Recent Biotechnological Approaches - Essay Example

? Recent biotechnological advancements The process of production and enrichment of biological materials for the welfare of the mankind from the naturally available sources is the main task of biotechnology. Biotechnology combines the life science with the technology to derive many useful products. The knowledge of science mixed with the engineering concepts lead to the production of biotechnological products. Biotechnology is a part of our life. In every day activity we use many biotechnological products such as bread, curd, yoghurt, cheese, rice cakes, wine, beer etc., Nowadays we can see many products being advertised as being enriched with vitamins, minerals, amino acids and growth factors etc. These enrichments are only possible with Biotechnology. In the agriculture sector, many technologies are used such as genetic manipulation and gene transfer, development of recombinant vaccines, molecular markers, DNA-based disease diagnosis and characterization, embryo transfer and in vitro propagation of plants. In the food industry, the food processing is the main part where biotechnology intermission is required. For the improvement of the bacterial strains, genetic modification of the strains for the food processing microorganisms by the identification, characterization and alteration is done. Thus biotechnology has vast applications in many fields. Biofuels: As the fossil fuels are very limited, the search for the alternative methods that are renewable and safe are looked upon. The biological fuels such as ethanol, methane, hydrogen etc., are increasing day by day. To improve the production quality of these biofuels, the biotechnological approaches are used. The drawbacks of these methods such as low yield, high cost of feed, ad lack of active micro organisms can be overcome by using biotechnological approaches. The use of bacterial consortia, the processing of the raw materials into easily fermentable foods and strain improvement are some of the methods that are used in the biofuel industry. (Kalia and Purohit 2008). Hydrogen is one of the most promising alternate biofuel. The production of hydrogen is now carried using the chemical methods of refining oils and natural gas. The hydrogen production was increased in the E.coli strain using the genetic modification techniques. Here the metabolic pathway is altered. The glucose metabolism towards the metabolic pyruvate formate lyase pathway by interrupting the succinate producing and lactate producing pathways. (Yoshida et al. 2006). By this technique the yield of hydrogen was increased from 1.08 mol/mol glucose to 1.83 mol/mol glucose which is 190 percent increase in the yields when compared to the wild strain hydrogen production. (Yoshida et al. 2006). The maize is used for the production of biofuel nowadays. The distillery soluble waste obtained after the ethanol production called as dried distiller grain soluble (DDGS), is usually left out as cattle feed. The researchers have found that this DDGS has a lot of nutritional value and if the feed is improved with amino acid and vitamin content, it can be used for swine and poultry. (Ufaz and Galili 2008). Lignocellulostic biomass is widely used as the main source of sugars for the fermentation to biofuels and other energy sources. These sugars are present bound to the plant cell walls. The process of overcoming these barriers by the use of some break through technologies is termed as “biomass recalcitrance”. (Tomes and Lakshmanan 2010). Pretreatment of the biomass and then using it as the raw material for biofuel production will result in better yield. As lignin is not degraded easily by the protease enzymes, some modification to the substrate is very essential. Lignin hinders its active site form the enzymes and also binds reversibly to the proteins, because of this nature of lignin the enzymatic conversion is very less. So an alternative approach of increasing the pore size of the biomass can help to increase the enzymatic activity. Enzymes such as cellulase and hemicellulase are used for the pretreatment and the fermentation technologies were developed accordingly. Some type of fermentation strategies that are adopted for this biomass recalcitrance are Separate hydrolysis and fermentation (SHF), Simultaneous saccharification and fermentation (SSF), Hybrid hydrolysis and fermentation (HHF), Non-isothermal simultaneous saccharification and fermentation (NSSF), simultaneous saccharification and co- fermentation (SSCF), Consolidated Bioprocessing (CBP). (Tomes and Lakshmanan 2010). Of these techniques, SSF, NSSF and SSCF are more promising techniques. However these techniques require optimum temperature and raw material concentration and thermo - tolerant conditions. SSCF can ferment only six and five carbon sugars. For all these processes the greatest challenge lies in the identification and engineering of the micro organisms. Selection and engineering are major problems in the biofuel industry because most of the micro organisms use glucose as the sole carbon source and they use other carbon sources only under starvation conditions. (Tomes and Lakshmanan 2010). To overcome all these difficulties, Consolidated Bioprocessing is preferred. In this process more than one micro organism is used for the conversion of the raw materials. First one type of micro organism will convert the raw material into the easily accessible form and the other micro organism will convert this into bio-fuel. This method is quiet promising than other methods but it needs further engineering to improve the efficiency and yield. (Tomes and Lakshmanan 2010). Vitamins and amino acids: The plants are used as a factory to produce vitamins by altering the principal synthesizing routes. Vitamins are very essential to animals and human beings. The vitamins are not stored in the body. So they must be taken in every day. The plants are the simplest sources through which this essential nutrient can be supplied. The field crops biosynthetic pathways are much adoptable for the production of the essential amino acids, vitamins and other enzymes. So plant biotechnologies aimed at improving the level of amino acids and vitamins in the main food crops and satisfy the human requirements. Some of the important components incorporated are methionine in leguminous plants, lysine and threonine in cereals and Vitamin A and E in crucifiers and rice. (Job 2002). The increase in the concentration of Vitamin A in rice is the major achievement in the plant biotechnology. The transfer of four genes that are necessary for the production of pro vitamin A from Narcissus and Erwinia species into the endosperm of the rice has resulted in the production of Golden rice. Initially the transgenic lines don’t have provitamin A in their line, the engineered genes were able to accumulate 85% of the beta-carotenes in the rice, imparting yellow color to the rice endosperm, and hence the term golden rice was coined. This golden rice was a big promise for the poor and hunger persons as one solution for all their food requirements. The Recommended Daily allowance of beta – carotene was very less than the required quality when cooked, so Golden Rice 2 was developed by altering the daffodil gene with that of a maize gene. Four units of beta carotene from the rice gets converted into one unit of carotenoids in human. (Paine et al. 2005). Lysine, methionine and tryptophan are present at a lower concentration in the plants. So enriching these amino acid values in food was targeted by many. Maize was enriched with lysine and tryptophan amino acids. This amino acid incorporation has increased the quality of the protein and the nutritional value. The High quality maize protein cultivars were developed by genetic engineering and its (LY038) use commercially is approved in many countries. The processes of improving the amino acids tryptophan and methionine have cleared the basic studies. Another important advantage of genetically engineered traits is that the same approach can be used for multi species level and can expect the same level of success in many. (Ufaz and Galili 2008). By understanding and altering the metabolic pathways of these plants, we can improve the crop quality. Site directed mutagenesis was used for this approach. The use of seed specific promoters for targeting the dihydrodipicolinate synthase (DHDPS) has produced lysine rich seeds. (Ufaz and Galili 2008). The lysine enhancement was done in Arabidopsis and tobacco plant seeds. The Met-lupin is the second successful GM crop that has proved beneficial in feeding trials. (Ufaz and Galili 2008). Agro bacterium mediated gene transfer and cloning strategies are used to improve and regulate the ketacarotenoids present in the unicellular green algae Haematococcus. This green alga produces a type of ketacarotenoid called as astaxanthin, which has pharmaceutical applications. It is a very good anti-oxidant. The plasmids were constructed using the reporter genes with selection marker genes. The co-cultivation of Agrobacterium and Haemococcus was done to transfer the cloned gene from the agrobacterium into the Haemococcus sp. (Kathiresan and Sarada 2009). Before starting agrobacterium mediated gene transfer in the micro algae, it is important to know the antibiotic sensitivity of the algae. This produced greater quality of Haemococcus than the particle bombardment method that was tried in the past. (Kathiresan and Sarada 2009). The Secondary metabolites are produced mainly by the filamentous fungi. Hence strain improvement of fungi can lead to the increase in the product yield. The strain improvement is performed by using random mutagenesis, screening and protoplast fusion. Genetic engineering and protein engineering are also used for the refinement of the products. Post translational modification of the gene, screening these genes by using a specific medium are the well known techniques adopted. Filamentous fungi are used for the production of antibiotics, organic acids and many bioactive compounds, enzymes and more products in the food industry. The most common techniques that are used for fungal strain improvement are Sexual crossing, Somatic crossing which includes hyphal anastomosis , protoplast fusion, random mutagenesis And screening of the fungal strains, Genetic engineering of the strains for the production of new qualities, etc.(Khachatourians and Arora 2001). Mutagenesis is successful in the improvement of the penicillin production in Penicillium chrysogenum, and enzymatic yields in Aspergillus sp., Genetic strain improvement is also further accompanied by process optimization programs which helps to obtain the best results out of a strain. The process optimization enables the microbes to utilize the carbon, nitrogen and other nutrient sources effectively and produce the product with greater yield. Other techniques used include, PEG –mediated protoplast transformation, electroporation, micro projectile bombardment of intact conidia and transformation of germinated conidia with lithium salt content. (Khachatourians and Arora 2001). The fungal gens are also mutated by using the site –directed mutagenesis through restricted enzyme mediated integration (REMI) and transposon mutagenesis by using polymerase chain reaction (PCR). The understanding of the genome sequence and the protein involved in the synthesis of the desired antibiotics, aminoacids can help to improve the strain. The characterization of the protein involved in the pathway can be done using the NMR spectroscopy. (Khachatourians and Arora 2001). The use of metabolic engineering for improving the strain, is more successful than the traditional methods. Metabolic engineering allows for the elimination of the by products from the pathway. This method is more beneficial as it eliminates some steps of downstream processing. Similarly there are no unexpected side effects like mutations in this process. The directed genetic modification process naturally eradicates the side effects. Metabolic engineering is used to design the micro organisms according to our needs. This will result in improved fermentation processes. (Brakage 2004). Antibiotics: Antibiotic production improvement is done by altering the metabolic flux. The fluxes are improved in the biosynthetic pathway to get the desired yield. Identification of the flux and improving them will improve the genes that are present in the flux and the expression rate will be very high. Metabolic engineering along with Genetic Engineering has proved to be the alternative technique for the traditional method of random mutagenesis and screening. Streptomyces is a more promising strain for the production of many antibiotics. The antibiotics are produced as secondary metabolite by the fungal strains. These antibiotics production is regulated by the metabolic pathways. Altering the metabolic pathway can increase or decrease the yield. (Chen, Smanski and Shen 2009).This is done for Streptomyces kanamyceticus strain developed from the wild type strain. The southern blot analysis and DNA sequencing methods have proved that amplification process was carried out for the entire kanamycin gene present in the chromosome. The amplified 145 kb gene is the largest Amplifiable unit of DNA ( AUD) so far reported. Rifamycins are also produced in the same way. (Jun- Shan et al. 2009). Thus the amplification using genetic engineering techniques has resulted in the increase in the kanamycin yield. (Yanai, Murakami and Bibb 2006). For the enrichment of vitamins, amino acids in the food industry , the strain improvement and genetic engineering methods were used. For the production of antibiotics, gene amplification, genetic modification, Gene insertion and deletion are practiced. The increase in the biofuel production was carried out by altering the metabolic fluxes in the pathway and by introducing mutation in the genes. References: Brakage, AA 2004, Molecular biotechnology of fungal [beta]-lactam antibiotics and related peptide synthetases, Springer. Chen, Y., Smanski, MJ and Shen, B. 2009, “Improvement of secondary metabolite production in Streptomyces by manipulating pathway regulation,” Applied microbiology and Biotechnology, vol.86, no.1, pp.19 - 25. Job, D 2002, “Plant Biotechnology in agriculture”, Biochimie, vol.84, pp.1105-1110. Jun-Shan, C., Jing-wei, Z., Wen-Qing, Q., Shao-hui, XY., Hui, K., and Jin-heng, H 2009, “Ion injection method used to select and cultivate rifamycin strain and the improvement of fermentation conditions,” Hebei Journal of Industrial Science and Technology. Kathiresan, S., and Sarada, R 2009, “Towards genetic improvement of commercially important microalga Haematococcus pluvialis for biotech applications,” Journal of Applied Phycology, vol.21, pp.553-558. Kalia, VP and Purohit, HJ 2008, “Microbial diversity and genomics aid of bioenergy,” Journal of industrial Biotechnology and microbiology, vol.35, no.5, pp.403-419. Khachatourians, GG and Arora, DK. 2001,Applied Mycology and Biotechnology, Springer. Paine, JA., Shipton, CA., Chaggar, S., Howells, RM., Kennedy, MJ., Vernon, G., Wright, SY., Hinchliffe, E., Adams, JL., Silverstone, AL., and Drake, R. 2005, “Improving the nutritional value of Golden Rice through increased pro-vitamin A content”, Nature Biotechnology, vol.23, no.4, pp.482-487. Tomes, D., and Lakshmanan, P 2010, Biofuels: Global impact on renewable energy , product agriculture, and technoligcal advancements, Springer. Ufaz, S and Galili, G 2008, “Improving the content of essential aminoacids in crop plants :Goals and opportunities,” Plant physiology, vol.147, pp. 954-961. Yanai, K., Murakami, T., and Bibb, M 2006, “Amplification of the entire kanamycin biosynthetic gene cluster during empirical strain improvement of Streptomyces kanamyceticus,” Proceedings of National Academy of Sciences, vol.103, no.25, pp.9661-9666 Yoshida, A., Nishimura, T., Kawaguchi, H., Inui, M., and Yukawa, H 2006, “Enhanced hydrogen production from glucose using ldh- and frd- inactivated Escherichia coli strains,” Applied microbiology and Biotechnology, vol.73, no.1, pp.67-72. Read More