Endophytic Fungi As Novel Resources Of Natural Therapeutics
Inconsistent use of certain prevalent antimicrobial drugs in the treatment of infectious diseases continuously generates a mysterious problem of antibiotic resistance. Many of the widely used antibiotics are found to be less effective against both Gram positive and Gram negative pathogens, thereby an urgent requisite on the discovery natural antibacterial compounds. Frequent reports on the identification of highly active metabolites with antimicrobial activity from the cultured endophytic fungi seem it as dependable source.
Fungal endophytes are ubiquitous in all plant species, an estimate of one million uncharacterized endophytic fungal species are existing in the whole plant kingdom. The major advent over the endophytes are their ability to synthesize plenty of diverse existing and novel chemical entity/secondary metabolites with remarkable bioactivity. The structurally diverse group of bioactive compounds encompasses alkaloids, flavonoids, phenols, steroids, terpenoids, xanthones, benzoquinones etc. The interaction between fungal endophytes and plants are inconstant, it may vary from mutualism to pathogenesis. At the endophytic state, fungi exhibited a symbiotic association by attaining nutrients and protection from the host and rendering some secondary metabolites to boost up host defense mechanism, growth condition etc. This give rise to alteration in some morphological and chemotypic characters, conjointly influences the life history traits of certain fungus and the host plant. Withania somnifera (L.) Dunal, popularly known as ashwagandha or as Indian ginseng is a commercially important medicinal plant. The dried roots are widely used in Ayurvedic medicine. The plants seems an effectual synthesizer of many secondary bioactive metabolites and are felicitous for treating many chronic diseases. Plant parts especially roots are used as a major component in the preparation of many rasayana herbs, which possess a broad spectrum remedial properties like memory enhancer, antistress, nerve tonic, immunomodulatory, cardioprotective, neuroprotective, antidiabetic and antioxidant.
A few endophytic works are only conducted with W. somnifera with regard to their microbiome, however it was not sufficient for exploring its maximal potencies. Thus we are enforced a farther exploration with W. somnifera for its microbiome.
Penicillium setosum isolated from the W. somnifera was used herewith for the evaluation of its antibacterial action. Since the discovery of penicillin, Penicillium species are remarkable for their antibacterial compound production. After this discovery, many other effective bioactive compounds are also isolated from Penicillium sp. with various pharmacological action such as anticancer, antifungal, anti-inflammatory and so on. The members of genus Penicillium, are widespread in nature. Very often, novel Penicillium spp. have been isolating and reporting from diverse environmental conditions such as from soil, air, food, leaf litter, fynbos biome etc. Many researchers are tend to be focused on the Penicillium spp isolated from unexplored habitat for the exploitation and discovery of its secondary bioactive metabolites. Thereby this microbial source has been continuously subjected for investigation and considered as a major source for drug discovery. A mass array of compounds could be present in an extract, so it won’t be tough to check the antibacterial activity of each compound separately. So bioautography technique was implemented in this study for the screening of antibacterial compounds. The method is an excellent and fastest tool to analyze and interpret the chemical nature of susceptive antibacterial compound present in the crude extract, which is applicative for all samples with disregard of their origin (from a plant extract or microbial extract). Bacteria’s become terrifically increasing their resistance, therefore a nimble screening of antibacterial compound from variable natural sources, could effectively concluded within short period of time.
Many bacteria can attach to surface of either living or inert, resulted in the formation of complex aggregation known as biofilms. So it is found in all environment, wherever bacteria exist. This obviously confer a major disquiet in the public heath related issues because of their active participation in the development of certain infectious diseases as well as device-related infections. It was also very common in food industry by affecting serious hygienic problems and economic losses due to food spoilage. Microbial assemblage are found to be ineffective against many conventionally using antibiotics, disinfectant etc. So the compounds that kill or inhibit the growth of bacteria want to be checked for their interference with biofilm formation.
