Fermentation Efficiency
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PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262304
Alaa Emara Rabee ◽  
Amr A. Sayed Alahl ◽  
Mebarek Lamara ◽  
Suzanne L. Ishaq

Lignocellulosic biomass such as barley straw is a renewable and sustainable alternative to traditional feeds and could be used as bioenergy sources; however, low hydrolysis rate reduces the fermentation efficiency. Understanding the degradation and colonization of barley straw by rumen bacteria is the key step to improve the utilization of barley straw in animal feeding or biofuel production. This study evaluated the hydrolysis of barley straw as a result of the inoculation by rumen fluid of camel and sheep. Ground barley straw was incubated anaerobically with rumen inocula from three fistulated camels (FC) and three fistulated sheep (FR) for a period of 72 h. The source of rumen inoculum did not affect the disappearance of dry matter (DMD), neutral detergent fiber (NDFD). Group FR showed higher production of glucose, xylose, and gas; while higher ethanol production was associated with cellulosic hydrolysates obtained from FC group. The diversity and structure of bacterial communities attached to barley straw was investigated by Illumina Mi-Seq sequencing of V4-V5 region of 16S rRNA genes. The bacterial community was dominated by phylum Firmicutes and Bacteroidetes. The dominant genera were RC9_gut_group, Ruminococcus, Saccharofermentans, Butyrivibrio, Succiniclasticum, Selenomonas, and Streptococcus, indicating the important role of these genera in lignocellulose fermentation in the rumen. Group FR showed higher RC9_gut_group and group FC revealed higher Ruminococcus, Saccharofermentans, and Butyrivibrio. Higher enzymes activities (cellulase and xylanase) were associated with group FC. Thus, bacterial communities in camel and sheep have a great potential to improve the utilization lignocellulosic material in animal feeding and the production of biofuel and enzymes.

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 254
Magdalena Zborowska ◽  
Hanna Waliszewska ◽  
Boguslawa Waliszewska ◽  
Slawomir Borysiak ◽  
Jakub Brozdowski ◽  

The aim of the study was to determine the quantitative and qualitative changes taking place in biomass components actively participating in methane fermentation, i.e., in carbohydrates, as a result of chemical pretreatment. Analyses were conducted on agricultural waste (corn stover, also called corn straw, and corncobs) as materials most commonly used in methane fermentation, as well as poplar wood, a material relatively rarely used in biogas production. Pretreatment with the aim of increasing efficiency of methane fermentation was carried out with the use of acid and alkaline solutions of different concentrations. The effect of pretreatment on carbohydrates was analyzed based on the quantitative and qualitative changes in this component. Due to the structural heterogeneity of carbohydrates, their varied reactivity and fermentability were determined in terms of holocellulose, cellulose, and pentosans. The chemical structure of cellulose was also analyzed. It is shown in this study that chemical pretreatment causes transformations of carbohydrate components, which differ quantitatively and qualitatively in the compared raw materials. It was found that the alkaline treatment caused smaller changes in the percentage shares of the carbohydrate biomass components as compared to the acid treatment. Moreover, it was observed that the compared materials differ in terms of quantitative changes in their chemical composition depending on the composition of the raw material prior to pretreatment. In the case of corn waste subjected to the action of 1 and 3% NaOH, the share of pentosans in the biomass increased. It was established that this is a change with a positive effect on fermentation efficiency. The action of acids and alkalis on the biomass led to similar structural changes in cellulose, which are adverse for the fermentation process.

2021 ◽  
Vol 37 ◽  
pp. e37094
Osania Emerenciano Ferreira ◽  
Gustavo Henrique Gravatim Costa ◽  
Aline Ferreira Silva ◽  
Nayara Abrão Montijo ◽  
Miguel Angelo Mutton ◽  

Sweet sorghum is currently being evaluated throughout the world as a raw material for biofuel production because its stem juices are rich in sugars that can be directly fermented to ethanol. In this work, the fermentative efficiency of three sweet sorghum genotypes was evaluated, aiming at ethanol production, harvested in two seasons, clean and whole stems, and the treatment of the juice and broth with amylolytic enzymes in order to use the present starch to increase the production of ethanol. The experiment was carried out in the 2013/2014 harvest, in the municipality of Jaboticabal, São Paulo, Brasil, located at 21°14’05’’S and 48°17’09’’W. The experimental design was completely randomized, with sub-subdivided plots and four replications. The primary treatments were the sweet sorghum genotypes (CV147, CV198, and BRS508), the secondary treatments, the type of harvest (whole stems and clean stems); the tertiary the two sampling times (102 and 116 days after sowing - d.a.s) and the quaternary the application of enzymes. In the fermentation process, the yeast PE-2 was used, at the end, the wine was recovered and characterized. Fermentation efficiency and liters of ethanol per ton of sorghum were calculated. The clarification of the juice with enzymatic treatment increases the quality of the fermentation broth and makes it possible to obtain wines with lower levels of RRTs and Brix. Fermentation efficiency is not affected by the genotype; however, it is influenced by the time of harvest and the technological quality of the juice. The use of amylolytic enzymes makes it possible to obtain wines with lower levels of RRTS and Brix. The best period of industrialization was at 102 d.a.s., and the processing of whole stalks resulted in less ethanol production.

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 53
Kampanat Phesatcha ◽  
Burarat Phesatcha ◽  
Metha Wanapat ◽  
Anusorn Cherdthong

The objective of this research is to investigate the effect of yeast (Saccharomyces cerevisiae) adding and roughage-to-concentrate ratio (R:C ratio) on nutrients utilization, rumen fermentation efficiency, microbial protein synthesis, and protozoal population in Thai native beef cattle. Four Thai native beef cattle, weighing an average of 120 ± 10 kg live weight, were randomly assigned to four dietary treatments using a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. Factor A was the level of roughage-to-concentrate ratio (R:C ratio) at 60:40 and 40:60; factor B was the levels of live yeast (LY) supplementation at 0 and 4 g/hd/d; urea–calcium-hydroxide-treated rice straw were used as a roughage source. Findings revealed that total intake and digestibility of dry matter (DM), organic matter (OM), and crude protein (CP) were increased (p < 0.05) by both factors, being greater for steers fed a R:C ratio of 40:60 supplemented with 4 g LY/hd/d. Ruminal ammonia nitrogen, total volatile fatty acid (VFA), and propionate (C3) were increased (p < 0.05) at the R:C ratio of 40:60 with LY supplementation at 4 g/hd/d, whereas rumen acetate (C2) and the C2 to C3 ratio were decreased (p < 0.05). With a high level of concentrate, LY addition increased total bacterial direct counts and fungal zoospores (p < 0.05), but decreased protozoal populations (p < 0.05). High-concentrate diet and LY supplementation increased nitrogen absorption and the efficiency of microbial nitrogen protein production. In conclusion, feeding beef cattle with 4 g/hd/d LY at a R:C ratio of 40:60 increased C3 and nutritional digestibility while lowering protozoal population.

Fermentation ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 8
Kampanat Phesatcha ◽  
Burarat Phesatcha ◽  
Metha Wanapat ◽  
Anusorn Cherdthong

The objective of the research was to evaluate the different levels of Mitragyna speciosa Korth leaves powder (MSLP) added to rations with 60:40 or 40:60 roughage to a concentrate (R:C ratio) on in vitro nutrient digestibility, rumen fermentation characteristics, microbial population, and methane (CH4) production. The treatments were arranged according to a 2 × 8 factorial arrangement in a completely randomized design. The two factors contain the R:C ratio (60:40 and 40:60) and the levels of MSLP addition (0, 1, 2, 3, 4, 5, 6, and 7% of the total substrate). There was no interaction between the R:C ratio and MSLP supplementation on gas production kinetics, ammonia nitrogen (NH3-N), and microbial populations. The gas production rate constant for the insoluble fraction (c) was increased by the R:C ratio at (40:60), whilst there was no difference obtained among treatments for cumulative gas production, whilst the gas production rate constant for the insoluble fraction (c) was increased by the R:C ratio at 40:60. The concentration of NH3-N was influenced by the R:C ratio and MSLP addition both at 4 and 8 h after incubation. In vitro dry matter degradability (IVDMD) and organic matter degradability (IVOMD) were significantly improved by the R:C ratio and supplementation of MSLP at 12 h. Increasing the R:C ratio and MSLP concentrations increased total volatile fatty acid (VFA) and propionic acid (C3) concentrations while decreasing acetic acid (C2) and butyric acid (C4) concentrations; thus, the C2:C3 ratio was reduced. MSLP addition reduced protozoa and methanogen populations (p < 0.05). The calculated CH4 production was decreased (p < 0.05) by the R:C ratios at 40:60 and supplementation of MSLP. Finally, the addition of MSLP as a phytonutrient may improve nutrient degradability and rumen fermentation properties while decreasing protozoa, methanogen population, and CH4 production.

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Agustin Krisna Wardani ◽  
Aji Sutrisno ◽  
Titik Nur Faida ◽  
Retno Dwi Yustina ◽  
Untung Murdiyatmo

Background. Oil palm trunk (OPT) with highly cellulose content is a valuable bioresource for bioethanol production. To produce ethanol from biomass, pretreatment is an essential step in the conversion of lignocellulosic biomass to fermentable sugars such as glucose and xylose. Several pretreatment methods have been developed to overcome biomass recalcitrance. In this study, the effects of different pretreatment methods such as alkali pretreatment, microwave-alkali, and alkaline peroxide combined with autoclave on the lignocellulosic biomass structure were investigated. Moreover, ethanol production from the treated biomass was performed by simultaneous saccharification and cofermentation (SSCF) under different temperatures, fermentation times, and cell ratios of Saccharomyces cerevisiae NCYC 479 and pentose-utilizing yeast, Pichia stipitis NCYC 1541. Results. Pretreatment resulted in a significant lignin removal up to 83.26% and cellulose released up to 80.74% in treated OPT by alkaline peroxide combined with autoclave method. Enzymatic hydrolysis of treated OPT resulted in an increase in fermentable sugar up to 93.22%. Optimization of SSCF by response surface method showed that the coculture could work together to produce maximum ethanol (1.89%) and fermentation efficiency (66.14%) under the optimized condition. Conclusion. Pretreatment by alkaline peroxide combined with autoclave method and SSCF process could be expected as a promising system for ethanol production from oil palm trunk and various lignocellulosic biomass.

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 7
Ayele Alemu ◽  
Minale Getachew ◽  
Gulam Mohammed Sayeed Ahmed ◽  
Vineet Tirth ◽  
Ali Algahtani

This study was conducted at the ethanol plant of Metehara sugar factory, at a laboratory scale, to assess the effect of recycling vinasse into the fermentation process on effluent reduction. Vinasse is an effluent produced from distilleries. The experimental design included vinasse concentrations at 4 dilution rates (0 (control), 20, 35, 50, and 65% of process water) with 2 replicates and 6 responses, as follows: ethanol yield, fermentation efficiency, residual sugar concentration, cell count, cell viability, and calcium oxide content. In this study, the actual operational parameters of the ethanol plant were maintained during the experiment. The result of the experiment indicates that, with up to 20% vinasse recycling, there was no influential impact on the ethanol yield, the fermentation efficiency, the residual sugar concentration, or the calcium oxide content, attributable to the recycling, as compared to the control. Above 20% vinasse recycling, ethanol yield and fermentation efficiency decreased sharply from those of the control. In addition, with 20% vinasse recycling put into practice, the amount of vinasse generated will be reduced by about 19.5% and about 114.2 tons of water will be saved per day. Moreover, the excess amount of vinasse produced by the distillery, which is beyond the handling capacity of bio-compost plant of the distillery, will reduce from 105 to 36.8 tons per day. Therefore, it is possible to recycle vinasse into the fermenter up to 20% on dilution water of Metehara distillery, without causing any impacts on the distillery’s performance.

2021 ◽  
Kedong Ma ◽  
Yubo Cui ◽  
Ke Zhao ◽  
Yuxuang Yang ◽  
Yidan Wang ◽  

Abstract Background: D-lactic acid played an important role in the establishment of PLA as a substitute for petrochemical plastics. But, so far, the D-lactic acid production was limited in only pilot scale, which was definitely unable to meet the fast growing market demand. To achieve industrial scale D-lactic acid production, the cost-associated problems such as high-cost feedstock, expensive nutrient sources and fermentation technology need to be resolved to establish an economical fermentation process.Results: In the present study, the combined effect of B vitamin supplementation and membrane integrated continuous fermentation on D-lactic acid production from agricultural lignocellulosic biomass by Lactobacillus delbrueckii was investigated. The results indicated the specific addition of vitamins B1, B2, B3 and B5 could reduce the yeast extract (YE) addition from 10 g/l to 3 g/l without obvious influence on fermentation efficiency. By employing cell recycling system in 350 h continuous fermentation with B vitamin supplementation, YE addition was further reduced to 0.5 g/l, which resulted in nutrient source cost reduction of 86%. A maximum D-lactate productivity of 18.56 g/l/h and optical purity of 99.5% were achieved and higher than most recent reports. Conclusion: These findings suggested the novel fermentation strategy proposed could effectively reduce the production cost and improve fermentation efficiency, thus exhibiting great potential in promoting industrial scale D-lactic acid production from lignocellulosic biomass.

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Shunchang Pu ◽  
Yu Zhang ◽  
Ning Lu ◽  
Cuie Shi ◽  
Shoubao Yan

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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