Analysis of photosynthetic performance and chemical composition of Pterocladiella capillacea (SG Gmelin) Santelices & Hommersand (Rhodophyta, Gelidiales) under different light intensities

Abstract

Climate change have attracted increasing interest from scientists, politicians and the general public, because of the alarming consequences of the rise in temperature and the incidence of solar radiation on the earth's surface give rise over the coming years. Light is one of the major abiotic factors that affect the growth, development and reproduction of the algae. The Photosynthetically Active Radiation (PAR) is the visible light range between 400 and 700 nm, used by organisms to perform photosynthesis. The light acts directly and indirectly influencing physiological aspects of macroalgae such as growth, development, reproduction, performance and photosynthetic acclimation. Despite already several environmental change in the marine environment as ocean acidification and temperature increases, sea and the incidence of ultraviolet radiation, among others, levels have been found there is still much uncertainty about the true magnitude of these impacts and other disturbances which may derive from climate change. To understand this dynamic is necessary to study the biological and physiological against environmental stresses in macroalgae aspects so that you can understand the impact of these changes and to determine whether particular species are sensitive or tolerant to these impacts. The main objective of this research is to characterize the physiological responses and chemical composition Pterocladiella capillacea (Rhodophyta, Gelidiales) subjected to two light intensities, one control and other stress. The parameters analyzed are: growth rate, photosynthetic performance, carbon, hydrogen and nitrogen tissue, pigment content (phycobiliproteins, chlorophyll a and carotenoids), total soluble proteins, antioxidant potential and amino acid content Micosporinas type (MAAs). The results of this study will complement previous ecophysiological work and thus increase knowledge about the life strategy of P. capillacea forward to changing scenarios of increased solar radiation. This master's project is part of the Aid to Research Biota/FAPESP No. 2013/50731-1 entitled Biodiversity and physiological chemistry of ecologically and economically important seaweeds. (AU)