Violi, JP, Mitrovic, SM, Colville, A, Main, BJ & Rodgers, KJ 2019, 'Prevalence of β-methylamino-L-alanine (BMAA) and its isomers in freshwater cyanobacteria isolated from eastern Australia.', Ecotoxicology and environmental safety, vol. 172, pp. 72-81.View/Download from: Publisher's site
Environmental exposure to the amino acid β-methylamino-L-alanine (BMAA) was linked to the high incidence of neurodegenerative disease first reported on the island of Guam in the 1940s and has more recently been implicated in an increased incidence of amyotrophic lateral sclerosis (ALS) in parts of the USA. BMAA has been shown to be produced by a range of cyanobacteria and some marine diatoms and dinoflagellates in different parts of the world. BMAA is commonly found with two of its constitutional isomers: 2,4- diaminobutyric acid (2,4-DAB) and N-(2-aminoethyl) glycine (AEG). These isomers are thought to be co-produced by the same organisms that produce BMAA and MS/MS analysis following LC separation can add an additional level of specificity over LC-FL. Although the presence of BMAA and 2,4-DAB in surface scum samples from several sites in Australia has been reported, which Australian cyanobacterial species are capable of BMAA, 2,4-DAB and AEG production remains unknown. The aims of the present studies were to identify some of the cyanobacterial genera or species that can produce BMAA, 2,4-DAB and AEG in freshwater cyanobacteria blooms in eastern Australia. Eleven freshwater sites were sampled and from these, 19 single-species cyanobacterial cultures were established. Amino acids were extracted from cyanobacterial cultures and analysed using liquid chromatography-tandem mass spectrometry. BMAA was detected in 17 of the 19 isolates, 2,4-DAB was detected in all isolates, and AEG was detected in 18 of the 19 isolates, showing the prevalence of these amino acids in Australian freshwater cyanobacteria. Concentrations of all three isomers in Australian cyanobacteria were generally higher than the concentrations reported elsewhere. This study confirmed the presence of BMAA and its isomers in cyanobacteria isolated from eastern Australian freshwater systems, and determined which Australian cyanobacterial genera or species were capable of producing them when cultured unde...
Violi, JP, Facey, JA, Mitrovic, SM, Colville, A & Rodgers, KJ 2019, 'Production of β-methylamino-L-alanine (BMAA) and Its Isomers by Freshwater Diatoms.', Toxins, vol. 11, no. 9.View/Download from: Publisher's site
β-methylamino-L-alanine (BMAA) is a non-protein amino acid that has been implicated as a risk factor for motor neurone disease (MND). BMAA is produced by a wide range of cyanobacteria globally and by a small number of marine diatoms. BMAA is commonly found with two of its constitutional isomers: 2,4-diaminobutyric acid (2,4-DAB), and N-(2-aminoethyl)glycine (AEG). The isomer 2,4-DAB, like BMAA, has neurotoxic properties. While many studies have shown BMAA production by cyanobacteria, few studies have looked at other algal groups. Several studies have shown BMAA production by marine diatoms; however, there are no studies examining freshwater diatoms. This study aimed to determine if some freshwater diatoms produced BMAA, and which diatom taxa are capable of BMAA, 2,4-DAB and AEG production. Five axenic diatom cultures were established from river and lake sites across eastern Australia. Cultures were harvested during the stationary growth phase and intracellular amino acids were extracted. Using liquid chromatography triple quadrupole mass spectrometry (LC-MS/MS), diatom extracts were analysed for the presence of both free and protein-associated BMAA, 2,4-DAB and AEG. Of the five diatom cultures analysed, four were found to have detectable BMAA and AEG, while 2,4-DAB was found in all cultures. These results show that BMAA production by diatoms is not confined to marine genera and that the prevalence of these non-protein amino acids in Australian freshwater environments cannot be solely attributed to cyanobacteria.
Gaw, S, Harford, A, Pettigrove, V, Sevicke-Jones, G, Manning, T, Ataria, J, Cresswell, T, Dafforn, KA, Leusch, FD, Moggridge, B, Cameron, M, Chapman, J, Coates, G, Colville, A, Death, C, Hageman, K, Hassell, K, Hoak, M, Gadd, J, Jolley, DF, Karami, A, Kotzakoulakis, K, Lim, R, McRae, N, Metzeling, L, Mooney, T, Myers, J, Pearson, A, Saaristo, M, Sharley, D, Stuthe, J, Sutherland, O, Thomas, O, Tremblay, L, Wood, W, Boxall, AB, Rudd, MA & Brooks, BW 2019, 'Towards Sustainable Environmental Quality: Priority Research Questions for the Australasian Region of Oceania.', Integrated environmental assessment and management, vol. 15, no. 6, pp. 917-935.View/Download from: Publisher's site
Environmental challenges persist across the world, including the Australasian region of Oceania, where biodiversity hotspots and unique ecosystems such as the Great Barrier Reef are common. These systems are routinely affected by multiple stressors from anthropogenic activities, and increasingly influenced by global megatrends (e.g., the food-energy-water nexus, demographic transitions to cities) and climate change. Here we report priority research questions from the Global Horizon Scanning Project, which aimed to identify, prioritize, and advance environmental quality research needs from an Australasian perspective, within a global context. We employed a transparent and inclusive process of soliciting key questions from Australasian members of the Society of Environmental Toxicology and Chemistry. Following submission of 78 questions, 20 priority research questions were identified during an expert workshop in Nelson, New Zealand. These research questions covered a range of issues of global relevance, including research needed to more closely integrate ecotoxicology and ecology for the protection of ecosystems, increase flexibility for prioritizing chemical substances currently in commerce, understand the impacts of complex mixtures and multiple stressors, and define environmental quality and ecosystem integrity of temporary waters. Some questions have specific relevance to Australasia, particularly the uncertainties associated with using toxicity data from exotic species to protect unique indigenous species. Several related priority questions deal with the theme of how widely international ecotoxicological data and databases can be applied to regional ecosystems. Other timely questions, which focus on improving predictive chemistry and toxicology tools and techniques, will be important to answer several of the priority questions identified here. Another important question raised was how to protect local cultural and social values and maintain indigenous engageme...
Scott, PD, Coleman, HM, Colville, A, Lim, R, Matthews, B, McDonald, JA, Miranda, A, Neale, PA, Nugegoda, D, Tremblay, LA & Leusch, FDL 2017, 'Assessing the potential for trace organic contaminants commonly found in Australian rivers to induce vitellogenin in the native rainbowfish (Melanotaenia fluviatilis) and the introduced mosquitofish (Gambusia holbrooki).', Aquatic Toxicology, vol. 185, pp. 105-120.View/Download from: Publisher's site
In Australia, trace organic contaminants (TrOCs) and endocrine active compounds (EACs) have been detected in rivers impacted by sewage effluent, urban stormwater, agricultural and industrial inputs. It is unclear whether these chemicals are at concentrations that can elicit endocrine disruption in Australian fish species. In this study, native rainbowfish (Melanotaenia fluviatilis) and introduced invasive (but prevalent) mosquitofish (Gambusia holbrooki) were exposed to the individual compounds atrazine, estrone, bisphenol A, propylparaben and pyrimethanil, and mixtures of compounds including hormones and personal care products, industrial compounds, and pesticides at environmentally relevant concentrations. Vitellogenin (Vtg) protein and liver Vtg mRNA induction were used to assess the estrogenic potential of these compounds. Vtg expression was significantly affected in both species exposed to estrone at concentrations that leave little margin for safety (p<0.001). Propylparaben caused a small but statistically significant 3× increase in Vtg protein levels (p=0.035) in rainbowfish but at a concentration 40× higher than that measured in the environment, therefore propylparaben poses a low risk of inducing endocrine disruption in fish. Mixtures of pesticides and a mixture of hormones, pharmaceuticals, industrial compounds and pesticides induced a small but statistically significant increase in plasma Vtg in rainbowfish, but did not affect mosquitofish Vtg protein or mRNA expression. These results suggest that estrogenic activity represents a low risk to fish in most Australian rivers monitored to-date except for some species of fish at the most polluted sites.
Mohammed Abdul, J, Colville, AE, Lim, RP, Vigneswaran, S & Kandasamy, JK 2012, 'Use of duckweed (Lemna disperma) to assess the phytotoxicity of the products of Fenton oxidation of metsulfuron methyl', Ecotoxicology And Environmental Safety, vol. 83, pp. 89-95.View/Download from: Publisher's site
Because of pressure on water supplies world-wide, there is increasing interest in methods of remediating contaminated ground waters. However, with some remediation processes, the breakdown products are more toxic than the original contaminant. Organic matter and salinity may also influence degradation efficiency. This study tested the efficiency of Fenton oxidation in degrading the sulfonylurea herbicide metsulfuron methyl (MeS), and tested the reaction products for phytotoxicity with the Lemna (duckweed) bioassay. The efficiency of degradation by Fentonâs reagent (Fe2Ã¾ Â¼0.09 mM; H2O2Â¼1.76mM, 4 h) decreased with increasing initial MeS concentration, from 98% with 5 mg/L MeS, to 63% with 70 mg/L MeS. Addition of NaCl (10 mM) and organic matter (humic acid at 0.2 and 2.0 mg C/L as Total Organic Carbon) reduced the efficiency of degradation at low initial MeS concentrations (5 and 10mg/L), but had no effect at high concentrations. The residual Fentonâs reagent after Fentonâs oxidation was toxic to Lemna. After removal of residual iron and H2O2, the measured toxicity to Lemna in the treated samples could be explained by the concentrations of MeS as measured by HPLC/UV detection, so there was no evidence of additional toxicity or amelioration due to the by-products or formulation materials.
Colville, AE, Jones, PM, Pablo, F, Krassoi, R, Hose, GC & Lim, RP 2008, 'Effects of chlorpyrifos on macroinvertebrate communities in coastal stream mesocosms', Ecotoxicology, vol. 17, no. 3, pp. 173-180.View/Download from: Publisher's site
This study measured the effects of a single pulse of chlorpyrifos at nominal concentrations of 1 and 10 mu g/l on the macroinvertebrate community structure of a coastal stream mesocosm system. Analysis of data using Principal Response Curves (PRC) and Monte Carlo tests showed significant changes in the treated stream mesocosms relative to that of the controls. These changes in the macroinvertebrate assemblages occurred within 6 h, and persisted for at least 124 days after dosing. Significant community-level effects were detected at the lowest concentration on days 2 and 16 post-dosing, giving a no-observed effect concentration (NOECcommunity) of 1.2 mu g/l (measured). The mayflies Atalophlebia sp. and Koorrnonga sp., Chironomidae and Acarina were all sensitive to chlorpyrifos and decreased in abundance in treated mesocosms after dosing. The fauna of these coastal stream mesocosms showed similar sensitivity to chlorpyrifos with that of other reported studies, but there was no evidence of recovery after 124 days.
Pablo, F, Krassoi, R, Jones, PR, Colville, AE, Hose, GC & Lim, RP 2008, 'Comparison of the fate and toxicity of chlorpyrifos - Laboratory versus a coastal mesocosm system', Ecotoxicology And Environmental Safety, vol. 71, no. 1, pp. 219-229.View/Download from: Publisher's site
The widespread use of chlorpyrifos for pest control in urban and rural environments poses a risk of contamination to aquatic environments via runoff, spray drift or spillage. The aim of this study was to assess the fate of chlorpyrifos and its toxicity t
Colville, AE & Lim, RP 2003, 'Microscopic structure of the mantle and palps in the freshwater mussels Velesunio ambigus and Hyridella depressa (Bivalvia : Hyriidae)', Mulluscan Research, vol. 23, pp. 1-20.View/Download from: Publisher's site
Burnstock, G, Campbell, G, Satchell, D & Smythe, A 1997, 'Evidence that adenosine triphosphate or a related nucleotide is the transmitter substance released by non-adrenergic inhibitory nerves in the gut', British Journal of Pharmacology, vol. 120, no. 4 SUPPL., pp. 337-357.
1. Stimulation of the vagal non-adrenergic inhibitory innervation caused the release of adenosine and inosine into vascular perfusates from the stomachs of guinea-pigs and toads. 2. Stimulation of portions of Auerbach's plexus isolated from turkey gizzard caused the release of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP). 3. ATP, added to solutions perfused through the toad stomach vasculature, was broken down to adenosine, inosine and adenine. 4. Of a series of purine and pyrimidine derivatives tested for inhibitory activity on the guinea-pig isolated taenia coli, ATP and ADP were the most potent. 5. ATP caused inhibition of twelve other gut preparations previously shown to contain non-adrenergic inhibitory nerves. The inhibitory action of ATP was not prevented by tetrodotoxin. 6. Quinidine antagonized relaxations of the guinea-pig taenia coli caused by catecholamines or adrenergic nerve stimulation. Higher concentrations of quinidine antagonized relaxations caused by ATP or non-adrenergic inhibitory nerve stimulation. 7. When tachyphylaxis to ATP had been produced in the rabbit ileum, there was a consistent depression of the responses to non-adrenergic inhibitory nerve stimulation but not of responses to adrenergic nerve stimulation. 8. It is suggested that ATP or a related nucleotide is the transmitter substance released by the non-adrenergic inhibitory innervation of the gut.
Sneddon, JD, Smythe, A, Satchell, D & Burnstock, G 1973, 'An investigation of the identity of the transmitter substance released by non adrenergic, non cholinergic excitatory nerves supplying the small intestine of some lower vertebrates', COMP.GEN.PHARM., vol. 4, no. 13, pp. 53-60.View/Download from: Publisher's site
Non adrenergic, non cholinergic excitatory postganglionic fibers in the splanchnic nerves supply the small intestine of the toad (Bufo marinus) and the lizard (Tiliqua rugosa). 5 Hydroxytryptamine, histamine, bradykinin, and prostaglandin E1 were rejected as the putative neurotransmitters in these nerves on the grounds that they do not have actions which parallel those of nerve stimulation or that drugs which antagonize their effects do not similarly antagonize the effects of nerve stimulation. ATP produces excitatory responses, which closely mimic those of non adrenergic, non cholinergic nerve stimulation. Quinidine causes parallel block of the responses to nerve stimulation and exogenously applied ATP, but this action may be non specific. While the results do not provide direct evidence for purinergic excitatory nerves to the small intestine of lower vertebrates, they are consistent with the hypothesis.
BURNSTOCK, G, SMYTHE, A & DUMSDAY, B 1972, 'ATROPINE RESISTANT EXCITATION OF URINARY-BLADDER - POSSIBILITY OF TRANSMISSION VIA NERVES RELEASING A PURINE NUCLEOTIDE', BRITISH JOURNAL OF PHARMACOLOGY, vol. 44, no. 3, pp. 451-+.View/Download from: Publisher's site
BURNSTOCK, G, SMYTHE, A & SATCHELL, DG 1972, 'COMPARISON OF EXCITATORY AND INHIBITORY EFFECTS OF NON-ADRENERGIC, NON-CHOLINERGIC NERVE-STIMULATION AND EXOGENOUSLY APPLIED ATP ON A VARIETY OF SMOOTH MUSCLE PREPARATIONS FROM DIFFERENT VERTEBRATE SPECIES', BRITISH JOURNAL OF PHARMACOLOGY, vol. 46, no. 2, pp. 234-+.View/Download from: Publisher's site