scholarly journals From Food Waste to Volatile Fatty Acids towards a Circular Economy

2021 ◽  
Author(s):  
Mónica Carvalheira ◽  
Anouk F. Duque
Keyword(s):  
Fatty Acids ◽  
Food Waste ◽  
Circular Economy ◽  
Volatile Fatty Acids ◽  
Animal Feed ◽  
Anaerobic Fermentation ◽  
Industrial Sector ◽  
Added Value ◽  
Microbial Cultures ◽  
Mixed Microbial Cultures

The food industrial sector generates large amounts of waste, which are often used for animal feed, for agriculture or landfilled. However, these wastes have a very reach composition in carbon and other compounds, which make them very attractive for valorization through biotechnological processes. Added value compounds, such as volatile fatty acids (VFAs), can be produced by anaerobic fermentation using pure cultures or mixed microbial cultures and food waste as carbon source. Research on valuable applications for VFAs, such as polyhydroxyalkanoates, bioenergy or biological nutrient removal, towards a circular economy is emerging. This enhances the sustainability and the economic value of food waste. This chapter reviews the various types of food waste used for VFAs production using mixed microbial cultures, the anaerobic processes, involved and the main applications for the produced VFAs. The main parameters affecting VFAs production are also discussed.

scholarly journals Influence of the total concentration and the profile of volatile fatty acids on polyhydroxyalkanoates (PHA) production by mixed microbial cultures

2021 ◽  
Author(s):  
Gloria Bravo-Porras ◽  
Luis A. Fernández-Güelfo ◽  
Carlos J. Álvarez-Gallego ◽  
María Carbú ◽  
Diego Sales ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Total Concentration ◽  
Degradation Process ◽  
Microbial Cultures ◽  
Dry Cell Weight ◽  
Cheap Alternative ◽  
Mixed Microbial Cultures ◽  
Pha Production ◽  
Dry Cell

AbstractPolyhydroxyalkanoates (PHAs) production from lignocellulosic biomass using mixed microbial cultures (MMC) is a potential cheap alternative for reducing the use of petroleum-based plastics. In this study, an MMC adapted to acidogenic effluent from dark fermentation (DF) of exhausted sugar beet cossettes (ESBC) has been tested in order to determine its capability to produce PHAs from nine different synthetic mixtures of volatile fatty acids (VFAs). The tests consisted of mixtures of acetic, propionic, butyric, and valeric acids in the range of 1.5–9.0 g/L of total acidity and with three different valeric:butyric ratios (10:1, 1:1, and 1:10). Experimental results have shown a consistent preference of the MMC for the butyric and valeric acids as carbon source instead other shorter acids (propionic or acetic) in terms of PHA production yield (estimated in dry cell weight basis), with a maximum value of 23% w/w. Additionally, valeric-rich mixtures have demonstrated to carry out a fast degradation process but with poor final PHA production compared with high butyric mixtures. Finally, high initial butyric and valeric concentrations (1.1 g/L and 4.1 g/L) have demonstrated to be counterproductive to PHA production.

scholarly journals Volatile Fatty Acids (VFAs) Generated by Anaerobic Digestion Serve as Feedstock for Freshwater and Marine Oleaginous Microorganisms to Produce Biodiesel and Added-Value Compounds

2021 ◽  
Vol 12 ◽  
Author(s):  
Alok Patel ◽  
Amir Mahboubi ◽  
Ilona Sárvári Horváth ◽  
Mohammad J. Taherzadeh ◽  
Ulrika Rova ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Food Waste ◽  
Environmental Sustainability ◽  
Volatile Fatty Acids ◽  
Oil Production ◽  
Added Value ◽  
Microbial Oil ◽  
Omega 3 ◽  
Freshwater Microalgae

Given an increasing focus on environmental sustainability, microbial oils have been suggested as an alternative to petroleum-based products. However, microbial oil production relies on the use of costly sugar-based feedstocks. Substrate limitation, elevated costs, and risk of contamination have sparked the search for alternatives to sugar-based platforms. Volatile fatty acids are generated during anaerobic digestion of organic waste and are considered a promising substrate for microbial oil production. In the present study, two freshwater and one marine microalga along with two thraustochytrids were evaluated for their potential to produce lipids when cultivated on volatile fatty acids generated from food waste via anaerobic digestion using a membrane bioreactor. Freshwater microalgae Auxenochlorella protothecoides and Chlorella sorokiniana synthesized lipids rich in palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (C18:2). This composition corresponds to that of soybean and jatropha oils, which are used as biodiesel feedstock. Production of added-value polyunsaturated fatty acids (PUFA) mainly omega-3 fatty acids was examined in three different marine strains: Aurantiochytrium sp. T66, Schizochytrium limacinum SR21, and Crypthecodinium cohnii. Only Aurantiochytrium sp. T66 seemed promising, generating 43.19% docosahexaenoic acid (DHA) and 13.56% docosapentaenoic acid (DPA) in total lipids. In summary, we show that A. protothecoides, C. sorokiniana, and Aurantiochytrium sp. T66 can be used for microbial oil production from food waste material.

scholarly journals Bio-based conversion of volatile fatty acids from waste streams to polyhydroxyalkanoates using mixed microbial cultures

2021 ◽  
Vol 323 ◽  
pp. 124604
Author(s):  
Mariel Perez-Zabaleta ◽  
Merve Atasoy ◽  
Kasra Khatami ◽  
Elsa Eriksson ◽  
Zeynep Cetecioglu
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Waste Streams ◽  
Microbial Cultures ◽  
Mixed Microbial Cultures

scholarly journals Assessment of Long-Term Fermentability of PHA-Based Materials from Pure and Mixed Microbial Cultures for Potential Environmental Applications

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 897
Author(s):  
Neda Amanat ◽  
Bruna Matturro ◽  
Marta Maria Rossi ◽  
Francesco Valentino ◽  
Marianna Villano ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Volatile Fatty Acids ◽  
Rapid Onset ◽  
Pilot Scale ◽  
Point Of View ◽  
Microbial Cultures ◽  
Extraction And Purification ◽  
Fermentation Pattern ◽  
Mixed Microbial Cultures

The use of polyhydroxyalkanoates (PHA) as slow-release electron donors for environmental remediation represents a novel and appealing application that is attracting considerable attention in the scientific community. In this context, here, the fermentation pattern of different types of PHA-based materials has been investigated in batch and continuous-flow experiments. Along with commercially available materials, produced from axenic microbial cultures, PHA produced at pilot scale by mixed microbial cultures (MMC) using waste feedstock have been also tested. As a main finding, a rapid onset of volatile fatty acids (VFA) production was observed with a low-purity MMC-deriving material, consisting of microbial cells containing 56% (on weight basis) of intracellular PHA. Indeed, with this material a sustained, long-term production of organic acids (i.e., acetic, propionic, and butyric acids) was observed. In addition, the obtained yield of conversion into acids (up to 70% gVFA/gPHA) was higher than that obtained with the other tested materials, made of extracted and purified PHA. These results clearly suggest the possibility to directly use the PHA-rich cells deriving from the MMC production process, with no need of extraction and purification procedures, as a sustainable and effective carbon source bringing remarkable advantages from an economic and environmental point of view.

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