Colin Munn - Academia.edu (original) (raw)

Papers by Colin Munn

Proceedings in Life Sciences, 1980

The Plymouth Student Scientist, 2009

This collection of articles features examples of coursework submitted by three students taking th... more This collection of articles features examples of coursework submitted by three students taking the module BIOL3309 „Marine Microbiology – Ecology & Applications‟ as part of the BSc Hons Marine Biology degree at Plymouth. In this module, students discuss recent research papers in regular seminars, and keep a portfolio of critical evaluations of papers that they have studied. This subject is arguably one of the fastest moving fields in marine science and recent discoveries, made possible by the application of new techniques (especially metagenomics and rapid DNA sequencing) have revolutionized our understanding of ocean processes and the interactions of microbes with other marine life. Thus, students taking this module are encouraged to monitor the latest issues of journals and to select papers of their own choice, so that they gain an appreciation of the most recent advances. Students are provided with detailed advice on approaches to studying scientific literature and are given a te...

The Plymouth Student Scientist, 2009

Phytoplankton is the main driver of ocean net primary production (Falkowski et al., 1998) and a d... more Phytoplankton is the main driver of ocean net primary production (Falkowski et al., 1998) and a dominant force behind biogeochemical cycling in the ocean. It is a component of one of the oldest and best described virus-host relationships (e.g. Suttle et al., 1990). Viruses have typically been viewed as pathogens of marine organisms but it has become clear that they also play a critical role in biogeochemical processes in marine systems, themselves falling into the category of dissolved organic matter (DOM) (Wilhelm & Suttle, 1999). Viruses play a large part in carbon (Middelboe & Lyck, 2002), sulphur (Hill et al., 1998) and iron cycling (Poorvin et al., 2004) in the world‟s oceans. Earth‟s climate has warmed by approximately 0.6°C during the last 100 years. The rate of warming has doubled in the second half of the century (Houghton, 2001). This rapid change has been attributed to the impact of anthropogenic activities on the atmosphere. Climate change is already affecting marine eco...

Infection and Immunity, 1982

The ability of virulent strains of Aeromonas salmonicida to resist the bactericidal activity of s... more The ability of virulent strains of Aeromonas salmonicida to resist the bactericidal activity of serum was quantitated. The A. salmonicida strains tested included virulent strains, mutants lacking the major surface A-protein, and mutants lacking A-protein and having a modified lipopolysaccharide structure. The sera evaluated included normal human, rabbit, and trout sera, immune trout serum, and immune rabbit serum containing antibodies to A-protein and lipopolysaccharide. Virulent strains of A. salmonicida displayed high or intermediate resistance to the bactericidal activity of complement both in the presence and absence of specific antibody. In normal sera, both A-protein and lipopolysaccharide contributed to serum resistance. In immune trout serum, the protection was conferred by A-protein.

Infection and Immunity, 1985

Mutants of the bacterial fish pathogen Aeromonas salmonicida selected for inability to digest cas... more Mutants of the bacterial fish pathogen Aeromonas salmonicida selected for inability to digest casein concomitantly lost hemolytic activity against horse erythrocytes under certain conditions. Mixtures of wild-type with mutant culture supernatants indicated that mutants produce an inactive precursor of a hemolysin which was activated by autogenous caseinase and, with less efficiency, by other serine proteases. Selective inhibition or repression of caseinase production in the wild-type strain also resulted in the production of an inactive precursor of a hemolysin. The precursor of hemolysin was also activated by a serum factor which appeared to exert its maximum effect at the bacterial surface or after entry into the bacterial cell. These results could affect the interpretation of studies evaluating the role of individual extracellular products in the pathogenesis of A. salmonicida infections.

1. Microbes in the Marine Environment. 2. Methods in Marine Microbiology. 3. Structure of Marine ... more 1. Microbes in the Marine Environment. 2. Methods in Marine Microbiology. 3. Structure of Marine Prokaryotes. 4. Physiology of Marine Prokaryotes. 5. Marine Bacteria. 6. Marine Archaea. 7. Marine Eukaryotic Microbes. 8. Marine Viruses. 9. The Role of Microbes in Ocean Processes. 10. Symbiotic Associations. 11. Human Disease - Bacteria and Viruses. 12. Human Disease - Toxic Dinoflagellates Diatoms. 13. Diseases of Marine Mammals. 14. Microbial Diseases of Fish. 15. Diseases of Invertebrates. 16. Marine Microbes and Human Society. 17. Concluding Remarks.

The ISME Journal, 2016

Members of the marine genus Rhodopirellula are attached living bacteria and studies based on cult... more Members of the marine genus Rhodopirellula are attached living bacteria and studies based on cultured Rhodopirellula strains suggested that three closely related species R. baltica, 'R. europaea' and 'R. islandica' have a limited geographic distribution in Europe. To address this hypothesis, we developed a nested PCR for a single gene copy detection of a partial acetyl CoA synthetase (acsA) from intertidal sediments collected all around Europe. Furthermore, we performed growth experiments in a range of temperature, salinity and light conditions. A combination of Basic Local Alignment Search Tool (BLAST) and Minimum Entropy Decomposition (MED) was used to analyze the sequences with the aim to explore the geographical distribution of the species and subspecies. MED has been mainly used for the analysis of the 16S rRNA gene and here we propose a protocol for the analysis of protein-coding genes taking into account the degeneracy of the codons and a possible overestimation of functional diversity. The high-resolution analysis revealed differences in the intraspecies community structure in different geographic regions. However, we found all three species present in all regions sampled and in agreement with growth experiments we demonstrated that Rhodopirellula species do not have a limited geographic distribution in Europe.

Applied and Environmental Microbiology, 2016

Pervasive environmental stressors on coral reefs are attributed with shifting the competitive bal... more Pervasive environmental stressors on coral reefs are attributed with shifting the competitive balance in favor of alternative dominants, such as macroalgae. Previous studies have demonstrated that macroalgae compete with corals via a number of mechanisms, including the production of potent primary and secondary metabolites that can influence coral-associated microbial communities. The present study investigates the effects of the Pacific brown macroalga Lobophora sp. (due to the shifting nature of the Lobophora species complex, it will be referred to here as Lobophora sp.) on coral bacterial isolates, coral larvae, and the microbiome associated with the coral Porites cylindrica. Crude aqueous and organic macroalgal extracts were found to inhibit the growth of coral-associated bacteria. Extracts and fractions were also shown to inhibit coral larval settlement and cause mortality at concentrations lower (<0.3 mg · ml −1 ) than calculated natural concentrations (4.4 mg · ml −1 ). Mi...

The Plymouth Student Scientist, May 3, 2014

Marine organisms are well known to have associations with microorganisms and little is known abou... more Marine organisms are well known to have associations with microorganisms and little is known about the specific nature of the microorganism host interactions. This study investigates the bacterial community composition in the sea anemone Anemonia viridis using Denaturing Gradient Gel Electrophoresis; bacterial community composition was assessed for spatial variance. The results show that there was no significant variation within a location or between the locations. These results are concordant with previous studies and suggest that bacterial populations are stable in Anemonia viridis .

FEMS Microbiology Letters, 2015

Cultivation-independent identification of the diversity of carB genes in a sediment sample within... more Cultivation-independent identification of the diversity of carB genes in a sediment sample within the genus Rhodopirellula, a step towards a true identification of species numbers in natural samples.

Marine Genomics, 2015

The ´Rhodopirellula islandica´ strain K833 has a lower temperature range for growth than other 2 ... more The ´Rhodopirellula islandica´ strain K833 has a lower temperature range for growth than other 2 genome-sequenced Rhodopirellula baltica and ´Rhodopirellula europaea´ strains. The draft genome of K833 was obtained as part of a larger study on the biogeography of Rhodopirellula species in European marine waters. The genome consists of 70 contigs with a genome size of 7439654 bp. With an average nucleotide identity of XXX % to related genomes of Rhodopirellula baltica and ´Rhodopirellula europaea´, it will be a valuable source for the study of temperature adaptation of planctomycetes.

Virologica Sinica, 2013

The cosmopolitan calcifying alga Emiliania huxleyi is one of the most abundant bloom forming cocc... more The cosmopolitan calcifying alga Emiliania huxleyi is one of the most abundant bloom forming coccolithophore species in the oceans and plays an important role in global biogeochemical cycling. Coccolithoviruses are a major cause of coccolithophore bloom termination and have been studied in laboratory, mesocosm and open ocean studies. However, little is known about the dynamic interactions between the host and its viruses, and less is known about the natural diversity and role of functionally important genes within natural coccolithovirus communities. Here, we investigate the temporal and spatial distribution of coccolithoviruses by the use of molecular fingerprinting techniques PCR, DGGE and genomic sequencing. The natural biodiversity of the virus genes encoding the major capsid protein (MCP) and serine palmitoyltransferase (SPT) were analysed in samples obtained from the Atlantic Meridional Transect (AMT), the North Sea and the L4 site in the Western Channel Observatory. We discovered nine new coccolithovirus genotypes across the AMT and L4 site, with the majority of MCP sequences observed at the deep chlorophyll maximum layer of the sampled sites on the transect. We also found four new SPT gene variations in the North Sea and at L4. Their translated fragments and the full protein sequence of SPT from laboratory strains EhV-86 and EhV-99B1 were modelled and revealed that the theoretical fold differs among strains. Variation identified in the structural distance between the two domains of the SPT protein may have an impact on the catalytic capabilities of its active site. In summary, the combined use of 'standard' markers (i.e. MCP), in combination with metabolically relevant markers (i.e. SPT) are useful in the study of the phylogeny and functional biodiversity of coccolithoviruses, and can provide an interesting intracellular insight into the evolution of these viruses and their ability to infect and replicate within their algal hosts. Coccolithovirus; Major capsid protein; Serine palmitoyltransferase; Functional biodiversity Coccolithoviruses are a group of viruses that infect Emiliania huxleyi, a coccolithophorid alga with a global distribution in temperate and sub-temperate oceanic regions, and therefore play a crucial role in biogeochemical cycling and primary productivity (van Rijssel M, et al., 2002). So far coccolithoviruses have been studied in mesocosm systems (

The Plymouth Student Scientist, 2010

Bacteria are found in numerous habitats within the vast marine realm. Many marine bacteria live t... more Bacteria are found in numerous habitats within the vast marine realm. Many marine bacteria live together as a biofilm which allows them to closely interact and intimately influence each other"s lives, mainly by the production of extracellular compounds such as antibiotics and exopolysaccharides. Coordination of the biofilm and communication between bacteria is controlled by a mechanism known as quorum sensing in which signal molecules called autoinducers are released and detected, resulting in an alteration of behaviour. These activities ultimately have implications on other organisms; controlling populations of invertebrates and algae, and affecting the health of eukaryotes, a major cause for concern in coral reefs worldwide. This paper reviews the interactions amongst bacterial species and the mechanisms directing them. It briefly discusses their effect on eukaryotes and hints at the increasing importance of understanding interactions between coral associated bacteria, and the mechanisms of bacterial infection in corals.

Reviews in Fish Biology and Fisheries, 1993

Phytochemistry, 1975

Kievitone, a phytoalexin of cowpea, increases following treatment of hypocotyls with &Cl,, actino... more Kievitone, a phytoalexin of cowpea, increases following treatment of hypocotyls with &Cl,, actinomycin D, cycloheximide or UV-irradiation. Cellular browning accompanies this increase. Kievitone production is restricted to the regions containing necrotic cells, whereas phenylalanine ammonialyase (PAL) activity increases throughout the hypocotyl. Kievitone biosynthesis is unlikely to be regulated by control of PAL activity.

Microbiology, 1985

H-lysin from Aeromonas salmonicida has been purified 1770-fold by freeze fractionation, ammonium ... more H-lysin from Aeromonas salmonicida has been purified 1770-fold by freeze fractionation, ammonium sulphate precipitation, ion exchange chromatography and gel filtration chromatography. The purified material was predominantly H-lysin, devoid of detectable T-lysin, caseinase or gelatinase activity, although glycerophospholipid: cholesterol acyltransferase (GCAT) activity was present. The results suggested that H-lysin and GCAT activities were due to different extracellular products. Studies of the kinetics of haemolysis indicated that the H-lysin had an enzymic mode of action, and that initial erythrocyte damage appeared to precede lysis of the cell. The H-lysin was lethal to cultured rainbow trout gonad cells and leucocytes, but when it was injected intravenously in rainbow trout no pathological effects were observed.

Marine Pollution Bulletin, 2012

The impacts of ocean acidification on coastal biofilms are poorly understood. Carbon dioxide vent... more The impacts of ocean acidification on coastal biofilms are poorly understood. Carbon dioxide vent areas 23 provide an opportunity to make predictions about the impacts of ocean acidification. We compared bio-24 films that colonised glass slides in areas exposed to ambient and elevated levels of pCO 2 along a coastal 25 pH gradient, with biofilms grown at ambient and reduced light levels. Biofilm production was highest 26 under ambient light levels, but under both light regimes biofilm production was enhanced in seawater 27 with high pCO 2. Uronic acids are a component of biofilms and increased significantly with high pCO 2. Bac-28 teria and Eukarya denaturing gradient gel electrophoresis profile analysis showed clear differences in the 29 structures of ambient and reduced light biofilm communities, and biofilms grown at high pCO 2 compared 30 with ambient conditions. This study characterises biofilm response to natural seabed CO 2 seeps and pro-31 vides a baseline understanding of how coastal ecosystems may respond to increased pCO 2 levels. 32

FEMS Microbiology Letters, 1983

FEMS Microbiology Letters, 1984

The cell surface of strains of Aeromonas salmonicida possessing an additional surface protein (A-... more The cell surface of strains of Aeromonas salmonicida possessing an additional surface protein (A-protein) was shown to be more hydrophobic than strains devoid of this protein, using the techniques of phase partitioning, agglutination in the presence of ammonium sulphate and hydrophobic interaction chromatography.

Proceedings in Life Sciences, 1980

The Plymouth Student Scientist, 2009

This collection of articles features examples of coursework submitted by three students taking th... more This collection of articles features examples of coursework submitted by three students taking the module BIOL3309 „Marine Microbiology – Ecology & Applications‟ as part of the BSc Hons Marine Biology degree at Plymouth. In this module, students discuss recent research papers in regular seminars, and keep a portfolio of critical evaluations of papers that they have studied. This subject is arguably one of the fastest moving fields in marine science and recent discoveries, made possible by the application of new techniques (especially metagenomics and rapid DNA sequencing) have revolutionized our understanding of ocean processes and the interactions of microbes with other marine life. Thus, students taking this module are encouraged to monitor the latest issues of journals and to select papers of their own choice, so that they gain an appreciation of the most recent advances. Students are provided with detailed advice on approaches to studying scientific literature and are given a te...

The Plymouth Student Scientist, 2009

Phytoplankton is the main driver of ocean net primary production (Falkowski et al., 1998) and a d... more Phytoplankton is the main driver of ocean net primary production (Falkowski et al., 1998) and a dominant force behind biogeochemical cycling in the ocean. It is a component of one of the oldest and best described virus-host relationships (e.g. Suttle et al., 1990). Viruses have typically been viewed as pathogens of marine organisms but it has become clear that they also play a critical role in biogeochemical processes in marine systems, themselves falling into the category of dissolved organic matter (DOM) (Wilhelm & Suttle, 1999). Viruses play a large part in carbon (Middelboe & Lyck, 2002), sulphur (Hill et al., 1998) and iron cycling (Poorvin et al., 2004) in the world‟s oceans. Earth‟s climate has warmed by approximately 0.6°C during the last 100 years. The rate of warming has doubled in the second half of the century (Houghton, 2001). This rapid change has been attributed to the impact of anthropogenic activities on the atmosphere. Climate change is already affecting marine eco...

Infection and Immunity, 1982

The ability of virulent strains of Aeromonas salmonicida to resist the bactericidal activity of s... more The ability of virulent strains of Aeromonas salmonicida to resist the bactericidal activity of serum was quantitated. The A. salmonicida strains tested included virulent strains, mutants lacking the major surface A-protein, and mutants lacking A-protein and having a modified lipopolysaccharide structure. The sera evaluated included normal human, rabbit, and trout sera, immune trout serum, and immune rabbit serum containing antibodies to A-protein and lipopolysaccharide. Virulent strains of A. salmonicida displayed high or intermediate resistance to the bactericidal activity of complement both in the presence and absence of specific antibody. In normal sera, both A-protein and lipopolysaccharide contributed to serum resistance. In immune trout serum, the protection was conferred by A-protein.

Infection and Immunity, 1985

Mutants of the bacterial fish pathogen Aeromonas salmonicida selected for inability to digest cas... more Mutants of the bacterial fish pathogen Aeromonas salmonicida selected for inability to digest casein concomitantly lost hemolytic activity against horse erythrocytes under certain conditions. Mixtures of wild-type with mutant culture supernatants indicated that mutants produce an inactive precursor of a hemolysin which was activated by autogenous caseinase and, with less efficiency, by other serine proteases. Selective inhibition or repression of caseinase production in the wild-type strain also resulted in the production of an inactive precursor of a hemolysin. The precursor of hemolysin was also activated by a serum factor which appeared to exert its maximum effect at the bacterial surface or after entry into the bacterial cell. These results could affect the interpretation of studies evaluating the role of individual extracellular products in the pathogenesis of A. salmonicida infections.

1. Microbes in the Marine Environment. 2. Methods in Marine Microbiology. 3. Structure of Marine ... more 1. Microbes in the Marine Environment. 2. Methods in Marine Microbiology. 3. Structure of Marine Prokaryotes. 4. Physiology of Marine Prokaryotes. 5. Marine Bacteria. 6. Marine Archaea. 7. Marine Eukaryotic Microbes. 8. Marine Viruses. 9. The Role of Microbes in Ocean Processes. 10. Symbiotic Associations. 11. Human Disease - Bacteria and Viruses. 12. Human Disease - Toxic Dinoflagellates Diatoms. 13. Diseases of Marine Mammals. 14. Microbial Diseases of Fish. 15. Diseases of Invertebrates. 16. Marine Microbes and Human Society. 17. Concluding Remarks.

The ISME Journal, 2016

Members of the marine genus Rhodopirellula are attached living bacteria and studies based on cult... more Members of the marine genus Rhodopirellula are attached living bacteria and studies based on cultured Rhodopirellula strains suggested that three closely related species R. baltica, 'R. europaea' and 'R. islandica' have a limited geographic distribution in Europe. To address this hypothesis, we developed a nested PCR for a single gene copy detection of a partial acetyl CoA synthetase (acsA) from intertidal sediments collected all around Europe. Furthermore, we performed growth experiments in a range of temperature, salinity and light conditions. A combination of Basic Local Alignment Search Tool (BLAST) and Minimum Entropy Decomposition (MED) was used to analyze the sequences with the aim to explore the geographical distribution of the species and subspecies. MED has been mainly used for the analysis of the 16S rRNA gene and here we propose a protocol for the analysis of protein-coding genes taking into account the degeneracy of the codons and a possible overestimation of functional diversity. The high-resolution analysis revealed differences in the intraspecies community structure in different geographic regions. However, we found all three species present in all regions sampled and in agreement with growth experiments we demonstrated that Rhodopirellula species do not have a limited geographic distribution in Europe.

Applied and Environmental Microbiology, 2016

Pervasive environmental stressors on coral reefs are attributed with shifting the competitive bal... more Pervasive environmental stressors on coral reefs are attributed with shifting the competitive balance in favor of alternative dominants, such as macroalgae. Previous studies have demonstrated that macroalgae compete with corals via a number of mechanisms, including the production of potent primary and secondary metabolites that can influence coral-associated microbial communities. The present study investigates the effects of the Pacific brown macroalga Lobophora sp. (due to the shifting nature of the Lobophora species complex, it will be referred to here as Lobophora sp.) on coral bacterial isolates, coral larvae, and the microbiome associated with the coral Porites cylindrica. Crude aqueous and organic macroalgal extracts were found to inhibit the growth of coral-associated bacteria. Extracts and fractions were also shown to inhibit coral larval settlement and cause mortality at concentrations lower (<0.3 mg · ml −1 ) than calculated natural concentrations (4.4 mg · ml −1 ). Mi...

The Plymouth Student Scientist, May 3, 2014

Marine organisms are well known to have associations with microorganisms and little is known abou... more Marine organisms are well known to have associations with microorganisms and little is known about the specific nature of the microorganism host interactions. This study investigates the bacterial community composition in the sea anemone Anemonia viridis using Denaturing Gradient Gel Electrophoresis; bacterial community composition was assessed for spatial variance. The results show that there was no significant variation within a location or between the locations. These results are concordant with previous studies and suggest that bacterial populations are stable in Anemonia viridis .

FEMS Microbiology Letters, 2015

Cultivation-independent identification of the diversity of carB genes in a sediment sample within... more Cultivation-independent identification of the diversity of carB genes in a sediment sample within the genus Rhodopirellula, a step towards a true identification of species numbers in natural samples.

Marine Genomics, 2015

The ´Rhodopirellula islandica´ strain K833 has a lower temperature range for growth than other 2 ... more The ´Rhodopirellula islandica´ strain K833 has a lower temperature range for growth than other 2 genome-sequenced Rhodopirellula baltica and ´Rhodopirellula europaea´ strains. The draft genome of K833 was obtained as part of a larger study on the biogeography of Rhodopirellula species in European marine waters. The genome consists of 70 contigs with a genome size of 7439654 bp. With an average nucleotide identity of XXX % to related genomes of Rhodopirellula baltica and ´Rhodopirellula europaea´, it will be a valuable source for the study of temperature adaptation of planctomycetes.

Virologica Sinica, 2013

The cosmopolitan calcifying alga Emiliania huxleyi is one of the most abundant bloom forming cocc... more The cosmopolitan calcifying alga Emiliania huxleyi is one of the most abundant bloom forming coccolithophore species in the oceans and plays an important role in global biogeochemical cycling. Coccolithoviruses are a major cause of coccolithophore bloom termination and have been studied in laboratory, mesocosm and open ocean studies. However, little is known about the dynamic interactions between the host and its viruses, and less is known about the natural diversity and role of functionally important genes within natural coccolithovirus communities. Here, we investigate the temporal and spatial distribution of coccolithoviruses by the use of molecular fingerprinting techniques PCR, DGGE and genomic sequencing. The natural biodiversity of the virus genes encoding the major capsid protein (MCP) and serine palmitoyltransferase (SPT) were analysed in samples obtained from the Atlantic Meridional Transect (AMT), the North Sea and the L4 site in the Western Channel Observatory. We discovered nine new coccolithovirus genotypes across the AMT and L4 site, with the majority of MCP sequences observed at the deep chlorophyll maximum layer of the sampled sites on the transect. We also found four new SPT gene variations in the North Sea and at L4. Their translated fragments and the full protein sequence of SPT from laboratory strains EhV-86 and EhV-99B1 were modelled and revealed that the theoretical fold differs among strains. Variation identified in the structural distance between the two domains of the SPT protein may have an impact on the catalytic capabilities of its active site. In summary, the combined use of 'standard' markers (i.e. MCP), in combination with metabolically relevant markers (i.e. SPT) are useful in the study of the phylogeny and functional biodiversity of coccolithoviruses, and can provide an interesting intracellular insight into the evolution of these viruses and their ability to infect and replicate within their algal hosts. Coccolithovirus; Major capsid protein; Serine palmitoyltransferase; Functional biodiversity Coccolithoviruses are a group of viruses that infect Emiliania huxleyi, a coccolithophorid alga with a global distribution in temperate and sub-temperate oceanic regions, and therefore play a crucial role in biogeochemical cycling and primary productivity (van Rijssel M, et al., 2002). So far coccolithoviruses have been studied in mesocosm systems (

The Plymouth Student Scientist, 2010

Bacteria are found in numerous habitats within the vast marine realm. Many marine bacteria live t... more Bacteria are found in numerous habitats within the vast marine realm. Many marine bacteria live together as a biofilm which allows them to closely interact and intimately influence each other"s lives, mainly by the production of extracellular compounds such as antibiotics and exopolysaccharides. Coordination of the biofilm and communication between bacteria is controlled by a mechanism known as quorum sensing in which signal molecules called autoinducers are released and detected, resulting in an alteration of behaviour. These activities ultimately have implications on other organisms; controlling populations of invertebrates and algae, and affecting the health of eukaryotes, a major cause for concern in coral reefs worldwide. This paper reviews the interactions amongst bacterial species and the mechanisms directing them. It briefly discusses their effect on eukaryotes and hints at the increasing importance of understanding interactions between coral associated bacteria, and the mechanisms of bacterial infection in corals.

Reviews in Fish Biology and Fisheries, 1993

Phytochemistry, 1975

Kievitone, a phytoalexin of cowpea, increases following treatment of hypocotyls with &Cl,, actino... more Kievitone, a phytoalexin of cowpea, increases following treatment of hypocotyls with &Cl,, actinomycin D, cycloheximide or UV-irradiation. Cellular browning accompanies this increase. Kievitone production is restricted to the regions containing necrotic cells, whereas phenylalanine ammonialyase (PAL) activity increases throughout the hypocotyl. Kievitone biosynthesis is unlikely to be regulated by control of PAL activity.

Microbiology, 1985

H-lysin from Aeromonas salmonicida has been purified 1770-fold by freeze fractionation, ammonium ... more H-lysin from Aeromonas salmonicida has been purified 1770-fold by freeze fractionation, ammonium sulphate precipitation, ion exchange chromatography and gel filtration chromatography. The purified material was predominantly H-lysin, devoid of detectable T-lysin, caseinase or gelatinase activity, although glycerophospholipid: cholesterol acyltransferase (GCAT) activity was present. The results suggested that H-lysin and GCAT activities were due to different extracellular products. Studies of the kinetics of haemolysis indicated that the H-lysin had an enzymic mode of action, and that initial erythrocyte damage appeared to precede lysis of the cell. The H-lysin was lethal to cultured rainbow trout gonad cells and leucocytes, but when it was injected intravenously in rainbow trout no pathological effects were observed.

Marine Pollution Bulletin, 2012

The impacts of ocean acidification on coastal biofilms are poorly understood. Carbon dioxide vent... more The impacts of ocean acidification on coastal biofilms are poorly understood. Carbon dioxide vent areas 23 provide an opportunity to make predictions about the impacts of ocean acidification. We compared bio-24 films that colonised glass slides in areas exposed to ambient and elevated levels of pCO 2 along a coastal 25 pH gradient, with biofilms grown at ambient and reduced light levels. Biofilm production was highest 26 under ambient light levels, but under both light regimes biofilm production was enhanced in seawater 27 with high pCO 2. Uronic acids are a component of biofilms and increased significantly with high pCO 2. Bac-28 teria and Eukarya denaturing gradient gel electrophoresis profile analysis showed clear differences in the 29 structures of ambient and reduced light biofilm communities, and biofilms grown at high pCO 2 compared 30 with ambient conditions. This study characterises biofilm response to natural seabed CO 2 seeps and pro-31 vides a baseline understanding of how coastal ecosystems may respond to increased pCO 2 levels. 32

FEMS Microbiology Letters, 1983

FEMS Microbiology Letters, 1984

The cell surface of strains of Aeromonas salmonicida possessing an additional surface protein (A-... more The cell surface of strains of Aeromonas salmonicida possessing an additional surface protein (A-protein) was shown to be more hydrophobic than strains devoid of this protein, using the techniques of phase partitioning, agglutination in the presence of ammonium sulphate and hydrophobic interaction chromatography.