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Govinda Rajulu M.B.,Mission Research | Thirunavukkarasu N.,Mission Research | Suryanarayanan T.S.,Vivekananda Institute of Tropical Mycology VINSTROM | Ravishankar J.P.,DG Vaishnav College | And 2 more authors.
Fungal Diversity

Fungal endophytes isolated from leaves of tree species of the forests of Western Ghats, southern India were screened for chitin modifying enzyme production. Thirtyone of the one hundred and sixty two isolates were positive for chitinase, while different isolates produced isoforms of the enzyme. Many isolates produced chitosanase that acted on chitosan with different degrees of acetylation. Modified chitin and different types of chitosans are used in biomedical applications including wound healing, drug delivery, gene delivery, tissue engineering, in the food industry as preservatives and emulsifying agents, and in biocatalysis. Horizontally transmitted endophytes appear to be a good source for a variety of chitin modifying enzymes with the potential to be used in biotechnology. The possibility of chitin modifying enzymes of endophytes in regulating plant defense against pathogens and pests in vivo should also be addressed. © Kevin D. Hyde 2010. Source

Suryanarayanan T.S.,Vivekananda Institute of Tropical Mycology VINSTROM | Murali T.S.,Mission Research | Murali T.S.,Manipal University India | Thirunavukkarasu N.,Mission Research | And 4 more authors.
Biodiversity and Conservation

Fungal endophytes of tropical trees are expected to be exceptionally species rich as a consequence of high tree diversity in the tropics and the purported host restriction among the endophytes. Based on this premise, endophytes have been regarded as a focal group for estimating fungal numbers because their possible hyperdiverse nature would reflect significantly global fungal diversity. We present our consolidated ten-year work on 75 dicotyledonous tree hosts belonging to 33 families and growing in three different types of tropical forests of the NBR in the Western Ghats, southern India. We conclude that endophyte diversity in these forests is limited due to loose host affiliations among endophytes. Some endophytes have a wide host range and colonize taxonomically disparate hosts suggesting adaptations in them to counter a variety of defense chemicals in their hosts. Furthermore, such polyphagous endophytes dominate the endophyte assemblages of different tree hosts. Individual leaves may be densely colonized but only by a few endophyte species. It appears that the environment (the type of forest in this case) has a larger role in determining the endophyte assemblage of a plant host than the taxonomy of the host plant. Thus, different tropical plant communities have to be studied for their endophyte diversity to test the generalization that endophytes are hyperdiverse in the tropics, estimate their true species richness, and use them as a predictor group for more accurate assessment of global fungal diversity. © 2011 Springer Science+Business Media B.V. Source

Kaushik N.K.,Malaria Research Laboratory | Murali T.S.,Manipal University India | Sahal D.,Malaria Research Laboratory | Suryanarayanan T.S.,Vivekananda Institute of Tropical Mycology VINSTROM
Acta Parasitologica

Eighty four different fungal endophytes isolated from sea grasses (5), marine algae (36) and leaves or barks of forest trees (43) were grown in vitro and the secondary metabolites secreted by them were harvested by immobilizing them on XAD beads. These metabolites were eluted with methanol and screened using SYBR Green I assay for their antiplasmodial activity against blood stage Plasmodium falciparum in human red blood cell culture. Our results revealed that fungal endophytes belonging to diverse genera elaborate antiplasmodial metabolites. A Fusarium sp. (580, IC50: 1.94 μg ml-1) endophytic in a marine alga and a Nigrospora sp. (151, IC50: 2.88 μg ml-1) endophytic in a tree species were subjected to antiplasmodial activity-guided reversed phase high performance liquid chromatography separation. Purification led to potentiation as reflected in IC50 values of 0.12 μg ml-1 and 0.15 μg ml-1 for two of the fractions obtained from 580. Our study adds further credence to the notion that fungal endophytes are a potential storehouse for a variety of novel secondary metabolites vested with different bioactivities including some that can stall the growth of the malaria parasite. © W. Stefański Institute of Parasitology, PAS. Source

Suryanarayanan T.S.,Vivekananda Institute of Tropical Mycology VINSTROM
Botanica Marina

A few recent investigations have established that marine-derived fungi associated with sponges are an excellent source of novel bioactive metabolites with the potential to function as drugs or drug leads. Given the high species diversity and wide distribution of sponges, it is reasonable to expect that they harbour marine-derived fungi with the ability to produce diverse secondary metabolites. For a more complete realisation of their technological potential, a thorough knowledge of the different taxa of marine-derived fungi associated with sponges is essential. There is scarce information on the interplay between sponges and associated marinederived fungi and between the marine-derived fungi and other sponge endosymbionts. Unravelling such interactions could be useful in recreating the sponge microcosm conditions in vitro for harvesting novel fungal metabolites. This is essential as many genes of fungal secondary metabolism are inactive in axenic cultures. This review addresses these issues by focusing on the isolation, identification, nature of association, secondary metabolites and potential interactions of marine-derived fungi of sponges and presents some future prospects regarding the bioprospecting of these fungi. Source

Suryanarayanan T.S.,Vivekananda Institute of Tropical Mycology VINSTROM
Fungal Ecology

Many fungi belonging to mostly Ascomycota inhabit living tissues of plants of all major lineages without causing any visible symptoms. Termed horizontally transmitted endophytes, they have been investigated mostly for their capacity to produce bioactive secondary metabolites. However, many questions regarding the interactions between endophytes and their plant hosts, phytophagous insects and other fungi remain unanswered. This review highlights some of these areas of endophyte biology about which very little or no knowledge exists. Information garnered' using modern methodologies' on these grey areas of 'endophytism' (endophytic mode of lifestyle) would help immensely in understanding the evolution of endophytes of aerial plant tissues and in exploiting endophytes in various fields of biotechnology. © 2013 Elsevier Ltd and The British Mycological Society. Source

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