Determination of monocyclic and polycyclic aromatic hydrocarbons in fish tissue
No abstract available.
Journal of the Association of Official Analytical ↗
Geology topics
J.L. Zajicek
Publications and source records attributed to J.L. Zajicek.
Variations of thiaminase I activity pH dependencies among typical Great Lakes forage fish and Paenibacillus thiaminolyticus.
The source of thiaminase in the Great Lakes food web remains unknown. Biochemical characterization of the thiaminase I activities observed in forage fish was undertaken to provide insights into potential thiaminase sources and to optimize catalytic assay conditions. We measured the thiaminase I activities of crude extracts from five forage fish species and one strain of Paenibacillus thiaminolyticus over a range of pH values. The clupeids, alewife Alosa pseudoharengus and gizzard shad Dorosoma cepedianum, had very similar thiaminase I pH dependencies, with optimal activity ranges (> or = 90% of maximum activity) between pH 4.6 and 5.5. Rainbow smelt Osmerus mordax and spottail shiner Notropis hudsonius had optimal activity ranges between pH 5.5-6.6. The thiaminase I activity pH dependence profile of P. thiaminolyticus had an optimal activity range between pH 5.4 and 6.3, which was similar to the optimal range for rainbow smelt and spottail shiners. Incubation of P. thiaminolyticus extracts with extracts from bloater Coregonus hoyi (normally, bloaters have little or no detectable thiaminase I activity) did not significantly alter the pH dependence profile of P. thiaminolyticus-derived thiaminase I, such that it continued to resemble that of the rainbow smelt and spottail shiner, with an apparent optimal activity range between pH 5.7 and 6.6. These data are consistent with the hypothesis of a bacterial source for thiaminase I in the nonclupeid species of forage fish; however, the data also suggest different sources of thiaminase I enzymes in the clupeid species.
Journal of Aquatic Animal Health↗
Quantitative polymerase chain reaction (PCR) assays for a bacterial thiaminase I gene and the thiaminase-producing bacterium Paenibacillus thiaminolyticus.
The thiaminase I enzyme produced by the gram-positive bacterium Paenibacillus thiaminolyticus isolated from the viscera of Lake Michigan alewives Alosa pseudoharengus is currently the only defined source of the thiaminase activity linked to thiamine (vitamin B1) deficiency in early mortality syndrome (EMS) in the larvae of Great Lakes salmonines. Diets of alewife or isolated strains of P. thiaminolyticus mixed in a semipurified diet and fed to lake trout Salvelinus namaycush have been shown to produce EMS in fry. We utilized quantitative polymerase chain reaction (Q-PCR) to aid in studies of the sources of P. thiaminolyticus and thiaminase I. Quantitative PCR assays were established to detect the thiaminase I gene of P. thiaminolyticus, the 16S rRNA gene from most species of bacteria, and the 16S rRNA gene specifically from P. thiaminolyticus and a few closely related taxa. The Q-PCR assays are linear over at least six orders of magnitude and can detect the thiaminase I gene of P. thiaminolyticus from as few as 1,000 P. thiaminolyticus cells/g of sample or the Paenibacillus 16S rRNA gene from as few as 100 P. thiaminolyticus cells/g of sample. The initial results from alewife viscera samples with high thiaminase activity yielded unexpectedly low densities of P. thiaminolyticus cells; Paenibacillus thiaminolyticus was detectable in 2 of 6 alewife viscera tested at densities on the order of 100 cells/g out of 100,000,000 total bacterial cells/g. The low numbers of P. thiaminolyticus detected suggest that alewives contain additional non-P. thiaminolyticus sources of thiaminase activity.
Journal of Aquatic Animal Health↗
Dreissenid mussels from the Great Lakes contain elevated thiaminase activity
We examined thiaminase activity in dreissenid mussels collected at different depths and seasons, and from various locations in Lakes Michigan, Ontario, and Huron. Here we present evidence that two dreissenid mussel species (Dreissena bugensis and D. polymorpha) contain thiaminase activity that is 5-100 fold greater than observed in Great Lakes fishes. Thiaminase activity in zebra mussels ranged from 10,600 to 47,900??pmol g - 1 ??min - 1 and activities in quagga mussels ranged from 19,500 to 223,800??pmol g - 1 ??min - 1 . Activity in the mussels was greatest in spring, less in summer, and least in fall. Additionally, we observed greater thiaminase activity in dreissenid mussels collected at shallow depths compared to mussels collected at deeper depths. Dreissenids constitute a significant and previously unknown pool of thiaminase in the Great Lakes food web compared to other known sources of this thiamine (vitamin B 1 )-degrading enzyme. Thiaminase in forage fish of the Great Lakes has been causally linked to thiamine deficiency in salmonines. We currently do not know whether linkages exist between thiaminase activities observed in dreissenids and the thiaminase activities in higher trophic levels of the Great Lakes food web. However, the extreme thiaminase activities observed in dreissenids from the Great Lakes may represent a serious unanticipated negative effect of these exotic species on Great Lakes ecosystems.
Journal of Great Lakes Research↗
Thiamine and fatty acid content of walleye tissue from three southern U.S. reservoirs
We determined the thiamine concentration in egg, muscle, and liver tissues of walleyes Sander vitreus and the fatty acid content of walleye eggs from three southern U.S. reservoirs. In two Tennessee reservoirs (Dale Hollow and Center Hill), in which there were alewives Alosa pseudoharengus in the forage base, natural recruitment of walleyes was not occurring; by contrast in Lake James Reservoir, North Carolina, where there were no alewives, the walleye population was sustained via natural recruitment. Female walleye tissues were collected and assayed for thiamine (vitamin B1) and fatty acid content. Thiamine pyrophosphate was found to be the predominant form of thiamine in walleye eggs. In 2000, mean total egg thiamine concentrations were similar among Center Hill, Dale Hollow, and Lake James reservoirs (2.13, 3.14, and 2.77 nmol thiamine/g, respectively). Egg thiamine concentration increased as maternal muscle (r 2 = 0.73) and liver (r2 = 0.68) thiamine concentration increased. Walleye egg thiamine does not appear to be connected to poor natural reproduction in Tennessee walleyes. Threadfin shad Dorosoma petenense, which are found in all three reservoirs, had higher thiaminase activity than alewives. Six fatty acids differed among the walleye eggs for the three reservoirs. Two were physiologically important fatty acids, arachidonic acid (20:4[n-6]) and docosahexaenoic acid (22:6[n-3]), which are important eicosanoid precursors involved in the regulation of biological functions, such as immune response and reproduction. ?? Copyright by the American Fisheries Society 2007.
Journal of Aquatic Animal Health↗
Determination of PCBs in fish using enzyme-linked immunosorbent assay (ELISA)
Polychlorinated biphenyls (PCBs) were determined in fish tissue using an enzyme-linked immunosorbent assay (ELISA). Standard curves for Aroclor 1248, 1254, and 1260 in catfish tissue were developed with ranges from 0.05 to 0.5 ppm and 0.5 to 5.0 ppm. Wild fish were initially analyzed using gas chromatography/electron-capture detection (GC/ECD) and those having residues within the standard curve ranges were analyzed with ELISA. Results obtained using ELISA and GC/ECD were not significantly different (p < 0.05) from 0.05 to 0.5 ppm. From 0.5 to 5.0 ppm, the standard curve for Aroclor 1254 was the best predictor of total PCB in wild fish samples.
Journal of Food Science↗
Can diet-dependent factors help explain fish-to-fish variation in thiamine-dependent early mortality syndrome?
To provide insight into the reasons why offspring of certain salmonine females exhibit early mortality syndrome (EMS) in the Great Lakes whereas others do not, we measured the egg concentrations of potential biochemical markers (stable isotopes of nitrogen and carbon, fatty acid signatures, and lipid-soluble carotenoids and vitamins) that are indicative of differing food web and trophic structure. To corroborate the presence of EMS, we also measured the egg content of thiamine vitamers. For all the stocks of coho salmon Oncorhynchus kisutch and Chinook salmon O. tshawytscha we studied, there was a very high correspondence between EMS and low concentrations of unphosphorylated thiamine in unfertilized eggs. For salmonine stocks in the Platte River, Thompson Creek, and the Swan River, Michigan, small but significant shifts occurred in measures of egg carotenoids, retinoids, ??15N depletion, and fatty acid profiles of fish producing normal offspring relative to those exhibiting EMS. Egg thiamine concentrations in Chinook salmon from the Little Manistee River, Michigan, in the low-EMS group were only marginally above the threshold for EMS induction. Along with this small thiamine differential, there was no evidence of differing food web or dietary factors between EMS-positive and normal Chinook salmon from the Little Manistee River. Further investigations are required to determine the potential dietary sources for the observed differences in biochemical markers between EMS-positive and normal fish. These findings are generally consistent with the hypothesis that a more diverse forage base may help to limit overall dietary content of species that contain thiaminase, such as alewives Alosa pseudoharengus, and may lead to improved embryonic survival for feral salmonids. ?? Copyright by the American Fisheries Society 2005.
Journal of Aquatic Animal Health↗
Effect of sample handling on thiamine and thiaminolytic activity in alewife
Alewives Alosa pseudoharengus were collected to evaluate handling and processing conditions that may affect the measurement of their thiamine-thiaminase content. Fish were captured by otter trawl, and reference samples of live fish were quick-frozen on dry ice immediately following capture. Other samples were placed on wet ice (4??C) or held in ambient lake water (21.5??C) for periods of up to 5 h before freezing. Total thiamine levels for reference samples averaged 26 nmol/g and consisted of 66, 15, and 19% thiamine pyrophosphate (TPP), thiamine monophosphate (TMP), and unphosphorylated thiamine (Th), respectively. After 120 min at either 4??C or 21.5??C, total thiamine concentrations were lower. At 21.5??C, the TPP proportion had decreased by 30 min and the proportion as Th increased after 60 min. In the groups sampled after 5 h, total thiamine concentrations were not altered but the proportion of TPP was lower and that of Th was higher than in reference samples. The stability of thiamine in thawed muscle samples from previously frozen alewives was poor (40% loss by 1 h at 22??C and 30% loss by 2 h at 4??C). Thiaminase activity averaged 5,975 pmol??g wet weight -1??min-1 in reference samples. In fresh-caught alewives, thiaminase activities were remarkably consistent throughout the sampling period. At 4??C, thiaminase activity in muscle tissue from previously frozen alewives was stable for the entire investigation period. At 25??C, the activity initially increased by 40% after 60 min but then decreased to 50% of initial value after 5 h. We conclude that sampling times greater than 25 min could cause some changes in the various thiamine forms and net loss in total thiamine. The thiamine content in previously frozen alewife samples is highly labile, requiring low temperatures during processing for analysis. ?? Copyright by the American Fisheries Society 2005.
Journal of Aquatic Animal Health↗
Effectiveness of egg immersion in aqueous solutions of thiamine and thiamine analogs for reducing early mortality syndrome
Protocols used for therapeutic thiamine treatments in salmonine early mortality syndrome (EMS) were investigated in lake trout Salvelinus namaycush and coho salmon Oncorhynchus kisutch to assess their efficacy. At least 500 mg of thiamine HCl/L added to egg baths was required to produce a sustained elevation of thiamine content in lake trout eggs. Thiamine uptake from egg baths was not influenced by a pH ranging from 5.5 to 7.5 or by a water hardness between 2 and 200 mg CaCO3/L. There was poorer thiamine uptake when initial thiamine levels were low, suggesting that current treatment regimes may not be as effective when thiamine levels are severely depressed and that higher treatment doses are necessary. Exposure of eggs to the more lipid-soluble thiamine analog allithiamine (1,000 mg/L) during water hardening increased egg thiamine levels by 1.5-2.5 nmol/g and was completely effective at reversing EMS. Another more lipid-soluble thiamine analog, benfotiamine (100 mg/L), reduced EMS but did not produce detectable increases in egg thiamine content. Although benfotiamine may be more effective than thiamine at mitigating EMS, it is more expensive than thiamine HCl or allithiamine. In addition, there still needs to be a more thorough examination of dose-response relationships. We conclude that allithiamine is an alternative to the use of thiamine in egg baths as a therapeutic treatment for salmonid EMS. ?? Copyright by the American Fisheries Society 2005.
Journal of Aquatic Animal Health↗
Development of thiamine deficiencies and early mortality syndrome in lake trout by feeding experimental and feral fish diets containing thiaminase
We conducted a laboratory investigation on the consequences of feeding predatory salmonids either experimental diets low in thiamine or diets containing alewife Alosa pseudoharengus . In experiment 1, adult lake trout Salvelinus namaycush were fed experimental diets containing bacterial thiaminase. In experiment 2, adult lake trout were fed natural prey species, alewives, and bloaters Coregonus hoyi . The diets consisted of four combinations of alewives and bloaters from Lake Michigan (100% alewives, 65% alewives–35% bloaters, 35% alewives–65% bloaters, and 100% bloaters), alewives from Cayuga Lake, a casein bacterial thiaminase, and a commercial trout diet. We assessed the effects of each diet on egg thiamine concentration and incidence of an embryonic early mortality syndrome (EMS). In experiment 1, incidence of EMS ranged from 0% to 100%. Significant relationships were found between the incidence of EMS and thiamine. In experiment 2, adult lake trout fed 100% alewives from either Lake Michigan or Cayuga Lake or fish fed the casein bacterial thiaminase diet produced eggs with low thiamine and swim-up fry with EMS. At either 35% or 65% alewives in the diet, egg thiamine was significantly lowered. The number of females that produced offspring that died from EMS were low but demonstrated the negative potential if feral lake trout foraged on either 35% or 65% alewives. Depleted egg thiamine and the onset of EMS required diets containing thiaminase for a minimum of 2 years in lake trout initially fully thiamine replete. We conclude that EMS can be caused by extensive feeding on 100% alewives and dietary levels of 35% or greater may prove detrimental to sustainable reproduction of salmonids in the Great Lakes. The data are consistent with that observed in feral lake trout, and it is concluded that EMS is the result of a thiamine deficiency.
Journal of Aquatic Animal Health↗
Thiamine and thiaminase status in forage fish of salmonines from Lake Michigan
Dietary sources of thiamine (vitamin B 1 ) and thiamine-degrading enzymes (thiaminases) are thought to be primary factors in the development of thiamine deficiency among Great Lakes salmonines. We surveyed major forage fish species in Lake Michigan for their content of thiamine, thiamine vitamers, and thiaminase activity. Concentrations of total thiamine were similar ( P ≤ 0.05) among most forage fishes (alewife Alosa pseudoharengus , bloater Coregonus hoyi , spottail shiner Notropis hudsonius , deepwater sculpin Myoxocephalus thompsonii , yellow perch Perca flavescens , ninespine stickleback Pungitius pungitius , and round goby Neogobius melanostomus ) and slightly lower in rainbow smelt Osmerus mordax . Concentrations of total thiamine were all above the dietary requirements of coldwater fishes, suggesting the thiamine content of forage fish is not the critical factor in the development of thiamine deficiency in Lake Michigan salmonines. Thiamine pyrophosphate was the predominant form of thiamine in most species of forage fish, followed by free thiamine and thiamine monophosphate. Total thiamine was slightly greater in summer collections of alewife and rainbow smelt than in spring and fall collections, but the same was not true for bloater. Thiaminase activity varied among species and was greatest in gizzard shad Dorosoma cepedianum , spottail shiner, alewife, and rainbow smelt. Thiaminase activity in alewife varied among collection locations, season (greatest in spring), and size of the fish. Size and condition factors were positively correlated with both total thiamine and thiaminase activity in alewife. Thus, thiamine and thiaminase activity in forage fishes collected in Lake Michigan varied among species, seasons, year caught, and size (or condition). Therefore, multiple factors must be considered in the development of predictive models for the onset of thiamine deficiency in Great Lakes salmonines. Most importantly, thiaminase activity was great in alewives and rainbow smelt, suggesting that these prey fish are key causative factors of the thiamine deficiency in Great Lakes salmonines.
Journal of Aquatic Animal Health↗
Thiamine content and thiaminase activity of ten freshwater stocks and one marine stock of alewives
Alewives Alosa pseudoharengus contain thiaminase activity that has been implicated in the development of a thiamine deficiency and associated effects in salmonines of the Great Lakes basin. Little is known about the factors that regulate thiaminase activity in alewives. We sampled alewives of uniform size (60-120 mm) during the summer of 1998 from the Gulf of St. Lawrence, seven of New York's Finger Lakes, one inland lake in Ontario, and two Great Lakes to assess possible relationships among thiamine, lipid content, fish abundance, lake morphometry, lake productivity, freshwater residency, and thiaminase activity. Thiaminase activity varied significantly among the 11 locations but was unrelated to thiamine concentration, which did not vary significantly. Alewife thiaminase activity in the Finger Lakes was negatively related to lipid content and positively related to measures of lake size (e.g., area, volume, and maximum depth). Activity in the one marine stock sampled in the Gulf of St. Lawrence was comparable to the highest values observed in the 10 freshwater stocks examined. Variation in alewife thiaminase activity has the potential to affect the extent of a thiamine deficiency associated with salmonines who feed on alewives as well as the viability of their offspring.
Big Rideau Lake, Finger Lakes, Gulf of St. Lawrenc↗
Comparison of an enzyme-linked immunosorbent assay (ELISA) to gas chromatography (GC) - measurement of polychlorinated biphenyls (PCBs) in selected US fish extracts
The analysis of PCBs in fish tissues by immunoassay methods was evaluated using fish collected from a US monitoring program, the National Contaminant Biomonitoring Program of the US Department of Interior, Fish and Wildlife Service. Selected composite whole fish samples, which represented widely varying concentrations and sources of PCBs, were extracted and subjected to congener PCB analysis by gas chromatography (GC) and total PCB analysis using an ELISA (ePCBs) calibrated against technical Aroclor 1248. PCB congener patterns in these fishes were different from the patterns found in commercial Aroclors or their combinations as demonstrated by principal component analysis of normalized GC congener data. The sum of the PCB congeners measured by GC (total-PCBs) ranged from 37 to 4600 ng/g (wet weight). Concentrations of PCBs as determined by the ELISA method were positively correlated with total-PCBs and the ePCBs/total-PCBs ratios for individual samples ranged from 1 to 6. Ratios of ePCBs/total-PCBs for dilutions of Aroclors 1242, 1254, and 1260 and for matrix spikes range from 0.6 for 1242 to 2.5 for 1254 and 1260. These results suggest that higher chlorinated PCB congeners have higher affinity for the anti-PCB antibodies. Partial least squares with latent variable analysis of GC and ELISA data of selected Aroclors and fish samples also support the conclusion that ELISA derived PCB concentrations are dependent on the degree on chlorination.
Chemosphere↗
Thiamine status of Tennessee and Great Lakes walleye populations: Report on early mortality syndrome workshop
No abstract available at this time
Conference Paper↗
Chemical characterization of sediments and pore water from the upper Clark Fork River and Milltown Reservoir, Montana
The upper Clark Fork River basin in western Montana is widely contaminated by metals from past mining, milling, and smelting activities As part of a comprehensive ecological risk assessment for the upper Clark Fork River, we measured physical and chemical characteristics of surficial sediment samples that were collected from depositional zones for subsequent toxicity evaluations Sampling stations included five locations along the upper 200 km of the river, six locations in or near Milltown Reservoir (about 205 km from the river origin), and two tributary reference sites Concentrations of As, Cd, Cu, Mn, Pb, and Zn decreased from the upper stations to the downstream stations in the Clark Fork River but then increased in all Milltown Reservoir stations to levels similar to uppermost river stations Large percentages (50 to 90%) of the total Cd, Cu, Pb, and Zn were extractable by dilute (3 n) HCl for all samples Copper and zinc accounted for greater than 95% of extractable metals on a molar basis Acid-volatile sulfide (AVS) concentrations were typically moderate (0 6 to 23 μmol/g) in grab sediment samples and appeared to regulate dissolved (filterable) concentrations of Cd, Cu, and Zn in sediment pore waters Acid volatile sulfide is important in controlling metal solubility in the depositional areas of the Clark Fork River and should be monitored in any future studies Spatial variability within a sampling station was high for Cu, Zn, and AVS, therefore, the potential for toxicity to sediment dwelling organisms may be highly localized.
Environmental Toxicology and Chemistry↗