Absract Archive   October 2008 Research Article Screening and Characterization of Biopolymers Polyhydroxybutyrate producing bacteria Abstract Four PHB producing bacterial colonies were isolated from the industrial effluents. However, only one bacterial colony among others yielded maximum PHB. Bacteria from this colony was characterized by morphological, biochemical and molecular probes and identified as Bacillus cereus SKC. The maximum PHB yield was recorded 18.7 and 8.2 % (w/w) dry weight basis respectively with glucose and maltose as the carbon source at pH 7.5 and temperature 400C. However, the PHB yield varies with pH, temperature, carbon, nitrogen and phosphorous source. The PHB was further subjected to FTIR and NMR spectroscopy. The PHB has shown characteristic NMR spectrogram by which the two PHB produced separately in presence of glucose and maltose could be easily distinguished. Keywords: Bacillus cereus SKC, Biopolymer, Polyhydroxybutyrate, Fermentation, Plasmid cure test, Polymerase chain reaction, Introduction The interest in the polyhydroxybutyrates (PHB) is increasing owing to its potential applications in medicine and agriculture. Some of the major applications of PHB are in drug delivery in developing medical sutures (Shih et al., 2006; Holmes, 1985) and bone marrow scaffold, tissue engineering devices and agricultural products (Chen, 2005). Chemically, PHB is equivalent to a very basic polymer, the polyhydroxyalkanoates. PHB was first described from Bacillus megaterium by Lemoigne (1926). PHB is a very common and widespread storage material as energy reserve in many microorganisms viz., Alcaligenes, Azotobacter, Bacillus, Nocardia, Pseudomonas, Rhizobium etc (Kato et al., 1992). There are many reports available on screening and identification of microorganism primarily aimed to isolate high PHB yielding microorganisms. However, reports are also available describing enhanced PHB production from microorganisms under various stress conditions and in response to various fermentation conditions such as pH, temperature and levels of carbon, nitrogen and other sources. Recently, Ralstonia eutropha have been identified as high PHB yielding bacteria even under very low glucose level (Alfredo et al., 2006). Similarly, Rhodobacter sphaeroides, photosynthetic bacteria produce very high amount of PHB when supplied with acetate as carbon source (Sangkharak et al., 2008). Valappil et al. (2006) have identified and characterized Bacillus cereus SPV that produce large amount of PHB with desirable material properties. These authors have also described the efficient recovery of the PHB from these newly characterized bacteria. Perhaps, currently PHB is being produced from Alcaligenes eutrophus (Fuller, 1990). The relatively high cost of PHB production compared to other polymers, the fermentation processes, substrates and product recovery have severely restricted its widespread applicability in various sectors (Shahhosseini, 2004). However, several studies have been undertaken to tackle this problem using different approaches (Yu, 2001; Chen et al., 2001; Marangoni et al., 2002 and Leibergesell et al., 1991). PHB productivity reported by several researchers, employing different microbes, substrates, and culture modes, ranges form 0.015 3.97g/l (Kim et al., 1992; Lee et al., 1995). The aim of the present study is to isolate and identify the high PHB yielding microorganism from industrial effluents and to optimize the fermentation processes in order to achieve enhanced PHB yield. About the Authors: 1 2Sarika Shiven Nair, 1Harish Reddy and 2Deepak Ganjewala 1Global Institute of Biotechnology, 3-6-276/2, Sai Triveni Chambers, Himayat Nagar Hyderabad-500029. (A.P.), India. 2Plant Biotechnology, School of Biotechnology, Chemical and Biomedical Engineering, Vellore Institute of Technology University, Vellore - 632 014 (T.N.), India For Correspondence Deepak Ganjewala Email: deepakganjawala73@yahoo.com Harish Reddy Email: whyharish@gmail.com Short Communications ONCOMIRS - “MicroRNAs with a role in cancer” Cancer is caused by uncontrolled proliferation and the inappropriate survival of damaged cells, which results in tumor formation. Cells have developed several safeguards to ensure that cell division, differentiation and death occur correctly and in a coordinated fashion, both during development and in the adult body. There are many regulatory factors which switch on or off tumour-suppressor genes and oncogenes involved in directing cellular proliferation and differentiation. Damage to these genes leads to tumorigenesis (He, L. et al., 2005). Earlier studies on cancer focused on protein-coding genes as most tumour suppressor genes and oncogenes are first transcribed from DNA into RNA, and are then translated into protein to exert their effects. But recent evidences indicate that small, non-protein-coding RNA molecules, called microRNAs (miRNAs), also function as tumour suppressors and oncogenes. MicroRNAs which are involved in tumorigenesis are called oncogenic miRNAs (oncomiRs). MicroRNAs MicroRNAs are small, non-coding, single-stranded RNAs of 18 to 24 nucleotides and constitute a novel class of post-transcriptional gene regulators that are found in both plants and animals. They are encoded in the genome and are localised on fragile chromosomal sites. Each miRNA has multiple target sites. There are estimated to be at least 300 miRNAs in the human genome, comprising ~ 1-4% of all expressed human genes making them one of the largest class of gene regulators. Biogenesis of MicroRNAs and Target Recognition MicroRNAs are first transcribed by RNA Polymerase II into large precursor RNAs, often several kilobases in length, called pri-miRNAs. In the nucleus, these pri-miRNAs are capped and polyadenylated prior to being processed by the RNase III enzyme, Drosha, and the double-stranded- RNA-binding protein, Pasha (also known as DGCR8), into ~70-nucleotide pre-miRNAs, which fold into imperfect stem-loop structures. The pre-miRNAs are then exported into the cytoplasm by the RAN GTP dependent transporter exportin 5. They undergo an additional processing step in which a double-stranded RNA of ~22 nucleotides in length, referred to as the miRNA:miRNA* duplex, is excised from the pre-miRNA hairpin by another RNAse III enzyme, Dicer. Subsequently, the miRNA:miRNA* duplex is incorporated into the miRISC complex as shown in Figure 1. The mature miRNA strand is preferentially retained in the functional miRISC complex and regulates its target gene by one of the two mechanisms........ Authors:Salma Mukthar Mir, P. Rajasekaran. Short Communications A simple strategy to purify Cyanobacterial cultures Abstract The isolation of pure cyanobacterial culture from heterotrophic bacteria, fungi and actinomycetes contaminated culture is a difficult task. In order to overcome the above task, a new strategy has been developed employing the double distilled and tap water as a medium having the pH of 7.12 and 8.65 respectively. Compared to double distilled water, tap water had less efficiency in this process. Through this process, the cyanobacteria culture contaminated with bacterial contaminants is obtained as a pure culture. Key Words: Cyanobacteria, bacterial contamination, pH, double distilled water Introduction The isolation of Blue Green Algae (BGA) from other contaminates like bacteria, fungi and actinomycetes has been a difficult task. The growth rate of the cyanobacteria is very low when compared to the growth of contaminating bacteria and fungi which results in the depletion of nutrients from the medium. The carbohydrates synthesised by BAG such as glucose, mannose, xylose and ribose (Parikh and Madamwar, 2006) can be used as a carbon source for the contaminants. The bacterial contaminations have been continuously checked by plating on Luria broth (LB) and incubated at 37º C (Henson et al., 2004). Due to the presence of contaminations, the estimation studies of chlorophyll, genomic DNA and an extra cellular study of polysaccharides and protein profile have been affected. Incase, if the contaminated BGA cultures which have a resistant to lysozyme, the pure genomic DNA of those BGA can be isolated employing lysozyme along with Dnase. The use of Lysozymes and Dnase was not cost-effective. Various approaches (Allen, 1952; Ferris and Hirsch, 1991) have been tried to develop more-efficient methods to purify contaminated cyanobacteria. This includes mechanical separation of the cyanobacteria and bacterial contaminants by micromanipulation, differential filtration and repeated transfer of cells (Allen, 1952). Other approach involves the use of an agent which was judged to be relatively harmless to the cyanobacteria but toxic to the bacterial contaminants. The various process parameters which are used for pure culture are phenol, sodium hypochlorite, detergents, sodium sulfide, UV or gamma irradiation, elevated temperature, and antibiotics (Ferris and Hirsch, 1991). Authors:Elango. V, Yuvakkumar. R, Rajendran. VJegan. S, Kannan. N. Review From in vivo Murine to in vitro Human Lymphocyte Immunizations - The changing face of Hybridoma Technology 1. Introduction 1.1. The immune system and adaptive responses The immune system is comprised of many different organs and tissues that are found through out the body. The lymphocytes are the central cells of the immune system, constituting 20 - 40 % of the body's white blood cells and are responsible for adaptive immunity and immunological attributes of diversity, specificity, memory, and self/ non self recognition. These lymphocytes circulate continuously in the blood and lymph, and are capable of migrating into tissue spaces and lymphoid organs, thereby providing a high degree of cellular integrity to the immune system. Adaptive immunity comprises of humoral and Cell-mediated responses. Humoral response involves the interaction of the B cells with antigen, resulting in their proliferation and differentiation into antibody secreting plasma cells. These antibodies serve as the effectors of humoral response facilitating neutralization and/or elimination of the antigens. Cell mediated immunity or cellular immunity is mediated by the effector T cells generated in response to an antigen and their products (such as cytokines). (1, 2, 3). A polyclonal humoral response is comprised of antibodies, derived from various clonal populations having varying specificities (for different epitopes, on the same immunogen), affinities and classes, and hence provides an effective defense against pathogens. On the other hand, monoclonal humoral response is comprised of antibodies (MAbs) that are derived from a single clone and are hence specific for a single epitope on a complex antigen and have a defined affinity for that epitope. (1,2) .... Author: M. Ravi. Mini Review Recent advancement in Typhoid research - a review Abstract Typhoid fever is endemic in South and Central America, the Middle East, South East and Far East Asia and the Indian subcontinent. It is estimated that more than 33 million cases of typhoid fever occur annually causing more than 500,000 deaths. Salmonella organism are extensively distributed in nature and causing widespread of disease in men and animals. Salmonella enterica serotype typhi causes typhoid fever, which is classically characterized by fever, headache, rose-colored rash, abdominal pains, diarrhea, paradoxical bradycardia and various other symptoms. This article discuses and summarizes important work in the literature in response to the epidemiology of typhoid fever, salmonella related to international trade and use of animal model to study typhoid. In this communication, we also reviewed the pathogenesis of Salmonella organism, diagnosis of typhoid fever and its treatment. Vaccination in relation to typhoid fever has been also focused. This review will let the reader to have a retrospective study on typhoid in concerned with Salmonellae. Key words: Salmonellae, typhoid fever, vaccine, pathogenesis, drug resistance Introduction Typhoid fever is an infectious disease of global distribution (House et al., 2001). It is a systemic infection caused by Salmonella enterica serotype typhi, remains an important worldwide cause of morbidity and mortality (Crum, 2003). It is a prolonged febrile illness and continues to be a health problem in developing countries where there is poor sanitation, poor standard of personal hygiene and prevalence of contaminated food. It is endemic in many parts of the developing world, and as global travel increases, illness can and do occur around the world in span of a day (Lifshitz, 1996). In urban areas where sewage disposal is lacking or inadequate, water supplies get contaminated and thus cause the outbreaks of typhoid. The contamination of food by carrier is the second most frequent route of infection (Hornick, 1985). A number of reports on typhoid were made ( Sharma et al., 2005; Toovey, 2006; Hirschhorn and Greaves, 2007; Stejskal, 2007; Ochiai et al., 2008). Authors:K.H.Khan, Deepak Ganjewala K.V. Bhaskara Rao.