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In recent years, microalgae have emerged as an alternative platform for large-scale
production of recombinant proteins for different commercial applications. As a production
platform, it has several advantages, including rapid growth, easily scale up and ability to grow with
or without the external carbon source. Genetic transformation of several species has been
established. Of these, Chlamydomonas reinhardtii has become significantly attractive for its
potential to express foreign proteins inexpensively. All its three genomes – nuclear, mitochondrial
and chloroplastic – have been sequenced. As a result, a wealth of information about its genetic
machinery, protein expression mechanism (transcription, translation and post-translational
modifications) is available. Over the years, various molecular tools have been developed for the
manipulation of all these genomes. Various studies show that the transformation of the chloroplast
genome has several advantages over nuclear transformation from the biopharming point of view.
According to a recent survey, over 100 recombinant proteins have been expressed in algal
chloroplasts. However, the expression levels achieved in the algal chloroplast genome are generally
lower compared to the chloroplasts of higher plants. Work is therefore needed to make the algal
chloroplast transformation commercially competitive. In this review, we discuss some examples
from the algal research, which could play their role in making algal chloroplast commercially
successful.