scholarly journals Bio-produced Propionic Acid: A Review

2017 ◽  
Vol 62 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Aladár Vidra ◽  
Áron Németh

Propionic acid is a platform chemical, antifungal agent and important chemical intermediate. Current industrial production of propionic acid is mainly through petrochemical processes because the conventional method of the propionic acid fermentation is uneconomical due to low product yield, productivity and product concentration caused by end-product inhibition. The coproduction of acetic and succinic acids in the propionic acid fermentation processes also makes downstream processing more complicated and costly. To the best of our knowledge there are several and recent reviews in the available literature on propionic acid fermentation processes and strain improvement techniques, but only a few on product recovery and purification, i.e. downstreaming. However, to realize a biorefinery, where propionic acid is a key intermediate, complex discussion of up-, and downstreaming is required. Therefore in this review a short overview of the whole bio-based propionic acid production process is presented including recent results of both upstream and downstream area. Thus the biosynthetic pathways, the significant results of native and recombinant producer strains as well as product recovery are discussed.

1972 ◽  
Vol 35 (5) ◽  
pp. 295-301 ◽  
Author(s):  
D. H. Hettinga ◽  
G. W. Reinbold

This review, appearing in three parts, is concerned with the growth, metabolism, and miscellaneous metabolic activities of propionibacteria. The first section, presented here, deals primarily with nutritional requirements, substrate and product inhibition, physical factors, associative action of other microorganisms, and enumeration and isolation of propionibacteria. The nutrition of propionic-acid bacteria has been extensively investigated and the absolute requirements for their nutrition are known. Since propionibacteria play an important role in the fermentation of Swiss cheeses, development of a completely selective medium and continued study of agents inhibitory and stimulatory to propionibacteria would be a valuable aid in solving many of the practical problems associated with Swiss cheese manufacture. Part two will discuss formation of propionate and acetate, the carboxylation, decarboxylation, and transcarboxylation reactions, the roles of biotin and vitamin B12, and the enzymes involved in the propionic-acid fermentation. The third and final section concerning miscellaneous metabolic activities will deal with erythritol metabolism, formation of diacetyl-acetoin and vitamin B12, production of previously undiscussed volatile compounds, propionin, lipids and phospholipids, and the production of slime. The third section also will include concluding comments to provide a brief summary of the important points developed in this review.


Author(s):  
Pieter Candry

Contribution to the International Chain Elongation Conference 2020 | ICEC 2020. An abstract can be found in the right column.


2013 ◽  
Vol 7 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Yuen Ling Ng ◽  
Yi Yang Kuek

Product inhibition is often the cause limiting the maximum product concentration attainable in fermentation. This study showed the product yield of p-cresol could be improved by in-situ product recovery (ISPR). Escherichia coli transformed with the hpd BCA operon from Clostridium difficile was shown in this study to express phydroxyphenylacetate decarboxylase which converted p-hydroxyphenylacetate into p-cresol under anaerobic fermentation. Toxicity of p-cresol found at a concentration as low as 5 mM in a broth spiked with p-cresol was shown to have limited the maximum product concentration at 1 ± 0.1 mM after 30 hours of batch fermentation. Product yield was however shown to increase by 51% when activated carbon was used to remove p-cresol in-situ production. The activated carbon concentrated p-cresol on the solid adsorbent which was subsequently separated by sedimentation and p-cresol recovered by ultrasonic-assisted solvent extraction. Desorption of p-cresol from the spent activated carbon allowed the adsorbent to be regenerated for further product recovery. The ISPR strategy reported here was shown to improve the yield of a toxic product, was sustainable, and when adapted to a continuous process would increase productivity.


2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Xiaoqing Wang ◽  
Davinia Salvachúa ◽  
Violeta Sànchez i Nogué ◽  
William E. Michener ◽  
Adam D. Bratis ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Yujin Cao ◽  
Rubing Zhang ◽  
Chao Sun ◽  
Tao Cheng ◽  
Yuhua Liu ◽  
...  

Succinate is a valuable platform chemical for multiple applications. Confronted with the exhaustion of fossil energy resources, fermentative succinate production from renewable biomass to replace the traditional petrochemical process is receiving an increasing amount of attention. During the past few years, the succinate-producing process using microbial fermentation has been made commercially available by the joint efforts of researchers in different fields. In this review, recent attempts and experiences devoted to reduce the production cost of biobased succinate are summarized, including strain improvement, fermentation engineering, and downstream processing. The key limitations and challenges faced in current microbial production systems are also proposed.


Author(s):  
Mario F. Castellón-Zelaya ◽  
Simón González-Martínez

Abstract The silage of the organic fraction of municipal solid waste (OFMSW) is a common practice in biogas plants. During silage, fermentation processes take place, affecting the later methanisation stage. There are no studies about how OFMSW silage affects methane production. This work aimed to determine the effects of silage (anaerobic acid fermentation) at different solids concentrations and temperatures on methane production. OFMSW was ensiled at 20, 35, and 55 °C with total solids (TS) concentrations of 10, 20, and 28% for 15 days. The ensiled OFMSW was then tested for methane production at the substrate to inoculum ratios (S/I) of 0.5, 1.0, and 1.5. Independently of the temperature, the production of the metabolites during silage increases with decreasing solids concentration. The highest metabolites production were lactic acid, ethanol, and acetic acid, representing together 95% of the total. Methane production from ensiled OFMSW at 10% solids concentration shows, under every tested condition, better methane production than from fresh OFMSW. Ensiled OFMSW produces more methane than fresh OFMSW, and methane production was highest at 35 °C.


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