Optimization Of Fermentation Process Research Articles

Improvement of nucleotide content of Cordyceps tenuipes by Schisandra chinensis: fermentation process optimization and application prospects.

Nucleotides are important components and the main indicators for judging Cordyceps quality. In this paper, the mixed fermentation process of Schisandra chinensis and Cordyceps tenuipes was systematically studied, and it was proposed that the fermentation products aqueous extract (S-ZAE) had antioxidant activity and anti-AChE ability. Herein, the results of a single factor showed that S. chinensis, yeast extract, inoculum amount, and pH had significant effects on nucleotide synthesis. The fermentation process optimization results were 3% glucose, 0.25% KH2PO4, 2.1% yeast extract, and S. chinensis 0.49% (m/v), the optimal fermentation conditions were 25℃, inoculum 5.8% (v/v), pH 3.8, 6 d. The yield of total nucleotides in the scale-up culture was 0.64 ± 0.027mg/mL, which was 10.6 times higher than before optimization. S-ZAE has good antioxidant and anti-AChE activities (IC50 0.50 ± 0.050mg/mL). This fermentation method has the advantage of industrialization, and its fermentation products have the potential to become good functional foods or natural therapeutic agents.

Optimization of fermentation process and characterization of non-alcoholic functional beverage from pigmented rice varieties

Traditional foods have recently gained importance because of their role in the United Nations’ sustainable development goals (SDG), ensuring health benefits and economic development. Fermented rice water (FRW) is a popular traditional drink among low socio-economic groups, especially in Southeast Asia. This study focused on optimizing fermentation conditions for sustainable food production and consumption of FRW using pigmented rice, followed by analyzing the nutritional, physicochemical and phytochemical properties. Fermenting cooked rice in water for 16 h at 37 °C produced bubbles, mild sourness and zero alcohol content. Flavors and sugar were added to optimized FRW as food additives to enhance palatability. Nutritional profiling showed that black flavored fermented rice water (FFRW) had the highest protein (0.06%), carbohydrate (13.25 g/100 mL) and calorific value (78.09 kcal/100 mL). However, brown FFRW had the highest vitamin B3 (3.12 mg/L) and mineral content. Phenolic and antioxidant activity was highest in black FFRW, followed by red and brown, with maximum bio-accessibility of polyphenols found in black FFRW (75.25%). All FFRW were microbiologically safe and stable during a storage period of 30 days at 4 °C. All FRW had >8 log CFU count, with black FFRW having the highest LAB count, indicating their possible probiotic potential in addressing malnutrition and undernourishment. Thus, FFRW holds the potential to be commercialized in the food and beverage sector due to its rich nutritional and functional properties. Furthermore, the consumption of FFRW will preserve traditional knowledge, ensure sustainable livelihoods and contribute to achieving development goals.

Characterization and optimization of gellan gum production by natural Sphingomonas sp. SM2

Gellan is one of the most important industrial microbial exopolysaccharides used for a wide range of applications in food, pharmaceutical, and oil. In this study, a native strain of Sphingomonas producing gellan gum was identified from rice roots. Various factors, including carbon and nitrogen sources, pH levels, fermentation duration, and aeration, were investigated to enhance the production of gellan by Sphingomonas sp. SM2. The highest efficiency in gum production was achieved by a medium composed of 30 g/L glucose. When the carbon-to-nitrogen ratio was 30, organic nitrogen caused this increase. By incorporating all relevant factors, the optimized fermentation process can yield a gum concentration of 8.64 ± 0.34 g/L. The total carbohydrate content of the native gum was found to be 52.62 ± 0.52%. The existence of mucilage surrounding the bacterial cells was verified by scanning electron microscopy images. The extracted gellan gum was characterized using FTIR, 1H NMR, and HPLC analyses. The structure of the gum was confirmed by comparing it with the standard gellan gum. The production of gellan gum by Sphingomonas sp. SM2 using the utilization of diverse carbon sources suggests its immense potential as a gellan producer.

Microbial chassis design and engineering for production of gamma-aminobutyric acid.

Gamma-aminobutyric acid (GABA) is a non-protein amino acid which is widely applied in agriculture and pharmaceutical additive industries. GABA is synthesized from glutamate through irreversible α-decarboxylation by glutamate decarboxylase. Recently, microbial synthesis has become an inevitable trend to produce GABA due to its sustainable characteristics. Therefore, reasonable microbial platform design and metabolic engineering strategies for improving production of GABA are arousing a considerable attraction. The strategies concentrate on microbial platform optimization, fermentation process optimization, rational metabolic engineering as key metabolic pathway modification, promoter optimization, site-directed mutagenesis, modular transporter engineering, and dynamic switch systems application. In this review, the microbial producers for GABA were summarized, including lactic acid bacteria, Corynebacterium glutamicum, and Escherichia coli, as well as the efficient strategies for optimizing them to improve the production of GABA.

Optimization of watermelon peel yogurt fermentation process and study on antioxidant capacity

This study aims to explore the variation patterns of total flavonoid and other antioxidant activities in watermelon peel yogurt, providing a basis for the production of a functional yogurt. Using watermelon peel as the raw material and total flavonoid content as the indicator, the optimal process of watermelon peel yogurt was optimized through single-factor and orthogonal experiments. The results indicate that yogurt fermented with a mass ratio of watermelon juice to milk at 1:3, fermentation time of 10 hours, and fermentation agent dosage of 0.10% exhibits a refreshing watermelon aroma, excellent texture, and almost no whey separation. After process optimization, the polysaccharide content of watermelon peel yogurt increased by 19%, and water-holding capacity rose to 63.3%. Texture analysis revealed a hardness of 81.50 g, viscosity of 20.00 g, adhesiveness of 1.20 mJ, elasticity of 8.83 mm, and a draw length of 6.76 mm. The physicochemical and microbiological properties of watermelon peel yogurt meet national standards, and it possesses a good free radical scavenging ability.

Evaluation of stress tolerance and design of alternative culture media for the production of fermentation starter cultures in cacao

Ecuador is one of the world's leading producers of cacao beans, and Nacional x Trinitario cacao represents one of the most distinctive varieties due to its flavor and aroma characteristics. This study aimed to evaluate the effect of the starter culture isolated from microbial diversity during the spontaneous fermentation of Nacional x Trinitario cacao. A total of 249 microbial isolates were obtained from spontaneous culture, with Lactiplantibacillus (45 %), Saccharomyces (17 %), and Acetobacter (2 %) being the most relevant genera for fermentation. Tolerance tests were conducted to select microorganisms for the starter culture. Lactiplantibacillus plantarum exhibited the highest tolerance at pH 5 and 6 % ethanol and tolerated concentrations up to 15 % for glucose and fructose. Acetobacter pasteurianus grew at pH 2 and 6 % ethanol, tolerating high sugar concentrations of up to 15 % for glucose and 30 % for fructose, with growth observed in concentrations up to 5 % for lactic and acetic acid. Subsequently, a laboratory-scale fermentation was conducted with the formulated starter culture (SC) comprising S. cerevisiae, L. plantarum, and A. pasteurianus, which exhibited high tolerance to various stress conditions. The fermentation increased alcoholic compounds, including citrusy, fruity aromas, and floral notes such as 2-heptanol and phenylethyl alcohol, respectively 1.6-fold and 5.6-fold compared to the control. Moreover, the abundance of ketones 2-heptanone and 2-nonanone increased significantly, providing sweet green herbs and fruity woody aromas. Cacao fermented with this SC significantly enhanced the favorable aroma-producing metabolites characteristic of Fine-aroma cacao. These findings underscore the potential of tailored fermentation strategies to improve cacao product quality and sensory attributes, emphasizing the importance of ongoing research in optimizing fermentation processes for the cacao industry.

Optimization of the fermentative production of L-methionine by engineered Escherichia coli

As the only essential amino acid containing elemental sulphur, L-methionine has important physiological and biochemical functions in living organisms. However, the fermentative production of L-methionine has not met the requirements of industrial production because of its low production level. In this paper, the fermentation process of an efficient L-methionine producing strain E. coli W3110ΔIJAHFEBC trc-fliY trc-malY/PAM glyA-22 metF constructed previously was systematically optimized. Based on the optimal initial glucose concentration, the effects of different fed-batch fermentation processes, including DO-Stat, pH-Stat, controlling residual sugar control at different level and feeding glucose with constant rate, on L-methionine fermentation were studied. It was found that the control of glucose concentration greatly affected the fermentation process. Subsequently, an optimal fed-batch fermentation process was developed, where the L-methionine titer was increased to 31.71 g/L, the highest yield reported to date, while the fermentation time was shortened to 68 h. Meanwhile, a fermentation kinetics model under the optimal fed-batch fermentation conditions was established, which fitted well with the biosynthesis process of L-methionine. This study may facilitate further development of the fermentative production of L-methionine.

Screening and Optimization of α-Glucosidase Inhibitor Production by Potent Strain of Bacillus subtilis Isolated from Peruyaan, Fermented Soy-Food of Northeast India

Background. Fermented soy foods exhibit the capability to inhibit the α-glucosidase enzyme. The bacteria isolated from these fermented soy foods may contribute to the production of a higher quantity of α-glucosidase inhibitor (α-GI) in optimized condition. Aim. The present study aims to isolate α-glucosidase inhibitor producing bacterial strain from peruyaan, a traditional fermented soy food of Arunachal Pradesh, optimize the production of α-GI for maximum yield, and assess the compounds. Result. Bacillus subtilis PM NEIST_4 (identified by 16S rRNA gene sequencing) was isolated as a potential strain that exhibit maximum α-glucosidase inhibition. This strain showed maximum α-GI productivity in Mueller Hinton Broth (MHB). The cultivation parameters for fermentation of MHB were optimized in order to maximize the yield of α-GIs. The α-GI productivity of 1616.613 ± 84.54 U/mL was observed before optimization, which increased by almost three times after optimization (4808.324 ± 13 U/mL). In vitro assays against α-glucosidase enzyme revealed a significant IC50 value of 596.532 ± 44.80 μg/mL after the optimized study compared to that before optimization (IC50 1705.617 ± 43.95 ug/mL). Besides, α-glucosidase enzyme inhibitory property of fermented MHB (FMHB) was found to be unaffected at varied range of pH and temperature. Oral gavaging of FMHB in sucrose-loaded Wistar rat exhibited maximum reduction in postprandial blood glucose at 400 mg/kg body weight. Furthermore, FMHB was fractionated using solvents of increasing polarity including n-hexane, ethyl acetate, and n-butanol. Ethyl acetate fraction that exhibited the strongest inhibitory action against the α-glucosidase enzyme (IC50 value of 251.55 ± 19.65 μg/mL), showed the presence of pyrrolopyrazine derivatives through GC-MS and LC-MS analyses. Conclusion. The present study demonstrated the isolation of a potent α-GI producing bacterial strain from traditional fermented soy food, and the optimization of the bacterial fermentation process was achieved to maximize the yield of α-GI. These findings underscore promising industrial potential of B. subtilis PM NEIST_4, advocating the use of indigenous microbial resources for the production of α-GI.

Optimization of Solid-State Fermentation Process of Radix Ranunculi ternate Using Response Surface Method and Addressing Its Antioxidant and Hypoglycemic Activity

Objective: The aim of this study was to optimize the fermentation process of Radix Ranunculi ternate via microbial fermentation and analyze the changes in the contents of the main components, the antioxidant and hypoglycemic capacities of the extract before and after fermentation. Methods: The solid-state fermentation process was optimized using single-factor tests and the response surface method, with the yield of the alcohol extract of R. ternate as an evaluation index. Results: The best fermentation process was optimized using solid-state endophytic fungus fermentation technology as follows: strain addition ratio of Chaetomium globosum/Fusarium equiseti = 1:1, fermentation for 5 d, sieve size of 40 mesh, liquid/material ratio of 0.8:1 mL·g−1, fermentation temperature of 31 °C, and inoculation amount of 7.5%. Under the optimized conditions, the contents of the water-soluble extract and total polysaccharides decreased by 12.71% and 12.95%, respectively. In the fermentation, the contents of the ethanol-soluble extract, flavonoids, saponins, polyphenols, organic acids, and total amino acids of the fermented R. ternate increased by 19.77%, 57.14%, 79.67%, 14.29%, 17.63%, and 3.82%, respectively. The scavenging rate for DPPH, ABTS+, and ·OH free radicals and inhibitory rate for α-amylase of the fermented R. ternate also increased by 19.02%, 14.17%, 7.53%, and 34.54%, respectively, compared with the unfermented R. ternate. Conclusions: Solid-state fermentation opens new avenues for the development and application of R. ternate as a natural antioxidant and hypoglycemic food.

Continuous H-B-E fermentation by Clostridium carboxidivorans: CO vs syngas

Leveraging renewable carbon-based resources for energy and chemical production is a promising approach to decrease reliance on fossil fuels. This entails a thermo/biotechnological procedure wherein bacteria, notably Clostridia, ferment syngas, converting CO or CO2 + H2 into Hexanol, Butanol and Ethanol (H-B-E fermentation). This work reports of Clostridium carboxidivorans performance in a stirred tank reactor continuously operated with respect to the gas and the cell/liquid phases. The primary objective was to assess acid and solvent production at pH 5.6 by feeding pure CO or synthetic syngas under gas flow differential conditions. Fermentation tests were conducted at four different dilution rates (DL) of the fresh medium in the range 0.034–0.25 h−1. The fermentation pathways of C. carboxidivorans were found to be nearly identical for both CO and syngas, with consistent growth and metabolite production at pH 5.6 within a range of dilution rates. Wash-out conditions were observed at a DL of 0.25 h−1 regardless of the carbon source. Ethanol was the predominant solvent produced, but a shift towards butanol production was observed with CO as the substrate and towards hexanol production with synthetic syngas. In particular, the maximum cell concentration (0.5 gDM/L) was obtained with pure CO at DL 0.05 h−1; the highest solvent productivity (60 mg/L*h of total solvent) was obtained at DL 0.17 h−1 by using synthetic syngas as C-source. The findings highlight the importance of substrate composition and operating conditions in syngas fermentation processes. These insights contribute to the optimization of syngas fermentation processes for biofuel and chemical production.

Optimization of Fermentation Process of Wheat Germ Protein by Aspergillus niger and Analysis of Antioxidant Activity of Peptide

Utilizing wheat embryos as the raw material and employing Aspergillus niger as the fermentation strain, wheat embryo polypeptides were produced through microbial liquid fermentation. The protein concentration post-fermentation served as the response variable, and the preparation process underwent optimization through single-factor testing and a response surface methodology, followed by the assessment of antioxidant activity. The findings revealed that the optimal conditions for wheat embryo peptide preparation via Aspergillus niger fermentation included a fermentation duration of 24 h, an inoculum volume of 4%, an initial pH of 7, and a protein concentration of 21.47 mg/mL. Peptides with different molecular weights were then prepared by dead-end filtration. The results showed that F6 (<3 kDa) had strong scavenging ability against DPPH, ABTS, and ·OH radicals, which provided a basis for the preparation of antioxidant peptides in wheat germ and related research.

Optimization of Fermentation Process for New Anti-Inflammatory Glycosylceramide Metabolite from Aspergillus sp.

A novel ceramide compound, named Aspercerebroside A (AcA), was successfully isolated from the ethyl acetate layer of the marine symbiotic fungus Aspergillus sp. AcA exhibited notable anti-inflammatory activity by effectively inhibiting the production of nitric oxide (NO) in RAW 264.7 cells at concentrations of 30 μg/mL and 40 μg/mL, offering a promising avenue for the treatment of inflammatory diseases. To optimize the yield of glycosylceramide (AcA), a series of techniques, including single-factor experiments, orthogonal experiments, and response surface optimization, were systematically employed to fine-tune the composition of the fermentation medium. Initially, the optimal carbon source (sucrose), nitrogen source (yeast extract powder), and the most suitable medium salinity (14 ppt) were identified through single-factor experiments. Subsequently, orthogonal experiments, employing an orthogonal table for planning and analyzing multifactor experiments, were conducted. Finally, a mathematical model, established using a Box-Behnken design, comprehensively analyzed the interactions between the various factors to determine the optimal composition of the fermentation medium. According to the model's prediction, when the sucrose concentration was set at 37.47 g/L, yeast extract powder concentration at 19.66 g/L, and medium salinity at 13.31 ppt, the predicted concentration of glycosylceramide was 171.084 μg/mL. The experimental results confirmed the model's accuracy, with the actual average concentration of glycosylceramide under these conditions measured at 171.670 μg/mL, aligning closely with the predicted value.

Statistical optimization of process variables for anti-hypercholesterolemic metabolites production from Monascus purpureus MTCC 369 fermented finger millet

Monascus purpureus fermented rice has been used for centuries to treat hypercholesterolemia, indigestion, and diarrhea in East Asian countries. Monacolin K, also known as lovastatin, a secondary metabolite synthesized by Monascus sp. in fermentation, is mainly responsible for reducing the level of blood lipids. Besides statins, sterols produced in this process have also been reported to have hypolipidemic effects. In the current study, statin and total sterol production by M. purpureus microbial type culture collection and Gene Bank MTCC 369 on finger millet (FM) substrate were investigated. The central composite design of the response surface methodology (RSM) was used for the optimization of different fermentation process independent variables such as fermentation time period, temperature, inoculum volume, and pH for maximum production of statins and total sterols by M. purpureus MTCC 369. The maximum statin (9.78 mg/g) and sterol (0.46 mg/g) production was achieved at a temperature of 29.44°C, pH 5.0, inoculum size 5.37 ml, and fermentation time of 13.8 days. Fermentation process factors such as fermentation time period and temperature were significant positive factors, while pH and inoculum volume were found to be insignificant factors. The interactive effects of the positively influencing variables have been demonstrated. Compared with the traditional production of these metabolites, using FM as a substrate is promising for the high production of anti-hypercholesterolemic metabolites. The current study was aimed at optimization of the solid-state fermentation process of statin and total sterol using RSM for nutritional FM so as to improve M. purpureus-fermented FM (like red yeast rice) with health-promoting properties. This is the first report on the optimization of statin and sterols from M. purpureus MTCC 369 fermented FM with a significant yield that is on par with that reported so far.

Optimization of liquid fermentation conditions for Coprinus comatus to enhance antioxidant activity

Coprinus comatus is an edible and medicinal fungus. In this study, the antioxidant activity of the fermentation product of C. comatus was investigated through optimization of fermentation process. The results indicated that the fermentation product of C. comatus had obvious scavenging ability for 2,2’-Azino-bis(3-ethylbenzothiazoline)-6-sulphonic acid (ABTS) free radical. The EC50 of the n-butanol extract from the fermentation product on ABTS·+ was 0.65 ± 0.02 mg/mL. On this basis, the liquid fermentation conditions of C. comatus were optimized through single factor and response surface optimization experiments according to the scavenging ability of ABTS·+ to improve the antioxidant capacity of the fermentation product. The results showed that when the 14% of C. comatus was fermented in a culture medium with a C/N ratio of 48:1 for 6 days, the ABTS·+ scavenging ability was the strongest, and the EC50 of n-butanol extract was 0.57 ± 0.01 mg/mL, which was 12.31% higher than the initial activity. This study laid the foundation for the development of C. comatus.

Statistical optimization and gamma irradiation on cephalosporin C production by Acremonium chrysogenum W42-I

Most antibiotics now used in clinical practice are cephalosporins. Acremonium (A.) chrysogenum W42-I is an intermediate strain out of W42 strain improvement program whose productivity is above that of the wild-type strain to produce the broad-spectrum antibacterial cephalosporin C (CPC). As a result, fermentation process optimization is considered because it offers the ideal environment for strains to reach their full potential. Our research aimed to combine a rational design to regulate the fermentation process environment and culture media as well as to develop mutants with high productivity. Different media were tested to obtain maximum CPC production. To maximize the production of CPC, some environmental parameters were experimentally optimized via the Box-Behnken design used for response surface methodology (RSM). There were 17 tests conducted, and each experiment's reaction was recorded. Improvement of the CPC production was further achieved via mutagenesis using gamma radiation. Results revealed that a pH of 4, an incubation period of 4 days, and an inoculum size of 1% v/v using the optimized media (CPC2) were the optimum conditions for enhancing the CPC production by 4.43-fold. In addition, gamma irradiation further enhanced production to reach 3.46-fold using an optimum dose of 2 KGy. In conclusion, in comparison to initial production levels, CPC production increased 4.43-fold because of nutritional and environmental optimization. The mutant AC8 demonstrated a roughly 3.46-fold increase in activity against its parent type. Moreover, subsequent AC8 mutant culture demonstrated excellent genetic stability.

Optimization of Fermentation Conditions for Biocatalytic Conversion of Decanoic Acid to Trans-2-Decenoic Acid

Trans-2-decenoic acid has a wide range of applications, including those in medicine, food, and health care. Therefore, the industrial production of trans-2-decenoic acid is particularly important. However, few studies have focused on medium-chain unsaturated fatty acids. Therefore, we aimed to optimize the fermentation process of decanoic acid biocatalysis to synthesize trans-2-decenoic acid using an engineered Escherichia coli constructed in the laboratory. Early-stage culture and the effect of the seed liquid culture time, culture temperature, inoculum amount, induction temperature, dissolution effects of the substrate solvent, metal ions, and substrate loading on the titer of trans-2-decenoic acid were evaluated. Based on a single-factor experimental optimization, a Box–Behnken design (BBD) was used for response surface testing using the substrate feeding concentration, inducer concentration, and MnCl2 concentration as response variables and trans-2-decenoic acid production as the response value. The optimal fermentation process was as follows: Seed culture time of 20 h, culture temperature of 37 °C, inoculation amount of 1%, induction temperature of 30 °C, substrate flow of 0.15 g/L, inducer concentration of 5.60 g/L, and MnCl2 concentration of 0.10 mM. Under these conditions, the average production of trans-2-decenoic acid was 1.982 ± 0.110 g/L, which was 1.042 g/L higher than that obtained in the basic LB medium. Compared with that of the previous period, the titer of the trans-2-decenoic acid studied increased by 1.501 ± 0.110 g/L, providing a basis for further research on the fermentation process of the biocatalytic decanoic acid synthesis of trans-2-decenoic acid.

Improved estimation of dark fermentation biohydrogen production utilizing a robust categorical boosting machine-learning algorithm

Dark fermentation is attracting great attention due to some capabilities such as wastewater treatment and biofuel production. In this study, the performance of different machine learning algorithms, including Bagging-Extreme Gradient Boosting (BagXGBoost), Categorical Boosting (CatBoost), K Nearest Neighborhood (KNN), Light Gradient Boosting Machine (LightGBM), and Decision Trees (DT) in the prediction of biohydrogen production from wastewater during dark fermentation is investigated. Effect of parameters Ni, Fe, biomass, pH, chemical oxygen demand (COD), HRT, acetate, ethanol, butyrate, and acetate/butyrate ratio as inputs were considered for the model development. A databank with 208 data points was culled from the literature. For the validation of the proposed models, various statistical criteria were determined. CatBoost and BagXGBoost exhibited superior performance in predicting fermentative hydrogen (H2) production. Shapley additive explanations were used for relative analysis, revealing the highest absolute SHAP values of 1.1, 1, and 0.07 for COD, nickel, and butyrate, respectively, highlighting their significance in H2 production. The insights gained from this study can contribute to further optimization of the dark biohydrogen fermentation process.

Isolation, functional evaluation, and fermentation process optimization of probiotic Bacillus coagulans.

Bacillus coagulans is a probiotic agent widely used in various industries. In this study, we isolated a novel strain of B. coagulans, X26, from soil and characterized its properties. X26 exhibited superior enzyme, acid, and biomass yields when compared with other bacterial probiotics and an antibiotic. Moreover, X26 significantly improved the body weight of rats, highlighting its potential for industrial development as a supplement for animals. To optimize the fermentation process of this bacterium, we adopted the response surface design. When X26 was cultured in a medium with 16.5 g/L maltose, 25.00 g/L yeast extract, and 3.5 g/L K2HPO4, the optimal yield was predicted to be 5.1 × 109 CFU/mL. Consistent with the prediction, the yield of X26 in a 500-mL flask culture was (5.12 ± 0.01) × 109 CFU/mL, and in a 30-L fermenter was (5.11 ± 0.02) × 109 CFU/mL, accounting for a 9.9-fold higher field than that with a basal medium before optimization. We further optimized the fermentation process in the 30-L and a 10-T fermenter, generating yields of (7.8 ± 0.2) × 109 CFU/mL (spore rate: 96.54%) and (8.7 ± 0.1) × 109 CFU/mL (spore rate: 97.93%), respectively. These yields and spore rates were achieved at 45-55°C, the typical fermentation temperature of B. coagulans. Our findings indicate that B. coagulans X26 is a promising probiotic with considerable potential for cost-effective industrial fermentation.

Visual Tools for Food Safety Assessment of Biotechnological Products

Food biotechnology, a revolutionary discipline, has transformed the way we produce, process and consume our food. It has enabled the development of new methods of crop genetic improvement, the creation of functional foods with health benefits, and the optimization of fermentation and food production processes. It has also provided innovative solutions to address the global challenges of food security and sustainability, while opening up new possibilities for nutrition and human health.

A microbial flora with superior pollutant removal efficiency and its fermentation process optimization

Microbial flora plays an important role in microorganism-enhanced technology. The pollutant degradation ability and viable counts of these agents are crucial to guarantee their practical application. In this study, an efficient pollutant-degrading microbial flora was screened, its medium components and culture conditions were optimized, and its effect was verified in zeolite trickling filter towers. After a 24 h culture under the optimal conditions, the viable count reached 4.76 × 109 cfu/mL, with the degradation rates of ammonia nitrogen (NH4+-N), nitrate nitrogen (NO3−-N), total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) increased to 93.5%, 100%, 68.3%, 32.6%, and 85%, respectively. After optimizing the feeding strategy, the concentration of viable bacteria reached 5.80 × 109 cfu/mL. In the application effect verification experiment, the degradation rates of NH4+-N, TN, TP, and COD in the experimental group reached 96.69%, 75.18%, 73.82%, and 90.83%, respectively, showing a significant improvement compared to the results of the control group. The main components in the control group were Dokdonella, Brevundimonas, Alishewanella, Rhodobacter, Pseudoxanthomonas, and Thauera, whereas those in the experimental group were Dokdonella, Proteocatella, Rhodobacter, Dechlomonas, and Nitrospira. Proteocatella, Dechlomonas, and Nitrosra, which were unique to the experimental group, are common bacteria used for nitrogen and phosphorus removal. This explains the difference in the sewage treatment capacity between the two groups. This study provides an alternative sewage treatment microbial flora with a reasonable production cost and high degradation efficiency for NH4+-N, TN, TP, and COD.