The advances in biotechnological field have made it possible to understand the genetic role behind molecular mechanisms to large extents. This in depth understanding of biological processes has paved ways to treat the untreatable aiding the human existence in multitudes of aspects like food, health, bioremediation, mining, biopharmaceutical production and much more. This microbial world is vast and has been a platform for human beings to explore their biological systems as they are simpler cells and can be manipulated with much ease than complex systems. The DNA harnessed within the cells are the molecular entities that have been targeted via recombinant DNA technology (RDT) or genetic engineering to direct the cellular machinery in the desired direction for production of certain metabolites or research for understanding biological procedures by creating genetically modified organisms or GMO’s. In its initial years, RDT was focused on transferring gene from one organism to another which was advancement over traditional selective breeding. Gradually, the technological development has made it possible to directly edit the gene of interest in the organism’s genome.
Genetic Engineering of Microbes to GMM’s
The genetically modified microorganisms (GMM) are created via genetic manipulation of native microorganism cells through genetic engineering that have proved beneficial in many aspects for the humans. The aim is the development of a desired trait in a suitable host organism that is able to enhance the yields or perform other functions that its wild counterpart is not able to do. The gene of interest is identified that could be from the same microorganism or from a different one, then the appropriate methods are employed for introduction of altering of interested gene in the host genome and finally the GMM is grown in sufficient cell densities to obtain the resultants. The RDT procedure here consists of several tools and techniques that are selected based on the type of biological cell being altered. The basic outline of this process includes the selection of gene transfer method firstly, followed by construction of the cloning vector with incorporated gene insert, then the promoters are selected for controlling gene expression and finally the resulting recombinant cells are identified through expression of selectable markers (Han, 2004). Commercially important GM microbes such as Escherichia coli, yeast, Bacillus, Corynebacterium, Pseudomonas, Streptomyces and Aspergillus are to name a few that have been employed in commercially important applications like food fermentation and production of antibiotics, amino acids, vaccines, therapeutic proteins.
Gene Transfer Methods
The gene of interest are identified as per the desired trait and once found, it needs to be transferred in the host cells via several methods like biotransformation, biolistic, gene gun, electroporation, conjugation under optimal cell growth, ionic, growth phase and all cellular conditions. Many of these work for microbes but transformation is the best applicable method as cloned plasmids are taken up by host cells subjected to their competence abilities by either treating with calcium chloride or by polyethylene glycol mediated fusion of protoplast and plasmid DNA. Electroporation can be done by making the recipient cells electro-competent transiently by exposing the microbial cells to high pulse voltage (Han, 2004). Conjugation is performed by mixing donor cells and receiver cells whereby the desired genes are transferred from the former to later due to presence of origin of transfer (oriT) on the plasmid DNA.
Cloning Vector Construction
Vector is a vehicle that carries the desired gene into the host cells and has other elements like promoters, selectable markers for selection. Cosmids, bacterial artificial chromosomes and plasmids are preferred for microbes that are designed depending on the type of transferring gene and the resulting application of recombinant microbe. The inducible promoters like lac promoter or arabinose promoters are incorporated to control the gene expression. Finally, the recombinant cells are selected via selectable marker gene that differentiates the recombinants from the non- recombinants. Antibiotic resistance genes are commonly used for the purpose but food industry applications avoid these genes and others like YAP1 in yeast cells are used.
Social & Ethical Implications
The applications of biotechnology are wide and the genetic engineering employs manipulating the natural entities that need to be discussed and explored from all aspects via bioethics to ensure its safety for entering the biological world. Thus, the benefits offered by GMM’s are not the only factors considered when evaluating its implications on the society. Recombinant insulin and growth hormones in 1984 produced from recombinant microorganisms were the first ever genetically manipulated products that came into market for human use.
One of the major concerns is the intended cross-species genetic transfer that is not nature derived but is human derived. The prominent questions that arise are the risks posed by such exchanges and should humans be performing such actions. The public concerns have been reported that consider intra species DNA transfer safe than inter species DNA transfer. But, it has been researched and proved that such biotechnological methods are a replica of what naturally occur in biological world. DNA transfers are a frequent phenomenon with the in vitro process being more controlled (Macer, 2003).
Another strong belief was the alteration of natural genomes and microbial-human interactions in cases when recombinant GMM’s gets released into the environment. to test this, there have been many field trials conducted with GMO’s and none adverse report has been obtained so far. A possibility was also raised that the recombinant proteins and other products produced by GMM’s may not pose the same biological properties and functions as that of the natural product and may cause health issues (Glenn, 2013). The researchers have tested the molecular structures and functioning of such products in living systems with no ill effect.
Personal Opinion
GMO’s have been prospective in solving the ever increasing issues due to human population burst. They offer solutions for food, healthcare, medicinal field, textiles, paper, therapeutic with the list rising each new day. The ethical issues and the social concerns being raised against the use of GMM’s are obvious as per public viewpoint. It should be dealt with vigilance by appointing public counseling sessions and spreading awareness regarding scientific basis behind genetic manipulation of microbes. The horizontal gene transfer is a big concern publically but is not a risk as bacterial genes even is get transferred to human genome supposedly via human gut micro biome, do not pose harm in any way. There have been multitudes of concerns regarding usage of GMM’s for manufacturing products for human use but no serious threats have been reported so far making them safe for utilization. Since, it has been few decades while the recombinant products are being consumed and if no cases have been subjected to any risk posed by genetic manipulation, then now a big ratio of worries can be ruled out.
References
Glenn, M, L. (2013). Ethical Issues in Genetic Engineering and Transgenics. ActionBioscience. Retrieved 27 May 2016 from http://www.actionbioscience.org/biotechnology/glenn.html.
Han, L. (2004). Genetically Modified Microorganisms. The GMO Handbook; Genetically Modified Animals, Microbes and Plants in Biotechnology. The Humana Press. Ch.2: 29-51.
Macer, D. (2003). Ethical, Legal and Social Issues of Genetically Modified Disease Vectors in Public Health. Social, Economic and Behavioral Research. Retrieved 28 May 2016 from http://apps.who.int/iris/bitstream/10665/68058/1/TDR_STR_SEB_ST_03.1.pdf.
