**1. Introduction**

The quest for novel biologically active secondary metabolites from microorganisms continues to rise due to emergence of drug resistance in pathogens causing life threatening diseases around the globe [1]. Particularly, methicillin resistant *Staphylococcus aureus* (MRSA) and methicillin resistant *Staphylococcus epidermidis* (MRSE) strains are not only exposed to hospital-acquired infections but also to community-acquired infections [2]. The mortality and morbidity associated with these infections are largely affecting economic conditions of patients and hospitals [3]. Therefore, there is an urgent need for developing novel and effective antimicrobial agents to overcome or delay acquired resistance to existing drugs. Reactive oxygen species (ROS) play an important role as signaling molecules involved in mitogenesis. However, high generation of ROS during aerobic metabolism creates oxidative stress within the intracellular milieu causing oxidative damage to cells [4]. The oxidative stress caused is often associated with many human diseases including cancer, diabetes [5], cardiovascular [6], and neurodegenerative diseases [7]. In order to withstand the oxidative stress caused, cells or organisms make use of antioxidants, that are able to block or delay the damage caused by several possible mechanisms such as halting chain reactions, preventing the formation of free radicals, neutralizing the singlet oxygen molecule, promoting anti-oxidant enzymes, and inhibiting pro-oxidative enzymes [8]. Formation of free radicals can be prevented by antioxidant systems present within the cells. However, these defense mechanisms are insufficient to prevent the damages that arise, therefore exogenous antioxidants through dietary intake and supplements are required [9]. Natural antioxidants are found abundantly in metabolites produced by microorganisms. These products have consistently been considered as mainstay for drugs with various interesting biological activities [10]. They are considered to be an excellent scaffold for the formulation and development of antibiotics, antioxidants, immunomodulators, enzyme inhibitors, anticancer agents, plant growth hormones, and insect control agents [11]. With many improved techniques under combinatorial chemistry for high throughput findings of novel compounds, natural products from microbial sources have been screened extensively and gained much attention owing to their massive chemical and biological diversity [12]. Under various screening strategies, the rate of discovery of natural products has increased many folds, of which around 22,250 bioactive compounds are of microbial origin [13]. Among microorganisms, actinomycetes have contributed nearly 45% of all the reported metabolites [14].

A major group of natural products from microbial origin have been identified from organisms that inhabit the soil. Since soil itself is a mixture of minerals and organic matter, the filamentous bacteria are predominantly more present in the gaps between the soil particles than their unicellular counterparts [15]. Actinobacteria are ubiquitous in soils. They are responsible for biodegradation and biodeterioration processes in nature. Their flexile and proven abilities have prompted biologists to screen these organisms from unexplored niche habitats in order to obtain novel molecules [16].

Western Ghats of India is considered as one of the global biodiversity hotspots covering an area of 180,000 km2 and harbors numerous species of plants, animals, and microbes [17]. The unique biodiversity of Western Ghats is conserved and protected by wildlife sanctuaries, national parks, and biosphere reserves situated in states where hill ranges run through, like Karnataka, Gujarat, Tamil Nadu, Maharashtra, and Kerala [18]. The forest regions in Western Ghats are largely underexplored, though in recent times few studies were carried out for bioprospection. Ganesan et al. [19] reported larvicidal, ovicidal, and repellent activities of *Streptomyces enissocaesilis* (S12–17) isolated from Western Ghats of Tamil Nadu, India. Actinobacterial strains isolated from Western Ghats soil of Tamil Nadu were reported to produce antimicrobial compounds against range of pathogens [20]. In the present study, the forest range in Western Ghats of Karnataka was studied for microbial population and taxonomical identification of potential actinobacteria. An attempt was also made to characterize microbial diversity for the potential to produce antioxidants and antimicrobial compounds.
