On the Optimization of Fermentation Conditions for Enhanced Bioethanol Yields from Starchy Biowaste via Yeast Co-Cultures

The present study aims to assess the impact of the type of yeast consortium used during bioethanol production from starchy biowastes and to determine the optimal fermentation conditions for enhanced bioethanol production. Three different yeast strains, Saccharomyces cerevisiae, Pichia barkeri, and Candida intermedia were used in mono- and co-cultures with pretreated waste-rice as substrate. The optimization of fermentation conditions i.e., fermentation time, temperature, pH, and inoculum size, was investigated in small-scale batch cultures and subsequently, the optimal conditions were applied for scaling-up and validation of the process in a 7-L fermenter. It was shown that co-culturing of yeasts either in couples or triples significantly enhanced the fermentation efficiency of the process, with ethanol yield reaching 167.80 ± 0.49 g/kg of biowaste during experiments in the fermenter.

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Optimization of Fermentation Conditions for Chinese Fermentation Paocai with Enterococcus faecium IN3531 as a Starter by Single Factor Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.884-885.471 ◽

2014 ◽

Vol 884-885 ◽

pp. 471-474

Author(s):

Wen Li Liu ◽

Lan Wei Zhang ◽

John Shi ◽

Hua Xi Yi

Keyword(s):

Enterococcus Faecium ◽

Starter Culture ◽

Titratable Acidity ◽

Inoculum Size ◽

Single Factor ◽

Fermentation Time ◽

Fermentation Conditions ◽

Bacteriocin Producer ◽

Optimization Of Fermentation ◽

Single Factor Experiment

The strain Enterococcus faeciumIN3531, a bacteriocin producer, was used as a starter culture for traditional fermentationpaocai in china. By single factor experiment, the technological conditionsof Chinese fermentation paocai using Enterococcus faecium IN3531 as a starterwere optimizated, andparameters of optimization included the initial saltconcentration, the inoculum size, the fermentation temperatureand the ratio of material to liquid. Theresearch results showed that,the suitable fermentationconditions were the initial saltconcentration of 2%,the inoculum size of 3%, the fermentation temperature of 37 °C, the ratio of materialto liquid of 30%, fermentation time of 108 hours. Titratable acidity in fermentationterminus was 0.80%.

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Optimization of Fermentation Conditions for Blue Pigment Production by Bacterial Strain T2013

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1073-1076.286 ◽

2014 ◽

Vol 1073-1076 ◽

pp. 286-291

Author(s):

Yong Zuo ◽

Peng Jiang ◽

Xiao Long Wang ◽

Bin Fu ◽

Xiao Long Yang ◽

...

Keyword(s):

Bacterial Strain ◽

Orthogonal Test ◽

Blue Pigment ◽

Liquid Volume ◽

Initial Value ◽

Fermentation Time ◽

Fermentation Conditions ◽

Inoculum Volume ◽

Optimization Of Fermentation ◽

Single Factor Experiment

The fermentation conditions of Bacterial Strain T2013 were studied. The fermentation conditions of T2013 were investigated with single-factor experiment. In addition to, the fermentation conditions were optimized through the orthogonal test. The results showed the highest production of blue pigment was obtained on condition that fermentation time was 2d, the liquid volume was 50ml in the 250ml shake-flask, the inoculum volume was 2%, the initial value of pH was 7.6, fermentation temperature was 37°C and the speed was 150r/min.The fermentation conditions of Bacterial Strain T2013 were preliminarily determined,whichprovides a theoretical basis for the industrial production of blue pigment.

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Yeasts from Chinese strong flavour Daqu samples: isolation and evaluation of their potential for fortified Daqu production

AMB Express ◽

10.1186/s13568-021-01337-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shunchang Pu ◽

Yu Zhang ◽

Ning Lu ◽

Cuie Shi ◽

Shoubao Yan

Keyword(s):

Volatile Compounds ◽

Rapd Analysis ◽

Kluyveromyces Lactis ◽

Inoculum Size ◽

Fermentation Efficiency ◽

Wickerhamomyces Anomalus ◽

Yeast Strains ◽

Saccharomyces Kudriavzevii ◽

Pichia Kluyveri ◽

The Impact

AbstractIn total, 16 yeast were isolated from Chinese strong flavour Daqu samples and underwent RAPD analysis and identification. Totally, 11 different species were identified among these isolates including Saccharomyces cerevisiae, Hanseniaspora vineae, Pichia kluyveri, Trichosporon asahii, Wickerhamomyces anomalus, Kluyveromyces lactis, Yarrowia lipolytica, Wickerhamomyces mori, Galactomyces geotrichum, Dabaryomyces hansenii, and Saccharomyces kudriavzevii. To understand the impact of these yeast strains on the quality and flavour of Daqu, we then assessed volatile compounds associated with Daqu samples fermented with corresponding strains. These analyses revealed strain YE006 exhibited the most robust ability to produce ethanol via fermentation but yielded relatively low quantities of volatile compounds, whereas strain YE010 exhibited relatively poor fermentation efficiency but produced the greatest quantity of volatile compounds. These two yeast strains were then utilized in a mixed culture to produce fortified Daqu, with the optimal inoculum size being assessed experimentally. These analyses revealed that maximal fermentation, saccharifying, liquefying, and esterifying power as well as high levels of volatile compounds were achieved when using a 2% inoculum composed of YE006/YE010 at a 1:2 (v/v) ratio. When the liquor prepared using this optimized fortified Daqu was compared to unfortified control Daqu, the former was found to exhibit significantly higher levels of flavour compounds and better sensory scores. Overall, our findings may provide a reliable approach to ensuring Daqu quality and improving the consistency and flavour of Chinese strong-flavour liquor through bioaugmentation.

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Experimental Whisky Fermentations: Influence of Wort Pretreatments

Foods ◽

10.3390/foods10112755 ◽

2021 ◽

Vol 10 (11) ◽

pp. 2755

Author(s):

Martina Daute ◽

Frances Jack ◽

Barry Harrison ◽

Graeme Walker

Keyword(s):

Ethanol Yield ◽

Small Scale ◽

Chemical Compositions ◽

Higher Alcohols ◽

Fermentation Performance ◽

Additional Process ◽

The Impact ◽

Storage Units ◽

Scotch Whisky ◽

Major Consideration

In addition to ethanol yield, the production of flavour congeners during fermentation is a major consideration for Scotch whisky producers. Experimental whisky fermentations can provide useful information to the industry, and this is the focus of this paper. This study investigated the impact of wort pretreatments (boiled, autoclaved, filtered) on fermentation performance and flavour development in Scotch whisky distillates as an alternative to freezing wort for storage. Our study showed that no significant sensorial differences were detected in low wines (first distillates), while the chemical compositions showed clear changes in increased levels of esters and higher alcohols in boiled and autoclaved wort. In contrast, filtered wort comprised overall lower levels of congeners. Regarding alcohol yield, all three pretreatments resulted in decreased yields. In practice, the pretreatment of wort prior to fermentation requires additional process operations, while freezing requires large storage units. The pretreatments adopted in this study significantly influence the composition of the malt wort used for experimental whisky fermentations, and this results in a poorer fermentation performance compared with untreated wort. We recommend the use of fresh or frozen wort as the best options for small-scale fermentation trials.

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Evaluation of Copper-Contaminated Marginal Land for the Cultivation of Vetiver Grass (Chrysopogon zizanioides) as a Lignocellulosic Feedstock and its Impact on Downstream Bioethanol Production

Applied Sciences ◽

10.3390/app9132685 ◽

2019 ◽

Vol 9 (13) ◽

pp. 2685 ◽

Cited By ~ 1

Author(s):

Emily M. Geiger ◽

Dibyendu Sarkar ◽

Rupali Datta

Keyword(s):

Contaminated Soil ◽

Ethanol Yield ◽

Dilute Acid Pretreatment ◽

Cellulose Content ◽

Bioethanol Production ◽

Vetiver Grass ◽

Acid Pretreatment ◽

Biofuel Feedstock ◽

Lignocellulosic Feedstock ◽

The Impact

Metal-contaminated soil could be sustainably used for biofuel feedstock production if the harvested biomass is amenable to bioethanol production. A 60-day greenhouse experiment was performed to evaluate (1) the potential of vetiver grass to phytostabilize soil contaminated with copper (Cu), and (2) the impact of Cu exposure on its lignocellulosic composition and downstream bioethanol production. Dilute acid pretreatment, enzymatic hydrolysis, and fermentation parameters were optimized sequentially for vetiver grass using response surface methodology (RSM). Results indicate that the lignocellulosic composition of vetiver grown on Cu-rich soil was favorably altered with a significant decrease in lignin and increase in hemicellulose and cellulose content. Hydrolysates produced from Cu exposed biomass achieved a significantly greater ethanol yield and volumetric productivity compared to those of the control biomass. Upon pretreatment, the hemicellulosic hydrolysate showed an increase in total sugars per liter by 204.7% of the predicted yield. After fermentation, 110% of the predicted ethanol yield was obtained for the vetiver grown on Cu-contaminated soil. By contrast, for vetiver grown on uncontaminated soil a 62.3% of theoretical ethanol yield was achieved, indicating that vetiver has the potential to serve the dual purpose of phytoremediation and biofuel feedstock generation on contaminated sites.

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Optimization of some fermentation conditions for bioethanol production from microalgae using response surface method

Bulletin of the National Research Centre ◽

10.1186/s42269-019-0205-8 ◽

2019 ◽

Vol 43 (1) ◽

Cited By ~ 2

Author(s):

Samar A. El-Mekkawi ◽

Sayeda M. Abdo ◽

Farag A. Samhan ◽

Gamila H. Ali

Keyword(s):

Algal Biomass ◽

Treatment Plant ◽

Pilot Scale ◽

Simultaneous Optimization ◽

High Rate ◽

Bioethanol Production ◽

Fermentation Time ◽

Fermentation Conditions ◽

Promising Source ◽

Bioethanol Yield

Abstract Background Algal biomass fermentation is one of the promising alternatives for bioethanol production. The bioethanol yield relies on fermentation conditions as the algal biomass amount, the yeast volume (% v/v), and the fermentation time. In this work, algal biomass harvested from a pilot-scale high rate algal pond (HRAP) was fermented anaerobically using immobilized Saccharomyces cerevisiae (ATCC 4126). The HRAP was constructed at the Zenin wastewater treatment plant (WTP), Giza, Egypt. A separate hydrolysis fermentation process (SHF) was applied for algal biomass. The effect of the algal biomass amount, the yeast volume (% v/v), and the time of fermentation as three independent variables were studied simultaneously and analyzed statistically using Design-Expert software V6.0.8. Results The harvested algal biomass from HRAP contains 45% carbohydrates and was dominated by Microcystis sp. The results revealed that optimum bioethanol yield 18.57 g/L is achieved by fermenting 98.7 g/L algae using 15.09% of the volume immobilized yeast for 43.6 h with a 95% confidence interval. Conclusion Microalgae grown on wastewater are a promising source of bioethanol production. Maximizing the ethanol production is achieved by optimizing the fermentation parameters as algal biomass, fermentation time, and yeast volume percent. The simultaneous optimization of the parameters using a statistical program is an effective way to maximize the production and predict a model that describes the relationship between these parameters and their response. The prospective research is going to study the effect of these predicted parameters on continuous fermentation on the semi-pilot scale.

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Study on the Optimization of Fermentation Conditions for Actinomycete F10

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.480-481.148 ◽

2011 ◽

Vol 480-481 ◽

pp. 148-152

Author(s):

Lei Yang ◽

Guo Ying Zhou ◽

Guang Tao Song

Keyword(s):

Antimicrobial Activity ◽

Dry Weight ◽

Fermentation Medium ◽

Fermentation Time ◽

Nutritional Factors ◽

Fermentation Conditions ◽

Antimicrobial Substances ◽

Initial Ph ◽

Optimization Of Fermentation ◽

Fermentation Media

In order to improve the yield of antimicrobial substances extracted from actinomycetes F10 strains fermentation, antimicrobial activity and cell dry weight were taken as the main indicators, we studied the effects on F10 strain’s biological activity of the different fermentation media, different carbon, nitrogen and other nutrients factor, and the initial pH and other non-nutritional factors. The results showed that the optimum fermentation medium is: yeast extract 0.5%, glucose 1%, KH2PO4 0.1%, NaCl 0.1%, CaCO30.3%, pH natural. Strain F10 optimal fermentation conditions were: initial pH 7.0, fermentation time 168h.

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Optimization of Mixed Fermentation Conditions by Mixed Culture of Kefir and Bacillus

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.618.303 ◽

2014 ◽

Vol 618 ◽

pp. 303-310

Author(s):

Tie Hua Zhang ◽

Xin Yu Zhang ◽

Mu Tian ◽

Shu Ning Zhong ◽

Zhi Yang Du

Keyword(s):

Monosodium Glutamate ◽

Skim Milk ◽

Viable Cell ◽

Fermented Milk ◽

Inoculum Size ◽

Mixed Fermentation ◽

Fermentation Time ◽

Fermentation Conditions ◽

Cell Counts ◽

Freeze Dried

Kefir is a kind of fermented milk that is produced by inoculating Kefir grains into milk, mainly consisting of bacteria and yeasts. Bacillus and their metabolites also have found some biotechnological applications in many aspects. The aim of the present study was to evaluate the mixed fermentation conditions by kefir and Bacillus. The results showed that kefir and Bacillus could be mixed fermentation, the suggested optimum fermentation conditions are the following: inoculum size was 4 mL of mixed fermentation agent for per 100 mL medium, the ratio to kefir and Bacillus is 2:1, fermentation temperature of 28 °C and fermentation time of 20 h. Under the optimum fermentation conditions, the viable cell counts of Lactic acid bacteria, yeast and Bacillus could above 1.0×1011, 4.0×1010, and 2.0×109CFU/mL respectively. After freeze-dried, by adding 10 % ( w/v ) skim milk, 3 % ( w/v ) glycerinum, 3 % trehalose and 1 % ( w/v ) Monosodium glutamate as for cryoprotectant, the viable cell counts could still above 107CFU/mL after 6 month.

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Evaluating and engineering Saccharomyces cerevisiae promoters for increased amylase expression and bioethanol production from raw starch

FEMS Yeast Research ◽

10.1093/femsyr/foaa047 ◽

2020 ◽

Vol 20 (6) ◽

Author(s):

Marthinus W Myburgh ◽

Shaunita H Rose ◽

Marinda Viljoen-Bloom

Keyword(s):

Saccharomyces Cerevisiae ◽

Corn Starch ◽

Consolidated Bioprocessing ◽

Ethanol Yield ◽

Small Scale ◽

Bioethanol Production ◽

Raw Starch ◽

Broken Rice ◽

Available Carbon ◽

Theoretical Ethanol Yield

ABSTRACT Bioethanol production from starchy biomass via consolidated bioprocessing (CBP) will benefit from amylolytic Saccharomyces cerevisiae strains that produce high levels of recombinant amylases. This could be achieved by using strong promoters and modification thereof to improve gene expression under industrial conditions. This study evaluated eight endogenous S. cerevisiae promoters for the expression of a starch-hydrolysing α-amylase gene. A total of six of the native promoters were modified to contain a promoter-proximal intron directly downstream of the full-length promoter. Varying results were obtained; four native promoters outperformed the ENO1P benchmark under aerobic conditions and two promoters showed better expression under simulated CBP conditions. The addition of the RPS25A intron significantly improved the expression from most promoters, displaying increased transcript levels, protein concentrations and amylase activities. Raw starch-utilising strains were constructed through co-expression of selected α-amylase cassettes and a glucoamylase gene. The amylolytic strains displayed improved fermentation vigour on raw corn starch and broken rice, reaching 97% of the theoretical ethanol yield and converting 100% of the available carbon to products within 120 h in small-scale CBP fermentations on broken rice. This study showed that enhanced amylolytic strains for the conversion of raw starch to ethanol can be achieved through turnkey promoter selection and/or engineering.

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Bioethanol Production by Using Detoxified Sugarcane Bagasse Hydrolysate and Adapted Culture of Candida tropicalis

Current Biochemistry ◽

10.29244/cb.2.1.1-12 ◽

2016 ◽

Vol 2 (1) ◽

pp. 1-12

Author(s):

Inda Setyawati ◽

Laksmi Ambarsari ◽

Siti Nur'aeni ◽

Suryani Suryani ◽

Puspa Julistia Puspita ◽

...

Keyword(s):

Ethanol Production ◽

Sugarcane Bagasse ◽

Ethanol Yield ◽

Renewable Resource ◽

Bioethanol Production ◽

Fermentation Inhibitors ◽

Renewable Materials ◽

Promising Alternative ◽

Fermentation Time ◽

Sugarcane Bagasse Hydrolysate

Ethanol is considered as the most promising alternative fuel, since it can be produced from a variety of agriculturally-based renewable materials, such as sugarcane bagasse. Lignocellulose as a major component of sugarcane bagasse is considered as an attractive renewable resource for ethanol production due to its great availability and relatively low cost. The major problem of lignocellulose is caused by its need for treatment to be hydrolyzed to simple sugar before being used for bioethanol production. However, pretreatment using acid as hydrolyzing agent creates some inhibitor compounds that reduce ethanol production because these compounds are potential fermentation inhibitors and affect the growth rate of the yeast. Reduction of these by-products requires a conditioning (detoxification and culture starter adaptation). Thus, the aim of this study was to evaluate bioethanol production by fermentation with and without detoxified sugarcane bagasse acid hydrolysate using adapted and non-adapted culture of C. tropicalis. According to this study, the highest ethanol amount was obtained about 0.43 % (v/v) with an ethanol yield of 2.51 % and theoretical yield of 4.92 % by fermentation of sugarcane bagasse hydrolysate with detoxification using the adapted strain of C. tropicalis at 72 hours fermentation time. Furthermore, the addition of 3 % glucose as co-substrate on detoxified-hydrolysate media only achieved the highest ethanol concentration 0.21 % after 24 hours fermentation with the ethanol yield 0.69 % and theoretical ethanol yield 1.35 %, thus it can be concluded that the addition of glucose could not increase the ethanol production.

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