Rodrigo Arantes Reis

Polysaccharides present in cultivated Teloschistes flavicans symbiosis: comparison with those of the thallus.

The chemical structures of polysaccharides present in aposymbiotically cultured myco- and photobionts of the lichen Teloschistes flavicans were determined, in order to compare them with those previously found in the intact thallus. The mycobiont was cultured on a solid Lilly and Barnett medium and the resulting colonies were freeze dried, defatted, and their polysaccharides were extracted successively with 2%, 10% and 30% aq. KOH, each at 100 degrees C. The extracts were neutralized (HOAc) and fractionated, giving rise to three homogeneous fractions, PFSK2 from 2% KOH, which contained a (1-->4),(1-->6)-linked alpha-glucan (1:1 ratio, pullulan), fraction PK10 from 10% KOH extraction, which was a linear (1-->3)-linked linear beta-glucan (laminaran), and fraction PK30 from 30% KOH extraction, being a branched (1-->3),(1-->6)-linked beta-glucan. The photobiont (Trebouxia sp. de Puymaly) was cultured in liquid nutrient medium, and after purification, a linear (1-->5)-linked beta-galactofuranan was characterized. The galactofuranan and the laminaran were not present in the symbiotic thallus, in contrast to the glucans, showing that the mycobiont alone produces them without participation of the photobiont.

An experimental evaluation of the effectiveness of beach ashtrays in preventing marine contamination

A presenca de residuos solidos no ambiente marinho e extensa. Praias sao tipicamente contaminadas com esses materiais, que podem causar impactos ecologicos. Residuos solidos nas praias podem causar ferimentos nas pessoas e podem prejudicar a atividade turistica. Neste estudo, hipoteses relativas ao uso de cinzeiros de praia foram testadas. Os resultados indicam que a taxa de abandono desse equipamento e pequena (1,5%) e que a quantidade media de pontas de cigarro (3,4 itens/cinzeiro) e maior do que as quantidades medias de outros tipos de lixo. Tambem se observou que pessoas com diferentes perfis socioeconomicos apresentaram percepcoes diferentes relativas a presenca de residuos solidos nas praias. Estes resultados sugerem que cinzeiros portateis podem ser um equipamento importante na reducao da contaminacao das praias e que diferencas socioeconomicas dos frequentadores das praias podem explicar parcialmente as diferentes percepcoes relativas a presenca de residuos no ambiente praial. Sugere-se que os gerentes costeiros usem esse tipo de informacao para planejar estrategias de reducao desse problema.

Linear β-mannose-containing polysaccharide, β-xylan, and amylose from the cultured photobiont Trebouxia sp. of the ascolichen Ramalina celastri

Abstract The cultured photobiont Trebouxia sp. of Ramalina celastri was successively extracted at 100°C with hot water, 2% aqueous KOH, and 10% aqueous KOH to give polysaccharide-containing fractions A (2.9%), B (3.9%), and C (0.9% yield) respectively. The intact biont contained 3.8% amylose, which was present in each fraction, and was identified by a blue color formed with iodine solution. In fraction A, and following retrogradation from aqueous solution, it was characterized by 13C-NMR spectroscopy. Fraction B was treated with α-amylase to give a water-soluble fraction consisting mainly of β-mannose-containing polysaccharides (1.5% yield), whose main component had dn/dc 0.162 and Mr 17 kDa. Fraction C was subjected to freeze–thawing and the precipitate was treated with α-amylase to give a resistant, linear, low molecular mass (1→4)-linked β-xylan. The β- D -mannopyranan preparation contained mainly of 3-O- (28%), 4-O- (11%), and 6-O-substituted Manp units (35%), with 3-O-substituted Rhap units (11%). A controlled Smith degradation provided a β-mannan with nonreducing end- (8%), 3-O- (85%) and 6-O-substituted units, showing (1→3)- and (1→6)-linked structures in the original polysaccharide. These could be present as block-type structures.

Plantas do Gênero Xylopia: Composição Química e Potencial Farmacológico

The family Annonaceae has representatives of great medical interest, and the Xylopia species deserves attention. The Xylopia genus is composed by approximately 160 species, with geographic distribution in tropical and subtropical regions of America, Africa and Asia. This genus can present shrubs or trees. In Brazil, they can be found at the North, North-west, Central-West and Central-South Regions. The phytochemical investigations resulted mainly in the isolation of alkaloids, diterpenos, quinolines and acetogenins, with the latter presenting very interesting biological properties such as the cytotoxic, antiprotozoal and the insecticide activities.This study aimed to review the botanical, chemical and pharmacological aspects of the Xylopia genus found in Brazil, highlighting the chemical components, as the well-known pharmacological effect .

Influence of ancient anthropogenic activities on the mangrove soil microbiome

Mangroves are highly productive ecosystems located at the transition between the terrestrial and marine environments. Mangroves play an important role in carbon storage, nutrient cycling and support for the marine food web. Mangrove soils are formed by fine particles rich in organic carbon and are subject to constant fluctuations in oxygen, salinity and nutrient availability due to fresh water flux and tidal variations. Microbes play an important role in nutrient cycling in mangrove soils; however, studies on the mangrove soil microbiome are scarce. Here we compare the microbiome of pristine mangrove soil located in an environmentally protected area in Guaratuba, Southern Brazil, with the microbiome of mangrove soil affected by the presence of carbonaceaous debris eroding from an archeological site known as Sambaqui. We show that although the Sambaqui site has a major effect on soil chemistry, increasing the soil pH by 2.6 units, only minor changes in the soil microbiome were detected indicating resilience of the microbial community to pH variations. The high alpha diversity indexes and predicted metabolic potential suggest that the mangrove soil microbiome not only provides important ecological services but also may host a broad range of microbes and genes of biotechnological interest.

Teloschistes flavicans (sw.) Norman como indicador de poluição atmosférica em Paranaguá – PR

A poluicao atmosferica proveniente de areas portuarias e responsavelpor um expressivo numero de mortes, merecendo destaque no litoralparanaense, area que abriga o maior porto graneleiro do Brasil. Apesardisso, o monitoramento da qualidade do ar nao e realizado devido ao altocusto. A alta sensibilidade dos liquens a poluicao atmosferica faz delesotimos bioindicadores para estudos de qualidade do ar. Este estudo utilizoua degradacao da clorofila em feofitina em liquens da especie Teloschistesflavicans, visando identificar areas de maior risco ambiental no municipiode Paranagua. Os resultados da analise de variância mostraram que, aodecorrer de 78 dias, as amostras localizadas na regiao portuaria e nas viasde acesso sofreram degradacao da clorofila em niveis significantementerepresentativos em relacao as amostras localizadas em areas residenciais(p≤0,001), demonstrando que o porto e as vias apresentam poluentesatmosfericos em niveis suficientes para causar a degradacao liquenica.