Bioethanol production from cassava peels using different microbial inoculants

Abstract

The potential of bioethanol production using different microbial inoculants for the simultaneous saccharification and fermentation of cassava peels from three cassava cultivars was investigated. Peels obtained from three cassava cultivars namely TME 0505, TME 419 and TME 4779, were washed, dried in a laboratory air oven dryer at 120°C for 3 h, ground into a fine texture and sieved with 1.5 µ nylon sieve. The sieved material was cultured using the following inoculant combinations: A = Rhizopus nigricans + Saccharomyces cerevisiae; B = Aspergillus niger + Saccharomyces cerevisiae; C = Rhizopus nigricans + Aspergillus niger + Saccharomyces cerevisiae; D = Rhizopus nigricans + Spirogyra africana + Saccharomyces cerevisae; E = Aspergillus niger + Spirogyra africana + Saccharomyces cerevisiae. These combinations have not been tested before on cassava peels. The control was inoculated with S. cerevisiae only. The cultures were distilled on the 21 st day and the quantity of ethanol produced in each treatment group recorded. Results obtained showed significant differences (P<0.05) in the amount of ethanol produced and in its concentration among the five inoculants. Significant differences (P<0.05) were also obtained in ethanol yield from the three cassava varieties. Cassava peels from TME 4779 gave the highest ethanol yield of 14.46 ± 2.08 g/cm 3 using R. nigricans + S. africana+ S. cerevisiae. Similarly, cassava peels from TME 0505 gave the second highest ethanol yield of 13.33 ± 0.67 g/cm 3 using the same combination, namely R. nigricans + S. africana + S. cerevisiae. Low ethanol yields of 4.82 ± 1.00, 6.43 ± 0.58 and 7.77 ± 0.88 g/cm 3 were obtained from the cassava peels of TME 419, TME 0505 and TME 4779, respectively using S. cerevisiae alone. The yield reported in this study competes favorably with those reported from cassava peels, potato peels and millet husks using other inoculant treatments by other workers. Inoculants used in this study thus showed great potential for bioethanol production from cassava peels.

Ethanol production from cassava peels using Saccharomyces cerevisiae via ethanologenic fermentation process

“…The results of this experiment were also more significant than those of Adegunloye and Udenze (2017), who found that cocoyam peel fermented with A. niger and S. cerevisiae produced an ethanol yield of 6% at its highest. However, the value obtained in the present work was lower compared to the peak ethanol concentration of 41 % (v/v) and peak yield of 14.46 ± 2.08 g/cm 3 given by Chibuzor et al (2016) when CP cultivar TME 4779 was treated with Rhizopus nigricans, Spirogyra africana and S. cerevisiae, respectively.…”

“…Using S. cerevisiae to produce simple sugars from CP under controlled conditions will require process parameter optimization, which could increase bioethanol yield. This study led to the conclusion that CP might be used as a source of carbon energy for the yeast that is fermenting to produce ethanol (Chibuzor, Uyoh, & Igile, 2016). The selection of yeast for this study may have been influenced by its greater tolerance for acidic environments and low pH levels than other microbes, such as bacteria.…”

Fruit preservation with bioethanol obtained from the fermentation of brewer’s spent grain with Saccharomyces carlsbergensis

“…BSG is interesting biomass with hydrolyzable fermentable sugars that can be converted to ethanol with different microorganisms through co-fermentation strategies (Rojas-Chamorro et al, 2020). Likewise, cassava peels, potato peels and millet husks with different microbial inoculants such as S. cerevisiae, Rhizopus nigricans, Aspergillus niger, Spirogyra africana showed great potential for bioethanol production (Chibuzor et al, 2016).…”

The potency of Mentega Cassava (Manihot esculenta) Variety Peels Waste as Raw Material for Bioethanol by Enzymatic Hydrolisis

“…There was previous research bioethanol production research using cassava peel as raw material. Different microbial inoculants such as Rhizopus nigricans, Spirogyra africana, Saccharomyces cerevisiae for the simultaneous saccharification and fermentation of cassava peels (Chibuzor et al, 2016). Production of bio-ethanol from cassava peels using Aspergillus niger and Saccharomyces cerevisiae (Adetunji et al, 2015) followed by research objectives.…”