The modular nature of the transcriptional unit makes it possible to design robust modules with predictable input-output characteristics using a ‘parts- off a shelf’ approach. Customized regulatory circuits composed of multiple such transcriptional units have immense scope for application in diverse fields of basic and applied research. Synthetic transcriptional engineering seeks to construct such genetic cascades. Here, we discuss the three principle strands of transcriptional engineering: promoter and transcriptional factor engineering, and programming inducibilty into synthetic modules. In this context, we review the scope and limitations of some recent technologies that seek to achieve these ends. Our discussion emphasizes a requirement for rational combinatorial engineering principles and the promise this approach holds for the future development of this field.

The aim of the present study is to optimize the PCR conditions required to amplify the promoter sequence of an amino acid transporter having an AT-rich base composition with a high number of tandem repeats. Results show that successful amplification can be achieved by performing a 2-step PCR at a lower extension temperature of 65 °C for an increased extension period of 1.5 min/kb, with MgCl₂ concentration ranging from 2.5 to 3.0 mM. The results also suggest that the DNA concentration of about 25–30 ng/µl was essential to achieve this amplification.

Gene expression is mediated through interaction between cis regulatory elements and its cognate transcription factors. Cis regulatory elements are defined as non-coding DNA sequences that provide the binding sites for transcription factors and are clustered in the upstream region of genes. ACGT cis regulatory element is one of the important cis regulatory elements found to be involved in diverse biological processes like auxin response, salicylic acid response, UV light response, ABA response and jasmonic acid response .We identified through in silico analysis that the upstream region of protein phosphatase 2C (PP2C) gene has a distinct genetic architecture of ACGT elements. In the present study, the activation of the full length promoter and its deletion constructs like 900 base pair, 500 base pair, 400 base pair and NRM were examined by stable transformation in Arabidopsis thaliana using β glucuronidase as the reporter gene. Evaluation of deletion constructs of PP2C- like promoter was carried out in the presence of phytohormones like abscisic acid (ABA), salicylic acid (SA) and jasmonic acid (JA). Our result indicated that the full length and 900 base pair promoter-reporter constructs of PP2C-like promoter was induced in response to ABA but not to methyl jasmonate and salicylic acid.

Lipases are versatile biocatalysts that catalyze a plethora of reactions such as hydrolysis, esterification, transesterification, aminolysis and acidolysis, making them one of the most sought biocatalysts for industrial applications. However, their widespread use in industry is hampered by problems arising mainly due to loss of activity, thermal denaturation, deactivation by organic solvents etc., which affect reaction yields and lead to impaired enzyme recyclability and reusability for successive runs. Methods such as enzyme immobilization, reaction engineering and molecular biology approaches are being used to alleviate these impediments. Lipase bio-imprinting and molecular biology techniques such as rational protein design and directed evolution have made it possible to engineer lipases having superior properties and selectivities, greatly enhancing their activities and operational stability thereby improving reaction yields. This review focuses on the applicability of the above-mentioned strategies to create tailor-designed lipase enzymes to suit specific reactions needs with an emphasis on the transesterification reaction to produce biodiesel.

Abstract: Biofuels have been hailed as the fuels of the future with the potential to completely replace petroleum sourced fuels and also help in combating some of the current environmental issues associated with the intensive use of petroleum based fuels. Biofuels are of two types: primary and secondary. Primary biofuels are derived from sources like firewood, animal wastes, forest and crop residues etc. and are used in their unprocessed forms. Secondary biofuels are obtained by processing biomass and have been classified based on feedstock and processing technologies into first, second, third and fourth generation fuels, with the recently emerged fourth generation fuels having become the highlight of future research in the area. Among the different types of biofuels, biodiesel and bioethanol are now being used as transportation fuels. Biodiesel production is carried out via the transesterification reaction by using suitable catalysts. Lipases (triacyl glycerol hydrolases EC 3.1.1.3) have emerged as robust biocatalysts to accomplish the enzymatic synthesis of biodiesel. This review focuses on the need for biofuels and the most recent research developments in this field and also a brief overview of biodiesel fuel and lipase enzyme has been presented.