Molecular Approaches to Assist the Screening and Monitoring of Postharvest Biocontrol Yeasts     

Leonardo Schena  Antonio Ippolito  Tirtza Zahavi  Lea Cohen  Samir Droby 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(7):681-691

Nineteen yeast isolates obtained from the surface of several fruits and vegetables grown in Southern Italy and Israel were compared by molecular analysis using arbitrarily primed polymerase chain reaction (AP-PCR) and random amplified polymorphic DNA technique (RAPD-PCR). Genetic analysis made it possible to distinguish between closely-related genitically different strains which had the same morphological characteristic, and to discard isolates which were genetically identical. Following PCR characterisation, 6 isolates were selected and tested for their biocontrol activity against major postharvest pathogens (Penicillium digitatum on grapefruit, Botrytis cinerea, Rhizopus stolonifer and Aspergillus niger on table grape and B. cinerea and R. stolonifer on cherry tomato). All the isolates showed a good biocontrol efficacy on both wounded and non-wounded fruits. Furthermore, the preharvest application of the most effective antagonist (LS15) on table grape resulted in a significant reduction in grey mold ranging from 28.3% to 38.2% compared to the untreated control. The RAPD-PCR technique was also useful for identifying and monitoring the survival of the antagonist after field application.  相似文献   

Use of L4 larvae of Nippostrongylus brasiliensis for the in vivo screening of anthelmintic drugs.          下载免费PDF全文

L Domínguez  J Salda?a  J Chernin 《Canadian journal of veterinary research》2000,64(3):160-163

Five groups of Wistar rats were subcutaneously infected with 5,000 L3 stage larvae of Nippostrongylus brasiliensis. Four groups were dosed orally with 5, 10, 15, and 20 mg/kg body weight of albendazole at 5 h postinfection, and one group served as an untreated control. The animals were euthanized and the intestines were dissected out 72 h postinfection and were incubated on a Baermann's apparatus to recover L4 stage larvae. No larvae were recovered from the 20 mg/kg albendazole-treated group, and means of 15, 33, and 175 L4 larvae were recovered from the 15, 10, and 5 mg/kg albendazole-treated groups, respectively. Levamisole and fenbendazole were also tested using the same procedure. Means of 100 and 1,887 L4 larvae were obtained from the 50 and 10 mg/kg of levamisole-treated groups respectively; while, 191 and 583 L4 larvae were recovered from rats treated with 50 and 10 mg/kg of fenbendazole, respectively. These results indicate that the L4 stage of N. brasiliensis could be useful for in vivo screening of new nematocide drugs.  相似文献   

Contribution of Major Ingredients during Baking of Biscuit Dough Systems   总被引：1，自引：0，他引：1  

S. Chevallier  P. Colonna  G. Della Valle  D. Lourdin 《Journal of Cereal Science》2000,31(3):241

Nineteen dough systems were made of a combination of two to nine of the following ingredients: flour, water, fats (coconut and/or palm oils), sugars (sucrose, invert) and chemical leaveners (ammonium bicarbonate, sodium bicarbonate, citric acid and sodium acid pyrophosphate). Their thermal behaviour was studied over a large temperature scale (20 °C to 160 °C). Thermal analysis of baking by three different methods (DSC, DMTA and TGA) at the same heating rate (3 °C/min) provided information about phase transitions, volume and mass changes of doughs during heating. Temperature ranges over which all ingredients reacted were identified. Melting transitions of fats occurred between 10 °C and 50 °C. Sugars increase temperatures of starch transitions. Chemical leaveners decrease rise temperature, whereas fats and sugars have a delaying effect on their action. The texture of biscuits results from interactions between ingredients; complete dough cannot thus be considered as merely a simple addition of all components.  相似文献   

Two epizootic Perkinsus spp. events in commercial oyster farms at Santa Catarina,Brazil     

Ana C. Luz Cunha  Vitor de A. Pontinha  Maria Alcina M. de Castro  Simone Sühnel  Sthefanie C. Medeiros  ngela M. Moura da Luz  Ricardo Harakava  Leonardo Tachibana  Danielle F. Mello  Naissa M. Danielli  Alcir L. Dafre  Aimê R. M. Magalhes  Jos Luiz P. Mourio 《Journal of fish diseases》2019,42(3):455-463

Perkinsus spp. have been detected in various bivalve species from north‐east Brazil. Santa Catarina is a South Brasil state with the highest national oyster production. Considering the pathogenicity of some Perkinsus spp., a study was carried out to survey perkinsosis in two oyster species cultured in this State, the mangrove oyster Crassostrea gasar and the Pacific oyster Crassostrea gigas. Sampling involved eight sites along the state coast, and oyster sampling was collected during the period between January 2013 and December 2014. For the detection of Perkinsus, Ray's fluid thioglycollate medium (RFTM) and histology were used, and for the identification of the species, PCR and DNA sequencing were used. Perkinsus spp. was found by RFTM in C. gigas and C. gasar from São Francisco do Sul. This pathology was also detected in C. gasar from Balneário Barra do Sul both, by RFTM and histology. Perkinsus marinus was identified in C. gigas and C. gasar from São Francisco do Sul and Perkinsus beihaiensis in C. gasar from Balneário Barra do Sul. This is the first report of P. marinus in C. gigas from South America. Results of this preliminary study suggest that both oyster species tolerate the species of Perkinsus identified, without suffering heavy lesions.  相似文献   

A general model of temporary aquatic habitat use: Water phenology as a life history filter     

Kurt C. Heim  Thomas E. McMahon  Leonardo Calle  Mark S. Wipfli  Jeffrey A. Falke 《Fish and Fisheries》2019,20(4):802-816

Temporary aquatic habitats are not widely appreciated fish habitat. However, fish navigate the transient waters of intertidal zones, floodplains, intermittent and ephemeral streams, lake margins, seasonally frozen lakes and streams, and anthropogenic aquatic habitats across the globe to access important resources. The selective pressures imposed by water impermanence (i.e., freezing, drying, tidal fluctuations), however, operate similarly across taxa and ecosystems. These similarities are formalized into a conceptual model relating habitat use to surface water phenology. Whereas all necessary life history functions (spawning, foraging, refuge, and dispersal) can be accomplished in temporary habitats, the timing, duration, and predictability of water act as a “life history filter” to which habitats can be used and for what purpose. Habitats wet from minutes to months may all be important—albeit in different ways, for different species. If life history needs co‐occur with accessibility, temporary habitats can contribute substantially to individual fitness, overall production and important metapopulation processes. This heuristic is intended to promote research, recognition and conservation of these frequently overlooked habitats that can be disproportionately important relative to their size or brevity of existence. There is a pressing need to quantify how use of temporary aquatic habitats translates to individual fitness benefits, population size and temporal stability, and ecosystem‐level consequences. Temporary aquatic habitats are being impacted at an alarming rate by anthropogenic activities altering their existence, phenology, and connectivity. It is timely that scientists, managers and policymakers consider the role these habitats play in global fish production.  相似文献   

Thermal preference,tolerance, and thermal aerobic scope in clownfish Amphiprion ocellaris (Cuvier, 1830) predict its aquaculture potential across tropical regions     

Gabriela Velasco-Blanco  Ana Denise Re  Fernando D&#;az  Leonardo Ibarra-Castro  Maria Isabel Abdo-de la Parra  Luz Estela Rodr&#;guez-Ibarra  Carlos Rosas 《International Aquatic Research》2019,11(2):187-197

The clownfish Amphiprion ocellaris is widely distributed in the coral reef ecosystems of tropical and subtropical regions of the West Indo Pacific, an area that hosts economically valuable species, and, thus, a suitable candidate for warm water aquaculture. This study determined the preferred temperature, critical threshold limits, represented by critical thermal maximum and critical thermal minimum, thermal window width, and aerobic metabolic scope of A. ocellaris clownfish acclimated to 20, 23, 26, 29, 32, and 35 °C. A positive response (P < 0.05) occurred when the preferred temperature significantly increased with increasing acclimation temperature. The preferred temperature obtained graphically was 30.0 °C. Acclimation temperature significantly affected the thermal tolerance which increased with acclimation temperature. The thermal window calculated for A. ocellaris was 301.5 °C2. The thermal metabolic scope obtained in animals acclimated at the interval from 23 to 32 °C (P > 0.05) had a mean value of 4240.8 mg O2 h−1 kg−1 w.w., revealing that A. ocellaris is a eurythermal species with a range of optimal physiological performance that closely matches the environmental conditions where it can be farmed. Therefore, the highest value of the thermal aerobic scopes corresponded to the intervals of the preferred temperature obtained for A. ocellaris. These results may partially explain their worldwide distribution pattern, as well as their aquaculture potential in tropical regions.  相似文献   

The control of floating macrophytes by grass carp in net cages: experiments in two tropical hydroelectric reservoirs          下载免费PDF全文

Fernando D Domingues  Fernando L R M Starling  Clarice C Nova  Bruna R Loureiro  Leonardo C e Souza  Christina W C Branco 《Aquaculture Research》2017,48(7):3356-3368

The efficiency of grass carp (Ctenopharyngodon idella Val.) for biological control of floating aquatic macrophytes in net cages was assessed in two eutrophic tropical hydroelectric reservoirs through experiments using three macrophyte species (Eichhornia crassipes, Pistia stratiotes and Salvinia auriculata). A total of twenty experiments were performed in these reservoirs with a duration period between 21 and 30 days, during distinct seasons of the year. Sets of experiments were conducted using the three macrophyte species simultaneously in both reservoirs, and additional experiments were performed in one reservoir involving the separate use of each species. All macrophytes demonstrated significant growth in the absence of fish with total per day biomass increase rate ranging from 0.06 to 17.00%. The presence of grass carp significantly reduced macrophyte biomass in both reservoirs independent of fish size, stocking rate and available cage space. In all seasons, grass carp grazing pressure was higher for S. auriculata and lower for P. stratiotes. The results show that grass carp in net cages was able to use aquatic macrophytes as the only food source, controlling massive plant growth (especially S. auriculata and E. crassipes). Fish cages, already implemented in several reservoirs in Brazil, are easily manageable units at relatively low cost. Thus, biocontrol of macrophytes using caged grass carp is proposed as an effective low‐budget ecotechnological tool to control consumable plants while avoiding the removal of desirable aquatic vegetation and the resultant impact on local fauna.  相似文献   

GnRHa‐induced Multiple Spawns and Volition Spawning of Captive Spotted Rose Snapper,Lutjanus guttatus,at Mazatlan,Mexico     

Leonardo Ibarra‐Castro  Luis Alvarez‐Lajonchère 《Journal of the World Aquaculture Society》2011,42(4):564-574

Sexual maturation and induced spawning treatments were carried out with captive spotted rose snapper, Lutjanus guttatus. A total of 3013 × 10⁶ eggs (64.7% were floating) were produced from eight treated females in 42 spawns induced with GnRHa implants during the course of the present study. GnRHa ethylene‐vinyl acetate copolymer effective doses were 204 ± 11 µg/kg in June 2005, and 224 ± 13 µg/kg in July 2005. General fertilization was 50.9 ± 34.5% and 12–14 h after spawning, viability of floating eggs was 90.4 ± 12.4%. Mean incubation period at 29–31 C was 18–20 h, and mean hatching was 94.4 ± 8.2% (73–100%). Newly hatched larvae were 2.18 ± 0.15 mm in total length (TL). One month after the last hormone experiment, previously GnRHa‐treated and untreated fish began spawning voluntarily. Hormone‐treated breeders had higher fecundity than untreated fish, producing 72.5 million eggs versus 13.9 million eggs for the untreated fish, over the following 11 mo. Combined data of volitional spawning for total egg fertilization, viability, hatching, and larval TL were 77.7 ± 1.8%, 90.3 ± 1.3%, 87.9 ± 2%, and 2.50 ± 0.12 mm, respectively. These results can ensure the sustainability of a commercial hatchery.  相似文献   

Exploring Chemical Diversity of Phorbas Sponges as a Source of Novel Lead Compounds in Drug Discovery     

Alessia Caso  Fernanda Barbosa da Silva  Germana Esposito  Roberta Teta  Gerardo Della Sala  Laura P. A. Nunes Cavalcanti  Alessandra Leda Valverde  Roberto Carlos C. Martins  Valeria Costantino 《Marine drugs》2021,19(12)

Porifera, commonly referred to as marine sponges, are acknowledged as major producers of marine natural products (MNPs). Sponges of the genus Phorbas have attracted much attention over the years. They are widespread in all continents, and several structurally unique compounds have been identified from this species. Terpenes, mainly sesterterpenoids, are the major secondary metabolites isolated from Phorbas species, even though several alkaloids and steroids have also been reported. Many of these compounds have presented interesting biological activities. Particularly, Phorbas sponges have been demonstrated to be a source of cytotoxic metabolites. In addition, MNPs exhibiting cytostatic, antimicrobial, and anti-inflammatory activities have been isolated and structurally characterized. This review provides an overview of almost 130 secondary metabolites from Phorbas sponges and their biological activities, and it covers the literature since the first study published in 1993 until November 2021, including approximately 60 records. The synthetic routes to the most interesting compounds are briefly outlined.  相似文献   

Soil microbiome biomass,activity, composition and CO2 emissions in a long-term organic and conventional farming systems     

Margherita Santoni  Leonardo Verdi  Shamina Imran Pathan  Marco Napoli  Anna Dalla Marta  Francesca Romana Dani  Gaio Cesare Pacini  Maria Teresa Ceccherini 《Soil Use and Management》2023,39(1):588-605

The implementation of environmentally friendly agricultural policies has increased the need to compare agricultural aspects of conventional (CON) and organic farming (ORG) systems. The objective of the present work was to compare the effects of an organic and conventional long-term experiment on bacterial and fungal biomass and activity, as well as soil CO₂ emission and readily available nitrogen forms in a soil cultivated with Helianthus annuus L. The microbial biomass was more active and abundant in ORG as well as soil CO₂ emission. Despite being less abundant, fungi were more active than bacteria in both ORG and CON experiments. 16S rRNA gene sequencing showed that the ORG treatment had a significantly greater bacterial richness than CON. Cyanobacteria, Actinobacteria and Proteobacteria were the most abundant phyla contributing more than others to the differences between the two systems. Moreover, the soil ${\mathit{NH}}_4^{+}$ and ${\mathit{NO}}_2^{-}$ content was not significantly different between ORG and CON, while ${\mathit{NO}}_3^{-}$ was less in ORG. ORG sunflower yield was significantly less compared with CON. While much remains to be discovered about the effects of these agricultural practices on soil chemical properties and microbial diversity, our findings may contribute to this type of investigation.  相似文献