Isolation and characterization of different strains of Bacillus licheniformis for the production of commercially significant enzymes Maria Ghani, Asma Ansari, Afsheen Aman, Rashida Rahmat Zohra, Nadir Naveed Siddiqui and Shah Ali Ul Qader* The Karachi Institute of Biotechnology and Genetic Engineering, University of Karachi, Karachi, Pakistan Abstract: Utilization of highly specific enzymes for various industrial processes and applications has gained huge momentum in the field of white biotechnology. Selection of a strain by efficient plate-screening method for a specific purpose has also favored and boosted the isolation of several industrially feasible microorganisms and screening of a large number of microorganisms is an important step in selecting a potent culture for multipurpose usage. Five new bacterial isolates of Bacillus licheniformis were discovered from indigenous sources and characterized on the basis of phylogeny using 16S rDNA gene analysis. Studies on morphological and physiological characteristics showed that these isolates can easily be cultivated at different temperatures ranging from 30ºC to 55ºC with a wide pH values from 3.0 to 11.0 All these 05 isolates are salt tolerant and can grow even in the presences of high salt concentration ranging from 7.0 to 12.0%. All these predominant isolates of B. licheniformis strains showed significant capability of producing some of the major industrially important extracellular hydrolytic enzymes including α-amylase, glucoamylase, protease, pectinase and cellulase in varying titers. All these isolates hold great potential as commercial strains when provided with optimum fermentation conditions. Keywords: B. licheniformis, commercial enzymes, amylolytic enzyme, protease, pectinase. INTRODUCTION Utilization of bacterial strains specifically from genus Bacillus is gaining momentum because of their ability to resist and survive under harsh industrial conditions. Bacillus licheniformis, Bacillus subtilis and Bacillus pumilus are some of the strains that are associated with food spoilage and with a wide range of different clinical conditions (Turnbull, 1997). B. licheniformis has proved itself as a multipurpose organism and has gained popularity along with B. subtilis. B. licheniformis is most commonly found in soil and as well as on the feathers of ground dwelling birds (Burtt and Ichida, 1999). With the rapid advancement in enzymology and fermentation technology, now commercially feasible quantities of different industrial enzymes are being produced by B. licheniformis (De-Boer et al., 1994). This strain is also used to produce a polypeptide antibiotic known as bacitracin (Vitkovic and Sadoff, 1977). B. licheniformis is capable of producing bacteriocin under aerobic conditions (Kayalvizhi and Gunasekaran, 2008; Anthony et al., 2009) as well as under anaerobic conditions against anaerobic microorganisms (Pattnaik et al., 2001). B. licheniformis in addition is a frequent contaminant of various industrial processes (Pirttijarvi et al., 2000). Although this organism is exploited industrially for the large-scale production of various enzymes, but it’s generally regarded as safe (GRAS) status is still a subject of debate (Salkinoja et al., 1999). This organism has been reported to produce some of the most important commercial enzymes including α-amylase, alkaline protease, keratinase and β-mannanase (Zhang, et al., 2002; Feng et al., 2003; Hmidet et al., 2009). It has been reported that B. licheniformis 749/C is a producer of multiple forms of β- lactamase (Lampen et al., 1980) and similarly another isolate BAS50 which was previously isolated from a petroleum reservoir at a depth of 1,500 meters, produces a lipopeptide surfactant (Yakimovet al., 1995). Most recently this organism has shown the ability to synthesize gold nanocubes and in broad prospect this isolate can be manipulated genetically for the synthesis of nanoparticles with tailored properties (Kalishwaralal et al., 2009). Keeping the significance of multiple uses of Bacillus licheniformis in view, present study was designed to isolate and screen various strains from indigenous sources for the production of commercially important enzymes. MATERIALS AND METHODS Isolation of bacteria Soil samples (1.0g) from vegetative field were collected aseptically and suspended in 100 ml of sterile water. Diluted sample was transferred in multiple flasks containing nutrient broth medium and incubated at 37ºC for 24 to 72 hours. After appearance of growth, a loop full of bacterial culture was then streaked onto nutrient agar medium and again incubated at 37ºC for 24 to 48 hours. *Corresponding author: e-mail: saqader@uok.edu.pk Pak. J. Pharm. Sci., Vol.26, No.4, July 2013, pp.691-697 691