scholarly journals Evaluation of Fed-Batch Fermentation for Production of Polyhydroxybutyrate With a Banana Pulp Juice Substrate From an Agro Industrial By-Product

2021 ◽  
Vol 5 ◽  
Author(s):  
Mónica Arias-Roblero ◽  
Vanny Mora-Villalobos ◽  
Carmela Velazquez-Carrillo
Keyword(s):  
Carbon Source ◽  
Ammonium Chloride ◽  
Batch Fermentation ◽  
Waste Product ◽  
Industrial Wastes ◽  
Gas Chromatography Mass Spectrometry ◽  
Fed Batch ◽  
Banana Juice ◽  
Phb Production ◽  
Fed Batch Fermentation

Pollution resulting from the persistence of plastics in the environment has driven the development of substitutes for these materials through fermentation processes using agro-industrial wastes. Polyhydroxybutyrate (PHB) is a rapidly biodegradable material with chemical and mechanical properties comparable to those of some petroleum-derived plastics. PHB accumulates intracellularly as an energy reserve in a wide variety of microorganisms exposed to nutritionally imbalanced media. The objective of this study was to evaluate the use of a banana waste product as a carbon source for PHB production. PHB was extracted by acid methanolysis and detected by gas chromatography-mass spectrometry. Eleven bacterial strains with potential for PHB production were evaluated by in vitro fermentation in a culture broth containing fructose as the carbon source and limited nitrogen. A 22 central composite rotational design was applied to optimize the concentrations of banana juice and ammonium chloride needed to maximize the PHB-producing biomass concentration. The process was then carried out in a 3 L fed-batch fermentation system that included an initial stage of biomass growth. Banana juice was used as the carbon source and fructose pulses were added to maintain the test sugar concentrations of 30, 40, and 50 g/L. The control strain, Cupriavidus necator (ATCC 17699), produced 2.816 g/L of PHB, while productivity of the most promising isolate, C. necator (CR-12), was 0.495 g/L. Maximum biomass production was obtained using 5% banana juice and 2 g/L ammonium chloride. PHB production was not detected in fed-batch fermentations supplemented with 30 or 40 g/L of fructose, while the mean PHB production in fermentations with 50 g/L of fructose was 1.3 g/L.

scholarly journals Bacterial Cellulose Synthesis by Gluconacetobacter xylinus: Enhancement via Fed-batch Fermentation Strategies in Glycerol Media

2021 ◽  
Vol 18 (22) ◽  
pp. 453
Author(s):  
Azila Adnan ◽  
Giridhar Nair ◽  
Mark Lay ◽  
Janis Swan
Keyword(s):  
Carbon Source ◽  
Bacterial Cellulose ◽  
Batch Culture ◽  
Batch Fermentation ◽  
Operation Mode ◽  
Volumetric Productivity ◽  
Fed Batch ◽  
Fed Batch Fermentation ◽  
Pulse Feed ◽  
Fed Batch Culture

Bacterial cellulose (BC) is an abundant polysaccharide, which is secreted by several genera of bacteria. It has remarkable characteristics, which include high purity, high tensile strength, high biocompatibility and non-toxic. The main feature that differentiates BC and plant cellulose (PC) is the absence of contaminants such as lignin, hemicellulose and pectin. However, the main drawbacks in producing BC are low yield and expensive carbon source. Due to that, this study was carried out to enhance BC volumetric productivity in fed-batch operation mode using glycerol as a carbon source. BC was produced in fill-and-draw and pulse-feed fed-batch cultures of Gluconacetobacter xylinus DSM 46604 in a 3-L bench-top bioreactor. The fed-batch fermentation trials were conducted in agitated and aerobic conditions at 30 ºC. For fill-and-draw fed-batch culture, a total of 24.2 g/L of BC accumulated in the bioreactor after 9 days, which corresponded to a yield and productivity of 0.2 g/g and 2.69 g/L/day, respectively. Pulse-feed fed-batch fermentation resulted in a yield and volumetric productivity of 0.38 g/g and 2.71 g/L/day, respectively. The pulse-feed fed-batch culture proved to be a better fermentation system for utilizing glycerol, which is a low-cost and abundant carbon source. HIGHLIGHTS Komagataeibacter species, which were formerly known as Acetobacter or Gluconacetobacter is one of the Gram-negative BC producers that secretes a large quantity of BC microfibrils extracellularly One of the main challenges in bacterial cellulose (BC) production is low productivity and high processing cost As fed-batch fermentation is one of the operation modes in bioprocess that can control the microbial growth rate, this operation mode is conducted to enhance the yield of BC, substrate consumption and also volumetric productivity Fill-and-draw and pulse feed fed-batch culture were conducted to enhance yield and volumetric productivity. The pulse-feed fed-batch culture resulted to be a favorable operation mode for utilizing glycerol, which is a low-cost and abundant carbon source GRAPHICAL ABSTRACT

A Study of Fermentation for Human Interleukin-11 with Recombinant E. Coli

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Kaili Zhao ◽  
Yiru Gan ◽  
Zisheng Jason Zhang
Keyword(s):  
Carbon Source ◽  
Batch Fermentation ◽  
Carbon Sources ◽  
Biological Properties ◽  
Operational Parameters ◽  
Fed Batch ◽  
E Coli ◽  
Dry Cell Weight ◽  
Fed Batch Fermentation ◽  
Interleukin 11

Recombinant human interleukin-11(rhIL-11) is still the only therapy drug for thrombocytopenia. Although the biological properties and clinical behaviors of rhIL-11 have been studied extensively, its bioprocess development data have rarely been reported. In this work, fermentation conditions for recombinant E. coli, which expressed interleukin-11 as a fusion protein, were investigated. Batch and fed-batch fermentation experiments were performed in shake flasks and in a BioFlo fermenter with different medium and carbon sources under different operational parameters. Based on the results of the study, M9Ca medium was shown as the better medium and glycerol was identified to be a better carbon source than glucose for the expression of rhIL-11. When glycerol was used as the carbon source in fed-batch fermentation, a dry cell weight of 9.2 g/L and a rhIL-11 expression of 22%, were achieved. The results could be used as references in the optimization of the fermentation process.

scholarly journals Homoethanol Production from Glycerol and Gluconate Using RecombinantKlebsiella oxytocaStrains

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Weiyi Tao ◽  
Yi Wang ◽  
Eric Walters ◽  
Hui Lin ◽  
Shuang Li ◽  
...  
Keyword(s):  
Carbon Source ◽  
Degradation Product ◽  
Batch Fermentation ◽  
Ethanol Yield ◽  
Cellulosic Biomass ◽  
Biodiesel Production ◽  
Utilization Rate ◽  
Fed Batch ◽  
Content Type ◽  
Fed Batch Fermentation

ABSTRACTGluconic acid, an oxidized cellulose degradation product, could be produced from cellulosic biomass. Glycerol is an inexpensive and renewable resource for fuels and chemicals production and is available as a byproduct of biodiesel production. Gluconate is a more oxidized substrate than glucose, whereas glycerol is a more reduced substrate than glucose. Although the production of homoethanol from glucose can be achieved, the conversion of gluconate to ethanol is accompanied by the production of oxidized byproduct such as acetate, and reduced byproducts such as 1,3-propanediol are produced, along with ethanol, when glycerol is used as the carbon source. When gluconate and glycerol are used as the sole carbon source byKlebsiella oxytocaBW21, the ethanol yield is about 62 to 64%. Coutilization of both gluconate and glycerol in batch fermentation increased the yield of ethanol to about 78.7% and decreased by-product accumulation (such as acetate and 1,3-propanediol) substantially. Decreasing by-product formation by deleting thepta,frd,ldh,pflA, andpduCgenes in strain BW21 increased the ethanol yield to 89.3% in the batch fermentation of a glycerol-gluconate mixture. These deletions produced the strainK. oxytocaWT26. However, the utilization rate of glycerol was significantly slower than that of gluconate in batch fermentation. In addition, substantial amounts of glycerol remain unutilized after gluconate was depleted in batch fermentation. Continuous fed-batch fermentation was used to solve the utilization rate mismatch problem for gluconate and glycerol. An ethanol yield of 97.2% was achieved in continuous fed-batch fermentation of these two substrates, and glycerol was completely used at the end of the fermentation.IMPORTANCEGluconate is a biomass-derived degradation product, and glycerol can be obtained as a biodiesel byproduct. Compared to glucose, using them as the sole substrate is accompanied by the production of by-products. Our study shows that through pathway engineering and adoption of a fed-batch culture system, high-yield homoethanol production that usually can be achieved by using glucose as the substrate is achievable using gluconate and glycerol as cosubstrates. The same strategy is expected to be able to achieve homofermentative production of other products, such as lactate and 2,3-butanediol, which can be typically achieved using glucose as the substrate and inexpensive biodiesel-derived glycerol and biomass-derived gluconate as the cosubstrates.

Sign in / Sign up

Export Citation Format

Share Document