Preliminary investigations on the chemical composition of the scale-boundary and cyst wall of Pyramimonas pseudoparkeae (Prasinophyceae)
1985; Elsevier BV; Volume: 51; Issue: 6 Linguagem: Inglês
10.1016/s0254-6299(16)31617-9
ISSN1727-9321
Autores Tópico(s)Microbial Metabolites in Food Biotechnology
ResumoScales of Pyramimonas pseudoparkeae Pienaar et Aken were isolated by differential centrifugation and treated with cellulase, pectinase, HCI, NaOH, EDTA, boiling water and alcian blue (pH 2,5 and pH 0,5). The component sugars and amino acids in the scales were detected in acid hydrolysates using TLC and an amino acid analyser. Scales are predominantly carbohydrate in composition and contain approximately 4% protein. Scale polysaccharide is pectinaceous in nature, containing polygalacturonic acid and neutral sugars, galactose, arabinose, xylose, rhamnose and (trace) fructose. The scale polysaccharide is sulphated. Aspartic and glutamic acid represent major amino acid residues in scale hydrolysates. The polyanionic nature of the scales may explain the external self-assembly of the scale-boundary. The scale-boundary may also contribute to the maintenance of the water and salt balance in the cell. Histochemical tests on the bilayered cyst wall revealed that the outer component, which withstood acetolysis, is probably composed of sporopollenin. The inner layer has the same staining properties as the scales and is probably similar in composition. This layer also contains a sulphated acidic polysaccharide and some lipoidal material. The cyst wall is PAS-negative. S. Afr. J. Bot. 1985, 51: 408–416 Skubbe van Pyramimonas pseudoparkeae Pienaar et Aken is met behulp van gedifferensieerde sentrifugering geisoleer en met sellulase, pektinase, HCI, NaOH, EDTA, kokende water en alsien blou (pH 2,5 en pH 0,5) behandel. Die suikers en aminosure in die suurhidrolisate van skubbe is bepaal deur gebruik te maak van dunlaag-chromatografie en ‘n aminosuuranaliseerder. Die skubbe bestaan hoofsaaklik uit koolhidrate en bevat ongeveer 4% proteien. Die sulfaatbevattende skub-polisaggariede is pektien-agtig en bevat poligalakturoonsuur en neutrale suikers soos galaktose, arabinose, xilose, ramnose en klein hoeveelhede fruktose. Aspartien-en glutamiensuur is die belangrikste aminosuurreste in skub-hidrolisate. Die poli-anioniese samestelling van die skubbe mag ‘n verklaring bied vir die eksterne self-saamvoeging van die skub-grens. Die skub-grens mag ook bydra tot die handhawing van die water en soutbalans in die sel. Histochemiese toetse op die tweelagige sistwand het aan die lig gebring dat die buitenste laag, wat asetolise weerstaan, waarskynlik saamgestel is uit sporopollenien. Die binneste laag het dieselfde kleuringseienskappe as die skubbe en is waarskynlik identies in samestelling. Hierdie laag bevat ook ‘n sulfaatbevattende suur-polisaggaried, asook lipoiede-materiaal. Die sistwand is PAS-negatief. S.-Afr. Tydskr. Plantk. 1985, 51: 408 – 416
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