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Content of GSH in fermented feeds from different treatments. 1 Effect of proportions in mixed yeast culture. 2 Effect of inoculum amounts. 3 Effect of initial water contents. Sc:Cu:Yl = A, 2:1:1; B, 3:2:1; C, 1:3:1; D, 3:1:2; E, 1:2:2; F, 2:3:2
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In order to realize the value-added utilization of food waste (FW), the preparation of crayfish (Procambarus clarkii) feed by yeast fermentation was investigated. Firstly, the suitable fermentation condition was obtained through a single factor experiment as follows: the initial moisture of the FW was adjusted to 60% with bran and inoculated with a...
Citations
... Thermotolerant strains are very useful for raising the temperature of SSF and fermentation [94]. Li et al. [95] have shown in their study that yeast fermentation using feed from food waste can replace crayfish's conventional diet by 30% which may in turn improve their antioxidant capacity and enhance non-specific immunity. The fermentation conditions were maintained, and initial moisture was maintained at about 60% of food waste bran and inoculated with 2% of the yeast mixture (Saccharomyces cerevisiae, Candida utilis, and Yarrowia lipolytica, 3:2:1). ...
Fermentation is derived from a Latin word fermentum, a process of chemical changes in an organic substrate by the action of microbial enzymes. The science of fermentation is called as zymology, and the first zymologist was Louis Pasteur. Study of fermentation is called as fermentation technology. Fermenter or bioreactor is the heart of fermentation technology where the whole study is involved. It is a container with biomechanical and biochemical environment that controls the transfer of oxygen, nutrient to the cells, and metabolic products from the cells. There are different types of fermenters like stirred tank fermenter, airlift fermenter, bubble column reactor, fluidized-bed reactor, packed bed reactor, and membrane bioreactor. There are different processes such as batch, continuous, and fed batch or semi-continuous. Secondary metabolites are produced either through submerged or solid-state fermentation process during the stationary phase of an organism. These metabolites are showing a rising demand in food, cosmetics, drugs, and other industries. The production of these metabolites can be improved by strain improvement through mutagenesis and r-DNA technologies. This chapter focuses on all these areas in detail.
... Compared with monoculture fermentation, mixed culture has historically received less attention; however, several recent reviews have focused on mixed microbial communities for protein production [13, [24][25][26][27][28][29][30]. Mixed cultures are complex communities with many syntrophic relationships, which can offer increased robustness compared with pure culture (Figure 3a). ...
Food waste represents a growing global crisis equivalent to ∼1.3 billion tonnes/year. This review provides an overview of the potential of food waste as a carbon source for microbial upcycling using anaerobic digestion (AD) for bioenergy coupled with single-cell protein (SCP) production. We estimate biogas potential from food waste to be sufficient to generate electricity for 26,500 UK households. Additionally, the concept of mixed communities is considered an alternative to traditional pure culture fermentation for SCP, and a literature review of 82 genera for SCP from food waste and biogas is presented. Improvements in the understanding of microbial community structure and function are still required to improve reactor performance. Future research should focus on providing insight into the AD microbiome, considering the role of syntrophic relationships in reactor stability, alongside integrated whole systems sustainability assessment of microbial upcycling technologies.
... These results indicated that the bio-fermented diet can signi cantly enhance the growth and development of juvenile yellow cat sh. Relevant studies have shown that the nal body weight, WGR, and SGR of Procambarus clarkii are signi cantly increased after feeding Procambarus clarkii with 30% kitchen waste fermentation [21] . The study on Largemouth bass also showed that biologically fermented diets signi cantly increased the WGR and SGR of Largemouth bass [22] . ...
To investigate the feeding effect of fermented feed, juvenile yellow catfish (1.23±0.54) g were fed with hard pellet feed and biological fermented feed in an indoor recirculating water system for 8 weeks. The study analyzed the effects of fermented diets on the growth performance, digestion, immunity, antioxidant capacity, and intestinal structure of yellow catfish. The results showed that: the fermented diet significantly increasedthe WGR, SGR, and VSI, but had no significant effect on the HSI. The fermented diet significantly increased the activities of Try, Lip, and AMS in the intestinal tract of yellow catfish. The fermented diet significantly increased the activities of ACP, AKP, CAT, and SOD in the serum of yellow catfish and significantly decreased the content of MDA in the serum. The fermented diet significantly increased the width and height of the intestinal villus and the thickness of the intestinal wall in the midgut of yellow catfish.The results indicate that fermented feed could effectively improve the growth performance, digestive enzyme activity, and immune and antioxidant capacity, and improve the intestinal tissue structure of yellow catfish. This provides a theoretical basis for the production of microbial fermented feed.
... Fed-batch fermentation was equally employed to produce vinegar from discarded onion juice by microbial fermentation using Acetobacter tropicalis KFCC 11476P [86]. Fermentation techniques, particularly, solid-state fermentation (SSF) is a widely researched and effective procedure for the bioconversion of agro-industrial food waste, which produces inexpensive enzymes, organic acids, vitamins, fermented feeds and aroma compounds [87,88]. SSF offers the following advantages: lower production cost, a higher output, less amount of waste generated, simpler equipment design, and organic culture media produced with solid food/agricultural waste [89]. ...
... Li et al. [86] investigated the use of Saccharomyces cerevisiae, Candida utilis, and Yarrowia lipolytica in SSF for the bioconversion of food waste obtained from a canteen to prepare fermented feed destined for crayfish farming. The study highlighted that replacing the basal diet with 30% of the food waste-derived fermented feed is suitable for crayfish growth [87]. SSF was previously investigated for the production of the packaging material poly-3-hydroxybutyrate (PHB) using a medium containing sugarcane molasses [92]. ...
Hunger (811 million people, 2020) and food waste (931 million tonnes annually, 2020) are long-standing interconnected challenges that have plagued humankind for centuries. Food waste originates from various sources, including consumption habits and failures within the food supply chain. Given the growing concerns regarding food insecurity, malnutrition, and hunger, there is a pressing need to recover and repurpose as much food waste as possible. A growing body of knowledge identifies the valorisation (including upcycling) of food waste as one of the strategies to fight hunger by positively impacting food availability and food security. This paper evaluates the potential role of food waste valorisation, including upcycling, in reducing global hunger. A literature search was conducted to examine how converting food waste into value-added products, such as food formulations and farming inputs, can contribute to increasing food availability. The benefits of waste-to-food operations in improving food availability through producing food ingredients and products from materials that would have been wasted or discarded otherwise were discussed.
... In the rumen, these probiotics scavenge oxygen, stabilize rumen pH, and produce several beneficial nutrient cofactors such as organic acids, peptides, and vitamins that stimulate and facilitate the growth and proliferation of the beneficial rumen microbiota (Elghandour et al. 2022), resulting in improved of nutriment digestibility, feed palatability, growth performance and milk production, animal health, and providing a clear economic advantage for sheep, buffalo, calf, and cow breeding (Anjum et al. 2018;Villot et al. 2019;Wang et al. 2022;Xue et al. 2022;Hiltz et al. 2023). In recent years, many experiments have proved that fermenting feeds such as potato peel, orange pulp, sobyan meals, and food waste with Saccharomyces cerevisiae before offering them to animals is a good strategy to reduce their antinutritional factors and improve their nutritional value (Hassaan et al. 2015;Maxwell et al. 2018;Guerra et al. 2021;Li et al. 2022). The LY, including the Saccharomyces cerevisiae, is the best microorganism that effaces fermented feeds in an aerobic environment and enhances their quality (Rai et al. 2019;Li et al. 2022). ...
... In recent years, many experiments have proved that fermenting feeds such as potato peel, orange pulp, sobyan meals, and food waste with Saccharomyces cerevisiae before offering them to animals is a good strategy to reduce their antinutritional factors and improve their nutritional value (Hassaan et al. 2015;Maxwell et al. 2018;Guerra et al. 2021;Li et al. 2022). The LY, including the Saccharomyces cerevisiae, is the best microorganism that effaces fermented feeds in an aerobic environment and enhances their quality (Rai et al. 2019;Li et al. 2022). Temperature is the most important parameter affecting the growth of Saccharomyces cerevisiae, which grows well between 25 and 33 °C. ...
Extraction of olive oil through a two-stage centrifugation process produces a large amount of phytotoxic waste known as alperujo. This research was performed to bioconvert alperujo into enriched ruminant feed by pretreatment with exog-enous fibrolytic enzymes (EFE) or/and live yeasts (LY). These additives were used in a completely randomized design with 3 EFE doses (0, 4, and 8 µl/g dry matter) and 3 LY doses (0, 4, and 8 mg/g dry matter) in a 3 × 3 factorial arrangement. Fermented alperujo with both EFE doses converted some of their hemicellulose and cellulose to simple sugars and increased bacterial abundance in the rumen. As a result, it shortens the lag time of rumen fermentation, increases the rate and amount of rumen fermentation, and improves digestibility. This improvement provides additional energy that can be used by ruminants to produce milk and by rumen microbiota to produce short-chain fatty acids. Fermented alperujo with a high dose of LY decreased their antinutritional compounds and reduced their high content of lipid. In the rumen, this waste became rapidly fermentable, and rumen bacteria became more abundance. Fermented alperujo with a high dose of LY + EFE accelerated rumen fermentation and improved rumen digestibility, energy available for milk production, and short-chain fatty acids compared to the use of LY or EFE alone. This synergistic interaction between these two additives increased protozoa abundance in rumen and the ability of rumen microbiota to bioconvert ammonia-nitrogen to microbial protein. Ultimately, fermentation alperujo with EFE + LY is a good strategy with minimum investment for a social sustainable economy and environment.
... Moreover, SSF is a sustainable process that has the potential to recover bioactive phenolic compounds and valorize waste materials, such as pineapple waste, wheat bran, brewer's grains, etc. [5,11,12]. Valorized material with enhanced nutritional properties has the potential to be used as animal feed [10,13]. Although bacteria, yeasts, and fungi can be used in SSF processes, filamentous fungi are most ...
Grape pomace is a sustainable source of bioactive phenolic compounds used in various industries. The recovery of phenolic compounds could be improved by biological pretreatment of grape pomace, as they are released from the lignocellulose structure by the activity of the enzymes produced. The influence of grape pomace pretreatment with Rhizopus oryzae under solid-state conditions (SSF) on the phenolic profile and chemical composition changes was studied. SSF was performed in laboratory jars and in a tray bioreactor for 15 days. Biological pretreatment of grape pomace resulted in an increase in the content of 11 individual phenolic compounds (from 1.1 to 2.5-fold). During SSF, changes in the chemical composition of the grape pomace were observed, including a decrease in ash, protein, and sugar content, and an increase in fat, cellulose, and lignin content. A positive correlation (r > 0.9) was observed between lignolytic enzymes and the hydrolytic enzyme’s xylanase and stilbene content. Finally, after 15 days of SSF, a weight loss of GP of 17.6% was observed. The results indicate that SSF under experimental conditions is a sustainable bioprocess for the recovery of phenolic compounds and contributes to the zero-waste concept by reducing waste.
In this experiment, glucose master liquor and corn steep liquor were used as carbon and nitrogen sources, and Candida utilis was used as a strain to ferment yeast feed. The OD value and number of yeast cells were used as response values to optimize the medium components of the yeast feed through a response surface methodology. The optimal medium components were a glucose master liquor concentration of 8.3%, a corn steep liquor concentration of 1.2%, and a KH2PO4 concentration of 0.14%. Under this condition of fermentation, the OD value was 0.670 and the number of yeast cells was 2.72 × 108/mL. Then, we fed Candida utilis feed to Dongliao black piglets, and the effects of the yeast feed on the piglets’ growth performance, fecal microbiota, and plasma metabolic levels were investigated through 16S rDNA sequencing and metabolomics. In total, 120 black piglets with an average initial weight of 6.90 ± 1.28 kg were randomly divided into two groups. One group was fed the basic diet (the CON group), and the other was supplemented with 2.5% Candida utilis add to the basic diet (the 2.5% CU group). After a pre-feeding period, the formal experiments were performed for 21 days. The results showed that the addition of Candida utilis to the diet did not affect growth performance compared with the control group. Meanwhile, no significant differences were observed in the serum biochemical indices. However, piglets in the 2.5% CU group had a significantly altered fecal microbiota, with an increased abundance of Clostridium_sensu_stricto_1, Lactobacillus, and Muribaculaceae_unclassified. Regarding the plasma metabolome, the 12 differential metabolites detected were mainly enriched in the histidine, tryptophan, primary bile acid, and caffeine metabolic pathways. Regarding the integrated microbiome–metabolome analysis, differential metabolites correlated with fecal flora to variable degrees, but most of them were beneficial bacteria of Firmicutes. Collectively, dietary Candida utilis feed had no adverse effect on growth performance; however, it played an important role in regulating fecal flora and maintaining metabolic levels.
The rapidly increasing population and climate change pose a great threat to our current food systems. Moreover, the high usage of animal-based and plant-based protein has its drawbacks, as these nutritional sources require many hectares of land and water, are affected by seasonal variations, are costly, and contribute to environmental pollution. Single-cell proteins (SCPs) are gaining a lot of research interest due to their remarkable properties, such as their high protein content that is comparable with other protein sources; low requirements for land and water; low carbon footprint; and short production period. This review explores the use of food waste as a sustainable feedstock for the advancement of SCP processes. It discusses SCP studies that exploit food waste as a substrate, alongside the biocatalysts (bacteria, fungi, yeast, and microalgae) that are used. The operational setpoint conditions governing SCP yields and SCP fermentation routes are elucidated as well. This review also demonstrates how the biorefinery concept is implemented in the literature to improve the economic potential of “waste-to-protein” innovations, as this leads to the establishment of multiproduct value chains. A short section that discusses the South African SCP scenario is also included. The technical and economic hurdles facing second-generation SCP processes are also discussed, together with future perspectives. Therefore, SCP technologies could play a crucial role in the acceleration of a “sustainable protein market”, and in tackling the global hunger crisis.
Biocatalysis plays a prominent role in both white and grey biotechnologies. Some well-known and a few lesser-known developments in biocatalysis have made it align even better with principles of green chemistry and green engineering and hence contributed to both white and grey biotechnologies in shaping a sustainable future. These include more efficient production of enzymes, use of process intensification techniques such as microwaves, ultrasonics, high pressure and flow catalysis. The market size of enzymes was estimated to be about USD 12.3 billion in 2022. Discovery of enzyme non-specificity as seen in their moonlighting and promiscuous behaviour has far-reaching consequences in biotechnology. The important roles of biocatalysis in production of biodiesel and bioethanol; valorization of whey and food waste in general are discussed. The waste generated in processing of coffee beans and coffee brewing, pegged globally at 10 million tons each year, deserves more attention as a part of the biorefinery concept.
