Bioengineering of Microalgae: Recent Advances, Perspectives, and Regulatory Challenges for Industrial Application

Advantages of Heterotrophic Microalgae as a Host for Phytochemicals Production

Currently, most commercial recombinant technologies rely on host systems. However, each host has their own benefits and drawbacks, depending on the target products. Prokaryote host is lack of post-transcriptional and post-translational mechanisms, making them unsuitable for eukaryotic productions like phytochemicals. Even there are other eukaryote hosts (e.g., transgenic animals, mammalian cell, and transgenic plants), but those hosts have some limitations, such as low yield, high cost, time consuming, virus contamination, and so on. Thus, flexible platforms and efficient methods that can produced phytochemicals are required. The use of heterotrophic microalgae as a host system is interesting because it possibly overcome those obstacles. This paper presents a comprehensive review of heterotrophic microalgal expression host including advantages of heterotrophic microalgae as a host, genetic engineering of microalgae, genetic transformation of microalgae, microalgal engineering for phytochemicals production, challenges of microalgal hosts, key market trends, and future view. Finally, this review might be a directions of the alternative microalgae host for high-value phytochemicals production in the next few years.

Experimental modeling of the microalgae cultivation in a photobioreactor using manure

The article studies the experimental process of cultivation of microalgae in a photobioreactor (PBR) to study the effect of technological conditions on the productivity of microalgae. This process allows obtaining initial data for the development of closed cycles of using the energy potential of alga mass in heat and power supply of various industries, including agricultural enterprises (livestock complexes, poultry farms, etc.) The scheme of a closed cycle of power supply of the cattle complex allows obtaining hot water, feed additives to the cattle ration, bio humus, motor biofuel and carbon dioxide, which is advisable to use in the process of cultivating microalgae. The experiments were carried out on a photobioreactor for cultivating microalgae with an intelligent control system. The developed photobioreactor differs from the known ones in the pulsating hydrodynamic regime of feeding the nutrient solution, which provides an increase in the productivity of the microalgae cultivation up to 15%. The experimental model of the cultivation conditions of the microalga Ch. Vulgaris on a combined diet (Tamiya medium + manure substrate) showed a noticeable increase in crop productivity when adding cattle manure extract to the nutrient medium in an amount from 30 to 60% (vol.). This can be used in the development of closed cycles of heat and power supply for cattle farms based on biofuels of the third generation, obtained from the phytomass of microalgae.