Influence of laboratory cultivation on species of Rhodophyta physiological evaluations and antifungal activity against phytopathogens

Abstract

The present study examined changes that took place in the physiology of three species of Rhodophyta by analysing the concentration of pigments and non-structural carbohydrates, comparatively evaluating algae collected from nature and after 28 days of laboratory cultivation. Another objective of the study was to determine whether the species retain their antifungal potential after the period of laboratory cultivation, correlating the changes in physiology and those from bioactivity. After carrying out laboratory cultivation, the results indicated a trend, in the three species of macroalgae, towards a reduction in pigment concentrations, mainly in the phycobiliproteins. For the non-structural carbohydrates no response pattern of the macroalgae was observed for the conditions evaluated. Extracts from the macroalgae, Ochtodes secundiramea and Palisada flagellifera, after laboratory cultivation showed a significant increase in antifungal potential which could be positively correlated with the change in concentration and ratios of chlorophyll-a and accessory pigments. Applying techniques of laboratory cultivation to macroalgae was an efficient tool for gaining knowledge of the physiology, and for obtaining biomass and compounds having biotechnological applications, without impacting on natural populations.

Marine Macroalgae, a Source of Natural Inhibitors of Fungal Phytopathogens

“…Colletotrichum is one of the most devastating genera of phytopathogenic fungi, due to its cross-infection capacity affecting a large range of hosts, including fruit trees (tropical and Mediterranean species), vegetables, and one of the most economically important plants, sugarcane [42,47,[65][66][67][68][69]. The enormous losses caused in strawberry cultures are noticeable [98].…”

“…The high inhibition of red algae observed against C. gloeosporioides and Colletotrichum musae can be related to the natural compounds produced by algae as a defence mechanism against microbial attack [101,102]. The sessile characteristic of the algae leads to the production of phenols [103] and terpenes (di-, sesquiterpenes) [102], including halogenated monoterpenes, [101] to self-protect under stress conditions [68], and other compounds, such as fatty acids [104], to which can be attributed antifungal activity against phytopathogenic fungi [102]. Moreover, Mani and Nagarathnam demonstrated the capacity of Î-carrageenan, a polysaccharide produced by the Rhodophyta group, to alter the membrane permeability of C. gloeosporioides, an antifungal mechanism that can suppress their development [69].…”

“…Disc diffusion technique [67,68] Kappaphycus alvarezii Poisoned food technique [69] Laurencia dendroidea Disc diffusion technique [67] Ochtodes secundiramea Disc diffusion technique [67,68] Palisada flagellifera Disc diffusion technique [68] Pterocladiella capillacea Disc diffusion technique [67] Colletotrichum musae…”

In vitro antagonism of Trichoderma asperellum against Colletotrichum gloeosporioides, Curvularia lunata, and Fusarium oxysporum

“…In addition, the fungus Colletotrichum gloeosporioides causes anthracnosis in fruits such as avocado (Persea americana), tomato (Solanum lycopersicum) and papaya (Carica papaya) [6], [7] and Curvularia lunata causes foliar spots in several important tropical food crops, including corn and rice (Oryza sativa) [8], [9], [10].…”