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101.
G. R. Xavier L. M. V. Martins M. C. P. Neves N. G. Rumjanek 《Biology and Fertility of Soils》1998,27(4):386-392
A large collection of cowpea rhizobia strains was obtained from soil samples collected from either a semi-arid or a tropical
rain forest area located at about the same latitude in the north-eastern region of Brazil and evaluated for their intrinsic
antibiotic resistance to eight commercial antibiotics. The aim of this study was to correlate antibiotic resistance of native
rhizobia strains to edaphic-climatic factors as a way to establish suitable inoculants for specific areas. A large diversity
regarding intrinsic antibiotic resistance was found, and 17 clusters were identified as varying from sensitive to gradually
resistant up to 500 μg·ml–1 of the antibiotics tested. Clustering analysis did not show any pattern related to the geographic region where isolates have
been obtained. On the other hand, an increase in the antibiotic-resistant rhizobia population was associated with an increase
in soil P and Al contents. lsolates which were sensitive to spectinomycin, ampicillin, streptomycin, chloramphenicol and tetracycline
were present at higher rates in soils devoid of Al. Rhizobia bacteria producing mucus type I (fluid and capable of spreading
over the solid media) were found preferentially in soil with Al concentrations up to 36 mg·kg–1, diminishing quickly at higher levels.
Received: 2 May 1997 相似文献
102.
Ammonia is considered a key component in the attraction of tephritid flies to protein-based lures. The addition of ammonium acetate to improve hydrolyzed protein-borax mixtures used to monitor tephritids has not been evaluated, although it has improved attraction to toxic baits. The presence of ammonium acetate crystals in a ventilated tube inside a trap containing hydrolyzed protein + borax, did not improve the capture of Anastrepha obliqua or Anastrepha serpentina flies in field experiments when compared with hydrolyzed protein + borax alone. In contrast, the addition of 1% ammonium acetate into the drowning solution of a hydrolyzed protein + borax mixture resulted in significantly reduced captures of both pests. Laboratory tests indicated that the emission of ammonia gas was increased 1.6–4.5-fold from traps that included ammonium acetate. These results confirm the hypothesis that a higher release of ammonia does not improve the attraction of tephritids when protein-derived odors are also present. 相似文献
103.
Ariana Silva Guimarães Paulo Travassos Pedro Walfir Martins E Souza Filho Fabrício Dias Gonçalves Francisco Costa 《Aquaculture Research》2010,41(6):828-838
The conversion of mangrove areas into shrimp farming ponds has been indicated as the main activity responsible for the reduction in the area of this ecosystem along the northeastern coast of Brazil. The present study was conducted using remote sensing methods and a geographical information system with the aim of quantifying the participation of this activity in the reduction of the mangrove areas along the northern coast of the State of Pernambuco (northeast, Brazil), where shrimp farming has been implanted in last recent years. From 1973 to 2005, there was reduction of about 2.052 ha of mangrove, 197 ha of which were converted into shrimp ponds. Thus, the real contribution of shrimp farming to this reduction was just 9.6% of the total area. Other anthropogenic activities, such as agriculture, urban expansion and tourism, contributed greatly to the reduction in the mangrove areas along the northern coast of the State of Pernambuco. 相似文献
104.
Kennya Gomes Silva Addam Scheila Anelise Pereira Gabriel Fernandes Alves Jesus Lucas Cardoso Nichola Syracuse Gustavo Ruschel Lopes Nicollas Breda Lehmann Bruno Correa da Silva Lúvia Souza de S Francisco Clio Maia Chaves Maurício Latera Martins Jos Luiz Pedreira Mourio 《Aquaculture Research》2019,50(10):2960-2971
This study evaluated the effects of dietary supplementation of organic acids blend (OAB) alone or in combination with essential oil, Lippia origanoides (OAE) for Nile tilapia fed supplemented diets for 30 days. Fish (1.1 ± 0.04 g) were fed control (Control), or OAB 0.5% or OAB 0.5% + essential oil 0.125% (OAE) respectively. At the end of the experiment, samples were collected for de hemato‐immunological, histological analysis of the intestine and liver, as well as microbiology of the intestine. The pH of the diets supplemented with OAB and OAE reduced 0.92 and 0.19 respectively. The growth and FCR were unaffected by the treatments, but survival was significantly higher in the OAB treatment. Fish fed the OAB diet showed reduced concentration of total heterotrophic bacteria and Pseudomonas sp. in the intestine. Increased glucose in fish fed OAB and high number of circulating monocytes in fish fed OAE diet were observed. The anterior intestine of fish fed OAE diet showed larger number of goblet cells and increased villi height. The diet supplemented with OAB, mainly, improved the intestinal health and survival of tilapia juveniles and can be used in juvenile production. 相似文献
105.
Natalino da Costa Sousa Mrcia Valria Silva do Couto Higo Andrade Abe Peterson Emmanuel Guimares Paixo Carlos Alberto Martins Cordeiro Emilly Monteiro Lopes Jonathan Stuart Ready Gabriel Fernandes Alves Jesus Mauricio Latera Martins Jos Luiz Pereira Mourio Paulo Csar Falanghe Carneiro Alexandre Nizio Maria Rodrigo Yudi Fujimoto 《Aquaculture Research》2019,50(12):3720-3728
Intensive fish farming has resulted in an increased concern for disease outbreaks. Probiotic use is one of the strategies being developed to improve fish health and productivity. Measures of probiotic colonization, growth performance, haematological characteristics and parasite load were used to evaluate the effect of diets supplemented with Enterococcus faecium on growth and health of Arapaima gigas juveniles. A completely randomized design with four treatments (diet with E. faecium at 1 × 106 CFU/g and 1 × 108 CFU/g, control diet and diet with the culture medium MRS) and three replicates was used. Ninety‐six Arapaima juveniles were distributed in 12 cages fed with the specified diet for 68 days. Colonization of the intestinal tract by lactic acid bacteria reduced the total number of heterotrophic bacteria in fish fed with probiotics compared to controls. Fish fed a supplemented diet containing 1 × 108 CFU/g presented higher values of weight gain, survival and fish growth uniformity, and lower values of feed conversion ratio. The prevalence of Trichodina sp. could have affected the survival of fish in the control group. Reduction in parasite load and an increase in haematocrit, the number of erythrocytes, thrombocytes, neutrophils and monocytes were also observed in fish fed the diet containing 1 × 108 CFU/g. Enterococcus faecium presented a probiotic effect in A. gigas juveniles and can be recommended for use at a concentration of 1 × 108 CFU/g to modify the gut microbiota, improve growth performance and haematology and reduce parasitic load. 相似文献
106.
Philip M. Harrison Eduardo G. Martins Dirk A. Algera Trina Rytwinski Brent Mossop Alf J. Leake Michael Power Steven J. Cooke 《Fish and Fisheries》2019,20(3):403-418
Potadromous fishes are vulnerable to involuntary entrainment through hydropower turbines. However, turbines can also provide a downstream passage route for potadromous fish. Here, we review evidence for turbine entrainment and passage in potadromous fish, and evaluate the effects of these processes on upstream and downstream populations. We develop conceptual frameworks and metrics to quantify vulnerability to turbine entrainment removals, and to quantify the efficiency of turbines as a downstream passage route. We highlight factors that influence these processes and provide case‐studies demonstrating their applicability. We found that juvenile potadromous fish are being entrained through turbines at rates high enough to impact upstream populations. Given that juvenile passage survival is often high, we argue that turbines provide an important downstream passage route for potadromous fish. We show that entrainment vulnerability is likely a function of interactions between in‐reservoir fish behaviour, habitat configuration and operations and thus not well captured by passage mortality estimates. Similarly, we show that while passage mortality can limit downstream passage efficiency, passage success is also dependent on reservoir and forebay navigation, along with survival and fitness in the downstream river. We advocate for a shift in focus away from estimates of passage mortality and injury, which have previously accounted for the majority of turbine passage research. Instead, we recommend an approach that focusses on quantification of the factors that influence downstream passage efficiency and entrainment vulnerability. Moreover, we highlight the need to better understand the broader scale impacts of these events on upstream and downstream populations. 相似文献
107.
Rodrigo Otávio
De Almeida Ozório Carlos Andrade Viriato Manuel Freitas Andrade Timóteo Luís Eugénio Castanheira da Conceição Luisa Maria Pinheiro Valente 《Journal of the World Aquaculture Society》2009,40(1):95-103
Although reported as a slow growing species, to date information regarding nutritional dynamics of blackspot seabream, Pagellus bogaraveo, is limited, especially during ongrowing phase. This study determined the effects of different feeding levels on growth response, body composition, and energy expenditure of blackspot seabream juveniles (initial weight = 64 g). Fish were allocated in nine indoor tanks (15 fish per tank) and fed a basal diet twice daily at increasing levels (2.5, 3.3, and 4.1 g feed/kg0.8/d) for 138 d. Growth response decreased with decreasing feeding levels, but only at 2.5 g feed/kg0.8/d (P < 0.001). Differences in growth rates were positively correlated with body lipid content (r2 = 0.90). Net protein utilization decreased with each increase in feeding level. The energy requirement for zero growth (maintenance) and the estimated energy loss on starvation were calculated as 22.6 and 17.9 kJ/kg0.8/d, respectively. The energy cost for protein and lipid gain was calculated as 3.8 and 1.4 kJ/kJ energy deposited, respectively. This study suggested that blackspot seabream may grow slower than the other close‐related species because of its higher demand of dietary protein energy in favor of lipid deposition. 相似文献
108.
109.
Martins ML Vieira FN Jerônimo GT Mouriño JL Dotta G Speck GM Bezerra AJ Pedrotti FS Buglione-Neto CC Pereira G 《Fish physiology and biochemistry》2009,35(1):219-222
This study evaluated the total and differential leukocyte counting and the phagocytic activity in Nile tilapia Oreochromis niloticus experimentally injected with Enterococcus sp. in the swim bladder. Fish were distributed in four treatments in triplicates of non-injected fish, fish injected with
1 ml of sterile saline solution 0.65%, and fish injected with 1 × 103 and 1 × 106 colony-forming units (CFU) of Enterococcus diluted in 1 ml sterile saline. Twenty-four hours after injection, the fish were anesthetized and the blood collected for
white blood cell (WBC) counts, differential counting of WBC, and phagocytic activity of blood leukocytes. The increased numbers
of WBC and lymphocytes were followed by decreased number of monocyte after infection. The percentages of phagocytic activities
in the blood were 55.3 and 55.9%, respectively, in tilapia injected with 1 × 103 and 1 × 106 CFU/ml. 相似文献
110.
Lisandra Magna Moura Rafael Silva Ramos dos Anjos Renata Oliveira Batista Naine Martins do Vale Cosme Damião Cruz José Eustáquio de Souza Carneiro Juarez Campolina Machado Pedro Crescêncio Souza Carneiro 《Euphytica》2018,214(10):181
The objectives of this study were to obtain information about genetic parameters of a partial diallel in common bean, as well as to evaluate the effects of growing seasons, locations and generations in these estimates in order to define the best strategies for the use of diallel analysis as methodology of selection of parents and populations in common bean breeding. Twelve parents were crossed in a partial diallel scheme (5?×?7), and the F1 and F2 generations were evaluated in four experiments (I, II, III, and IV). The effects of seasons were determined in the Experiments I and II, in which the F1 generation was evaluated in two distinct growing seasons. To quantify the effect of locations, we used Experiments III and IV, in which the F2 generation was evaluated in the same season, but at different locations, and to quantify the effect of generations, the experiments II (generation F1) and III (F2 generation) were evaluated in the same season and location. As for grain yield the genetic control varied according to the environment. An effect of interaction on the genetic parameters of the diallel was observed for generation, whereas for grain yield, effects of season and location were observed. For plant architecture, parental combining ability should therefore be estimated using the F1 generation, while for grain yield, both the F1 and F2 can be used. The recombination between the best hybrids is a promising strategy for extraction of superior black bean lines. 相似文献