ORCID Profile
0000-0001-7427-7510
Current Organisations
Logifish Consulting
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University of Adelaide
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Publisher: Wiley
Date: 13-10-2017
Publisher: Wiley
Date: 05-1989
Publisher: Elsevier BV
Date: 10-2004
DOI: 10.1016/J.CBPC.2004.06.016
Abstract: This paper describes the development and validation of a competitive, polyclonal antibody enzyme-immunoassay (EIA) for the measurement of salmon and trout insulin-like growth factor-II (IGF-II). A polyclonal antiserum was raised against a synthetic peptide epitope, corresponding to amino acid residues 1-9 of the N-terminus of mature Atlantic salmon (Salmo salar) IGF-II. The antiserum was purified by hydrophobic charge induction chromatography (HCIC). The partially purified immunoglobulins were used in an enzyme-immunoassay system (EIA) resulting in a highly specific assay for salmon IGF-II with cross-reactivity of less than 0.01% for recombinant salmon IGF-I and recombinant salmon growth hormone (GH), and 5.57% for salmon insulin (sIns). The recombinant salmon IGF-II (rsIGF-II) standard curve limit of detection was 1.37 ng/ml with an EC(50) of 44.97+/-0.82 ng/ml. Intra- and interassay coefficients of variation were determined at 7.47% (n=15) and 7.42% (n=15), respectively. Added rsIGF-II was adequately recovered from acid-treated Atlantic salmon and rainbow trout (Oncorhynchus mykiss) plasma s les. Parallel dose-response inhibition curves were demonstrated for the plasma of both fish species tested. Circulating IGF-II levels of 22.26+/-2.66 and 18.24+/-1.43 ng/ml were determined for acid-treated plasma of normal adult Atlantic salmon and rainbow trout, respectively. This EIA should prove to be useful in the study of factors which influence circulating plasma levels of IGF-II in these fish species.
Publisher: Wiley
Date: 08-2002
Publisher: Wiley
Date: 07-1993
Publisher: Elsevier BV
Date: 10-2006
DOI: 10.1016/J.CBPA.2006.06.010
Abstract: The effects of aquaculture related stressors on circulating levels of GH, IGF-I and for the first time, IGF-II in Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) were investigated. Specifically, circulating growth factor levels were measured in four different experiments. Two 24 h confinement stressor procedures, (one with Atlantic salmon, the other with rainbow trout) following a hypo-osmotic stressor (freshwater bath) in salt water acclimated, adult, Atlantic salmon and during a 22 day starvation and re-feeding protocol with juvenile Atlantic salmon. Handling and confinement resulted in significant decreases in circulating levels of all three growth factors in Atlantic salmon, and IGF-I and IGF-II (but not GH) in rainbow trout. A 2-3 h freshwater bath to remove gill parasites on a commercial Atlantic salmon aquaculture operation caused a significant decrease in circulating GH and IGF-I concentrations, but no significant change in IGF-II concentration, 2 days post bathing. Starvation for a period of 15 days in Atlantic salmon resulted in a significant increase in circulating GH levels and a significant decrease in circulating IGF-I and IGF-II. Re-feeding of starved fish for 7 days resulted in a significant decrease in GH to the concentration measured in continually fed fish, however re-feeding did not change plasma levels of IGF-I and IGF-II relative to continually starved fish. The results presented here confirm previously observed handling and confinement stressor induced effects on GH and IGF-I and, for the first time, on IGF-II in salmonids. Furthermore this study confirms the nutritional regulation of GH, IGF-I and IGF-II in juvenile Atlantic salmon.
Publisher: Hindawi Limited
Date: 10-03-2011
Publisher: Elsevier BV
Date: 11-1987
DOI: 10.1016/0016-6480(87)90036-0
Abstract: Chronic confinement for 1 month caused a significant elevation of plasma cortisol but suppressed the levels of plasma testosterone and 11-ketotestosterone in sexually mature male brown trout. An acute handling stress for 1 hr elevated blood cortisol and ACTH levels and also suppressed circulating androgens. This androgen suppression in response to acute stress was accompanied by an elevation of plasma gonadotropin levels. These findings are discussed in relation to stress-induced suppression of reproductive function in mammals and the possible biological consequences of such a suppression in fish are outlined.
Publisher: Elsevier BV
Date: 1997
DOI: 10.1016/S0739-7240(96)00095-1
Abstract: A remote infusion and blood collection device (Dracpac) was used on free-ranging red deer stags to deliver i.v. a range of ACTH1-24 doses and collect blood for cortisol determination. In Experiment 1, conducted in September, saline and 1, 4, and 16 IU ACTH/100 kg bodyweight were infused (n = 5-7 per treatment). In Experiment 2 (November), 16 and 64 IU ACTH/100 kg were infused (n = 5 per treatment) and the response of animals to restraint was also assessed (n = 6). Pre-infusion concentrations of plasma cortisol were low (mean 6.5 +/- 1.0 ng/ml), and unaffected by infusion of saline. ACTH significantly elevated plasma cortisol concentrations, with mean peak concentrations occurring 20-40 min postinfusion. Duration of the response was dose dependent, ranging from 80-160 min. With increasing doses of ACTH, maximal peak heights plateaued at approximately 40 and 60 ng/ml in September and November, respectively whereas the areas under the curves tended to increase. The minimum dose of ACTH that resulted in a maximal peak cortisol response was 4 IU. The maximum peak height of the cortisol response to 16 IU tended to be higher (P < 0.10) in November compared with September, suggesting that adrenal responsiveness may change over this period. The adrenal response to a 16-IU ACTH challenge in Experiment 2 resulted in similar plasma cortisol concentrations to an acute stress event (restraint). Four IU/100 kg ACTH i.v. is recommended as an appropriate dose for ACTH infusion studies in red deer stags. When used in conjunction with the Dracpac technique, it becomes a stress-free, repeatable procedure for assessing aspects of adrenal cortex physiology in free-ranging deer.
Publisher: Science Alert
Date: 15-10-2017
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.APPET.2017.03.038
Abstract: There has been a decline in the consumption of potatoes in developed countries worldwide due to many factors including the introduction of new foods and meal trends. In turn, this shift in eating patterns has dramatically affected the Australian potato industry which represents the largest horticulture contributor to gross food revenue. Many factors may influence consumers' food preferences, including the in idual's nutrition knowledge, lifestyle factors, personal preferences, attitudes and beliefs. The present study aimed to capture an understanding of the consumer's level of nutritional knowledge and what currently drives consumer decision making. Participants aged between 25 and 54 years responded to an online survey which included 52 questions specifically looking at potatoes, nutritional knowledge, views, eating habits and lifestyle factors, preferences and beliefs. Questions in the survey included multiple choice, rank and scale responses and free answers. A total of 1208 males and females (males n = 598, females n = 610) were included in the final analysis. The results show that the majority (88.5%) of the participants consume potatoes (not including hot chips/french fries) 4 times per week or less (41.6% ≤ 1 week 46.9% 2-4 times/week). Overall, 33% of the participants stated that their potato consumption over the last five years had decreased. The main reasons stated for this decrease were that potatoes were high in carbohydrates (30%) and that starchy vegetables were not a healthy option (23%). Results showed that consumers believe that potatoes are good for all ages, are versatile, convenient, good value for money and delicious. However, the results indicate the majority of people have limited knowledge regarding the nutrient composition of potatoes and associate them negatively with carbohydrates.
Publisher: Elsevier BV
Date: 10-2007
Publisher: Elsevier BV
Date: 03-1990
DOI: 10.1016/0016-6480(90)90230-J
Abstract: In a series of experiments, the effect of cortisol on the ability of rainbow trout (Salmo gairdneri) ovarian follicles to secrete sex steroids in vitro was investigated. The basal rate of secretion of sex steroids (oestradiol and testosterone) was suppressed in a dose-dependent manner by the addition of cortisol to the incubation medium. This suppression was evident using physiological levels of cortisol (less than 100 ng ml-1). The possibility of elevated plasma cortisol levels (due to stress) reducing the reproductive ability of sexually maturing female trout through a direct effect of cortisol on the ovary is discussed.
Publisher: MDPI AG
Date: 25-12-2020
DOI: 10.3390/NU12010061
Abstract: High amylose wheat (HAW) has a higher resistant starch content and lower glycaemic index than standard amylose wheat (SAW), which may be associated with health benefits. This study aimed to determine the effects of replacing SAW with HAW on metabolic and reproductive parameters in male and female mice. Male and female C57BL/6 mice were randomly ided into groups (n = 8/group/sex) and fed either a SAW65 (65% SAW w/w control), HAW35 (35% HAW w/w), HAW50 (50% HAW w/w) or HAW65 (65% HAW w/w) diet for eight weeks. In male but not female, the HAW65 group had a lower abdominal circumference, relative total fat mass, relative gonadal fat mass and plasma leptin concentration compared to the HAW35 group. There were no differences in fasting blood glucose concentrations or plasma concentrations of cholesterol, triglycerides or non-esterified fatty acids between groups in either males or females. The HAW-fed males had a higher testicular weight and HAW-fed females spent less time in diestrus and a longer time in metestrus compared to the SAW-fed mice. Higher dietary intake of HAW appears to reduce abdominal fat deposition compared to the lower level of HAW in a sexually dimorphic manner. The impacts on reproductive parameters in the HAW-fed mice require further investigation.
Publisher: Elsevier BV
Date: 02-2004
DOI: 10.1016/J.YGCEN.2003.10.002
Abstract: This paper describes the development and validation of a commercially available radioimmunoassay (RIA) for the detection of fish insulin-like growth factor-I (IGF-I). The assay was developed using recombinant barramundi IGF-I as antigen and recombinant tuna IGF-I as radiolabelled tracer and standard. Assay sensitivity was 0.15 ng/ml, inter-assay variation was 16% (n = 9) and intra-assay variation was 3% (n = 10). Cross reactivity of less than 0.01% was found with salmon insulin, salmon IGF-II and barramundi IGF-II, less than 0.5% with human IGF-I and less than 1% with human IGF-II. Parallel dose-response inhibition curves were shown for barramundi (Lates calcarifer), coho salmon (Oncorhynchus kisutch), Southern Bluefin tuna (Thunnus maccoyii), tilapia (Oreochromis mossambicus), and seabream (Pagrus auratus) IGF-I. The assay was then used to measure stress related changes in different aquacultured fish species. Salt water acclimated Atlantic salmon smolts (Salmo salar) bathed for 2 h in fresh water showed significantly lower IGF-I concentrations than control smolts two days after the bath (53.1 compared to 32.1 ng/ml), with levels of IGF-I also lower in smolts exhibiting stunted growth (stunts). Capture and confinement of wild tuna in sea-cages resulted in a significant decrease in IGF-I levels (28 ng/ml) when compared to tuna captured and s led immediately (48 ng/ml), but had recovered to starting levels after 3 weeks (43 ng/ml). Handling and isolation in silver perch (Bidyanus bidyanus) led to a gradual decline in IGF-I over a 12 h period (36-19 ng/ml) but showed signs of recovery by 24 h (24 ng/ml) and had recovered fully 72 h after treatment (40 ng/ml). A similar trial in black bream (Acanthopagrus butcherii) showed comparable results with IGF-I levels gradually decreasing (40-26 ng/ml) over 24 h, results that were mirrored by cortisol concentrations which increased during this time (1-26 ng/ml). In the studies presented here changes in IGF-I levels were not observed for at least 3 h after exposure to the stressor. We suggest this is due to the endocrine nature of IGF-I regulation and the clearance rate of IGF-I in vivo.
Publisher: Elsevier BV
Date: 1992
Publisher: Elsevier BV
Date: 11-1989
DOI: 10.1016/0016-6480(89)90163-9
Abstract: Implantation of a cortisol-releasing pellet (60 mg kg-1 fish) into the peritoneal cavity of brown trout, Salmo trutta L. (sexually maturing males and females), and rainbow trout, Salmo gairdneri Richardson (maturing males and immature fish of both sexes), significantly elevated their plasma cortisol level. At 18 days postimplantation, cortisol-implanted sexually maturing male brown trout had smaller gonads, a lower plasma testosterone level, and less gonadotropin in their pituitary gland than control fish. Plasma levels of 11-ketotestosterone and gonadotropin were not significantly affected. Cortisol-implanted sexually maturing female brown trout had smaller gonads, reduced plasma levels of 17 beta-oestradiol, testosterone, and vitellogenin, and a lower pituitary gland gonadotropin content than control fish. The plasma gonadotropin level was unaffected. At 36 days post-implantation, cortisol treatment of maturing male rainbow trout significantly suppressed plasma gonadotropin levels. Plasma levels of testosterone, 11-ketotestosterone, and 17 alpha,20 beta-dihydroxy-4-pregnen-3-one, pituitary gonadotropin content, and gonad size were not significantly affected. In sexually immature female rainbow trout, cortisol administration suppressed the level of vitellogenin in the plasma, compared to control-implanted fish. The 17 beta-oestradiol level was not affected. Cortisol implantation did not affect the plasma testosterone level in sexually immature male trout. These results suggest that prolonged elevation of plasma cortisol, to levels well within physiological range, can affect a wide range of reproductive parameters in both brown and rainbow trout. Further, some effects are manifest in immature as well as in mature fish. These findings are discussed in relation to the effects of cortisol treatment on the state of health of the treated fish.
Publisher: Elsevier BV
Date: 02-1992
Publisher: Elsevier BV
Date: 02-1993
Publisher: Elsevier BV
Date: 1997
Publisher: Springer Science and Business Media LLC
Date: 19-08-2016
Publisher: Elsevier BV
Date: 1991
Publisher: Informa UK Limited
Date: 13-04-2017
DOI: 10.1080/00071668.2017.1293798
Abstract: 1. This study aimed to determine the minimal duration required for feeding male broilers (Cobb 500) with a flaxseed oil diet while still retaining long chain omega-3 polyunsaturated fatty acid (n-3 LCPUFA) accumulation in the meat at a desirable level. 2. Three groups of broilers (60 each) were fed on a 3% flaxseed oil (high α-linolenic acid (ALA)) diet for either 6, 4 or 2 weeks prior to slaughter. During the remaining time they were maintained on a 3% macadamia oil (low ALA) diet. A fourth group (control, n = 60) was fed on a commercial diet for 6 weeks. 3. No significant difference was observed in growth performance of broilers between groups. The amounts of total n-3 and n-3 LCPUFA in breast and thigh meat were not different between broilers fed the flaxseed oil diet for 4 and 6 weeks, but they were lower (P < 0.001) in those fed the flaxseed diet for only 2 weeks. 4. These results suggest comparable levels of n-3 LCPUFA in the meat can be achieved by only feeding the flaxseed oil diet in the last 3-4 weeks of the growth period this would result in a ≥ 9.4% reduction in the use of flaxseed oil compared to 6 weeks of feeding thereby reducing the cost of the enrichment process.
Publisher: Elsevier BV
Date: 11-2007
Publisher: Elsevier BV
Date: 07-2013
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/AN14743
Abstract: We have previously demonstrated that feeding chickens a diet containing high levels of the n-3 PUFA α-linolenic acid (ALA) significantly increases the content of the principal omega-3 long-chain polyunsaturated fatty acids, eicosapentaenoic acid and docosahexaenoic acid, in their meat and eggs. However, the effect of the diet on production characteristics of the birds has not been assessed. This study aimed to determine the effect of feeding male and female Cobb 500 broilers (n = 3840) a high ALA diet (containing 2.5% flaxseed oil) compared with a standard commercial Control diet (containing 2.5% tallow) on growth, feed conversion ratio and mortality until 6 weeks of age. As expected the dietary flaxseed oil significantly increased breast meat levels of omega-3 polyunsaturated fatty acids (~4-fold), with most eicosapentaenoic acid and docosahexaenoic acid being deposited in the phospholipid fraction. Both male and female birds fed the high ALA diet were significantly heavier at 6 weeks of age (77 g heavier in females, 87 g heavier in males). They also had a significantly (10%) lower feed conversion ratio, and a mortality rate that was not different from the Control diet across the 6-week feeding period. These findings indicate that a high ALA diet has the potential to enrich chicken breast meat with eicosapentaenoic acid and docosahexaenoic acid without loss of growth rate or feed efficiency, or increase in fat content of breast meat.
Publisher: Informa UK Limited
Date: 29-10-2019
Publisher: Hindawi Limited
Date: 13-10-2016
DOI: 10.1111/ARE.12617
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/AN16268
Abstract: Manipulation of the fatty acid composition of chicken feed has been shown to be effective for improving the nutritional value of chicken products. Currently, however, evaluation of the effectiveness of this approach requires invasive blood s ling or post mortem tissue s ling of the birds. Preen oil can be collected non-invasively from live birds. So this study aimed to test the hypothesis that the fatty acid composition of preen oil reflects that of the blood. Male and female meat chickens (Cobb 500) were fed a diet supplemented with 4% (w/w) flaxseed oil (high n-3 polyunsaturates) or beef tallow (mostly monounsaturates and saturates) for 6 weeks. Preen oil and whole blood s les (n = 9 birds per sex/diet treatment group) were collected freshly post mortem for fatty acid analysis. Preen oil analysis showed that ~97% of fatty acids were saturates, with a small percentage of n-6 polyunsaturates and traces of other types. There were negligible n-3 polyunsaturates in preen oil. Proportions of some saturated fatty acids were slightly, but significantly, affected by diet (C16:0 (P 0.05) and C17:0 (P 0.01)) or by gender (C10:0 and C18:0) (P 0.05). Some fatty acids with odd numbers of carbon atoms (e.g. C17:0 and C19:0) were found in relatively high concentrations in preen oil, despite not being detectable in either the diet or blood. In conclusion, the fatty acid composition of preen oil does not accurately reflect the fatty acid profile of the blood it is not, therefore, a suitable alternative for determining fatty acid status of meat chickens.
Publisher: Springer Science and Business Media LLC
Date: 1999
Publisher: Elsevier BV
Date: 1994
Publisher: Elsevier BV
Date: 06-2004
Publisher: Elsevier BV
Date: 07-1991
DOI: 10.1016/0016-6480(91)90109-J
Abstract: Two experiments, one using 0+ the other 1+ rainbow trout, were conducted to investigate the effect of prolonged starvation on plasma growth hormone levels. The results from both experiments were essentially the same. As expected, starvation resulted in cessation of growth and in a lower coefficient of condition, whereas fed fish continued to grow and remained in good condition. Starvation had relatively little effect on the plasma cortisol level in one experiment levels were elevated temporarily in starved fish, although by the end of the experiment there was no longer any difference between starved and fed fish, and in the other experiment plasma cortisol levels remained very low throughout the course of the experiment in both starved and fed fish. In contrast, in both experiments starvation had a pronounced effect on the plasma growth hormone level, which rose steadily during both experiments, such that it was six times higher after 1 month of starvation in 0+ fish, and five times higher after 6 weeks of starvation in 1+ fish. Thus, paradoxically, fed fish had very low plasma growth hormone levels and grew rapidly, whereas starved fish had elevated plasma growth hormone levels but did not grow. In both experiments a strong negative correlation was observed between the plasma growth hormone level and the coefficient of condition of the fish. The results are discussed with regard to the well-established metabolic changes that occur during starvation, and it is suggested that a major role of growth hormone during starvation is to aid in the mobilisation of fatty acids and glycerol from adipose stores.
Publisher: Elsevier BV
Date: 07-1991
DOI: 10.1016/0016-6480(91)90108-I
Abstract: The acute stress of handling followed by confinement for a period of 1 or 24 hr caused a typical stress response in rainbow trout (elevation of plasma ACTH and cortisol) and a significant reduction in the concentration of circulating growth hormone. The chronic stress of low oxygen levels in both crowded and uncrowded tanks of fish caused a significant elevation of circulating GH levels, an effect which was abolished by the provision of additional aeration to the rearing tanks. This chronic elevation of GH levels was closely correlated with an elevation of plasma cortisol in the same fish. These findings are discussed in relation to stress-induced growth suppression and to the links between the hypothalamic-pituitary-interrenal axis and somatotrope activity.
Publisher: Elsevier BV
Date: 06-2004
Publisher: Cambridge University Press (CUP)
Date: 12-04-2017
DOI: 10.1017/S2040174417000216
Abstract: The content of omega-3 long-chain polyunsaturated fatty acids ( n −3 LCPUFA) in chicken meat can be boosted by feeding broilers a diet containing α-linolenic acid (ALA, from flaxseed oil), some of which is converted by hepatic enzymes to n −3 LCPUFA. However, most of the accumulated n −3 polyunsaturated fatty acid (PUFA) in meat tissues is still in the form of ALA. Despite this, the levels of chicken diets are being enhanced by the inclusion of vegetable and marine sources of omega-3 fats. This study investigated whether the capacity of chicken for n −3 LCPUFA accumulation could be enhanced or inhibited by exposure to an increased supply of ALA or n −3 LCPUFA in ovo . Breeder hens were fed either flaxseed oil (High-ALA), fish oil (high n −3 LCPUFA) or tallow- (low n −3 PUFA, Control) based diets. The newly hatched chicks in each group were fed either the High-ALA or the Control diets until harvest at 42 days’ post-hatch. The n −3 PUFA content of egg yolk and day-old chick meat closely matched the n −3 PUFA composition of the maternal diet. In contrast, the n −3 PUFA composition of breast and leg meat tissues of the 42-day-old offspring closely matched the diet fed post-hatch, with no significant effect of maternal diet. Indeed, there was an inhibition of n −3 LCPUFA accumulation in meat of the broilers from the maternal Fish-Oil diet group when fed the post-hatch High-ALA diet. Therefore, this approach is not valid to elevate n -3 LCPUFA in chicken meat.
Publisher: Elsevier BV
Date: 07-1991
DOI: 10.1016/0016-6480(91)90107-H
Abstract: This study describes the development of a highly specific and very sensitive radioimmunoassay for salmonid growth hormone. Antiserum raised against chinook (Oncorhynchus tshawytscha) GH2, which did not recognize 125I-sPRL and 125I-sGTH (at 1:1000 initial dilution), was able to inhibit growth when injected into rainbow trout (Oncorhynchus mykiss). 125I-sGH2, used as tracer, was not recognized by anti-sGTH or by anti-sPRL. Mammalian GH and ACTH and salmonid GTH, TSH, and PRL did not cross-react in the sGH assay. The inhibition curves for pituitary extracts and plasma from salmonids were parallel to the salmon GH standard, whereas those from carp, tilapia, and catfish showed no significant cross reactivity. The RIA ED90 and ED50 values were 0.2 and 1.5 ng/ml, respectively. Using this RIA for measuring GH release by cultured pituitary cell we observed a strong inhibiting effect of SRIF (10(-6) M) and a stimulatory effect of hGRF (10(-6) M). This RIA allowed us also to detect daily fluctuations in the plasma GH concentration in cannulated rainbow trout.
Publisher: Hindawi Limited
Date: 31-01-2003
Publisher: CSIRO Publishing
Date: 1995
DOI: 10.1071/MF9951201
Abstract: Territorial male demoiselles (Chromis dispilus) engaged in egg brooding and defence were hand-netted from nest sites by ers and injected in situ with either des-Gly10 (D-Ala6) luteinizing-hormone-releasing hormone ethylamide (LHRHA), human chorionic gonadotrophin (hCG), 17α,20β- dihydroxy-4-pregnen-3-one (17,20βP), testosterone (T), or 11-ketotestosterone (11KT) in order to examine the effect of elevated plasma steroid concentrations on the transition from brooding to spawning display behaviour (when plasma concentrations of steroids are typically elevated). Blood s les were analysed for 17,20βP, T, and 11KT by radioimmunoassay. The effect of egg presence on behaviour was assessed by removing the eggs from the nests of some fish. Underwater injections with hCG, LHRHA or gonadal steroids all resulted in increases in plasma 17,20βP, T and 11KT concentrations but did not stimulate the transition from brooding to display behaviour. Egg removal resulted in vacation of the territory by most fish within 24 h. There was no evidence of transition from brooding to display behaviour during the period after egg removal over which fish remained at the nest. The results indicate that bioactive gonadotrophin-releasing hormone, gonadotrophin or gonadal steroids alone do not stimulate the transition from brooding to display and spawning behaviour in male demoiselles. Egg presence has a marked effect on the strength of association with the nest, but loss of eggs did not trigger the onset of display behaviour. It seems likely that a combination of events, including elevation of plasma concentrations of gonadal steroids and egg loss (hatching), stimulates the transition from brooding to display behaviour.
Publisher: Elsevier BV
Date: 04-2014
Abstract: This study aimed to assess bacterial spoilage of half shell Pacific and Sydney rock oysters during storage using microbial culture and 16S rRNA pyrosequencing. Odour and pH of oyster meats were also investigated. Estimation of microbiological counts by microbial culture highlighted growth of psychrotrophic bacteria. During storage, odour scores (a score describing deterioration of fresh odours where a score of 1 is fresh and 4 is completely spoiled) increased from 1.0 to 3.0 for Pacific oysters and from 1.3 to 3.4 for Sydney rock oysters. pH results obtained for both species fluctuated during storage (range 6.28-6.73) with an overall increase at end of storage. Pyrosequencing revealed that the majority of bacteria at Day 0 represented taxa from amongst the Proteobacteria, Tenericutes and Spirochaetes that have not been cultured and systematically described. During storage, Proteobacteria became abundant with Pseudoalteromonas and Vibrio found to be dominant in both oyster species at Day 7. Analysis of the pyrosequencing data showed significant differences in bacterial profiles between oyster species and storage time (both P = 0.001). As oysters spoiled, bacterial profiles between oyster species became more similar indicating a common spoilage profile. Data presented here provides detailed insight into the changing bacterial profile of shucked oysters during storage and has identified two genera, Pseudoalteromonas and Vibrio, as being important in spoilage of shucked oysters.
Location: Australia
Location: United Kingdom of Great Britain and Northern Ireland
Location: Australia
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for John Carragher.