Sustaining ethanol production from lime pretreated water hyacinth biomass using mono and co-cultures of isolated fungal strains with Pichia stipitis

Abstract

Background: The high rate of propagation and easy availability of water hyacinth has made it a renewable carbon source for biofuel production. The present study was undertaken to screen the feasibility of using water hyacinth's hemicelluloses as a substrate for alcohol production by microbial fermentation using mono and co-cultures of Trichoderma reesei and Fusarium oxysporum with Pichia stipitis. Results: In separate hydrolysis and fermentation (SHF), the alkali pretreated water hyacinth biomass was saccharified by crude fungal enzymes of T. reesei, F. oxysporum and then fermented by P. stipitis. In simultaneous saccharification and fermentation (SSF), the saccharification and fermentation was carried out simultaneously at optimized conditions using mono and co-cultures of selected fungal strains. Finally, the ethanol production kinetics were analyzed by appropriate methods. The higher crystalline index (66.7%) and the Fourier transform infrared (FTIR) spectra showed that the lime pretreatment possibly increased the availability of cellulose and hemicelluloses for enzymatic conversion. In SSF, the co-culture fermentation using T. reesei and P. stipitis was found to be promising with a higher yield of ethanol (0.411 g g

Comparative Studies on Production of Bioethanol from Rice Straw Using Bacillus subtilis and Trichoderma viride as Hydrolyzing Agents

“…The proximate analysis of Rice straw (Fig 1), Showed the cellulose and lignin content of rice straw was 33.5% and 7.18% respectively which was relatively high, this was somewhat lower than 40.8% and 7.8% obtained by [19], and this is probable the result of varying environmental, soil and growth conditions in which the plant were obtained. Moisture content of 7.86% was recorded, [20] reported a range of moisture content of 8.5 -9.1% (dm) as well as [21]. The results from the proximate analysis shows that the digestibility of rice straw is hindered by many physicochemical, structural, and compositional factors which require a suitable pretreatment in order to enhance the susceptibility of biomass for hydrolysis.…”

Biological Characterization and Instrumental Analytical Comparison of Two Biorefining Pretreatments for Water Hyacinth (Eichhornia crassipes) Biomass Hydrolysis

“…The smoothed and normalized diffractograms of XRD analysis of untreated WHB (A), pretreated WHB with alkaline pretreatment (B), and with biological pretreatment (C), within the range of 2θ where the signals of interest can be seen are presented in Figure 3. In general terms, the treated biomass generates better-defined signals than the untreated one, which shows the elimination of non-crystalline components due to the effects of pretreatments, added to a slight increase in the signals that denote the crystalline structure of cellulose [33,45,46]. The spectrum generated by the untreated WHB is typical for this biomass [45] and for the biomass of other aquatic plants such as lemna [33], where a substantial increase in the baseline is appreciated in the value of 2θ where the peak of the 002 planes should be, without defining the rest of the planes.…”

Production of Second Generation Ethanol from Water Hyacinth: A Review

“…Entretanto, já foram descritos métodos físicos, químicos e estratégias híbridas para o pré-tratamento do aguapé. Dentre os vários métodos utilizados destaca-se o pré-tratamento ácido, 63 alcalino, [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64] biológico, 65 com água quente, 66 micro-alcalino, 47 ultrassom alcalino combinado, 67 catalítico por liquefação hidrotermal, 68 com peróxido de cálcio, 12 microemulsões líquidas iónicas isentas de tensoativos, 69 conversão termoquímica 70 e micro-ondas assistido organo-solvente alcalino. 71 A eficiência do pré-tratamento é baseada no desempenho da hidrólise.…”

“…As cepas mais utilizadas para a produção de etanol através do aguapé são Saccharomyces cerevisiae, Pichia stipits e Zymomonas mobilis. Porém já foram descritos processos fermentativos do aguapé utilizando as cepas de Trichoderma reesei em monoculturas ou associadas a Pichia stipits; 49 Candida shehatae, 86 e Candida intermedia. 34 Outra alternativa interessante é a utilização de bactérias termotolerantes como o Clostridium thermocellum para a fermentação do aguapé.…”