The alcoholic fermentative efficiency of medicinal fungus Ustilagomaydis to unravel mechanisms of fruit waste deconstruction with the aid of Separate Hydrolysis and Fermentation (SHF) method

Author Name(s): *Priya Pradhan, Nishant Kumar Soni, Lalitesh Chaudhary, Archana Tiwari
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The insistence for the fossil fuels is expanding day by day; this is to be met to fight for the economic development of the country. The environmental imprint and commercial performance of the existing suite of biofuel production approaches make them unsatisfactory to dislocate fossil fuels and diminish their influence on the account of greenhouse gas. To combat the decrease in economic growth and increase in the demand of people, researches opted for biofuels. First generation biofuels are acknowledged to be made from agro products, the second generation biofuels are made from lingo cellulosic biomass and the third and fourth generation of biofuel production encompasses ‘‘algal conversion into biofuels’’. So, to combat this issue of reliance on other countries and food versus fuel issue one has to move forward for the production of sustainable energy using reuse and recycle strategy. In this research paper we had focused on environmental remediation process with the aid of fruit pomace residues.


Fossil, Biofuel, Cellulosic, Pomace,Remediation


Energy catastrophe and climatic changes are crucial subjects around the globe. The hunt for alternate energies has provided number of ways to produce electrical energy, such as wind farms, hydropower machinery, or solar cells. Earlier it was foretold that in near future, the crude oil will route out within 40 to 70 years, and natural gas will get finish within 50 years [1]. Subsequently, fossil fuel, which is principally used in automobile sector, should be swapped with non- or less-emitted carbon dioxide fuels. Worldwide average temperature is prophesied to upsurge from 1.4 to 5.8°C by the year 2100 plus carry on to intensify long after that [2].

Utilization of renewable biomass possessions to harvest liquid biofuels such as bio-ethanol offers striking explanations in the reduction of GHG emissions, further declining dependence on overseas oils, addressing energy security concerns, establishing rural and agronomic economies, and growing sustainability of the world transport system [3]. Biofuel denotes to numerous liquid, gaseous and solid fuels resulting from organic i.e. biological materials known as biomass [3, 4]. These comprises of product such as bio-ethanol, bio-methanol, oils derived from vegetable, bio-diesel, bio-synthetic gas (bio-syngas), bio-char, bio-oil, bio-gas, bio-hydrogen and Fischer-Tropsch liquids [3]. First generation biofuels are fuels manufactured from agrarian crops such as oil seed, sugar crops, and grains [4, 5]. Second generation biofuels are retrieved from non-food biomass i.e. lignocellulose materials such as energy crops (vegetative grasses), forest residues, husks, stalks and straws [4, 6]. Third cohort biofuel are fuels shaped from photosynthetic algae also acknowledged as oilgae [5].

In the course of the process of fermentation, partial oxidation of biological complexes occur and for this reason less energy is acquired when equated with aerobic oxidation of the compounds. In contradiction, term industrial fermentation typically states to either aerobic or anaerobic processes, whereas fermentation in biological context defines a stringent anaerobic process, which occurs if pyruvic acid do not move in the Krebs cycle and if electrons from glucose metabolism pathway do not enter electron transport system (ETC). This in turn will enhance the production of ethanol as well as help in the process of environment remediation in the end.

The main objective of the present study is to explore the novel organism Ustilagomaydisfor the production of ethanol as it has not been explored earlier for the production of alcohols and to remediate the environment from waste materials as well as to fight with the growing issue of global warming introducing the carbon neutral fuels. Thus, the study will also revolve around the issue of food vs. fuel concern, GHGs emissions, reliance on fossil fuels, etc.


Mounting energy costs, growing demand for energy, uncertainty in oil trading countries, and anxieties for the environment, arouse curiosity in fuels such as ethanol. As gasoline charges continue to upsurge and more gravity is put on the administration to capitalize in or reassure production of unconventional fuels, agrarians, companies, co-ops, and investors have shown more attentiveness in the probability of producing ethanol. Literature suggests the feasibility of generating ethanol concentrated on food based materials in an assortment of geographical locations. Various farmers efficaciously harvest heaps of crops every year in an edict to sell. Conversely, most of these ranchers are facing problem of lots of leftover and do not even know how to efficiently use the surplus amount of crops produced. Therefore, it became one of the important issues to reconnoiter and find supplementary applications of these crops. However, because of ethical issues such as food vs. fuel, this has been deserted in research. This study therefore affords insights of how else waste could be used instead of being disposed as waste without harming the environment.

The evaluation demonstrates that ethanol production from selected alternative feedstock’s: apple pomace and guava pomace along with malt extract to compare as such to avoid the disposal of the leftovers as garbage. Only with a profound understandings of growth conditions and a thorough classification of the organism it was possible to improve the fermentation by unraveling specific problems with the stability, shortening the fermentation time and find high titres of the end product. The composition of apple and guava pomace, their variability and enzymatic digestibility were considered in order to appraise their potential as raw materials for manufacturing desired products. Alcohol-soluble complexes were principally made up of glucose and fructose (two carbon sources readily fermentable by microorganisms). Apple pomace as well as guava pomace had shown high susceptibility to thermal hydrolysis at temperature 60oC. Owing to the compositional differences among the samples, the final glucose content of thermal hydrolyzates obtained under the same operational conditions may differ in up to some percent. The conversion of pomaces into reducing sugars with the aid thermal hydrolysis offers the potential for radical technical encroachment through solicitation of modern biotechnology techniques to comprehend truly low costs for the production of bioethanol.

In the present study, experimental design using statistical software was considered since the effect of pH, temperature, reducing sugar concentration and their interactions was the main motive to work on to the metabolism of organism. During the work conducted, SGR of the organism was considered with the supplementation of dried pomaces in the media. Apple pomace when compared with the earlier studies, it was concluded that the batch of apples considered were having lesser sugar concentration (glucose, 4 mg/ 100 g) as compared to the literature cited (glucose, 6.5 mg/ 100 g).

Moving ahead with the glucose concentration of guava pomace it came out to be 6.3 mg/100 g. Further, Ustilagomaydiswas new to the field of bioprocess technology as it was never used earlier for the production of bioethanol, therefore, its adaptation to the environment and its consumption of the glucose was major concern.Considering the application of general linear model on to the experimental design, it was seen that at specific growth rate for 18 hours, very fluctuating cell densities were observed, this might be due to the reason that organism is being provided with different conditions and diverse interactions. This approach tremendously proved its efficiency as with interactions being prominent, effective data points for the substrate was analyzed. Considering, Walsh et al., when media was supplemented with guava pomace, it was observed that specific growth rate of the organism came out to be 0.2882/ hour which was in very close vicinity to the value given in the literature that is 0.29-0.30/ hour, later when the study was conducted on apple pomace it was observed that specific growth rate of the organism (0.2700) came out to be less than obtained earlier with the guava pomace. These results were taken in comparison to the control media for which the specific growth rate came out to be 0.2189. Further these results were confirmed their authenticity when the regression (R2) values were calculated with the F-distribution analysis. Coefficient of determination for guava pomace came out to be 0.8554 (85.54 %) and for apple it came out to be 0.8291 (82.91%). The results gave the present study a peculiar direction that the regression line approximates the real data points. And somewhere around the best interaction is considered by the ANOVA analysis which is why the probability values are less than 0.05, indicating the results are significant at 95 % confidence interval statistically.

Moreover, the effective data points from the experimental model obtained after the statistical analysis for guava pomace were 28oC, pH 4.5 and 5 g sugar concentration. Similarly for apple pomace, data points at which maximum specific growth rate observed were 28oC, 4.5 pH units and 10 g of reducing sugar concentration. These probable models predicted that the organism is active at acidic pH unlike other organisms and is very susceptible to the carbohydrate concentration since at 5 g of sugar concentration its specific growth rate increased and when 10 g of substrate utilization was there very less but specific growth rate decreased. These results were carried further for ethanol production, which is the desired product of the study.

Nevertheless, on fermentation at the probable conditions discussed earlier, ethanol production with the consumption of reducing sugars of guava pomace came out to be 1.76 g/100 ml, followed by apple pomace was 0.93 g/100 ml and further malt extract broth that was the control provided 1.49 g/100 ml ethanol. This gave the current study a track that with fewer quantity of substrate (5 g) effectual amount of ethyl alcohol (1.76 g/100 ml) can be produced and also guava pomace is an encouraging and comparable substrate for the production of bioethanol.

Furthermore, the retention time for gas chromatography was considered for the analysis of ethanol in the fermentation media. For standard ethanol it came out to be 0.65 minutes additionally, for the samples it came out to be near the range of ethanol i.e. for malt (control) it came out to be 0.683 minutes, for guava and apple in the fermentation media it came out to be 0.683 minutes and 0.733 minutes respectively. Concluding remarks state that if stringent bans are made on the manufacture of food ethanol, ethanol out of waste and ligno-cellulosic ethanol will blossom well and due to this, the costs of enzymes for hydrolysis may fall. In addition, a breakthrough in genetic engineering will direct an organism, which will directly convert waste into ethanol.

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