Enhancing the Feasibility ofMicrocystis aeruginosaas a Feedstock for Bioethanol Production under the Influence of Various Factors

Abstract

Microcystis aeruginosa, a freshwater microalga, is capable of producing and accumulating different types of sugars in its biomass which make it a good feedstock for bioethanol production. Present study aims to investigate the effect of different factors increasing growth rate and carbohydrates productivity of M. aeruginosa. MF media (modified BG11 media) and additional ingredients such as aminolevulinic acid (2 mM), lysine (2.28 mM), alanine (1 mM), and Naphthalene acetic acid (1 mM) as cytokine promoted M. aeruginosa growth and sugar contents. Salmonella showed growth-assisting effect on M. aeruginosa. Enhanced growth rate and carbohydrates contents were observed in M. aeruginosa culture grown at 25°C under red LED light of 90 μmolm−2s−1 intensity. More greenish and carbohydrates rich M. aeruginosa biomass was prepared (final OD660 nm = 2.21 and sugar contents 10.39 mM/mL) as compared to control (maximum OD660 nm = 1.4 and sugar contents 3 mM/mL). The final algae biomass was converted to algae juice through a specific pretreatment method. The resulted algae Juice was used as a substrate in fermentation process. Highest yield of bioethanol (50 mM/mL) was detected when Brettanomyces custersainus, Saccharomyces cerevisiae, and Pichia stipitis were used in combinations for fermentation process as compared to their individual fermentation. The results indicated the influence of different factors on the growth rate and carbohydrates productivity of M. aeruginosa and its feasibility as a feedstock for fermentative ethanol production.

Pretreatment optimization of the biomass of Microcystis aeruginosa for efficient bioethanol production

“…6). The highest amount of bioethanol was found 60 mM/ml, higher than the amount of bioethanol in our previous work (Khan et al 2016).

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“…First M. aeruginosa (KMMCC-1135) was cultured in MF media under red LED light of 5000 lx with a continuous supply of 2% CO 2 (Khan et al 2016). Conical flasks (500 ml) were used for the culture of M. aeruginosa .…”

“…Efficient pretreatment of the biomass means to released and convert all the stored carbohydrates to fermentable sugars which will aid in the availability of higher quantities of sugars for the producer microorganisms. Our previous studies (Khan et al 2016) shown that growth rate and carbohydrates synthesis of M. aeruginosa can be enhanced by optimizing different culture parameters. Beside extraction of sugars for bioethanol synthesis, the biomass of M. aeruginosa can also be used for the extraction of cytotoxic and antimicrobial agents (Ishida et al 1997).…”

The promising future of microalgae: current status, challenges, and optimization of a sustainable and renewable industry for biofuels, feed, and other products

“…Mata et al [ 60 ] reported that an aerated culture of microalgae under 12,000 lx intensities for 12 h of daylight produced a higher biomass yield, whereas biomass decreased when the light intensity was reduced. Khan et al [ 71 ] reported that microcystis aeruginosa give maximum biomass and carbohydrates productivity at red LED light of about 5000 lx. Daliry et al most recently reported the maximum growth rate and lipid production by Chlorella vulgaris at light intensities of 5000–7000 lx [ 72 ].…”

Crude microcystins extracted from Microcystis aeruginosa exert anti-obesity effects by downregulating angiogenesis and adipogenesis related signaling molecules in HUVEC and 3 T3-L1 cells

“…Microcystis aeruginosa (KMMCC-1135) used in this study was obtained from the Korea Marine Microalgae Culture Center (KMMCC) and was cultured under stress conditions in MF media [33] supplemented with NaCl. When the culture attained log phase growth (OD 660 = 1), it was subjected to high temperature(35°C for one week ) and then dewatered to yield a concentrated culture (OD 660 = 1.8).…”