Abundance, Diversity and Prospects of Marine Fungi and Biotechnological Applications

 

Gopi, K, Jayaprakashvel, M*

Department of Marine Biotechnology, AMET University, Kanathur, Chennai – 603112, Tamil Nadu, India

 

ABSTRACT:

The ocean is considered to be a great reservoir of biodiversity. Microbial communities in marine environments are ecologically relevant as intermediaries of energy, and play an important role in nutrient regeneration cycles as decomposers of dead and decaying organic matter. In this sense, marine-derived fungi can be considered as a source of enzymes of industrial and/or environmental interest. Fungal strains isolated from different substrates, such as invertebrates, decaying wood, seawater, sediments, and mangrove detritus, have been reported to be producers of hydrolytic and/or oxidative enzymes, with alginate lyase, amylase, cellulase, chitinase, glucosidase, inulinase, keratinase, ligninase, lipase, nuclease, phytase, protease, and xylanase being among the enzymes produced by fungi of marine origin. Every organism in ecosystem naturally dependent other resources as their food that can be living things or non-living things (e.g. Plants dependent energy from sunlight to produce organic compounds and animal dependent energy from organic compounds). This phenomenon creates the food web in the biosphere of the earth. Among these, fungi contribute the major role as decomposer, parasitic and symbiotic association.

 

 

 

1. INTRODUCTION:

Marine microbial communities (bacteria, fungi, algae, plankton, and viruses) are considered important ecological components in marine environments due to their performance in biogeochemical processes. Marine fungi have been classified as obligate or facultative: obligate marine fungi are those that grow and sporulate exclusively in a marine or estuarine habitat, whereas facultative marine fungi are those from freshwater or terrestrial origin that are able to grow (and possibly sporulate) in marine environment.

 

As a more general classification of these organisms, the term “marine-derived fungi” is often used because most of the fungi isolated from marine samples are not demonstrably classified as obligate or facultative marine microorganisms. Fungus is a heterotrophic eukaryotic organism, which digests food externally and absorbs nutrients directly through its cell walls like digestive system of animals. Most fungi reproduce by spores and have a thallic body composed of microscopic tubular cells called hyphae^[1].

 

Based on the approach of fungi for their food source, fungi are classified as facultative parasites (biotrophs) those obtain their nutrients from a living host (plant or animal), saprophytes/saprobes (saprotrophs) which are obtaining their nutrients from dead plants or animals and parasites (necrotrophs) which are infect a living host, but kill host cells in order to obtain their nutrients.

 

 

Figure.1. Classification of fungi based on their nutritional resources

 

Fungi are more closely-related to animals than plants. But a few decades ago, studies and reports by mycologists suggested that fungi are members of the plant kingdom, new knowledge which has become available recommends that fungi share an evolutionary ancestry with animals^[2]. Figure 1 explains the Classification of fungi based on their nutritional resources.

 

2. Abundance and diversity of fungi:

Fungi have been functioning as precious sources of natural products for industrial as well as biomedical development for decades. Fungi are important contributory in every ecosystem, intimately associated with vital processes like the decomposition, recycling and transportation of nutrients in different environments (Hawksworth, 1991) ^[3-4]. The general characters among all true fungi are the presence of chitin structure in the cell wall and in most species, the presence of zygotic meiosis processes. The well known fungi includes mushrooms, molds and yeasts. However, fungal growth exists in an incredible morphological appearance of sizes, shapes and colors ^[5]. Due to their microscopic size, fungi are often unobserved and their role in nature and human life underestimated. Hence scientists continue the important work of documenting fungal diversity with systematic and classification of fungi will continue to change (Merje and Catherine, 2012). Fungi are hyper diverse in the ecosystem, but inadequately known, despite their ecological and economic impacts. For example, the Tedersoo et al conducted the biodiversity of fungi by means of nearly 15,000 top soil samples collected from 365 sites worldwide and sequenced their genomes. From that study, found a remarkable decline in fungal species richness with distance from the equator ^[6-7]. For some specialist groups of fungi, diversity depends more on the abundance of host plants than host diversity or geography. The findings relate a huge gap between known and described fungal species and the actual numbers of different fungi in the world's soils (Turner et al., 1983).

 

3. Properties of marine fungi:

Many marine fungi are known to reduce the toxicity of sodium ions by sequestering mechanism of vacuoles present in fungi or have a very efficient sodium efflux based on an ATPase (Benito et al., 2002) system of fungi (Jennings, 1983). The low water potential is one of the problems posed by sea water salt concentration. To survive in marine environments the straminipilan fungi, the thraustochytrids and labyrinthulids regulate absolute requirement for sodium for their growth and sporulation (Jennings, 1986) ^[8-9].  Therefore, organisms living in it need to maintain water potentials lower than that of seawater in their cells to enable water uptake. Marine fungi maintain this gradient by accumulation of osmolytes production in their cell such as glycerol, mannitol, polyol and trehalose (Blomberg and Adler, 1992).

 

A number of the most unique structures of chemical compound came from obligate marine species. Since a very small amount of obligate species has been investigated, the marine environment still represents a virtually unused resource for both fungal and chemical diversity^[10-12]. The relationships between fungi and their hosts (plants or animals) especially with respect to chemical ecology are relatively little known. However, endophyte studies on marine grasses and mangroves clearly show that these marine habitats represent rich sources for both marine obligate and marine facultative fungi (Leano, 2002; Barata, 2002; Kumaresan et al, 2002).

 

4. CONCLUSION:

Studies related to the prospecting of marine-derived fungal enzymes could result in the discovery of new enzymes that are different from their terrestrial counterparts and also increase our understanding about the diversity and ecology of this microbial group. In the biosphere system of the Earth, fungi are a major contributor due to their uniqueness in biological properties along with their abundance and diversity. Therefore, without fungi plant’s existence is not possible on this planet because of fungi recycle the dead matter into the nutrition of plants. Hence the study of fungi in different habitat will be useful to benefit the human being through different applications such as industrial, agricultural, pharmaceutical and etc.

 

5. REFERENCES:

1.       Carris, L. M., Little, C. R. and Stiles, C. M. 2012. Introduction to Fungi. The Plant Health Instructor. DOI: 10.1094.

2.       Burnett, J.H. 1987. Evolutionary biology of the fungi: Aspects of Macro and Microevolution of the fungi. University press, Cambridge. Pp 340- 341.

3.       Hawksworth, D.L. 1991. The fungal dimension of biodiversity, magnitude, significance and conservation. Mycol Res, 95: 641-655.

4.       Merje Toome, M. and Catherine Aime. 2012. Kingdom Fungi. Biological Science Fundamentals And Systematic – Kingdom fungi. Encyclopedia of Life Support Systems (EOLSS).

5.       Benito, B., Garciadeblás, B. and Rodriguez-Navarro, A. 2002. Potassium-or sodium-efflux ATPase, a key enzyme in the evolution of fungi. Microbiology, 148: 933-941.

6.       Jennings, D.H. 1986. Fungal growth in the sea. In: The Biology of Marine Fungi (ed. S.T. Moss) Cambridge University Press, London: 1-10.

7.       Blomberg, A and Adler L. Physiology of osmotolerance in fungi. 1992. Adv Microbiol Physiol. 33:145–212.

8.       Leano, 2002. Ecology of straminipiles from mangrove habitats, in Fungi in Marine Environments, ed. K. D. Hyde, Fungal Diversity Press: Hong Kong.

9.       Barata, M. 2002. Fungi on the halophyte Spartina maritima in salt marshes, in Fungi in Marine Environments, ed. K. D. Hyde, Fungal Diversity Press: Hong Kong.

10.     Kumaresan, V., Suryanarayana, T.S. and Johnson, J.A. (2002). Ecology of mangrove endophytes. In: Fungi in Marine Environment (ed. K.D. Hyde) Fungal Diversity Research Series 7: 145-166.

11.   Curtis, M.P. and Reddy, J., 2015. Organization and positive psychology with diversity. Indian Journal of Science and Technology, 8(36).

12.   Muthezhilan, R., Vinoth, S., Gopi, K., and Jaffar Hussain, A. (2014). Dye Degrading Potential of Immobilized Laccase from Endophytic Fungi of Coastal Sand Dune Plants. International Journal of ChemTech Research, 6(9), 4154-4160.

 

 

 

Accepted on 22.10.2017      © RJPT All right reserved

Research J. Pharm. and Tech 2017; 10(12): 4386-4388.