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Microalgae as sustainable renewable energy feedstock for biofuel production.

Medipally SR, Yusoff FM, Banerjee S, Shariff M - Biomed Res Int (2015)

Bottom Line: Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels.The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction.This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Marine Biotechnology, Institute of Bioscience, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia.

ABSTRACT
The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources. According to life cycle analysis, microalgae biofuel is identified as one of the major renewable energy sources for sustainable development, with potential to replace the fossil-based fuels. Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels. Algae-based biofuels are technically and economically viable and cost competitive, require no additional lands, require minimal water use, and mitigate atmospheric CO2. However, commercial production of microalgae biodiesel is still not feasible due to the low biomass concentration and costly downstream processes. The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction. Commercial production can also be accomplished by improving the genetic engineering strategies to control environmental stress conditions and by engineering metabolic pathways for high lipid production. In addition, new emerging technologies such as algal-bacterial interactions for enhancement of microalgae growth and lipid production are also explored. This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties.

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Related in: MedlinePlus

Possible interactions between microalgae and bacteria: solid arrows indicate the positive interactions and dashed arrows indicate the negative interactions [118, 119].
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fig2: Possible interactions between microalgae and bacteria: solid arrows indicate the positive interactions and dashed arrows indicate the negative interactions [118, 119].

Mentions: Microalgae and bacteria perform symbiotic relationship by establishing “phycosphere” [104, 105] as plants and bacteria do in the “rhizosphere” [106]. Microalgae produce extracellular products for the development of matrix like substance on their surfaces, which encourages and provides the environment for the formation of bacterial biofilms [107, 108]. Teplitski et al. [109] reported the existence of microalgae-bacteria interactions in the unicellular microalgae Chlamydomonas reinhardtii. To date, only limited studies have been carried out about the existence of interactions between bacterial biofilms and microalgae [110–112]. These studies suggest that the bacteria encourage the growth of microalgae by producing the vitamins and other growth factors, and the organic matters produced by the microalgae simultaneously encourage bacterial growth. They also have negative interactions between each other; microalgae inhibit the bacterial growth by increasing the temperature, pH, and dissolved oxygen concentration (DOC) or by producing inhibitory metabolites [113, 114], and in the same manner bacteria also can inhibit the microalgae growth by secreting algicidal compounds [115] (Figure 2). Recent reports suggested that the presence of these positive interactions between microalgae and bacteria enhances the microalgae biomass and biodiesel production [116, 117].


Microalgae as sustainable renewable energy feedstock for biofuel production.

Medipally SR, Yusoff FM, Banerjee S, Shariff M - Biomed Res Int (2015)

Possible interactions between microalgae and bacteria: solid arrows indicate the positive interactions and dashed arrows indicate the negative interactions [118, 119].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385614&req=5

fig2: Possible interactions between microalgae and bacteria: solid arrows indicate the positive interactions and dashed arrows indicate the negative interactions [118, 119].
Mentions: Microalgae and bacteria perform symbiotic relationship by establishing “phycosphere” [104, 105] as plants and bacteria do in the “rhizosphere” [106]. Microalgae produce extracellular products for the development of matrix like substance on their surfaces, which encourages and provides the environment for the formation of bacterial biofilms [107, 108]. Teplitski et al. [109] reported the existence of microalgae-bacteria interactions in the unicellular microalgae Chlamydomonas reinhardtii. To date, only limited studies have been carried out about the existence of interactions between bacterial biofilms and microalgae [110–112]. These studies suggest that the bacteria encourage the growth of microalgae by producing the vitamins and other growth factors, and the organic matters produced by the microalgae simultaneously encourage bacterial growth. They also have negative interactions between each other; microalgae inhibit the bacterial growth by increasing the temperature, pH, and dissolved oxygen concentration (DOC) or by producing inhibitory metabolites [113, 114], and in the same manner bacteria also can inhibit the microalgae growth by secreting algicidal compounds [115] (Figure 2). Recent reports suggested that the presence of these positive interactions between microalgae and bacteria enhances the microalgae biomass and biodiesel production [116, 117].

Bottom Line: Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels.The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction.This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Marine Biotechnology, Institute of Bioscience, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia.

ABSTRACT
The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources. According to life cycle analysis, microalgae biofuel is identified as one of the major renewable energy sources for sustainable development, with potential to replace the fossil-based fuels. Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels. Algae-based biofuels are technically and economically viable and cost competitive, require no additional lands, require minimal water use, and mitigate atmospheric CO2. However, commercial production of microalgae biodiesel is still not feasible due to the low biomass concentration and costly downstream processes. The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction. Commercial production can also be accomplished by improving the genetic engineering strategies to control environmental stress conditions and by engineering metabolic pathways for high lipid production. In addition, new emerging technologies such as algal-bacterial interactions for enhancement of microalgae growth and lipid production are also explored. This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties.

Show MeSH
Related in: MedlinePlus