Available online www.jocpr.com Journal of Chemical and Pharmaceutical Research, 2017, 9(10):152-158 Review Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 152 A Review on Endophytic Actinomycetes and their Applications Gayathri Segaran, Ranjitha Dhevi V Sundar, Sugashini Settu, Saranya Shankar and Mythili Sathiavelu * School of Bio Science and Technology, VIT University, Vellore, Tamil Nadu, India _____________________________________________________________________________ ABSTRACT Actinomycetes were also known as actinobacteria and there are Gram-positive, Spore forming, filamentous actinobacteria which usually contain about 57-75% of G+C content in their DNA. Actinomycetes are considered as a unique group of microorganism which locus between the true bacteria and the true fungi. Streptomyces genera occupy 50% of actinobacteria, in which 75% of commercially useful antibiotics produced by these genera. Pectinase, amylase, lipase, protease, cellulose and xylanase are industrially significant enzymes that are produced by the actinomycetes. About 22,500 bioactive compounds were produced by microbes, among this 17%, 38% and 45% were isolated from unicellular bacteria, fungi and actinomycetes respectively. The main aim of this review is to determine the various applications of endophytic actinomycetes. Keywords: Endophytic actinomycetes; Streptomycetes; Antimicrobial activity; Enzymes; Bioactive compounds _____________________________________________________________________________ INTRODUCTION Actinomycetes were also known as actinobacteria, derived from the Greek word where aktis refers to "lightning" and mykes refers to the fungus which was originally classified as an interposed group between fungi and bacteria [1]. Waheeda K et al. reported that endophytic microorganisms are those which do not cause any immediate and negative effect while colonizing living internal tissue [2]. Actinomycetes are considered as a unique group of microorganism which locus between the true bacteria and the true fungi. Nearly all plant species serves as a source for endophytes and accepted as a promising source of novel medicinal compounds [3]. Using microorganism 23,000 of active secondary metabolites was produced, in that 10,000 were isolated from actinomycetes. Of these, Streptomyces species produces 7,600 bioactive compounds. Depending upon the source of isolation the biological function of actinomycetes varies [4]. As like plants, endophytic microorganism has the capacity to produce secondary metabolites thereby it serves as an optimistic source for the novel compound [5]. Although previous studies reported that several bio-pharmacological compounds were isolated from endophytes with activities such as antiviral, anti-inflammatory, antimicrobial and antitumor activities but there is less information about their antioxidant activities [3]. Axenic plant is a low-stress tolerance which is considered to be a partial absence of endophytic microbes [6]. When the endophyte affects the plant it grows faster in compare to the unaffected plants [7]. If the leaves are pretreated with heteroauxin and zircon solution it results in adequate isolation of actinomycete [5]. Based on the method of isolation, actinomycetes diversity varies [2]. The organization and diversity of endophytic actinomycetes are very much important to know about their ecological roles and also it helps in the screening of beneficial strains. Using terminal restriction fragment length polymorphism (T-RFLP) density of the endophytic actinobacteria in wheat roots can be identified [8]. Varieties of natural products are produced and medicinal property can be improved by the plants which have ethno-botanical history that serves as the reservoir of endophytic actinomycetes [9].