peng Jiang; Xiaowen Zhang; Dong Xu; Chang Li; Matteo Pellegrini; Chunhui Wu; Yitao Wang; Michelle Joyce Slade Kaczurowski; Xin Lin; Leila Tirichine; Thomas Mock; Naihao Ye. Single‐base methylome profiling of the giant kelp Saccharina japonica reveals significant differences in DNA methylation to microalgae and plants. New Phytologist 2019, 225, 234 -249.
AMA StyleXiao Fan, Wentao Han, Linhong Teng, Peng Jiang, Xiaowen Zhang, Dong Xu, Chang Li, Matteo Pellegrini, Chunhui Wu, Yitao Wang, Michelle Joyce Slade Kaczurowski, Xin Lin, Leila Tirichine, Thomas Mock, Naihao Ye. Single‐base methylome profiling of the giant kelp Saccharina japonica reveals significant differences in DNA methylation to microalgae and plants. New Phytologist. 2019; 225 (1):234-249.
Chicago/Turabian StyleXiao Fan; Wentao Han; Linhong Teng; Peng Jiang; Xiaowen Zhang; Dong Xu; Chang Li; Matteo Pellegrini; Chunhui Wu; Yitao Wang; Michelle Joyce Slade Kaczurowski; Xin Lin; Leila Tirichine; Thomas Mock; Naihao Ye. 2019. "Single‐base methylome profiling of the giant kelp Saccharina japonica reveals significant differences in DNA methylation to microalgae and plants." New Phytologist 225, no. 1: 234-249.
Golden tides dominated by Sargassum spp. are occurring at an accelerated rate worldwide. In China, Sargassum has started to bloom in the Yellow Sea and led to tremendous economic losses, but the underlying biological causes and mechanisms are still unclear. Although algae-associated bacteria were suggested to play crucial roles in algal blooms, the profiles of bacteria associated with drifting Sargassum remain unexplored. In this study, the community structures and functions of Sargassum-associated bacteria were analyzed using the high-throughput sequencing data of the V5–V7 hypervariable region of the 16S rRNA gene. Molecular identification revealed that the golden tide analyzed in the Yellow Sea was dominated by a single species, Sargassum horneri. They were a healthy brown color nearshore but were yellow offshore with significantly decreased chlorophyll contents (P < 0.01), which indicates that yellow S. horneri was under physiological stress. The structural and functional analyses of bacterial communities indicated that the drifting S. horneri had an obvious selectivity on their associated bacteria against surrounding seawater. Although the bacterial communities phylogenetically differed between brown and yellow S. horneri (P < 0.01), their dominant functions were all nitrogen and iron transporters, which strongly indicates microbial contribution to blooming of the algal host. For the first time, potential epiphytic and endophytic bacteria associated with Sargassum were independently analyzed by a modified co-vortex method with silica sand. We showed that the composition of dominant endophytes, mainly Bacillus and Propionibacterium, was relatively consistent regardless of host status, whereas the epiphytic operational taxonomic units (OTUs) greatly varied in response to weakness of host status; however, dominant functions were consistent at elevated intensities, which might protect the host from stress related to nitrogen or iron deficiency. Thus, we propose that host physiological status at different intensities of functional demands, which were related to variable environmental conditions, may be a critical factor that influences the assembly of epiphytic bacterial communities. This study provided new insight into the structure and potential functions of associated bacteria with golden tide blooms.
Xiangyuan Mei; Chunhui Wu; Jin Zhao; Tian Yan; Peng Jiang. Community Structure of Bacteria Associated With Drifting Sargassum horneri, the Causative Species of Golden Tide in the Yellow Sea. Frontiers in Microbiology 2019, 10, 1192 .
AMA StyleXiangyuan Mei, Chunhui Wu, Jin Zhao, Tian Yan, Peng Jiang. Community Structure of Bacteria Associated With Drifting Sargassum horneri, the Causative Species of Golden Tide in the Yellow Sea. Frontiers in Microbiology. 2019; 10 ():1192.
Chicago/Turabian StyleXiangyuan Mei; Chunhui Wu; Jin Zhao; Tian Yan; Peng Jiang. 2019. "Community Structure of Bacteria Associated With Drifting Sargassum horneri, the Causative Species of Golden Tide in the Yellow Sea." Frontiers in Microbiology 10, no. : 1192.
Phycobiliproteins (PBPs) are light-harvesting protein found in cyanobacteria, red algae and the cryptomonads. They have been widely used as fluorescent labels in cytometry and immunofluorescence analysis. A number of PBPs has been produced in metabolically engineered Escherichia coli. However, the recombinant PBPs are incompletely chromophorylated, and the underlying mechanisms are not clear. In this work, a pathway for SLA-PEB [a fusion protein of streptavidin and allophycocyanin that covalently binds phycoerythrobilin (PEB)] biosynthesis in E. coli was constructed using a single-expression plasmid strategy. Compared with a previous E. coli strain transformed with dual plasmids, the E. coli strain transformed with a single plasmid showed increased plasmid stability and produced SLA-PEB with a higher chromophorylation ratio. To achieve full chromophorylation of SLA-PEB, directed evolution was employed to improve the catalytic performance of lyase CpcS. In addition, the catalytic abilities of heme oxygenases from different cyanobacteria were investigated based on biliverdin IXα and PEB accumulation. Upregulation of the heme biosynthetic pathway genes was also carried out to increase heme availability and PEB biosynthesis in E. coli. Fed-batch fermentation was conducted for the strain V5ALD, which produced recombinant SLA-PEB with a chromophorylation ratio of 96.7%. In addition to reporting the highest chromophorylation ratio of recombinant PBPs to date, this work demonstrated strategies for improving the chromophorylation of recombinant protein, especially biliprotein with heme, or its derivatives as a prosthetic group.
Huaxin Chen; Peng Jiang. Metabolic engineering of Escherichia coli for efficient biosynthesis of fluorescent phycobiliprotein. Microbial Cell Factories 2019, 18, 58 .
AMA StyleHuaxin Chen, Peng Jiang. Metabolic engineering of Escherichia coli for efficient biosynthesis of fluorescent phycobiliprotein. Microbial Cell Factories. 2019; 18 (1):58.
Chicago/Turabian StyleHuaxin Chen; Peng Jiang. 2019. "Metabolic engineering of Escherichia coli for efficient biosynthesis of fluorescent phycobiliprotein." Microbial Cell Factories 18, no. 1: 58.
Besides heat stress, the 70 kDa heat shock proteins (HSP70s) have been shown to respond to cold stress. However, the involved cis-acting elements remain unknown. The hsp70 gene from the green macroalga Ulva prolifera (Uphsp70) has been cloned, from which one heat shock element HSE and one low-temperature-responsive element LTR were found in the promoter. Using the established transient expression system and quantitative GUS assay, a series of element deletion experiments were performed to determine the functions of HSE and LTR in response to temperature stress. The results showed that under cold stress, both HSE and LTR were indispensable, since deletion leads to complete loss of promoter activity. Under heat stress, although the HSE could respond independently, coexistence with LTR was essential for high induced activity of the Uphsp70 promoter. Therefore, synergistic effects exist between HSE and LTR elements in response to temperature stress in Ulva, and extensive bioinformatics analysis showed that the mechanism is widespread in algae and plants, since LTR coexists widely with HSE in the promoter region of hsp70. Our findings provide important supplements to the knowledge of algal and plant HSP70s response to temperature stress. We speculated that for algal domestication and artificial breeding, HSE and LTR elements might serve as potential molecular targets to temperature acclimation.
Chunhui Wu; Caiyun Zheng; Gengsheng Ji; Peng Jiang. Synergistic effects of HSE and LTR elements from hsp70 gene promoter of Ulva prolifera (Ulvophyceae, Chlorophyta) upon temperature induction 1. Journal of Phycology 2019, 55, 738 -743.
AMA StyleChunhui Wu, Caiyun Zheng, Gengsheng Ji, Peng Jiang. Synergistic effects of HSE and LTR elements from hsp70 gene promoter of Ulva prolifera (Ulvophyceae, Chlorophyta) upon temperature induction 1. Journal of Phycology. 2019; 55 (3):738-743.
Chicago/Turabian StyleChunhui Wu; Caiyun Zheng; Gengsheng Ji; Peng Jiang. 2019. "Synergistic effects of HSE and LTR elements from hsp70 gene promoter of Ulva prolifera (Ulvophyceae, Chlorophyta) upon temperature induction 1." Journal of Phycology 55, no. 3: 738-743.
Fusion protein of streptavidin and allophycocyanin holo-α subunit (ApcA) is fluorescent and is able to bind biotin. This fusion protein (SLA) can be used as fluorescent label in immunofluorescence assay. In this study, one or two repeats of ApcA were fused to the protein SLA, with the aim to improve its brightness. The fusion proteins SLA2 (two repeats of ApcA) and SLA3 (three repeats of ApcA), together with lyase (cpcS) and phycoerythrobilin synthesizing enzymes (Ho1 and PebS), were co-expressed in Escherichia coli. These fusion proteins were purified by affinity chromatography. While SLA2 and SLA3 shared similar absorbance spectra, fluorescence spectra and biotin-binding activities with SLA, their brightness were much higher than that of SLA. When used as fluorescent labels in immunofluorescence assay, SLA2 and SLA3 showed higher detection sensitivity than SLA. These results suggested that SLA2 and SLA3 were the preferable fluorescent labels in immunofluorescence assays.
Huaxin Chen; Peng Jiang. Combinational biosynthesis and characterization of fusion proteins with tandem repeats of allophycocyanin holo-α subunits, and their application as bright fluorescent labels for immunofluorescence assay. Journal of Bioscience and Bioengineering 2018, 126, 778 -782.
AMA StyleHuaxin Chen, Peng Jiang. Combinational biosynthesis and characterization of fusion proteins with tandem repeats of allophycocyanin holo-α subunits, and their application as bright fluorescent labels for immunofluorescence assay. Journal of Bioscience and Bioengineering. 2018; 126 (6):778-782.
Chicago/Turabian StyleHuaxin Chen; Peng Jiang. 2018. "Combinational biosynthesis and characterization of fusion proteins with tandem repeats of allophycocyanin holo-α subunits, and their application as bright fluorescent labels for immunofluorescence assay." Journal of Bioscience and Bioengineering 126, no. 6: 778-782.
Protoplast isolation was relevant for gene manipulation in Ulva, and universal protocols have been proposed based on evaluation for various wildly collected species. However, only clonal laboratory cultures were practical for genetic transformation, and whether applicability of such universal protocol existed for these artificial cultures has never been investigated. In this research, samples in different physiological states or developmental stages were tested in U. prolifera. The results proved that the protoplast yields were strongly dependent on the characteristics of samples. Neither Fv/Fm value nor chlorophyll content exhibited an ideal correlation with the protoplast yields. Alternatively, specific growth rate, coupled with developmental stage, could serve as an effective combined index to determine the right time for protoplast isolation. According to this instruction, here we reported the highest yields of protoplast ((31.5±1.9)×10 6 cells/g f. wt.) in U. prolifera, following comparison between protocols, and further optimizations on enzyme content, incubation period, starting biomass and pretreatment. This specified protocol for artificially cultured clonal samples could meet the need for protoplast-mediated genetic transformation in U. prolifera.
Chunhui Wu; Peng Jiang; Jin Zhao; Huihui Fu. High efficiency of protoplast preparation for artificially cultured Ulva prolifera (Ulvophyceae, Chlorophyta). Journal of Oceanology and Limnology 2018, 36, 1806 -1811.
AMA StyleChunhui Wu, Peng Jiang, Jin Zhao, Huihui Fu. High efficiency of protoplast preparation for artificially cultured Ulva prolifera (Ulvophyceae, Chlorophyta). Journal of Oceanology and Limnology. 2018; 36 (5):1806-1811.
Chicago/Turabian StyleChunhui Wu; Peng Jiang; Jin Zhao; Huihui Fu. 2018. "High efficiency of protoplast preparation for artificially cultured Ulva prolifera (Ulvophyceae, Chlorophyta)." Journal of Oceanology and Limnology 36, no. 5: 1806-1811.
Recurrent green tides have been recorded in the Yellow Sea for 11 consecutive years. The origin of floating green algae in the Yellow Sea, however, remains a subject of debate. Previous studies suggest that the major bloom-forming green alga Ulva prolifera represent a unique ecotype different from other attached populations of U. prolifera in China. In this study, 97 green algal samples collected during the 2012 green-tide event and from other locations along the coastline of China were analyzed. Based on the sequences of nuclear ribosomal RNA gene (rDNA) internal transcribed spacer (ITS) region and 5S rDNA spacer region, the green alga U. prolifera in the samples were identified. The intraspecific genetic diversity within U. prolifera was then examined using sequences of 5S rDNA spacer and a marker of sequence characterized amplified region (SCAR) highly specific for bloom-forming U. prolifera in the Yellow Sea. The screening results for SCAR marker demonstrated that U. prolifera attached to aquaculture rafts in Subei Shoal belong to the same ecotype of the bloom-forming U. prolifera in the Yellow Sea. These findings offer genetic evidence that aquaculture rafts in Subei Shoal are a major source of floating green algae in the Yellow Sea.
Qing-Chun Zhang; Ren-Cheng Yu; Zhen-Fan Chen; Li-Mei Qiu; Yun-Feng Wang; Fan-Zhou Kong; Hui-Xia Geng; Yue Zhao; Peng Jiang; Tian Yan; Ming-Jiang Zhou. Genetic evidence in tracking the origin of Ulva prolifera blooms in the Yellow Sea, China. Harmful Algae 2018, 78, 86 -94.
AMA StyleQing-Chun Zhang, Ren-Cheng Yu, Zhen-Fan Chen, Li-Mei Qiu, Yun-Feng Wang, Fan-Zhou Kong, Hui-Xia Geng, Yue Zhao, Peng Jiang, Tian Yan, Ming-Jiang Zhou. Genetic evidence in tracking the origin of Ulva prolifera blooms in the Yellow Sea, China. Harmful Algae. 2018; 78 ():86-94.
Chicago/Turabian StyleQing-Chun Zhang; Ren-Cheng Yu; Zhen-Fan Chen; Li-Mei Qiu; Yun-Feng Wang; Fan-Zhou Kong; Hui-Xia Geng; Yue Zhao; Peng Jiang; Tian Yan; Ming-Jiang Zhou. 2018. "Genetic evidence in tracking the origin of Ulva prolifera blooms in the Yellow Sea, China." Harmful Algae 78, no. : 86-94.
Algae-bacteria associations occurred widely in marine habitats, however, contributions of bacteria to macroalgal blooming were almost unknown. In this study, a potential endophytic strain SI-3 was isolated from Ulva prolifera, the causative species for the world's largest green tide in the Yellow Sea, following a strict bleaching treatment to eliminate epiphytes. The genomic sequence of SI-3 was determined in size of 4.8 Mb and SI-3 was found to be mostly closed to Pseudomonas stutzeri. To evaluate the characteristics of SI-3 as a potential endophyte, the genomes of SI-3 and other 20 P. stutzeri strains were compared. We found that SI-3 had more strain-specific genes than most of the 20 P. stutzeri strains. Clusters of Orthologous Groups (COGs) analysis revealed that SI-3 had a higher proportion of genes assigned to transcriptional regulation and signal transduction compared with the 20 P. stutzeri strains, including four rhizosphere bacteria, indicating a complicated interaction network between SI-3 and its host. P. stutzeri is renowned for its metabolic versatility in aromatic compounds degradation. However, significant gene loss was observed in several aromatic compounds degradation pathways in SI-3, which may be an evolutional adaptation that developed upon association with its host. KEGG analysis revealed that dissimilatory nitrate reduction to ammonium (DNRA) and denitrification, two competing dissimilatory nitrate reduction pathways, co-occurred in the genome of SI-3, like most of the other 20 P. stutzeri strains. We speculated that DNRA of SI-3 may contribute a competitive advantage in nitrogen acquisition of U. prolifera by conserving nitrogen in NH4+ form, as in the case of microalgae bloom. Collectively, these data suggest that Pseudomonas sp. strain SI-3 was a suitable candidate for investigation of the algae-bacteria interaction with U. prolifera and the ecological impacts on algal blooming.
Huihui Fu; Peng Jiang; Jin Zhao; Chunhui Wu. Comparative Genomics of Pseudomonas sp. Strain SI-3 Associated With Macroalga Ulva prolifera, the Causative Species for Green Tide in the Yellow Sea. Frontiers in Microbiology 2018, 9, 1458 .
AMA StyleHuihui Fu, Peng Jiang, Jin Zhao, Chunhui Wu. Comparative Genomics of Pseudomonas sp. Strain SI-3 Associated With Macroalga Ulva prolifera, the Causative Species for Green Tide in the Yellow Sea. Frontiers in Microbiology. 2018; 9 ():1458.
Chicago/Turabian StyleHuihui Fu; Peng Jiang; Jin Zhao; Chunhui Wu. 2018. "Comparative Genomics of Pseudomonas sp. Strain SI-3 Associated With Macroalga Ulva prolifera, the Causative Species for Green Tide in the Yellow Sea." Frontiers in Microbiology 9, no. : 1458.
Large scale green tides have bloomed successively in the Yellow Sea since 2007. The floating ecotype of Ulva prolifera, which is responsible for the environmental disaster, drifted a long distance during the blooming time and was exotic to the coastal area. The Yellow Sea green tide can be a potential source to incur bio-invasion. In this study, the distribution pattern and propagule pressure of the floating ecotype was investigated along the Qingdao coastline, which was seriously impacted by the green tide. Two out of 661 attached Ulva specimens collected in different seasons were identified as the floating ecotype by molecular markers, indicating that a few individuals of the floating ecotype had settled down, and their attached population could have spontaneously established. In seawater and sediments, the proportion of the floating ecotype in Ulva propagules reached up to 32% and 69% respectively when the floating algae was accumulating on seashore, which was a great propagule pressure to the local ecosystem. Results of the field test indicated that the available resources and the competition between the floating ecotype and the local Ulva species might be the main restrictions for settlement. Though the current scale of the established population is still small, the risk of biological invasion by the floating ecotype exists and it deserves more attention.
Jin Zhao; Peng Jiang; Ri Qiu; Yingying Ma; Chunhui Wu; Huihui Fu; Huaxin Chen; Fuchao Li. The Yellow Sea green tide: A risk of macroalgae invasion. Harmful Algae 2018, 77, 11 -17.
AMA StyleJin Zhao, Peng Jiang, Ri Qiu, Yingying Ma, Chunhui Wu, Huihui Fu, Huaxin Chen, Fuchao Li. The Yellow Sea green tide: A risk of macroalgae invasion. Harmful Algae. 2018; 77 ():11-17.
Chicago/Turabian StyleJin Zhao; Peng Jiang; Ri Qiu; Yingying Ma; Chunhui Wu; Huihui Fu; Huaxin Chen; Fuchao Li. 2018. "The Yellow Sea green tide: A risk of macroalgae invasion." Harmful Algae 77, no. : 11-17.
Rapid accumulations of unattached green macroalgae, referred to as blooms, constitute ecological disasters and occur in many coastal regions. Ulva are a major cause of blooms, owing to their high nitrogen utilization capacity, which requires nitrate reductase (NR) activity; however, molecular characterization of Ulva NR remains lacking. Herein we determined the crystal structure and performed an enzymatic analysis of the cytochrome b5 reductase domain of Ulva prolifera NR (UpCbRNR). The structural analysis revealed an N-terminal FAD-binding domain primarily consisting of six antiparallel β strands, a C-terminal NADH-binding domain forming a Rossmann fold, and a three β-stranded linker region connecting these two domains. The FAD cofactor was located in the cleft between the two domains and interacted primarily with the FAD-binding domain. UpCbRNR shares similarities in overall structure and cofactor interactions with homologs, and its catalytic ability is comparable to that of higher plant CbRNRs. Structure and sequence comparisons of homologs revealed two regions of sequence length variation potentially useful for phylogenetic analysis: one in the FAD-binding domain, specific to U. prolifera, and another in the linker region that may be used to differentiate between plant, fungi, and animal homologs. Our data will facilitate molecular-level understanding of nitrate assimilation in Ulva.
Cai You; Changshui Liu; Yingjie Li; Peng Jiang; Qingjun Ma. Structural and enzymatic analysis of the cytochrome b5 reductase domain of Ulva prolifera nitrate reductase. International Journal of Biological Macromolecules 2018, 111, 1175 -1182.
AMA StyleCai You, Changshui Liu, Yingjie Li, Peng Jiang, Qingjun Ma. Structural and enzymatic analysis of the cytochrome b5 reductase domain of Ulva prolifera nitrate reductase. International Journal of Biological Macromolecules. 2018; 111 ():1175-1182.
Chicago/Turabian StyleCai You; Changshui Liu; Yingjie Li; Peng Jiang; Qingjun Ma. 2018. "Structural and enzymatic analysis of the cytochrome b5 reductase domain of Ulva prolifera nitrate reductase." International Journal of Biological Macromolecules 111, no. : 1175-1182.
Jing Wu; Huaxin Chen; Jin Zhao; Peng Jiang. Fusion proteins of streptavidin and allophycocyanin alpha subunit for immunofluorescence assay. Biochemical Engineering Journal 2017, 125, 97 -103.
AMA StyleJing Wu, Huaxin Chen, Jin Zhao, Peng Jiang. Fusion proteins of streptavidin and allophycocyanin alpha subunit for immunofluorescence assay. Biochemical Engineering Journal. 2017; 125 ():97-103.
Chicago/Turabian StyleJing Wu; Huaxin Chen; Jin Zhao; Peng Jiang. 2017. "Fusion proteins of streptavidin and allophycocyanin alpha subunit for immunofluorescence assay." Biochemical Engineering Journal 125, no. : 97-103.
Ulva spp. dominates green tides around the world, which are occurring at an accelerated rate. The competitive nitrogen assimilation efficiency in Ulva is suggested to result in ecological success against other seaweeds. However, molecular characterization of genes involved in nitrogen assimilation have not been conducted. Here, we describe the identification of the nitrate reductase (NR) gene from a green seaweed Ulva prolifera, an alga which is responsible for the world's largest green tide in the Yellow Sea. By using rapid amplification of cDNA ends (RACE) and genome walking, the NR gene from U. prolifera (UpNR) was cloned, which consisted of six introns and seven exons encoding 863 amino acids. According to sequence alignment, the NR in U. prolifera was shown to possess all five essential domains and 21 key invariant residues in plant NRs. The GC content of third codon position of UpNR (82.75%) was as high as those of green microalgae, and the intron number supported a potential loss issue from green microalga to land plant. Real-time quantitative PCR results showed that UpNR transcript level was induced by nitrate and repressed by ammonium, which could not be removed by addition of extra nitrate, indicating that U. prolifera preferred ammonium to nitrate. Urea would not repress NR transcription by itself, while it weakened the induction effect of nitrate, implying it possibly inhibited nitrate uptake rather than nitrate reduction. These results suggest the use of UpNR as a gene-sensor to probe the N assimilation process in green tides caused by Ulva.This article is protected by copyright. All rights reserved.
Yang Guo; Hao Zhe Wang; Chun Hui Wu; Hui Hui Fu; Peng Jiang. Cloning and characterization of nitrate reductase gene in Ulva prolifera (Ulvophyceae, Chlorophyta). Journal of Phycology 2017, 53, 1035 -1043.
AMA StyleYang Guo, Hao Zhe Wang, Chun Hui Wu, Hui Hui Fu, Peng Jiang. Cloning and characterization of nitrate reductase gene in Ulva prolifera (Ulvophyceae, Chlorophyta). Journal of Phycology. 2017; 53 (5):1035-1043.
Chicago/Turabian StyleYang Guo; Hao Zhe Wang; Chun Hui Wu; Hui Hui Fu; Peng Jiang. 2017. "Cloning and characterization of nitrate reductase gene in Ulva prolifera (Ulvophyceae, Chlorophyta)." Journal of Phycology 53, no. 5: 1035-1043.
Baosheng Ge; Xiaojun Lin; Yao Chen; Xiangfa Wang; Huaxin Chen; Peng Jiang; Fang Huang. Combinational biosynthesis of dual-functional streptavidin-phycobiliproteins for high-throughput-compatible immunoassay. Process Biochemistry 2017, 58, 306 -312.
AMA StyleBaosheng Ge, Xiaojun Lin, Yao Chen, Xiangfa Wang, Huaxin Chen, Peng Jiang, Fang Huang. Combinational biosynthesis of dual-functional streptavidin-phycobiliproteins for high-throughput-compatible immunoassay. Process Biochemistry. 2017; 58 ():306-312.
Chicago/Turabian StyleBaosheng Ge; Xiaojun Lin; Yao Chen; Xiangfa Wang; Huaxin Chen; Peng Jiang; Fang Huang. 2017. "Combinational biosynthesis of dual-functional streptavidin-phycobiliproteins for high-throughput-compatible immunoassay." Process Biochemistry 58, no. : 306-312.
Ulva prolifera is a green macroalgae with an extremely high growth rate that can accumulate biomass with considerable protein content. To set up an available seaweed expression system, a prior step is to isolate endogenous and strong constitutive promoters. For this reason, the full-length genomic actin1 gene from U. prolifera (Upactin1) was cloned and its 5′ flanking sequence was obtained by genome walking. The Upactin1 open reading frame consisted of 1134 nucleotides encoding 377 amino acid residues. Besides 4 exons and 3 introns in the coding region, an extra leader intron was identified in the 5′ untranslated region. According to quantitative GUS assays based on transient expression, the promoter activity of the Upactin1 5′ flanking region was found to be several times higher than that of the widely-used cauliflower mosaic virus 35S (CaMV35S) in all tested species of Ulva. In addition, precise deletion of the leader intron led to a significant decrease of promoter strength in U. prolifera, and almost entire loss of strength in U. linza and U. pertusa. To our knowledge, this is the first report to prove function of a leader intron in algae. The 5′ flanking region of Upactin1 was shown to be a much stronger promoter than the foreign CaMV35S, and its activity was highly dependent on the presence of the leader intron. We propose that the Upactin1 promoter could serve as an endogenous and strong constitutive element for genetic engineering of U. prolifera.
Chunhui Wu; Peng Jiang; Yang Guo; Jianguo Liu; Jin Zhao; Huihui Fu. Isolation and characterization of Ulva prolifera actin1 gene and function verification of the 5′ flanking region as a strong promoter. Bioengineered 2017, 9, 124 -133.
AMA StyleChunhui Wu, Peng Jiang, Yang Guo, Jianguo Liu, Jin Zhao, Huihui Fu. Isolation and characterization of Ulva prolifera actin1 gene and function verification of the 5′ flanking region as a strong promoter. Bioengineered. 2017; 9 (1):124-133.
Chicago/Turabian StyleChunhui Wu; Peng Jiang; Yang Guo; Jianguo Liu; Jin Zhao; Huihui Fu. 2017. "Isolation and characterization of Ulva prolifera actin1 gene and function verification of the 5′ flanking region as a strong promoter." Bioengineered 9, no. 1: 124-133.
The fusion protein (SLA) of streptavidin and allophycocyanin α subunit (holo-ApcA) was biosynthesized in Escherichia coli by a dual plasmid system. The recombinant SLA, purified by affinity chromatography, showed spectral properties similar to natural allophycocyanin α subunit (ApcA). Spectral and Zinc staining analysis indicated that the recombinant SLA covalently bound phycocyanobilin (PCB). To improve chromophorylation rate of recombinant SLA, an in vitro chromophore attachment reaction system was established, which contained partially chromophylated SLA, PCB and lyase CpcS. Spectral analysis showed that PCB bound to the recombinant SLA rapidly during the reaction. The chromophorylation rate of SLA was improved from 21.1% to 86.5%. Immunofluorescence assay showed that SLA with high chromophorylation rate had higher detection signal. Thus, in vitro chromophore attachment is an effective way to improve the chromophorylation rate of recombinant phycobiliprotein.
Jing Wu; Huaxin Chen; Peng Jiang. Chromophore attachment to fusion protein of streptavidin and recombinant allophycocyanin α subunit. Bioengineered 2017, 9, 108 -115.
AMA StyleJing Wu, Huaxin Chen, Peng Jiang. Chromophore attachment to fusion protein of streptavidin and recombinant allophycocyanin α subunit. Bioengineered. 2017; 9 (1):108-115.
Chicago/Turabian StyleJing Wu; Huaxin Chen; Peng Jiang. 2017. "Chromophore attachment to fusion protein of streptavidin and recombinant allophycocyanin α subunit." Bioengineered 9, no. 1: 108-115.
Allophycocyanin (APC) is generally used as fluorescent labels. In this study, apcA genes from a mesophilic cyanobacterium Synechocystis sp. PCC 6803 and a thermophilic cyanobacterium Thermosynechococcus elongatus BP-1 were cloned into expression vectors to construct pathway for biosynthesis of allophycocyanin holo-α subunits (named as holo-ApcAS for Synechocystis sp. PCC 6803 and holo-ApcAT for T. elongatus BP-1) in Escherichia coli. The two holo-ApcAs were successfully reconstituted in E. coli and purified by metal affinity chromatography. Spectral analysis showed that the two proteins have similar spectroscopic properties, with absorbance maximum both at 614 nm and emission maximum at 639 nm for holo-ApcAS and 638 nm for holo-ApcAT. At high temperature, the recombinant holo-ApcAT was much more stable than the recombinant holo-ApcAS. Holo-ApcAS was most fluorescent at pH 8.5 and stable in pH range of 6.0–9.0 while holo-ApcAT was most fluorescent at pH 6.0 and stable in pH range of 5.0–7.0, with residual fluorescence intensity no less than 90% of the maximum fluorescence. These findings will pave the way for further protein engineering to achieve high stable APC from extremophiles.
Huaxin Chen; Qiuzi Liu; Jin Zhao; Peng Jiang. Biosynthesis, spectral properties and thermostability of cyanobacterial allophycocyanin holo-α subunits. International Journal of Biological Macromolecules 2016, 88, 88 -92.
AMA StyleHuaxin Chen, Qiuzi Liu, Jin Zhao, Peng Jiang. Biosynthesis, spectral properties and thermostability of cyanobacterial allophycocyanin holo-α subunits. International Journal of Biological Macromolecules. 2016; 88 ():88-92.
Chicago/Turabian StyleHuaxin Chen; Qiuzi Liu; Jin Zhao; Peng Jiang. 2016. "Biosynthesis, spectral properties and thermostability of cyanobacterial allophycocyanin holo-α subunits." International Journal of Biological Macromolecules 88, no. : 88-92.