Phaeocystis globosa is an important unicellular eukaryotic alga that can also form colonies.P.globosa can cause massive harmful algal blooms and plays an important role in the global carbon or sulfur cycling.Thus far,...Phaeocystis globosa is an important unicellular eukaryotic alga that can also form colonies.P.globosa can cause massive harmful algal blooms and plays an important role in the global carbon or sulfur cycling.Thus far,the ecophysiology of P.globosa has been investigated by numerous studies.However,the proteomic response of P.globosa to nitrogen depletion remains largely unknown.We compared four protein preparation methods of P.globosa for two-dimensional electrophoresis(2-DE)(Urea/Triton X-100 with trichloroacetic acid(TCA)/acetone precipitation;TCA/acetone precipitation;Radio Immuno Precipitation Assay(RIPA)with TCA/acetone precipitation;and Tris buffer).Results show that the combination of RIPA with TCA/acetone precipitation had a clear gel background and showed the best protein spot separation effect,based on which the proteomic response to nitrogen depletion was studied using 2-DE.In addition,we identified six differentially expressed proteins whose relative abundance increased or decreased more than 1.5-fold(P<0.05).Most proteins could not be identified,which might be attributed to the lack of genomic sequences of P.globosa.Under nitrogen limitation,replication protein-like,RNA ligase,and sn-glycerol-3-phosphate dehydrogenase were reduced,which may decrease the DNA replication level and ATP production in P.globosa cells.The increase of endonucleaseⅢand transcriptional regulator enzyme may affect the metabolic and antioxidant function of P.globosa cells and induce cell apoptosis.These findings provide a basis for further proteomic study of P.globosa and the optimization of protein preparation methods of marine microalgae.展开更多
The microalga Phaeocystis globosa is recognized as a harmful alga and also one of the few keystone phytoplankton genera that shape the structure and function of marine ecosystems.P.globosa possess a complex polymorphi...The microalga Phaeocystis globosa is recognized as a harmful alga and also one of the few keystone phytoplankton genera that shape the structure and function of marine ecosystems.P.globosa possess a complex polymorphic life cycle,exhibiting phase alternation between free-living cells of approximately 3-6μm in diameter and gelatinous colonies(palmelloid stage)reaching several millimeters.The knowledge on the factors that induced the morphological transition of P.globosa in the last two decades was reviewed.Emphasis is given to infochemicals,an additional biological factor induced by predator,with the attempt to reveal a relevant mechanism of induced morphological defense.展开更多
Objective:To determine the antibacterial,antifungal,antiprotozoal,cytotoxic,and phytochemical properties of ethanol extracts of leaves of Voacanga globosa(Blanco) Merr.(V.globosa). Methods:The extracts were tested aga...Objective:To determine the antibacterial,antifungal,antiprotozoal,cytotoxic,and phytochemical properties of ethanol extracts of leaves of Voacanga globosa(Blanco) Merr.(V.globosa). Methods:The extracts were tested against bacteria and fungus through disc diffusion assay; against protozoa through growth curve determination,antiprotozoal and cytotoxicity assays. Results:The extract revealed antibacterial activities,inhibiting the growth of Staphylococcus aureus,Bacillus cereus,Pseudomonas aeruginosa,Micrococcus luteus,and Salmonella typhimurium.Antifungal assay showed that it inhibited Candida albicans.The antiprotozoal assay against Trichomonas vaginalis and Entamoeba histolytica showed that V.globosa can inhibit the parasites,wherein the action can be comparable to metronidazole.With the in situ cell death detection kit.Trichomonas vaginalis and Entamoeba histolytica exposed to V.globosa leaf extract was observed to fluoresce simultaneously in red and yellow signals signifying apoptotic-like changes.Preliminary phytochemical screening revealed the chemical composition of plant extract containing alkaloids,saponins,2-deoxysugars,and hydrolysabie tannins.Conclusions: Thus,thus study provides scientific evidence on the traditional use of V.globosa leaf extract in treating microbial diseases.Further,the leaf extract can possibly be used to produce alternative forms of antimicrobials.展开更多
Phaeocystis globosa Scherffel is one of the common harmful algae species in coastal waters of the southeastern China.In this study,sandwich hybridization integrated with nuclease protection assay(NPA-SH)was used to qu...Phaeocystis globosa Scherffel is one of the common harmful algae species in coastal waters of the southeastern China.In this study,sandwich hybridization integrated with nuclease protection assay(NPA-SH)was used to qualitatively and quantitatively detect P. globosa.Results showed that this method had good applicability and validity in analyzing the samples from laboratory cultures and from fields.The linear regression equation for P.globosa was obtained,and the lowest detection number of cells was 1.8×104 cells.Statistics showed that there was no distinct difference between the results of detecting the microalgae by NPA-SH and traditional microscopy. This technique has good reliability,accuracy,and can give a remarkably high sample processing rate.Sandwich hybridization integrated with nuclease protection assay will provide an effcient alternative to microscopic method for monitoring and investigating the bloom of P.globosa.展开更多
The colony-forming Phaeocystis species are causative agents of dense bloom occurrences in coastal waters worldwide. It is difficult to separate them because of the different morphologies associated with their colonial...The colony-forming Phaeocystis species are causative agents of dense bloom occurrences in coastal waters worldwide. It is difficult to separate them because of the different morphologies associated with their colonial stages. In this study we applied molecular approaches to analyze the genetic variation of Phaeocystis globosa and Phaeocystis pouchetii from several geographic regions, and to assist in tracing the dispersal of bloom-forming Phaeocystis species in coastal waters of China. The sequences of the internal transcribed spacers ( ITS1 and ITS2) of rDNA and the 5.8S ribosomal RNA gene of Phaeocystis strains were determined. Sequence comparison shows that P.globosa was the most divergent to P. pouchetii, exhibiting sequence divergence higher than 0.08. However, lower genetic divergences existed between strains of P. globosa. The sequence comparison of the Phaeocystis rDNA ITS clearly shows that the species isolated from the southeast coast of China is identified as P. globosa rather than P. cf. pouchetii or other species. Furthermore, the significance of rDNA variation in distinct global populations of P. globosa suggested it might have had sufficient time to accumulate detectable mutations at the rDNA locus, supporting the hypothesis of ancient dispersal of P.globosa to many areas, meaning that P. globosa blooms in the coastal waters of China are endemic rather than a newly introduced species or a foreign source. Finally, based on the high divergent region of rDNA ITS, a pair of species-specific primers for P. globosa were designed, they could be useful to detect the presence of this species in mixed plankton assemblages or flagellate stages that are recognized with diffculties by means of conventional microscopy.展开更多
基金the National Natural Science Foundation of China(Nos.42176142,41906111,41806127)the Marine Economic Development Project of Guangdong Province(No.2023B1111050011)+1 种基金the Basic and Applied Basic Research Project of Guangzhou(Nos.2023A04J1548,2023A04J1549)the Outstanding Innovative Talents Cultivation Funded Programs for Doctoral Students of Jinan University(No.2021CXB010)。
文摘Phaeocystis globosa is an important unicellular eukaryotic alga that can also form colonies.P.globosa can cause massive harmful algal blooms and plays an important role in the global carbon or sulfur cycling.Thus far,the ecophysiology of P.globosa has been investigated by numerous studies.However,the proteomic response of P.globosa to nitrogen depletion remains largely unknown.We compared four protein preparation methods of P.globosa for two-dimensional electrophoresis(2-DE)(Urea/Triton X-100 with trichloroacetic acid(TCA)/acetone precipitation;TCA/acetone precipitation;Radio Immuno Precipitation Assay(RIPA)with TCA/acetone precipitation;and Tris buffer).Results show that the combination of RIPA with TCA/acetone precipitation had a clear gel background and showed the best protein spot separation effect,based on which the proteomic response to nitrogen depletion was studied using 2-DE.In addition,we identified six differentially expressed proteins whose relative abundance increased or decreased more than 1.5-fold(P<0.05).Most proteins could not be identified,which might be attributed to the lack of genomic sequences of P.globosa.Under nitrogen limitation,replication protein-like,RNA ligase,and sn-glycerol-3-phosphate dehydrogenase were reduced,which may decrease the DNA replication level and ATP production in P.globosa cells.The increase of endonucleaseⅢand transcriptional regulator enzyme may affect the metabolic and antioxidant function of P.globosa cells and induce cell apoptosis.These findings provide a basis for further proteomic study of P.globosa and the optimization of protein preparation methods of marine microalgae.
基金Supported by the Key Deployment Project of Center for Ocean Mega-Science,Chinese Academy of Sciences(No.COMS2019R04)the National Overseas High-level Talent Project,Taishan Scholar Program from Shandong Province of China(No.tsqn20190403)the Shuangbai Plan from Yantai City(No.2018020)。
文摘The microalga Phaeocystis globosa is recognized as a harmful alga and also one of the few keystone phytoplankton genera that shape the structure and function of marine ecosystems.P.globosa possess a complex polymorphic life cycle,exhibiting phase alternation between free-living cells of approximately 3-6μm in diameter and gelatinous colonies(palmelloid stage)reaching several millimeters.The knowledge on the factors that induced the morphological transition of P.globosa in the last two decades was reviewed.Emphasis is given to infochemicals,an additional biological factor induced by predator,with the attempt to reveal a relevant mechanism of induced morphological defense.
基金supported by a research grant from the Commission on Higher Education(CHED) of the Philippines
文摘Objective:To determine the antibacterial,antifungal,antiprotozoal,cytotoxic,and phytochemical properties of ethanol extracts of leaves of Voacanga globosa(Blanco) Merr.(V.globosa). Methods:The extracts were tested against bacteria and fungus through disc diffusion assay; against protozoa through growth curve determination,antiprotozoal and cytotoxicity assays. Results:The extract revealed antibacterial activities,inhibiting the growth of Staphylococcus aureus,Bacillus cereus,Pseudomonas aeruginosa,Micrococcus luteus,and Salmonella typhimurium.Antifungal assay showed that it inhibited Candida albicans.The antiprotozoal assay against Trichomonas vaginalis and Entamoeba histolytica showed that V.globosa can inhibit the parasites,wherein the action can be comparable to metronidazole.With the in situ cell death detection kit.Trichomonas vaginalis and Entamoeba histolytica exposed to V.globosa leaf extract was observed to fluoresce simultaneously in red and yellow signals signifying apoptotic-like changes.Preliminary phytochemical screening revealed the chemical composition of plant extract containing alkaloids,saponins,2-deoxysugars,and hydrolysabie tannins.Conclusions: Thus,thus study provides scientific evidence on the traditional use of V.globosa leaf extract in treating microbial diseases.Further,the leaf extract can possibly be used to produce alternative forms of antimicrobials.
基金supported by the National Hi-Tech Research and Development Program(863)of China(No.2006AA09Z178,2001AA635090)the National Nat-ural Science Foundation of China(No.40706044)
文摘Phaeocystis globosa Scherffel is one of the common harmful algae species in coastal waters of the southeastern China.In this study,sandwich hybridization integrated with nuclease protection assay(NPA-SH)was used to qualitatively and quantitatively detect P. globosa.Results showed that this method had good applicability and validity in analyzing the samples from laboratory cultures and from fields.The linear regression equation for P.globosa was obtained,and the lowest detection number of cells was 1.8×104 cells.Statistics showed that there was no distinct difference between the results of detecting the microalgae by NPA-SH and traditional microscopy. This technique has good reliability,accuracy,and can give a remarkably high sample processing rate.Sandwich hybridization integrated with nuclease protection assay will provide an effcient alternative to microscopic method for monitoring and investigating the bloom of P.globosa.
基金This study was supported by the National Natural Science Foundation of China under contract No. 39970063the Natural Science Foundation of Guangdong Province, China under contract No. 001213the Red-tide Key Project of the Natural Science Foundatio
文摘The colony-forming Phaeocystis species are causative agents of dense bloom occurrences in coastal waters worldwide. It is difficult to separate them because of the different morphologies associated with their colonial stages. In this study we applied molecular approaches to analyze the genetic variation of Phaeocystis globosa and Phaeocystis pouchetii from several geographic regions, and to assist in tracing the dispersal of bloom-forming Phaeocystis species in coastal waters of China. The sequences of the internal transcribed spacers ( ITS1 and ITS2) of rDNA and the 5.8S ribosomal RNA gene of Phaeocystis strains were determined. Sequence comparison shows that P.globosa was the most divergent to P. pouchetii, exhibiting sequence divergence higher than 0.08. However, lower genetic divergences existed between strains of P. globosa. The sequence comparison of the Phaeocystis rDNA ITS clearly shows that the species isolated from the southeast coast of China is identified as P. globosa rather than P. cf. pouchetii or other species. Furthermore, the significance of rDNA variation in distinct global populations of P. globosa suggested it might have had sufficient time to accumulate detectable mutations at the rDNA locus, supporting the hypothesis of ancient dispersal of P.globosa to many areas, meaning that P. globosa blooms in the coastal waters of China are endemic rather than a newly introduced species or a foreign source. Finally, based on the high divergent region of rDNA ITS, a pair of species-specific primers for P. globosa were designed, they could be useful to detect the presence of this species in mixed plankton assemblages or flagellate stages that are recognized with diffculties by means of conventional microscopy.
