This research was aimed at evaluating the potentials of soil bacteria to elaborate L-asparaginase; an important therapeutic enzyme involved in the treatment of lymphoblastic leukemia. Fourteen soil samples were collected but pooled into seven composite samples to represent their various locations. The samples were analyzed using standard microbiological protocols. A total of 125 bacterial species were isolated by pour plate technique. Marian market dump-site soil (MMDS) sample harboured 26 (20.8%) of the isolated bacteria while Satellite Town dump-site soil (STDS) sample harboured 6 (4.8%) of the total bacteria. Results of the primary screening tests revealed that only 35 (28%) of total bacteria could elaborate L-asparaginase production potential by the rapid plate technique. However, only 6 (17.1%) of the positive bacteria could demonstrate such potentials in liquid medium. The six bacteria were preliminarily identified as species of the genera Pseudomonas, Corynebacterium, Bacillus, Erwinia and Escherichia. These results demonstrate the potentials of dumpsite bacteria to produce value-added biopharmaceutical products for applications in health care.
L-asparaginase (EC 18.104.22.168) belongs to a group of homologues amidohydrolases family, which catalyzes the hydrolysis of amino acid L-asparagine to L-aspartate and ammonia. They are naturally occurring enzymes expressed and produced by animal tissues, bacteria, plants and in the serum of certain rodents, but not in mankind (Muthusivaramapandian et al., 2008). Large number of microorganisms that include Erwinia carotovora, Pseudomonas stutzeri, Pseudomonas aeruginosa (Abdel-Fatteh et al., 2002) and Escherichia coli (Qin et al., 2003) has been known to produce L-asparaginase. Different types of asparaginase can be used for different industrial and pharmaceutical purposes.
Asparaginases are used to reduce the formation of acrylamide, a suspected carcinogen in starchy food products such as snacks and biscuit (Bansal et al., 2010). By adding asparaginase before baking or frying the food, asparagine is converted into another common amino acid, aspartic acid and ammonia (Lalitha and Ramanjaneyulu, 2016). L-asparagine is an essential amino acid used for nutritional requirement of both normal cells and cancer cells. Since several type of tumor cell requires l-asparagine for protein synthesis, they are deprived of an essential factor in the presence of L-asparaginase. This enzyme is widely used in the treatment of acute lymphatic leukemia. Lymphatic tumor cells require huge amount of L-asparaginase for malignant growth.
L-asparaginase + H2O L-asparaginase Aspartic acid + Ammonia (NH3).
L-asparaginase was produced by wide range of bacteria, fungi, actinomycetes, algae and plants (Prasad et al., 2013). Microbes are better source for the production of L-asparaginase, because they can easily be cultured, extracted and purified.
L-asparaginase has lots of medical and industrial applications. Ever since, L-asparaginase anti-tumor activity was first demonstrated, its production using microbial systems has attracted considerable attention owing to their cost effective and eco-friendly nature.
1.2 Objectives of study
The overall aim of the proposed study is the production of L-asparaginase (anti-cancerous) enzyme from bacteria.
Isolation of pure cultures of bacteria from .soil samples
Primary screening of purified isolates for L-asparaginase production
Secondary screening of positive bacteria for L-asparaginase production in liquid medium.