Lidia Medina Araujo

Chemical analyses confirm a rare case of seed dispersal by bees

It has been suggested that dispersal of seeds of Coussapoa asperifolia magnifolia could have endozoochoric dispersal by frugivorous birds and monkeys because the fruits are red when ripe, or exozoochoric dispersal, because the exocarp is mucilaginous and sticky. However, our field observations showed only stingless bees collecting the exocarp with seeds of C. asperifolia magnifolia, which are used for building and repairing their nests, from which the plants sprout. This paper aimed to determine the fruit chemical composition, since we postulated that C. asperifolia magnifolia is neither consumed by birds nor monkeys due to being very sticky and apparently resinous. Apolar extract analyses revealed the fruits are not resinous but extremely rich in waxes (mainly esterified triglycerides), and polar extract analyses revealed the sugar content to be close to the sensorial minimum level. This probably accounts for why only stingless bees are seen visiting fruits and dispersing seeds.ZusammenfassungDie Pflanzen der Gattung Coussapoa besitzen Früchte, die denen von Schwarzbeeren ähneln. Von einigen Autoren wurde vermutet, dass wegen der attraktiven roten Farbe der reifen Früchte deren Verbreitung durch den Verdauungstrakt von Früchte fressenden Vögeln und Affen erfolgt. Sie vermuteten zudem eine externe Verbreitung durch Anheftung an Federn und Fell, da die Früchte schleimig und klebrig sind. Allerdings fanden wir bei unseren Feldbeobachtungen ausschließlich Stachellose Bienen, die Teile von Früchten mit Samen von C. asperifolia magnifolia sammelten, um damit ihr Nest zu bauen bzw. zu reparieren und von wo die Pflanzen dann auskeimten. Wir bestimmten die chemische Zusammensetzung er Früchte von C. asperifolia magnifolia, da wir annahmen, das die Früchte wegen ihrer klebrigen und offensichtlich harzigen Eigenschaften nicht von Affen oder Vögeln gefressen werden. Unserer chemischen Analysen ergab zunächst, dass die Früchte nicht harzig sind. Sie sind extrem reich an Wachsen (vor allem veresterte Trglyceride), dafür ist aber der Zuckergehalte außerordentlich gering. Diese Analysen legen nahe, dass Früchte von C. asperifolia magnifolia ungenießbar für Affen und Vögel sind. Auf der anderen Seite sind die Triglycerid-reichen Früchte hervorragend geeignet, um Bienennester unter den heißen und feuchten Klimabedingungen in Amazonien zu verschließen. Dies würde erklären, warum wir ausschließlich Stachellose Bienen beim Besuch dieser Früchte und deren Verbreitung beobachteten. Trotz der großen Diversität an Stachellosen Bienen im Amazonasgebiet scheint die Verbreitung von Früchten durch Bienen (Mellitochory) hier ein eher seltenes Phänomen zu sein.

Physiochemical analysis and centesimal composition of Pleurotus ostreatus mushroom grown in residues from the Amazon

The objective of the present work was to evaluate the nutritional composition of mushrooms produced in alternative substrates in agricultural and agro-industrial residues from the Amazon. C, N, pH, moisture, soluble solids, protein, lipids, total fibers, ashes, carbohydrates and energy were determined. Substrates were formulated from Simarouba amara Aubl. and Ochroma piramidale Cav. ex. Lam. Sawdust and from Bactris gasipaes Kunth and Saccharum officinarum stipe. Results showed that the nutritional composition of P. ostreatus varied according to the cultivation substrate and that it can be considered important food due to its nutritional characteristics such as: high protein content; metabolizable carbohydrates and fiber; and low lipids and calories contents.

Composição mineral de uma linhagem de Pleurotus ostreatus cultivada em resíduos madeireiros e agroindustriais da região amazônica

Mushrooms belonging to the Pleurotus gender are grown in several lignocellulosic substrates due to the decomposing activity of these organisms that result from their enzymatic metabolism. The objective of the present study was to analyze the mineral composition of Pleurotus ostreatus and the cultivation substrates prepared with wood and agroindustrial residues from the Amazon region. Macro (P, K, Ca and Mg) and micronutrients (Fe, Zn, Cu, Mn and Na) of mushroom and substrates were analyzed. Substrates were formulated from Simarouba amara Aubl. and Ochroma piramidale Cav. ex. Lam. sawdust and crushed Bactris gasipaes Kunth, and Saccharum officinarum (sugar cane). The samples were solubilized by acid digestion (nitric-peridrol). The elements Ca, Mg, Fe, Cu, Zn and Mn were determined by atomic absorption spectrometry; Na and K, by atomic emission, and P by colorimetry. The mineral composition of the mushroom varied with the substrate. Different substrates made possible the production of a mushroom rich in K, P, Mg, and Fe, essential to human nutrition and health. Potassium was the mineral with the highest content in the mushroom for all substrates tested (36.83-42.18 g.kg –1 ) followed by phosphorus (6.95-10.60 g.kg –1 ) and magnesium (1.57-2.50 g.kg –1 ).