Enhancing rotifer Brachionus calyciflorus population growth with commercial probiotics

The effect of a commercial probiotic (NanoCrusta, Altacrusta, Mexico City, Mexico) on the growth performance of Brachionus calyciflorus Pallas, 1766, was evaluated. In a first approach, probiotics were supplied in four densities (2.0 × 10³, 1.1 × 10⁵, 2.1 × 10⁵ and 2.1 × 10⁶ cells/ml), alone and in combination with Chlorella vulgaris (1 × 10⁶ cells/ml). The test rotifer did not grow on the probiotic alone. However, when probiotics + C. vulgaris were added, the maximum densities (D_max; ind/ml) and population growth rates (r) observed were higher. In the second experiment, probiotics were supplied at five higher densities (2.1 × 10⁶, 4.2 × 10⁶, 8.5 × 10⁶, 1.7 × 10⁷ and 3.4 × 10⁷ cells/ml) with C. vulgaris and a control treatment with only C. vulgaris (probiotic‐free). Treatments supplied with probiotics between 2.1 × 10⁶ and 1.7 × 10⁷ cells/ml showed significantly higher D_max and r than the control treatment. The results showed a positive effect of probiotic bacteria when supplied with C. vulgaris. The best outcome showed a D_max 2.16 times and an r 1.63 times higher than the density of the control treatment. Growth rates were higher in the treatments with probiotics compared to the control. We conclude that application of NanoCrusta is feasible to improve B. calyciflorus production, but the effects need to be tested in larger scales.     

Biological Activities of Chickpea in Human Health (Cicer arietinum L.). A Review

Plant Foods for Human Nutrition - Chickpea is one of the most consumed legumes worldwide. Among their benefits are the high protein concentration that reflects not only at the nutritional level but...     

Nutritional Contribution of Biofloc within the Diet of Growout and Broodstock of Litopenaeus vannamei,Determined by Stable Isotopes and Fatty Acids

The relative contributions of feed sources were determined through the isotopic signal (δ¹³C and δ¹⁵N) and fatty acid profile of feed items, shrimp muscle, and eggs of Litopenaeus vannamei reared in a biofloc system. In the growout phase, the isotope analysis showed the biofloc particle size class ≥250 μm contributed 55–100%; size ≥50 < 250 μm contributed 0–22%; and artificial feed contributed 0–45%. Principal component analysis applied to fatty acid profiles showed that biofloc ≥250 μm and artificial feed were the most important items in shrimp growout. For the egg production, isotope analysis suggested that the most important feed sources according to their relative contributions were polychaetes (0–100%), followed by artemia biomass (0–86%) and semi‐moist feed (0–66%), with lower contributions from squid, mussel, and the muscle of L. vannamei broodstock that had been cultured in biofloc. In terms of fatty acids, the most important items were artemia, polychaetes, and semi‐moist feeds. This work clarified the importance of feed sources for shrimp during culture in biofloc systems and during reproduction. Analysis of stable isotopes and fatty acids can be successfully used to trace the assimilation of nutrients during the nutrition of shrimp.     

Potential bioavailability of protein and lipids in feed ingredients for the three‐spot cichlid Amphilophus trimaculatus: An in vitro assessment

For the commercial culture of the three‐spot cichlid (Amphilophus trimaculatus), it is important to have available a set of protein and lipid ingredients suitable for feed manufacturing, which allow to optimize the culture at affordable costs. The in vitro digestibility was evaluated with pH‐stat technique, using stomach and intestine multi‐enzymatic extracts from A. trimaculatus juveniles. The digestion of protein ingredients was taken place both in acid and in alkaline conditions, quantifying the total of free amino acids at the end of the hydrolysis, whereas the digestion of lipid ingredients was taken place only in alkaline conditions. The digestive enzymes of this species showed a better affinity to raw materials of animal origin such as beef meal, fish meal and premium chicken meal, which presented better digestibility. The best lipid ingredient that could be used is the fish oil. However, it is possible to use ingredients from the plant sources, such as soy or cereals, and vegetable oils such as olive, corn or soy oil. It is necessary to complement this study in vitro with the digestibility analysis in vivo, in order to determine the inclusion percentages in feeds and costs and therefore to develop an efficient feed formulation for the aquaculture of A. trimaculatus.     

Aboveground biomass,transpiration and water use efficiency in eucalypt plantation fertilized with KCl,NaCl and phonolite rock powder

Potassium has important physiological functions in eucalypt plantations, increasing their productivity when applied to soil via mineral fertilizers. There is interest in identifying alternative sources to KCl owing to its high cost and limited reserves. The aim of the study was to test the effect of replacing KCl with NaCl and phonolite rock powder. Two comparisons were made: (1) application of 283 kg ha^?1 of KCl compared with that of 2125 kg ha^?1 of phonolite rock powder (equivalent to 170 kg ha^?1 of K₂O in both treatments); (2) application of 139 kg ha^?1 of NaCl compared with that of 183 kg ha^?1 of KCl (equivalent to 2.33 kmol Na and K, respectively). Radial growth, soil water content, leaf water potential (Ψ), accumulated transpiration, stem volume and biomass increment, as well as water use efficiency (WUE) were evaluated. In the first comparison, both fertilizations presented equal values for all characteristics evaluated. In the second, the accumulated transpiration in trees fertilized with KCl was 17% higher than that in plants fertilized with NaCl. In contrast, the WUE was 20% higher in the trees fertilized with NaCl than in those fertilized with KCl, reflecting the lower water consumption for the same increment in stem volume and biomass. We conclude that phonolite rock powder and NaCl are possible substitutes for conventional K fertilization performed with KCl.

     

Untersuchungen zum Einfluß von Sonnenlicht auf das Schwärmverhalten von Borkenkäfern

Zusammenfassung Mit Hilfe elektronischer Meßmethoden sowie durch verschiedene weitere Versuchsanordnungen konnte gezeigt werden, daß der Buchdrucker in seinem Anflugverhalten an Pheromonquellen maßgeblich durch die jeweils herrschenden Lichtverhältnisse beeinflußt wird. Es bestand eine deutliche Präferenz von besonnten Standorten. In sonnigen Zeitabschnitten, auch innerhalb von nur wenigen Minuten, waren signifikant höhere Anflugzahlen zu vereichnen als in Phasen mit Bewölkung. Für den Kupferstecher gilt dies nur in eingeschränktem Maße.Diese Zusammenhänge konnten auch anhand von nord-bzw. südexponierten Fallen aufgezeigt werden. Die besonnte Fallenseite fing 4,2mal mehr Buchdrucker als die der Sonne abgewandte Seite. Beim Kupferstecher betrug der Faktor nur 1,66. Die beschriebenen Ergebnisse fanden ihre Bestätigung auch in der Befallssituation im Kalamitätsgebiet. Bei beginnendem Stehendbefall wurden vom Buchdrucker zunächst südexponierte Bestandesränder und hier die zur tageszeitlichen Hauptschwärmzeit besonnten Stämme besetzt.

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Influencing the flight behaviour of bark beetles by light conditions

With the aid of eletronic registration equipment and other experimental methods, it could be shown that the flight behaviour of spruce bark beetles to pheromone sources is strongly influenced by the prevailing light conditions. There is a definite preference for sunny conditions. Even during sunny periods of only a few minutes, significantly more beetles were flying than during overcast periods.A similar pattern of behaviour was observed for P.chalcographus, but there was no statistical evidence. This preference was also seen when pheromone baited traps were set up in a northerly direction with low sunlight levels and a southerly direction with strong sunlight. In the traps facing south 4,2 times more lps typographus were caught than in the north facing traps. P. chalcographus preferred the sunnier traps at a radio of 1,66.These results confirm the fact that at the beginning of an infestation of forest the southerly regions were first to be attacked by spruce bark beetles. Even there trees were first affected where they were exposed to sun during the daily main period of flight activity.

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Mit 2 Abbildungen und 1 Table.     

Changes in understory species diversity during theNothofagus pumilio forest management cycle

Human commercial activities must be compatible with sustainable management to achieve species conservation in the natural environment. After harvesting, diversity and abundance of understory species differ substantially from the pre-harvest situation. Have knowledge of the changes that logging produces in all components of the system allows us to develop management alternatives with reduced impacts. The objective of this work was to evaluate changes in density, biomass and diversity of understory species along a forest shelterwood cut system management cycle in aNothofagus pumilio forest. Six forest management situations (postharvesting stands and different phases of forest development) were sampled in a pureN. pumilio forest of Tierra del Fuego (Argentina) of middle-high site class (fromclass I toIII). Species number, density and biomass were modified substantially after a shelterwood cut. These were being greatest after cutting and falling substantially when the forest canopy closes during theinitial growth phase, returning to values similar to this virgin forest when themature phase was reached. The impact of the forest management on understory species diversity is analyzed and discussed. The silvicultural practices applied toN. pumilio forest in Tierra del Fuego permit the introduction of alien flora to the system, and produce great changes during the forest management cycle. To Celina Matteri, Itatí Ferraro, and Rosa Kofalt for their aid in taxonomical identification. To Juan Manuel Cellini, Ricardo Vukasovic and Gregorio Martínez Pastur for their participation in the field work; and to the sawmillLos Castores, Universidad Nacional de la Patagonia Austral, Centro Austral de Investigaciones Científicas and Instituto Nacional de Tecnología Agropecuaria for the institutional and financial support.     

Die Lufttemperatur als limitierender Faktor für die Schwärmaktivität zweier rindenbrütender Fichtenborkenkäferarten,lps typographus L. undPityogenes chalcographus L. (Col., Scolytidae)

Single catches of bark beetles in pheromone baited traps were registered by the aid of a new instrument. It consists of an electronical weather station in connection with a pheromone trap with infrared sensors as additional equipment. So it was possible also to register weather data at the moment of every catching event. It could be shown that the flight behaviour of both species of bark beetles was influenced by air temperature.I. typographus did not fly beneath a minimum temperature of 16.5°C. There was also an upper limit of 30°C for flight activity of this species.P. chalcographus has a threshold of temperatures about 16.8–17°C, for activity. No upper limit of temperature could be observed up to 35°C. Both of them,I.typ. andP. chalc., reacted very sensitive and spontaneous to these temperature thresholds.     

Effect of tillage and N fertilization on microbial physiological profile of soils cultivated with wheat

Microbial diversity might be a good indicator of ecosystem disturbance and functioning. We determined the effect of soil disturbances, such as N fertilization and tillage management, on soil microbial communities in a Typic Argiudoll of the El Salado river basin (Argentina). Microbial activity and substrate utilization provided a metabolic fingerprint of the soil microbial community. Univariate and multivariate analyses were used to differentiate responses to N fertilization and tillage at each of three growth stages of wheat (Triticum aestivum L.). Tillage had an adverse effect on microbial diversity, in which reduced and conventional tillage treated soils had different populations. However, N fertilization also altered microbial diversity depending on the crop developmental stage considered. Metabolism of carboxylic acids and carbohydrates were the main indicators of functional microbial activity and diversity. Although the substrate consumption profile of 32 C substrates did not provide insights into the fundamental ecological interactions that may induce changes in microbial population, it allowed us to demonstrate the alterations of microbial diversity as a result of tillage. We conclude that tillage and N fertilization altered microbial diversity.     

A New Simple Method for the Evaluation of Mineral Elements in Different Oilseeds

A method for the analysis of seven mineral contents—that is, potassium (K), calcium (Ca), phosphorus (P), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu)—was investigated in some oilseeds like flax, sesame, pumpkin, quinoa, and yellow mustard. X-ray Spectral Analysis method with Spectrometer EDX-900HS was used for the analytical concentrations of the macro and micro elements of the oilseeds. A relatively high level of Zn content was found in sesame and pumpkin seeds, while the highest level of Fe content was found in mustard seeds. Regarding the macro elements (K, Ca, and P) content, the highest levels of concentration were found in flax and mustard seeds. The highest values of Cu were obtained in sesame seeds while those of Mn were in pumpkin and brown flax seeds. The results showed that the method is a reliable and simple analytical procedure to characterize mineral elements in oilseeds with a very high analytical performance.