Effects of inoculum size on ethanol inhibition modeling and other fermentation parameters

1987 ◽  
Vol 29 (5) ◽  
pp. 633-638 ◽  
Author(s):  
J. L. Vega ◽  
A. R. Navarro ◽  
E. C. Clausen ◽  
J. L. Gaddy
2015 ◽  
Vol 1113 ◽  
pp. 273-278
Author(s):  
I. Norazlina ◽  
K.H. Ku Halim ◽  
Shareena Fairuz Abd Manaf ◽  
Muhammad Afiquddin Abu Bakar

The production of xylanase by Aspergillusniger ATCC 16404 via solid state fermentation (SSF) system using oil palm leaves (OPL) as substrate was investigated. Fermentation parameters studied using one factor at a time (OFAT) technique, were carbon-nitrogen (C/N) ratio, mineral solution size and inoculums size. It was found that the optimum C/N ratio was at 0.4 with xylanase activity at 16.046 U/min. Meanwhile, the optimum size for both mineral solution size and inoculum size were at 1 ml with the xylanase activity recorded at 14.500 U/min and 19.057 U/min respectively. This shows that that the utilization of OPL as substrates in xylanase production using Aspergillusniger ATCC 16404 was a successful.


2019 ◽  
Vol 63 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Joseph Adetunji Elegbede ◽  
Agbaje Lateef

Xylanases are important in producing several commercially valued bioproducts. In this study, xylanases were produced by Aspergillus niger L3 and Trichoderma longibrachiatum L2 using corncob, an agricultural waste, as sole carbon source. The impact of important fermentation parameters at individual and interactive levels were studied using Taguchi L9 orthogonal array. Substantial variation in enzyme synthesis was observed among designated factor levels. The optimal conditions to produce xylanases were 20% inoculum size, 24 h fermentation time, substrate concentration of 15 g/l at pH 5.5 for A. niger L3; and inoculum size 12.5%, 72 h fermentation time, substrate concentration of 15 g/l at pH 5.5 for T. longibrachiatum L2. Validation of outcomes of the optimal combination of parameters resulted in a significant improvement of approximately 208.09 and 192.59% in the yield of xylanase by A. niger L3 (28.69 to 88.39 U/ml) and T. longibrachiatum L2 (22.13 to 64.75 U/ml), respectively. The study therefore established the optimal valorization of corncob to produce xylanase by the fungal isolates.


2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
K. Mukhtar ◽  
M. Asgher ◽  
S. Afghan ◽  
K. Hussain ◽  
S. Zia-ul-Hussnain

Two commercial strains of Saccharomyces cerevisiae, Saf-Instant (Baker's yeast) and Ethanol red (Mutant) were compared for ethanol production during hot summer season, using molasses diluted up to 6- Brix containing 4%-5% sugars. The yeasts were then propagated in fermentation vessels to study the effects of yeast cell count and varying concentrations of Urea, DAP, inoculum size and Lactrol (Antibiotic). Continuous circulation of mash was maintained for 24 hours and after this fermenter was allowed to stay for a period of 16 hours to give time for maximum conversion of sugars into ethanol. Saccharomyces cerevisiae strain (Saf-instant) with cell concentration of 400 millions/mL at molasses sugar level of 13%–15% (pH , Temp. ), inoculum size of 25% (v/v), urea concentration, 150 ppm, DAP, 53.4 ppm and Lactrol,150 ppm supported maximum ethanol production (8.8%) with  L ethanol per tone molasses (96.5% yield), and had significantly lower concentrations of byproducts. By selecting higher ethanol yielding yeast strain and optimizing the fermentation parameters both yield and economics of the fermentation process can be improved.


Author(s):  
Nguyễn Thị Hồng Thu ◽  
Đặng Minh Nhật ◽  
Nguyễn Hoàng Dung

Sugar palm (Arenga pinnata) is a feather palm native to tropical Asia. In Vietnam, it is named Búng Báng or Đoác and grown only on the highlands in the central or northern part of Vietnam. It is utilized for many purposes, especially for Ta Vat wine production - a characteristic and unique product of Co Tu ethnic minority. However, because of the natural fermentation used in the production, the product quality is inconsistent. The purpose of this study was to examine a new procedure of using palm sap for making Ta Vat wine. Some characteristics of the sap, which was collected at Nam Giang district, Quang Nam province are determined, proving the potential of the sap for making wine product. The quality of sap changes quickly at room temperature. At low temperature (4 - 60C), the changes in sap quality are apparently slower. Examining some factors affecting its quality during the wine fermentation process, we determined the best parameters for the fermentation process as follows: inoculum size of 3% with cell density of about 1x108 cells/ml, the addition of the extract from the bark of Ceylon ironwood (Mesua ferrea L.) 4%. Keywords: Arenga pinnata, sap, Ceylon ironwood bark, Mesua ferrea L., wine fermentation.


2020 ◽  
Vol 21 (13) ◽  
pp. 1304-1315
Author(s):  
Junmei Zhou ◽  
Lianghong Yin ◽  
Chenbin Wu ◽  
Sijia Wu ◽  
Jidong Lu ◽  
...  

Objective: Alkaline Carboxymethyl Cellulase (CMCase) is an attractive enzyme for the textile, laundry, pulp, and paper industries; however, commercial preparations with sufficient activity at alkaline conditions are scarce. Methods: High CMCase-producing bacterial isolate, SX9-4, was screened out from soil bacteria, which was identified as Flavobacterium sp. on the basis of 16S rDNA sequencing. Results: The optimum pH and temperature for CMCase reaction were 8.0 and 55°C, respectively. Alkaline CMCase was stable over wide pH (3.0-10.6) and temperature (25-55°C) ranges. Enzyme activity was significantly inhibited by the bivalent cations Mn2+ and Cu2+, and was activated by Fe2+. To improve the alkaline CMCase production of SX9-4, fermentation parameters were selected through onefactor- at-a-time and further carried out by response surface methodologies based on a central composite design. Conclusion: High CMCase production (57.18 U/mL) was achieved under the optimal conditions: 10.53 g/L carboxymethylcellulose sodium, 7.74 g/L glucose, 13.71 g/L peptone, and 5.27 g/L ammonium oxalate.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 591
Author(s):  
Nayely Padilla-Montaño ◽  
Leandro de León Guerra ◽  
Laila Moujir

Species of the Celastraceae family are traditionally consumed in different world regions for their stimulating properties. Celastrol, a triterpene methylene quinone isolated from plants of celastraceas, specifically activates satiety centers in the brain that play an important role in controlling body weight. In this work, the antimicrobial activity and mechanism of action of celastrol and a natural derivative, pristimerin, were investigated in Bacillus subtilis. Celastrol showed a higher antimicrobial activity compared with pristimerin, being active against Gram-positive bacteria with minimum inhibitory concentrations (MICs) that ranged between 0.16 and 2.5 µg/mL. Killing curves displayed a bactericidal effect that was dependent on the inoculum size. Monitoring of macromolecular synthesis in bacterial populations treated with these compounds revealed inhibition in the incorporation of all radiolabeled precursors, but not simultaneously. Celastrol at 3 µg/mL and pristimerin at 10 µg/mL affected DNA and RNA synthesis first, followed by protein synthesis, although the inhibitory action on the uptake of radiolabeled precursors was more dramatic with celastrol. This compound also caused cytoplasmic membrane disruption observed by potassium leakage and formation of mesosome-like structures. The inhibition of oxygen consumption of whole and disrupted cells after treatments with both quinones indicates damage in the cellular structure, suggesting the cytoplasmic membrane as a potential target. These findings indicate that celastrol could be considered as an interesting alternative to control outbreaks caused by spore-forming bacteria.


2021 ◽  
pp. 108201322110165
Author(s):  
Luciano M Guardianelli ◽  
María V Salinas ◽  
María C Puppo

Amaranth flour from germinated (GA) and non-germinated (A) seeds (0%-C, 5%, 15%, 25%) were mixed with wheat flour for breadmaking. Fermentation parameters of dough (time-tf, maximum volume-Vmax) were obtained. Specific volume (Vsp) of breads, crust color, texture and relaxation of crumb were analyzed. A high amount of germinated amaranth flour decreased Vmax and increased tf, obtaining breads with low Vsp and darkness crust. A firmed and chewy crumb, although with a more aerated structure (high area occupied by alveoli) was obtained. The GA25 bread presented the softer crumb. The elastic modulus-E1 of crumb increased and the relaxation time-T1 decreased with higher amounts of amaranth flour, suggesting the formation of a more structured crumb; mainly in the case of non-germinated amaranth flour. Wheat flour resisted the inclusion of 25% of germinated amaranth seeds (GA25) without substantial changes in bread quality.


Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 216
Author(s):  
Alberto Millán ◽  
Núria Sala ◽  
Mercè Torres ◽  
Ramon Canela-Garayoa

The compound 2,5-di(hydroxymethyl)furan (DHMF) is a high-value chemical block that can be synthesized from 5-hydroxymethylfurfural (HMF), a platform chemical that results from the dehydration of biomass-derived carbohydrates. In this work, the HMF biotransformation capability of different Fusarium species was evaluated, and F. striatum was selected to produce DHMF. The effects of the inoculum size, glucose concentration and pH of the media over DHMF production were evaluated by a 23 factorial design. A substrate feeding approach was found suitable to overcome the toxicity effect of HMF towards the cells when added at high concentrations (>75 mM). The process was successfully scaled-up at bioreactor scale (1.3 L working volume) with excellent DHMF production yields (95%) and selectivity (98%). DHMF was purified from the reaction media with high recovery and purity by organic solvent extraction with ethyl acetate.


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