Prospective of biodiesel production utilizing microalgae as the cell factories: A comprehensive discussion

Abstract

Microalgae are sunlight-driven miniature factories that convert atmospheric CO 2 to polar and neutral lipids which after esterification can be utilized as an alternative source of petroleum. Further, other metabolic products such as bioethanol and biohydrogen produced by algal cells are also being considered for the same purpose. Microaglae are more efficient than the conventional oleaginous plants in capturing solar energy as they have simpler cellular organization and high capacity to produce lipids even under nutritionally challenged and high salt concentrations. Commercially, microalgae are cultivated either in open pond systems or in closed photobioreactors. The photobioreactor systems including tubular bioreactors, plate reactors and bubble column reactors have their own advantages as they provide sterile conditions for growing algal biomass. Besides, other culture conditions such as light intensity, CO 2 concentration, nutritional balance, etc, in closed reactors remain controlled. On the other hand, though the open ponds provide a cost-effective option to utilize natural light facility for algal cells, the tough maintenance of optimal and stable growth conditions makes it difficult to manage the economy of the process. Further, these systems are much more susceptible to contamination with unwanted microalgae and fungi, bacteria and protozoa that feed on algae. Recently, some work has been done to improve lipid production from algal biomass by implementing in silico and in vitro biochemical, genetic and metabolic engineering approaches. This article represents a comprehensive discussion about the potential of microalgae for the production of valuable lipid compounds that can be further used for biodiesel production.

Larvae and fry culture of white cachama ( Piaractus orinoquensis ) in biofloc systems at different carbon/nitrogen (C/N) ratios

“…This treatment had no additions of molasses, favouring conditions of autotrophic (Avnimelech, 2009). The different C/N ratios among treatments make possible the presence of algae for the lowest ratios (10/1) since the microalgae have a great capacity to contribute and produce lipids (Verma et al, 2010), a condition that can explain the difference in lipid percentages between autotrophic and heterotrophic treatments (Becerril-Cortés et al, 2018).…”

A Review of The Micro-Algae Are Being Harvested to Make Biofuel

“…It is considered to be the most problematic area of production (Greenwell et al 2010) and as a key factor limiting commercial exploitation of microalgae (Olgu', 2003). It has been suggested that 20-30% of the cost of microalgal biomass is due to harvesting costs (Mata et al 2010;Molina Grima et al 2003;Verma et al 2010). 50% of the biomass cost of microalgae has been reported (Greenwell et al 2010).…”

Optimization of the glycerol production fromDunaliella tertiolectaandDunaliellaisolates

“…Large demands of environmental friendly glycerol are covered through bio-fuel production which generates glycerol as a by-product [13, 18]. Beyond the high prices and availability fluctuations [19], there are many impurities in biofuel [19], which raise the purification costs as complex purification processes are needed [20, 21].…”

“…Additionally, bio-fuel production utilizes enormous agricultural areas necessary to nourish the world population [23, 24]. Therefore, a sustainable and less area-intensive production process for the extensively required raw material glycerol is of great importance [18, 25]. Used cooking oil might be a sustainable alternative for the bio-fuel and glycerol production [26], but also does not reach a glycerol purify higher than 99.7% [22].…”