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31.
Identification of digestible carbohydrate sources for inclusion in formulated diets for juvenile spiny lobsters, Jasus edwardsii 总被引：1，自引：1，他引：0
Carbohydrates are a key ingredient in crustacean formulated diets because of their potential to greatly improve production efficiency. For the culture of spiny lobsters where daily food intake is limited, carbohydrates have the potential for delivering a low cost source of energy that could spare protein for growth. Therefore, the digestibility of different carbohydrate sources including refined sugars, mussel glycogen, algal polysaccharides, carboxymethyl cellulose (CMC) and starches (i.e., native, dextrinised, gelatinised) were assessed in juvenile spiny lobster (30–60 g). This was done by measuring the rate of carbohydrate hydrolysis in vitro using enzyme homogenates and postprandial haemolymph glucose concentrations following ingestion of semi-purified diets containing different carbohydrate levels and sources. Fresh mussel gonads and a practical formulated diet were also included for comparison. Storage polysaccharides (i.e., gelatinised starches, dextrin, mussel glycogen) and the structural polysaccharide CMC were the best digested carbohydrate sources in vitro. CMC was more digestible than the algal polysaccharides, agar and alginate, and therefore may have potential as a binding agent in formulated diets for J. edwardsii. The poor hydrolysis of sucrose and trehalose suggests that their use as an energy source might be limited in J. edwardsii. Native wheat starch was the best digested among the various plant starches tested. Gelatinisation of starches markedly improved their digestibility suggesting that pre-treatment of the dietary starch source would have a beneficial influence on the digestibility of diets for J. edwardsii. Consumption of the semi-purified diets (i.e., 1% BW) containing the digestible starch sources (i.e., 27% dry weight), as well as the practical diet, resulted in high haemolymph glucose concentrations (> 5 mmol l− 1) and a prolonged hyperglycaemic response (> 24 h) suggesting that these carbohydrate sources are well digested and absorbed, but possibly poorly utilised. In contrast, the fresh mussel gonad diet (i.e., 27% glycogen by dry weight) appeared to be better utilised (reduced glycaemia after 12 h). A lower inclusion level (i.e., 7%) of gelatinised maize starch reduced the peak (1.87 mmol l− 1) and extent (12 h) of the glycaemic response. Using lower inclusion levels (< 27%) of the rapidly digested starches (i.e., gelatinised, dextrinised) identified in this study, or incorporating digestible carbohydrate sources resulting in slower appearance of haemolymph glucose (i.e., native wheat starch, CMC), in formulated diets may have the potential to improve their utilisation for growth of juvenile spiny lobsters. 相似文献
32.
Van-Tuyen Le Samuel Bertrand Thibaut Robiou du Pont Fabrice Fleury Nathalie Caroff Sandra Bourgeade-Delmas Emmanuel Gentil Cedric Log Gregory Genta-Jouve Olivier Grovel 《Marine drugs》2021,19(7)
Very little is known about chemical interactions between fungi and their mollusc host within marine environments. Here, we investigated the metabolome of a Penicillium restrictum MMS417 strain isolated from the blue mussel Mytilus edulis collected on the Loire estuary, France. Following the OSMAC approach with the use of 14 culture media, the effect of salinity and of a mussel-derived medium on the metabolic expression were analysed using HPLC-UV/DAD-HRMS/MS. An untargeted metabolomics study was performed using principal component analysis (PCA), orthogonal projection to latent structure discriminant analysis (O-PLSDA) and molecular networking (MN). It highlighted some compounds belonging to sterols, macrolides and pyran-2-ones, which were specifically induced in marine conditions. In particular, a high chemical diversity of pyran-2-ones was found to be related to the presence of mussel extract in the culture medium. Mass spectrometry (MS)- and UV-guided purification resulted in the isolation of five new natural fungal pyran-2-one derivatives—5,6-dihydro-6S-hydroxymethyl-4-methoxy-2H-pyran-2-one (1), (6S, 1’R, 2’S)-LL-P880β (3), 5,6-dihydro-4-methoxy-6S-(1’S, 2’S-dihydroxy pent-3’(E)-enyl)-2H-pyran-2-one (4), 4-methoxy-6-(1’R, 2’S-dihydroxy pent-3’(E)-enyl)-2H-pyran-2-one (6) and 4-methoxy-2H-pyran-2-one (7)—together with the known (6S, 1’S, 2’S)-LL-P880β (2), (1’R, 2’S)-LL-P880γ (5), 5,6-dihydro-4-methoxy-2H-pyran-2-one (8), (6S, 1’S, 2’R)-LL-P880β (9), (6S, 1’S)-pestalotin (10), 1’R-dehydropestalotin (11) and 6-pentyl-4-methoxy-2H-pyran-2-one (12) from the mussel-derived culture medium extract. The structures of 1-12 were determined by 1D- and 2D-MMR experiments as well as high-resolution tandem MS, ECD and DP4 calculations. Some of these compounds were evaluated for their cytotoxic, antibacterial, antileishmanial and in-silico PTP1B inhibitory activities. These results illustrate the utility in using host-derived media for the discovery of new natural products. 相似文献
33.
Beaugrand J Gebruers K Ververken C Fierens E Dornez E Goddeeris BM Delcour JA Courtin CM 《Journal of agricultural and food chemistry》2007,55(19):7682-7688
To quantify Triticum aestivum xylanase inhibitor (TAXI) and xylanase inhibiting protein (XIP) type proteins in cereals in general and wheat ( T. aestivum) in particular, a robust enzyme-linked immunosorbent assay (ELISA) using an uncommon enzyme-antibody sandwich format was developed. Bacillus subtilis glycoside hydrolase family (GH) 11 and Aspergillus oryzae GH 10 xylanases were selected for coating ELISA plate wells to capture TAXI and XIP, respectively, prior to probing with antibodies. The detection threshold of the developed ELISA was much lower than that of the currently used xylanase inhibitor assay and the recently described Western blot approach. Because of its broad dynamic range (TAXI, 30-600 ng/mL, and XIP, 3-60 ng/mL), one proper standard extract dilution can be used for analyzing different wheat varieties, whereas for the currently used colorimetric assay, often different dilutions need to be analyzed. The TAXI ELISA for wheat was successfully adapted for barley ( Hordeum vulgare) and could also be used for other cereals. 相似文献
34.
Carlton JM Hirt RP Silva JC Delcher AL Schatz M Zhao Q Wortman JR Bidwell SL Alsmark UC Besteiro S Sicheritz-Ponten T Noel CJ Dacks JB Foster PG Simillion C Van de Peer Y Miranda-Saavedra D Barton GJ Westrop GD Müller S Dessi D Fiori PL Ren Q Paulsen I Zhang H Bastida-Corcuera FD Simoes-Barbosa A Brown MT Hayes RD Mukherjee M Okumura CY Schneider R Smith AJ Vanacova S Villalvazo M Haas BJ Pertea M Feldblyum TV Utterback TR Shu CL Osoegawa K de Jong PJ Hrdy I Horvathova L Zubacova Z Dolezal P 《Science (New York, N.Y.)》2007,315(5809):207-212
We describe the genome sequence of the protist Trichomonas vaginalis, a sexually transmitted human pathogen. Repeats and transposable elements comprise about two-thirds of the approximately 160-megabase genome, reflecting a recent massive expansion of genetic material. This expansion, in conjunction with the shaping of metabolic pathways that likely transpired through lateral gene transfer from bacteria, and amplification of specific gene families implicated in pathogenesis and phagocytosis of host proteins may exemplify adaptations of the parasite during its transition to a urogenital environment. The genome sequence predicts previously unknown functions for the hydrogenosome, which support a common evolutionary origin of this unusual organelle with mitochondria. 相似文献
35.
Determination of microbial community structures of shrimp floc cultures by biomarkers and analysis of floc amino acid profiles 总被引：1，自引：0，他引：1
Zhi Yong Ju Ian Forster Lytha Conquest Warren Dominy Wenhao Cedric Kuo & Floyd David Horgen 《Aquaculture Research》2008,39(2):118-133
Simple, rapid and reliable methods are required to monitor the microbial community change in aquatic pond for better animal performance. Four floc (suspended organic matter) samples were collected from outdoor raceways and tanks used for culturing Pacific white shrimp Litopenaeus vannamei. Twenty‐two chlorophyll (Chl) and carotenoid pigments were separated, identified and quantified using high‐performance liquid chromatography–ultraviolet/Vis‐mass spectrometry in the freeze‐dried floc samples. Algal community composition (diatoms, chlorophytes, cyanobacteria, dinoflagellates and cryptophytes) was determined by measuring concentrations of the respective taxonomic biomarkers (carotenoid fucoxanthin, lutein, zeaxanthin, peridinin and alloxanthin) as independent variables and Chl a as the dependent variable using a multiple regression model. This analysis found that the phytoplankton community of the floc samples from two groups of shrimp tanks (32 g L?1‐salinity) were diatom‐dominated (81.7% and 84.4%); and two floc samples from shrimp raceways (5 and 18 g L?1‐salinity) were chlorophyte‐dominated (75.4% and 82.3%). Assessment of total algal and bacterial biomass by quantification of Chl a and muramic acid, respectively, indicated that the 18 g L?1‐salinity raceway sample was bacteria‐dominated, whereas the other three floc samples were algae‐dominated. Sample protein quality was evaluated by its essential amino acid (AA) score and index. Arginine and lysine were found to be the two most limiting AAs for all floc samples. 相似文献
36.
We report on the in situ synthesis and stabilization of manganese dioxide (MnO2) onto four different silk yarns (mulberry, tasar, muga and eri silks). A new ultrasound-assisted procedure was used to reduce permanganate (MnO4 ?) and yielded MnO2 nanoparticles (NPs) on/in the different silk fibers. Using a factorial design we assessed the influence of the silk type, manganese precursor concentration, sonication time, and temperature. The results indicated no measurable effect of the process parameters on the silk structures, but significant correlation with the rate of degradation of methylene blue (MB) and the fraction of permanganate consumed. Further optimization of the factorial model identified the optimal process conditions for each silks: mulberry (150 min sonication, 20 mM permanganate), eri (360 min, 10 mM), tasar (150 min, 10 mM) and Muga (20 min, 10 mM). The operational stability (successive catalysis) of the optimum hybrids showed good performance over 5 cycles and most importantly reduced direct dye absorption relatively to dye oxidation. Overall, we found that all silks could template the formation and stabilization of different MnO2 polymorphs and yielded catalytic instead of stoichiometric hybrid fibers. 相似文献
37.
Eggshell matrix proteins as defense mechanism of avian eggs 总被引：1，自引：0，他引：1
This study focused on the role of eggshell matrix proteins as a function of potential natural antimicrobial defenses of avian eggs. The electrophoretic profile of SDS-PAGE showed that the soluble eggshell matrix proteins had three major bands of 15 000, 36 000, and 66 000 and several minor bands comprising 17 000, 25 000, 30 000, and 75 000, while insoluble matrix proteins were consisting of various bands comprising at least 16 distinct migration bands between 10 000 and 200 000. Three bacteria species, Pseudomonas aureginosa, Bacillus cereus, and Staphylococcus aureus, were found to be inhibited in the presence of soluble eggshell matrix proteins (100 microg/mL). On the other hand, Escherichia coli and Salmonella enteritidis were weakly inhibited at only an early stage of incubation time (up to 4 h). Scanning electron microscopy revealed that eggshell matrix proteins might interact and disrupt the membrane integrity of bacteria. The present study clearly indicated that avian eggshell matrix proteins possess a potential of novel antimicrobial defensin mechanism. 相似文献
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39.
Low feed consumption has been suggested as a major impediment for the development of effective formulated diets for spiny lobsters. To seek an explanation for the low feed consumption, this study compared the feed consumption, appetite revival, foregut evacuation and fecal production of different sizes of spiny lobster Jasus edwardsii juveniles fed a fresh natural diet (i.e. mussel flesh) and a dry formulated diet. In addition, the effect of feeding frequency was determined by feeding juvenile lobsters the same ration of formulated diet at different time intervals. i.e., same ration delivered 3 week− 1, 1 day− 1, 2 day− 1, 5 day− 1 and 5 night− 1. Lobster (10–15 g) growth and feed consumption (1.15% BW day− 1) was maximized when receiving a single ration daily of the formulated diet. A slow appetite revival (AR > 18 h) on the formulated diet was consistent with the negative effect of increasing feeding frequency on growth and consumption. In addition, there appeared to be no major advantage in dry matter intake by providing the nutrient dense dry formulated diet to Jasus edwardsii. Lobsters fed fresh mussel flesh (79.8% moisture) consumed similar levels of dry matter as those lobsters fed the dry formulated feed (7.3% moisture). This appears to be due to high moisture gain and expansion of the dry feed in the lobster foregut. Foregut evacuation lasted 10 h for the two diets but a delay in initial foregut evacuation and processing of the formulated diet was evident, and may have negatively affected feed consumption, appetite revival and dry matter digestibility (61.2%) of the dry formulated diet compared to the mussel flesh diet (89.2%). Appetite revival on mussel flesh was almost complete by 12 h after a satiation ration and was governed primarily by the rate of foregut evacuation. Differences in the timing of foregut evacuation and fecal production between the two diets suggested that a greater proportion of the formulated diet entered the midgut directly.The results indicate that J. edwardsii cannot achieve high levels of feed consumption on formulated diets because gut throughput is reduced due to a small foregut capacity, expansion of the feed post-ingestion, lengthy foregut filling time (1–2 h) and clearance time (10 h), combined with slow gut throughput time (34–42 h) and appetite revival (> 18 h). A slow appetite revival and difficulties in processing and digestion of formulated diets appear as major issues to be resolved to improve the performance of formulated diets required for the commercial aquaculture of J. edwardsii and possibly other spiny lobsters. 相似文献
40.
Barnabas Neba Nfornkah Tchamba Martin Louis Zapfack Djomo Chimi Cedric Mairong Nsakii Frederick Bonaventure Sonke 《Journal of Sustainable Forestry》2019,38(7):670-685
ABSTRACTForest Management Unit (FMU) is a growing phenomenon in Cameroon, impacting biodiversity negatively. This study was initiated to assess vascular epiphytes’ species loss on exploited trees to suggest conservation strategies. We hypothesized that: 1) epiphyte loss in this managed forest was significantly high and different with respect to phorophyte species; 2) epiphyte diversity loss has threatened status. Epiphyte survey was conducted on four most exploited trees in this study area. 63 exploited trees (Phorophytes) were surveyed. Shannon, Chao1 and Sorensen’s similarity indexes were used. Kruskal–wallis test was used to test the hypotheses. We recorded (70 epiphyte species, 33 genera and 12 families). Orchidaceae constituted highest epiphyte species with 43 species (61.4%). Epiphytes diversity was similar with respect to different phorophyte species (Sorensen?50%). Shannon’s index (3.36) showed a high epiphyte diversity loss. Kruskal–wallis showed no significant difference in epiphyte loss between phorophytes but a significant difference between zones, with canopies losing the highest epiphytes. With one epiphyte species’ status almost threatened and epiphyte diversity loss (significant); strict sustainable conservation methods like: epiphyte shade-houses and relocation are solicited. More data are needed from similar and different managed forest strata for epiphyte conservation policy enactment in Cameroon. 相似文献