The need for nutritional sources safer than traditional animal products has renewed interest generally in plants and particularly in microalgae. Microalgae have diverse uses in aquaculture, their applications are mainly to provide nutrition and to enhance the colour of the flesh of salmonids. The larvae of molluscs, echinoderms and crustaceans as well as some fish larvae feed on microalgae. Several studies have confirmed that a live multi-specific, low bacterial and microalgal biomass remains essential for shellfish hatcheries. Major advances are expected from new production system, designs and operations from batch run open tanks to more sophisticated continuously-run and closed loop reactors. Currently, studies are underway to examine the cost-effectiveness of the on-and off-site microalgal production systems which can only be achieved by substantial scaling-up and improved quality control. In order to attain sustainability in the usage of microalgae, a systems-based approach is required which integrates different fields such as biotechnology, bioprocess and management procedures.

Fungal endophytes occur in leaves of angiosperm and gymnosperm trees. The occurrence and distribution of fungal endophytes in the leaves of trees growing in four different types of tropical forests in the Western Ghats were studied. One thousand five hundred leaf segments from five different hosts were screened for each forest type. Endophyte communities of trees of the semi-evergreen forest showed the highest species diversity. More endophyte isolates were recovered during the wet season. Although several genera of endophytes were common for different hosts growing in different forests, the dominant endophyte was different for different forest types. Our results suggest that although tropical trees individually may be endophyte rich, the overall endophyte diversity of the entire plant community is not exceptional.Key words: tropical forests, fungal endophytes, fungal diversity, foliar endophytes.

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

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