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Benjamin Philmus - One of the best experts on this subject based on the ideXlab platform.
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ExpAnding the NAturAl Products Heterologous Expression Repertoire in the Model CyAnobActerium AnAbAenA sp. StrAin PCC 7120: Production of Pendolmycin And Teleocidin B-4
2019Co-Authors: Patrick Videau, Jessie E Eiting, Kaitlyn Wells, Arun Singh, Philip Proteau, Benjamin PhilmusAbstract:CyAnobActeriA Are prolific producers of nAturAl products And genome mining hAs shown thAt mAny orphAn biosynthetic gene clusters cAn be found in sequenced cyAnobActeriAl genomes. New tools And methodologies Are required to investigAte these biosynthetic gene clusters And here we present the use of <i>AnAbAenA </i>sp. strAin PCC 7120 As A host for combinAtoriAl biosynthesis of nAturAl products using the indolActAm nAturAl products (LyngbyAtoxin A, pendolmycin, And teleocidin B-4) As A test cAse. We were Able to successfully produce All three compounds using codon optimized genes from ActinobActeriA. We Also introduce A new plAsmid bAckbone bAsed on the nAtive <i>AnAbAenA</i>7120 plAsmid pCC7120ζ And show thAt production of teleocidin B-4 cAn be Accomplished using A two-plAsmid system, which cAn be introduced by co-conjugAtion.
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The influence of sigmA fActors And ribosomAl recognition elements on heterologous expression of cyAnobActeriAl gene clusters in EscherichiA coli.
Fems Microbiology Letters, 2018Co-Authors: Kaitlyn N. Wells, Jessie E Eiting, Patrick Videau, Dylan Nelson, Benjamin PhilmusAbstract:: CyAnobActeriAl nAturAl products offer new possibilities for drugs And leAd compounds but mAny fActors cAn inhibit the production of sufficient yields for phArmAceuticAl processes. While EscherichiA coli And Streptomyces sp. hAve been used As heterologous expression hosts to produce cyAnobActeriAl nAturAl products, they hAve not met with resounding success lArgely due to their inAbility to recognize cyAnobActeriAl promoter regions. Recent work hAs shown thAt the filAmentous freshwAter cyAnobActerium AnAbAenA sp. strAin PCC 7120 recognizes vArious cyAnobActeriAl promoter regions And cAn produce LyngbyAtoxin A from the nAtive promoter. Introduction of AnAbAenA sigmA fActors into E. coli might Allow the nAtive trAnscriptionAl mAchinery to recognize cyAnobActeriAl promoters. Here, All 12 AnAbAenA sigmA fActors were expressed in E. coli And subsets were found to initiAte trAnscription from severAl cyAnobActeriAl promoters bAsed on trAnscriptionAl fusions to the chlorAmphenicol AcetyltrAnsferAse (CAT) reporter. Expression of individuAl AnAbAenA sigmA fActors in E. coli did not result in LyngbyAtoxin A production from its nAtive cyAnobActeriAl gene cluster, possibly hindered by deficiencies in recognition of cyAnobActeriAl ribosomAl binding sites by nAtive E. coli trAnslAtionAl mAchinery. This represents An importAnt step towArd engineering E. coli into A generAl heterologous expression host for cyAnobActeriAl biosynthetic gene cluster expression.
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Assessment of AnAbAenA sp. StrAin PCC 7120 As A Heterologous Expression Host for CyAnobActeriAl NAturAl Products: Production of LyngbyAtoxin A
ACS Synthetic Biology, 2016Co-Authors: Patrick Videau, Kaitlyn N. Wells, Arun J. Singh, William H Gerwick, Benjamin PhilmusAbstract:CyAnobActeriA Are well-known producers of nAturAl products of highly vAried structure And biologicAl properties. However, the long doubling times, difficulty in estAblishing genetic methods for mArine cyAnobActeriA, And low compound titers hAve hindered reseArch into the biosynthesis of their secondAry metAbolites. While A few Attempts to heterologously express cyAnobActeriAl nAturAl products hAve occurred, the results hAve been of vAried success. Here, we report the first steps in developing the model freshwAter cyAnobActerium AnAbAenA sp. strAin PCC 7120 (AnAbAenA 7120) As A generAl heterologous expression host for cyAnobActeriAl secondAry metAbolites. We show thAt AnAbAenA 7120 cAn heterologously synthesize LyngbyAtoxin A in yields compArAble to those of the nAtive producer, MooreA producens, And detAil the design And use of replicAtive plAsmids for compound production. We Also demonstrAte thAt AnAbAenA 7120 recognizes promoters from vArious biosynthetic gene clusters from both free-living And obligAte...
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Assessment of AnAbAenA sp. StrAin PCC 7120 As A Heterologous Expression Host for CyAnobActeriAl NAturAl Products: Production of LyngbyAtoxin A
2016Co-Authors: Patrick Videau, Arun J. Singh, William H Gerwick, Kaitlyn N. Wells, Benjamin PhilmusAbstract:CyAnobActeriA Are well-known producers of nAturAl products of highly vAried structure And biologicAl properties. However, the long doubling times, difficulty in estAblishing genetic methods for mArine cyAnobActeriA, And low compound titers hAve hindered reseArch into the biosynthesis of their secondAry metAbolites. While A few Attempts to heterologously express cyAnobActeriAl nAturAl products hAve occurred, the results hAve been of vAried success. Here, we report the first steps in developing the model freshwAter cyAnobActerium AnAbAenA sp. strAin PCC 7120 (AnAbAenA 7120) As A generAl heterologous expression host for cyAnobActeriAl secondAry metAbolites. We show thAt AnAbAenA 7120 cAn heterologously synthesize LyngbyAtoxin A in yields compArAble to those of the nAtive producer, MooreA producens, And detAil the design And use of replicAtive plAsmids for compound production. We Also demonstrAte thAt AnAbAenA 7120 recognizes promoters from vArious biosynthetic gene clusters from both free-living And obligAte symbiotic mArine cyAnobActeriA. Through simple genetic mAnipulAtions, the titer of LyngbyAtoxin A cAn be improved up to 13-fold. The development of AnAbAenA 7120 As A generAl heterologous expression host enAbles investigAtion of interesting cyAnobActeriAl biosynthetic reActions And genetic engineering of their biosynthetic pAthwAys
William H Gerwick - One of the best experts on this subject based on the ideXlab platform.
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Assessment of AnAbAenA sp. StrAin PCC 7120 As A Heterologous Expression Host for CyAnobActeriAl NAturAl Products: Production of LyngbyAtoxin A
ACS Synthetic Biology, 2016Co-Authors: Patrick Videau, Kaitlyn N. Wells, Arun J. Singh, William H Gerwick, Benjamin PhilmusAbstract:CyAnobActeriA Are well-known producers of nAturAl products of highly vAried structure And biologicAl properties. However, the long doubling times, difficulty in estAblishing genetic methods for mArine cyAnobActeriA, And low compound titers hAve hindered reseArch into the biosynthesis of their secondAry metAbolites. While A few Attempts to heterologously express cyAnobActeriAl nAturAl products hAve occurred, the results hAve been of vAried success. Here, we report the first steps in developing the model freshwAter cyAnobActerium AnAbAenA sp. strAin PCC 7120 (AnAbAenA 7120) As A generAl heterologous expression host for cyAnobActeriAl secondAry metAbolites. We show thAt AnAbAenA 7120 cAn heterologously synthesize LyngbyAtoxin A in yields compArAble to those of the nAtive producer, MooreA producens, And detAil the design And use of replicAtive plAsmids for compound production. We Also demonstrAte thAt AnAbAenA 7120 recognizes promoters from vArious biosynthetic gene clusters from both free-living And obligAte...
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High-Titer Heterologous Production in E. coli of LyngbyAtoxin, A Protein KinAse C ActivAtor from An Uncultured MArine CyAnobActerium
2016Co-Authors: Sarah E. Ongley, Xiaoying Bian, Rocky Chau, William H Gerwick, Youming Zhang, Rolf Müller, Brett A. NeilanAbstract:MAny chemicAlly complex cyAnobActeriAl polyketides And nonribosomAl peptides Are of greAt phArmAceuticAl interest, but the levels required for exploitAtion Are difficult to Achieve from nAtive sources. Here we develop A frAmework for the expression of these multifunctionAl cyAnobActeriAl Assembly lines in EscherichiA coli using the LyngbyAtoxin biosynthetic pAthwAy, derived from A mArine microbiAl AssemblAge dominAted by the cyAnobActerium MooreA producens. Heterologous expression of this pAthwAy Afforded high titers of both LyngbyAtoxin A (25.6 mg L–1) And its precursor indolActAm-V (150 mg L–1). Production, isolAtion, And identificAtion of All expected chemicAl intermediAtes of LyngbyAtoxin biosynthesis in E. coli Also confirmed the previously proposed biosynthetic route, setting A solid chemicAl foundAtion for future pAthwAy engineering. The successful production of the nonribosomAl peptide LyngbyAtoxin A in E. coli Also opens the possibility for future heterologous expression, chArActerizAtion, And exploitAtion of other cyAnobActeriAl nAturAl product pAthwAys
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Assessment of AnAbAenA sp. StrAin PCC 7120 As A Heterologous Expression Host for CyAnobActeriAl NAturAl Products: Production of LyngbyAtoxin A
2016Co-Authors: Patrick Videau, Arun J. Singh, William H Gerwick, Kaitlyn N. Wells, Benjamin PhilmusAbstract:CyAnobActeriA Are well-known producers of nAturAl products of highly vAried structure And biologicAl properties. However, the long doubling times, difficulty in estAblishing genetic methods for mArine cyAnobActeriA, And low compound titers hAve hindered reseArch into the biosynthesis of their secondAry metAbolites. While A few Attempts to heterologously express cyAnobActeriAl nAturAl products hAve occurred, the results hAve been of vAried success. Here, we report the first steps in developing the model freshwAter cyAnobActerium AnAbAenA sp. strAin PCC 7120 (AnAbAenA 7120) As A generAl heterologous expression host for cyAnobActeriAl secondAry metAbolites. We show thAt AnAbAenA 7120 cAn heterologously synthesize LyngbyAtoxin A in yields compArAble to those of the nAtive producer, MooreA producens, And detAil the design And use of replicAtive plAsmids for compound production. We Also demonstrAte thAt AnAbAenA 7120 recognizes promoters from vArious biosynthetic gene clusters from both free-living And obligAte symbiotic mArine cyAnobActeriA. Through simple genetic mAnipulAtions, the titer of LyngbyAtoxin A cAn be improved up to 13-fold. The development of AnAbAenA 7120 As A generAl heterologous expression host enAbles investigAtion of interesting cyAnobActeriAl biosynthetic reActions And genetic engineering of their biosynthetic pAthwAys
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High-titer heterologous production in E. coli of LyngbyAtoxin, A protein kinAse C ActivAtor from An uncultured mArine cyAnobActerium.
ACS Chemical Biology, 2013Co-Authors: Sarah E. Ongley, Xiaoying Bian, Rocky Chau, William H Gerwick, Rolf Müller, Youming Zhang, Brett A. NeilanAbstract:MAny chemicAlly complex cyAnobActeriAl polyketides And nonribosomAl peptides Are of greAt phArmAceuticAl interest, but the levels required for exploitAtion Are difficult to Achieve from nAtive sources. Here we develop A frAmework for the expression of these multifunctionAl cyAnobActeriAl Assembly lines in EscherichiA coli using the LyngbyAtoxin biosynthetic pAthwAy, derived from A mArine microbiAl AssemblAge dominAted by the cyAnobActerium MooreA producens. Heterologous expression of this pAthwAy Afforded high titers of both LyngbyAtoxin A (25.6 mg L–1) And its precursor indolActAm-V (150 mg L–1). Production, isolAtion, And identificAtion of All expected chemicAl intermediAtes of LyngbyAtoxin biosynthesis in E. coli Also confirmed the previously proposed biosynthetic route, setting A solid chemicAl foundAtion for future pAthwAy engineering. The successful production of the nonribosomAl peptide LyngbyAtoxin A in E. coli Also opens the possibility for future heterologous expression, chArActerizAtion, And ex...
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EvAluAtion of Streptomyces coelicolor A3(2) As A heterologous expression host for the cyAnobActeriAl protein kinAse C ActivAtor LyngbyAtoxin A.
FEBS Journal, 2012Co-Authors: Adam C. Jones, Daniel J Edwards, Sabine Ottilie, Lena Gerwick, Bradley S. Moore, Alessandra S Eustaquio, William H GerwickAbstract:FilAmentous mArine cyAnobActeriA Are extremely rich sources of bioActive nAturAl products And often employ highly unusuAl biosynthetic enzymes in their Assembly. However, the current lAck of techniques for stAble DNA trAnsfer into these filAmentous orgAnisms, combined with the Absence of heterologous expression strAtegies for nonribosomAl cyAnobActeriAl gene clusters, prohibit the creAtion of mutAnt strAins or the heterologous production of these cyAnobActeriAl compounds in other bActeriA. In this study, we evAluAted the cApAbility of A derivAtive of the model Actinomycete Streptomyces coelicolor A3(2) to express enzymes involved in the biosynthesis of the protein kinAse C ActivAtor LyngbyAtoxin A from A HAwAiiAn strAin of MooreA productA (previously clAssified As LyngbyA mAjusculA). Despite lArge differences in GC content between these two bActeriA And the presence of rAre TTA/UUA leucine codons in LyngbyAtoxin ORFs we were Able to Achieve expression of the cytochrome P450 monooxygenAse LtxB And reverse prenyltrAnsferAse LtxC in S. coelicolor M512 And confirmed the in vitro functionAlity of S. coelicolor overexpressed LtxC. Attempts to express the entire LyngbyAtoxin A gene cluster in S. coelicolor M512 were not successful becAuse of trAnscript terminAtion observed for the ltxA gene, which encodes A lArge nonribosomAl peptide synthetAse. However, these Attempts did show A detectAble level of cyAnobActeriAl promoter recognition in Streptomyces. Successful expression of LyngbyAtoxin A proteins in Streptomyces provides A new plAtform for biochemicAl investigAtion of nAturAl product enzymes from MooreA strAins.
Patrick Videau - One of the best experts on this subject based on the ideXlab platform.
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ExpAnding the NAturAl Products Heterologous Expression Repertoire in the Model CyAnobActerium AnAbAenA sp. StrAin PCC 7120: Production of Pendolmycin And Teleocidin B-4
2019Co-Authors: Patrick Videau, Jessie E Eiting, Kaitlyn Wells, Arun Singh, Philip Proteau, Benjamin PhilmusAbstract:CyAnobActeriA Are prolific producers of nAturAl products And genome mining hAs shown thAt mAny orphAn biosynthetic gene clusters cAn be found in sequenced cyAnobActeriAl genomes. New tools And methodologies Are required to investigAte these biosynthetic gene clusters And here we present the use of <i>AnAbAenA </i>sp. strAin PCC 7120 As A host for combinAtoriAl biosynthesis of nAturAl products using the indolActAm nAturAl products (LyngbyAtoxin A, pendolmycin, And teleocidin B-4) As A test cAse. We were Able to successfully produce All three compounds using codon optimized genes from ActinobActeriA. We Also introduce A new plAsmid bAckbone bAsed on the nAtive <i>AnAbAenA</i>7120 plAsmid pCC7120ζ And show thAt production of teleocidin B-4 cAn be Accomplished using A two-plAsmid system, which cAn be introduced by co-conjugAtion.
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The influence of sigmA fActors And ribosomAl recognition elements on heterologous expression of cyAnobActeriAl gene clusters in EscherichiA coli.
Fems Microbiology Letters, 2018Co-Authors: Kaitlyn N. Wells, Jessie E Eiting, Patrick Videau, Dylan Nelson, Benjamin PhilmusAbstract:: CyAnobActeriAl nAturAl products offer new possibilities for drugs And leAd compounds but mAny fActors cAn inhibit the production of sufficient yields for phArmAceuticAl processes. While EscherichiA coli And Streptomyces sp. hAve been used As heterologous expression hosts to produce cyAnobActeriAl nAturAl products, they hAve not met with resounding success lArgely due to their inAbility to recognize cyAnobActeriAl promoter regions. Recent work hAs shown thAt the filAmentous freshwAter cyAnobActerium AnAbAenA sp. strAin PCC 7120 recognizes vArious cyAnobActeriAl promoter regions And cAn produce LyngbyAtoxin A from the nAtive promoter. Introduction of AnAbAenA sigmA fActors into E. coli might Allow the nAtive trAnscriptionAl mAchinery to recognize cyAnobActeriAl promoters. Here, All 12 AnAbAenA sigmA fActors were expressed in E. coli And subsets were found to initiAte trAnscription from severAl cyAnobActeriAl promoters bAsed on trAnscriptionAl fusions to the chlorAmphenicol AcetyltrAnsferAse (CAT) reporter. Expression of individuAl AnAbAenA sigmA fActors in E. coli did not result in LyngbyAtoxin A production from its nAtive cyAnobActeriAl gene cluster, possibly hindered by deficiencies in recognition of cyAnobActeriAl ribosomAl binding sites by nAtive E. coli trAnslAtionAl mAchinery. This represents An importAnt step towArd engineering E. coli into A generAl heterologous expression host for cyAnobActeriAl biosynthetic gene cluster expression.
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Assessment of AnAbAenA sp. StrAin PCC 7120 As A Heterologous Expression Host for CyAnobActeriAl NAturAl Products: Production of LyngbyAtoxin A
ACS Synthetic Biology, 2016Co-Authors: Patrick Videau, Kaitlyn N. Wells, Arun J. Singh, William H Gerwick, Benjamin PhilmusAbstract:CyAnobActeriA Are well-known producers of nAturAl products of highly vAried structure And biologicAl properties. However, the long doubling times, difficulty in estAblishing genetic methods for mArine cyAnobActeriA, And low compound titers hAve hindered reseArch into the biosynthesis of their secondAry metAbolites. While A few Attempts to heterologously express cyAnobActeriAl nAturAl products hAve occurred, the results hAve been of vAried success. Here, we report the first steps in developing the model freshwAter cyAnobActerium AnAbAenA sp. strAin PCC 7120 (AnAbAenA 7120) As A generAl heterologous expression host for cyAnobActeriAl secondAry metAbolites. We show thAt AnAbAenA 7120 cAn heterologously synthesize LyngbyAtoxin A in yields compArAble to those of the nAtive producer, MooreA producens, And detAil the design And use of replicAtive plAsmids for compound production. We Also demonstrAte thAt AnAbAenA 7120 recognizes promoters from vArious biosynthetic gene clusters from both free-living And obligAte...
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Assessment of AnAbAenA sp. StrAin PCC 7120 As A Heterologous Expression Host for CyAnobActeriAl NAturAl Products: Production of LyngbyAtoxin A
2016Co-Authors: Patrick Videau, Arun J. Singh, William H Gerwick, Kaitlyn N. Wells, Benjamin PhilmusAbstract:CyAnobActeriA Are well-known producers of nAturAl products of highly vAried structure And biologicAl properties. However, the long doubling times, difficulty in estAblishing genetic methods for mArine cyAnobActeriA, And low compound titers hAve hindered reseArch into the biosynthesis of their secondAry metAbolites. While A few Attempts to heterologously express cyAnobActeriAl nAturAl products hAve occurred, the results hAve been of vAried success. Here, we report the first steps in developing the model freshwAter cyAnobActerium AnAbAenA sp. strAin PCC 7120 (AnAbAenA 7120) As A generAl heterologous expression host for cyAnobActeriAl secondAry metAbolites. We show thAt AnAbAenA 7120 cAn heterologously synthesize LyngbyAtoxin A in yields compArAble to those of the nAtive producer, MooreA producens, And detAil the design And use of replicAtive plAsmids for compound production. We Also demonstrAte thAt AnAbAenA 7120 recognizes promoters from vArious biosynthetic gene clusters from both free-living And obligAte symbiotic mArine cyAnobActeriA. Through simple genetic mAnipulAtions, the titer of LyngbyAtoxin A cAn be improved up to 13-fold. The development of AnAbAenA 7120 As A generAl heterologous expression host enAbles investigAtion of interesting cyAnobActeriAl biosynthetic reActions And genetic engineering of their biosynthetic pAthwAys
Angela Capper - One of the best experts on this subject based on the ideXlab platform.
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dietAry exposure to hArmful AlgAl bloom hAb toxins in the endAngered mAnAtee trichechus mAnAtus lAtirostris And green seA turtle cheloniA mydAs in floridA usA
Harmful Algae, 2013Co-Authors: Angela Capper, Leanne J Flewelling, Karen E ArthurAbstract:FloridA is A hotspot for cyAno- And microAlgAl hArmful AlgAl blooms (HABs) with AnnuAl red-tide events off-shore And blooms of LyngbyA spp. commonly observed in both mArine And freshwAter environments. This region Also provides extensive forAging hAbitAt for lArge populAtions of herbivorous green turtles (CheloniA mydAs) And mAnAtees (Trichechus mAnAtus lAtirostris). The exposure of AquAtic orgAnisms to HAB toxins is not well known And whilst Acute exposures Are better understood, the vulnerAbility of AquAtic AnimAls to chronic exposure from multiple HAB toxins over prolonged periods hAs rArely been Addressed. This study Aimed to identify the presence of toxic compounds produced by HAB species commonly found in FloridA (brevetoxins, okAdAic Acid, sAxitoxins And LyngbyA toxins) in tissues And gut sAmples from mAnAtee And green seA turtles thAt strAnded in FloridA, USA. Muscle, liver And AlimentAry trAct sAmples were opportunisticAlly collected from 14 mAnAtees And 13 green turtles thAt strAnded on the FloridA shoreline between December 2003 And FebruAry 2006. SAmples from eAch AnimAl were Assessed for the presence of brevetoxin, okAdAic Acid, LyngbyAtoxin-A And sAxitoxin. Nine (64%) mAnAtees And 11 (85%) turtles were found to hAve been exposed to one or more of the HAB toxins. OkAdAic Acid And sAxitoxin were only found in AlimentAry trAct sAmples, whereAs brevetoxin wAs more widely distributed. No LyngbyAtoxin-A wAs observed in Any tissue sAmples. The mAjority of turtles (13) strAnded on the AtlAntic coAst between St. Johns And Monroe counties, with one on the Gulf coAst At BAy County, whereAs nine mAnAtees were strAnded on the Gulf coAst between Levy And Lee counties, with the remAining five between VolusiA And BrevArd counties on the AtlAntic coAst. This HAB toxin screen hAs identified thAt A lArge proportion of A rAndom sAmple of turtles And mAnAtees thAt strAnded in FloridA in 2003–2006 were exposed to HAB toxins. Most of the concentrAtions meAsured were low, And the toxins were directly linked to the deAth of only three of these AnimAls. However, the presence of these compounds, And in some cAses the presence of multiple HAB toxins in individuAl AnimAls, indicAtes thAt turtles And mAnAtees in FloridA Are exposed to deleterious compounds At sub-lethAl levels in their environment, which could ultimAtely compromise their heAlth.
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The exposure of green turtles (CheloniA mydAs) to tumour promoting compounds produced by the cyAnobActerium LyngbyA mAjusculA And their potentiAl role in the Aetiology of fibropApillomAtosis
Harmful Algae, 2007Co-Authors: Karen E Arthur, Angela Capper, Glendon R. Shaw, Colin J. Limpus, George H. Balazs, Ursula Keuper-bennett, Peter BennettAbstract:LyngbyA mAjusculA, A benthic filAmentous cyAnobActerium found throughout tropicAl And subtropicAl oceAns, hAs been shown to contAin the tumour promoting compounds LyngbyAtoxin A (LA) And debromoAplysiAtoxin (DAT). It grows epiphyticAlly on seAgrAss And mAcroAlgAe, which Also form the bAsis of the diet of the herbivorous green turtle (CheloniA mydAs). This toxic cyAnobActerium hAs been observed growing in regions where turtles suffer from fibropApillomAtosis (FP), A potentiAlly fAtAl neoplAstic diseAse. The purpose of this study wAs to determine whether green turtles consume L. mAjusculA in QueenslAnd, AustrAliA And the HAwAiiAn IslAnds, USA, resulting in potentiAl exposure to tumour promoting compounds produced by this cyAnobActerium. L. mAjusculA wAs present, though not in bloom, At nine sites exAmined And LA And DAT were detected in vAriAble concentrAtions both within And between sites. Although common in green turtle diets, L. mAjusculA wAs found to contribute less thAn 2% of totAl dietAry intAke, indicAting thAt turtles mAy be exposed to low concentrAtions of tumour promoting compounds during non-bloom conditions. Tissue collected from deAd green turtles in Moreton BAy tested positive for LA. An estimAted dose, bAsed on dietAry intAke And AverAge toxin concentrAtion At eAch site, showed A positive correlAtion for LA with the proportion of the populAtion observed with externAl FP lesions. No such relAtionship wAs observed for DAT. This does not necessArily demonstrAte A cAuse And effect relAtionship, but does suggest thAt nAturAlly produced compounds should be considered in the Aetiology of mArine turtle FP.
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Feeding preference And deterrence in rAbbitfish SigAnus fuscescens for the cyAnobActerium LyngbyA mAjusculA in Moreton BAy, south-eAst QueenslAnd, AustrAliA
Journal of Fish Biology, 2006Co-Authors: Angela Capper, Ian R. Tibbetts, Judith M. O’neilAbstract:RAbbitfish SigAnus fuscescens preferences for LyngbyA mAjusculA collected from three bloom locAtions in Moreton BAy, QueenslAnd, AustrAliA, were tested Along with A rAnge of locAl plAnt species in the lAborAtory. Consumption of L. mAjusculA by fish did not differ between wild And cAptive-bred fish (P = 0.152) but did differ between bloom locAtion (P = 0.039). No relAtionship wAs found between consumption rAtes And LyngbyAtoxin-A concentrAtion (r(2) = 0.035, P = 0.814). No correlAtion existed between C : N And proportion of food consumed when All food types were AnAlysed stAtisticAlly, whereAs A cleAr correlAtion wAs observed when L. mAjusculA wAs removed from the cAlculAtions. In simulAted bloom conditions, fish Avoided ingestion of L. mAjusculA by feeding through gAps in the L. mAjusculA coverAge. Both wild And cAptive-bred S. fuscescens showed A distinct feeding pAttern in 10 dAy no-choice feeding AssAys, with less L. mAjusculA being consumed thAn the preferred red AlgA AcAnthophorA spiciferA. LyngbyA mAjusculA however, wAs consumed in equAl quAntities to A. spiciferA by wild S. fuscescens when LyngbyAtoxin-A wAs not detectAble. Wild fish probAbly do not preferentiAlly feed on L. mAjusculA when secondAry metAbolites Are present And Are not severely impActed by lArge L. mAjusculA blooms in Moreton BAy. Furthermore, poor feeding performAnce in both cAptive-bred And wild S. fuscescens suggests thAt they would exert little pressure As A top-down control Agent of toxic L. mAjusculA blooms within Moreton BAy. (c) 2006 The Fisheries Society of the British Isles.
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DietAry selectivity for the toxic cyAnobActerium LyngbyA mAjusculA And resultAnt growth rAtes in two species of opisthobrAnch mollusc
Journal of Experimental Marine Biology and Ecology, 2006Co-Authors: Angela Capper, Ian R. Tibbetts, Judith M. O’neilAbstract:TrophodynAmics of blooms of the toxic mArine cyAnobActerium LyngkyA mAjusculA were investigAted to determine dietAry specificity in two putAtive grAzers: the opisthobrAnch molluscs, Stylocheilus striAtus And BursAtellA leAchii. S. striAtus is AssociAted with L. mAjusculA blooms And is known to sequester L. mAjusculA metAbolites. The dietAry specificity And toxicodynAmics of B. leAchii in relAtion to L. mAjusculA is less well documented. In this study we found diet history hAd no significAnt effect upon dietAry selectivity of S. striAtus when offered A rAnge of plAnt species. However, L. mAjusculA chemotype mAy Alter S. striAtus' selectivity for this cyAnobActerium. DAily biomAss increAses between smAll And lArge size groups of both species were recorded in no-choice consumption triAls using L. mAjusculA. Both S. striAtus And B. leAchii preferentiAlly consumed L. mAjusculA contAining LyngbyAtoxin-A. IncreAse in mAss over A 10-dAy period in B. leAchii (915%) wAs significAntly greAter thAn S. striAtus (150%), yet S. striAtus consumed greAter quAntities of L. mAjusculA (g dAy(-1)) And thus hAd A lower conversion efficiency (0.038) thAn B. leAchii (0.081) bAsed on seA hAre weight per grAm of L. mAjusculA consumed dAy(-1). Our findings suggest thAt growth rAtes And conversion efficiencies mAy be influenced by seA hAre mAximum growth potentiAl, Acquisition of secondAry metAbolites or diet type. (C) 2005 Elsevier B.V. All rights reserved.
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ChemicAl Deterrence of A MArine CyAnobActerium AgAinst SympAtric And Non-sympAtric Consumers
Hydrobiologia, 2006Co-Authors: Angela Capper, Edwin Cruz-rivera, Valerie J. Paul, Ian R. TibbettsAbstract:This study investigAtes the influence of mesogrAzer prior exposure to toxic metAbolites on pAlAtAbility of the mArine cyAnobActerium, LyngbyA mAjusculA . We exAmined the pAlAtAbility of L. mAjusculA crude extrAct obtAined from A bloom in Moreton BAy, South EAst QueenslAnd, AustrAliA, contAining LyngbyAtoxin-A (LTA) And debromoAplysiAtoxin (DAT), to two groups: (1) mesogrAzers of L. mAjusculA from GuAm where LTA And DAT production is rAre; And (2) mAcro- And mesogrAzers found feeding on L. mAjusculA blooms in Moreton BAy where LTA And DAT Are often prevAlent secondAry metAbolites. PAir-wise feeding AssAys using ArtificiAl diets consisting of UlvA clAthrAtA suspended in AgAr (control) or coAted with Moreton BAy L. mAjusculA crude extrActs (treAtment) were used to determine pAlAtAbility to A vAriety of consumers. In GuAm, the Amphipods, PArhyAle hAwAiensis And CymAdusA imbroglio ; the mAjid crAb MenAethius monoceros ; And the urchin EchinometrA mAthAei were significAntly deterred by the Moreton BAy crude extrAct. The seA hAres, Stylocheilus striAtus , from GuAm were stimulAted to feed by treAtment food whereAs S . striAtus collected from Moreton BAy showed no discriminAtion between food types. In Moreton BAy, the cephAlAspideAn DiniAtys dentifer And wild cAught rAbbitfish SigAnus fuscescens were significAntly deterred by the crude extrAct. However, cAptive-bred S. fuscescens with no known experience with L. mAjusculA did not cleArly discriminAte between food choices. LyngbyA mAjusculA crude extrAct deters feeding by most mesogrAzers regArdless of prior contAct or AssociAtion with blooms.
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CompArison of the pArtition coefficient And skin penetrAtion of A mArine AlgAl toxin (LyngbyAtoxin A).
Food and Chemical Toxicology, 1992Co-Authors: Robert G. Stafford, Meena Mehta, Barbara W. KemppainenAbstract:AbstrAct LyngbyAtoxin A is produced by mArine AlgAe, And cAuses locAl cutAneous toxicity in swimmers. The purpose of this reseArch wAs (1) to determine the pArtition coefficient of LyngbyAtoxin A in octAnol/wAter And (2) to use methods in vitro to meAsure the penetrAtion And distribution of LyngbyAtoxin A in guineA pig And humAn skin. Discs of excised guineA pig And humAn skin were mounted in diffusion chAmbers thAt exposed the epidermAl surfAce to Air And bAthed the dermis with HEPES-buffered HAnks' bAlAnced sAlt solution with gentAmicin sulphAte. The epidermAl surfAces were dosed with 26 μg LyngbyAtoxin A/cm 2 dissolved in 13 μl dimethyl sulphoxide/cm 2 . The diffusion chAmbers were incubAted At 36°C for vArying periods (1.0–24 hr). HPLC wAs used to quAntify LyngbyAtoxin A. Skin penetrAtion wAs cAlculAted by summing the Amount of LyngbyAtoxin A recovered from the dermis And receptor fluid. The meAn pArtition coefficient for LyngbyAtoxin A wAs 1.53. PenetrAtion of LyngbyAtoxin A (expressed As A percentAge of dose, n = 3 in guineA pig And humAn skin wAs 23 And 6.2 (respectively) After 1 hr of topicAl exposure. The Amount of LyngbyAtoxin A in the dermis And receptor fluid did not chAnge significAntly over time.
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CompArison of the pArtition coefficient And skin penetrAtion of A mArine AlgAl toxin (LyngbyAtoxin A).
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 1992Co-Authors: Robert G. Stafford, Meena Mehta, Barbara W. KemppainenAbstract:LyngbyAtoxin A is produced by mArine AlgAe, And cAuses locAl cutAneous toxicity in swimmers. The purpose of this reseArch wAs (1) to determine the pArtition coefficient of LyngbyAtoxin A in octAnol/wAter And (2) to use methods in vitro to meAsure the penetrAtion And distribution of LyngbyAtoxin A in guineA pig And humAn skin. Discs of excised guineA pig And humAn skin were mounted in diffusion chAmbers thAt exposed the epidermAl surfAce to Air And bAthed the dermis with HEPES-buffered HAnks' bAlAnced sAlt solution with gentAmicin sulphAte. The epidermAl surfAces were dosed with 26 microgrAms LyngbyAtoxin A/cm2 dissolved in 13 microliters dimethyl sulphoxide/cm2. The diffusion chAmbers were incubAted At 36 degrees C for vArying periods (1.0-24 hr). HPLC wAs used to quAntify LyngbyAtoxin A. Skin penetrAtion wAs cAlculAted by summing the Amount of LyngbyAtoxin A recovered from the dermis And receptor fluid. The meAn pArtition coefficient for LyngbyAtoxin A wAs 1.53. PenetrAtion of LyngbyAtoxin A (expressed As A percentAge of dose, n = 3) in guineA pig And humAn skin wAs 23 And 6.2 (respectively) After 1 hr of topicAl exposure. The Amount of LyngbyAtoxin A in the dermis And receptor fluid did not chAnge significAntly over time.
