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Poly-γ-glutamic acid (γ-PGA) is widely used in the field of biomedicine, food, agriculture, and ecological remediation. For the biosynthesis of γ-PGA, the pigments and remaining glutamate are two big problems that impede γ-PGA production by fermentation, and a trade-off between the decolorization rate and γ-PGA recovery rate during the purification process was found. The optimized static activated carbon adsorption conditions for treating the 2-times diluted cell-free supernatant (i.e., feed solution) was as follows: 0.51% 200-mesh, 1000 iodine value, coal-based activated carbon, pH 6.0, 140 min, and 40 °C. Under the optimized conditions, the decolorization rate reached 94.42%, and the recovery rate of γ-PGA was 94.22%. During the adsorption process, the pigments were adsorbed on the activated carbon surface in a monolayer, and the process was a spontaneous, heat-absorbing, and entropy-increasing process. Then, the decolorization flow rate optimized for the dynamic decolorization experiment was 1 BV/h. However, the remaining glutamate was still a problem after the activated carbon adsorption. After isoelectric point (IEP) precipitation of glutamic acid, the glutamic acid can be recovered, and the residual pigment can be further removed. Finally, an integrated decolorization process of activated carbon adsorption and IEP precipitation of glutamic acid was developed. After the integrated process, the decolorization and glutamic acid precipitation rates were 95.80% and 49.02%, respectively. The recovered glutamic acid can be reused in the next fermentation process.

Background Poly-γ-glutamic acid (γ-PGA) is biodegradable, water-soluble, environment-friendly, and edible. Consequently, it has a variety of industrial applications. It is crucial to control production cost and increase output for industrial production γ-PGA. Results Here γ-PGA production from sugarcane molasses by Bacillus licheniformis CGMCC NO. 23967 was studied in shake-flasks and bioreactors, the results indicate that the yield of γ-PGA could reach 40.668 g/L in a 5L stirred tank fermenter. Further study found that γ-PGA production reached 70.436 g/L, γ-PGA production and cell growth increased by 73.20% and 55.44%, respectively, after FeSO 4 ·7H 2 O was added. Therefore, we investigated the metabolomic and transcriptomic changes following FeSO 4 ·7H 2 O addition. This addition resulted in increased abundance of intracellular metabolites, including amino acids, organic acids, and key TCA cycle intermediates, as well as upregulation of the glycolysis pathway and TCA cycle. Conclusions These results compare favorably with those obtained from glucose and other forms of biomass feedstock, confirming that sugarcane molasses can be used as an economical substrate without any pretreatment. The addition of FeSO 4 ·7H 2 O to sugarcane molasses may increase the efficiency of γ-PGA production in intracellular.

β-poly( l -malic acid) (PMLA) is a water-soluble biopolymer used in medicine, food, and other industries. However, the low level of PMLA biosynthesis in microorganisms limits its further application in the biotechnological industry. In this study, corn steep liquor (CSL), which processes high nutritional value and low-cost characteristics, was selected as a growth factor to increase the PMLA production in strain, Aureobasidium melanogenum , and its metabolomics change under the CSL addition was investigated. The results indicated that, with 3 g/L CSL, PMLA production, cell growth, and yield (Y p/x ) were increased by 32.76%, 41.82%, and 47.43%, respectively. The intracellular metabolites of A. melanogenum , such as amino acids, organic acids, and key intermediates in the TCA cycle, increased after the addition of CSL, and the enrichment analysis showed that tyrosine may play a major role in the PMLA biosynthesis. The results presented in this study demonstrated that the addition of CSL would be an efficient approach to improve PMLA production.

ß-poly (L-malic acid) (PMLA) is a polyester ligated by malate subunits. It has a wide prospective application as an anti-cancer drug carrier, and its malate subunits have a great application in the food industry. The strain Aureoabsidium melanogenum could produce a high amount of PMLA during fermentation, and different substrates addition could influence the production. In this study, we directly added potassium acetate, corn steep liquor, MgSO4, MnSO4, vitamin B1, vitamin B2, and nicotinamide as the fermentation substrate to the basic fermentation medium based on a generated random matrix that represented the added value. The PMLA production and four secondary indexes, pH, biomass, osmotic pressure, and viscosity were measured after 144 h fermentation. Finally, a total of 212 samples were collected as the dataset, by which the machine learning methods were deployed to predict the PMLA production by different substrates’ concentrations and the secondary indexes. The results indicated that PMLA production was negatively correlated with corn steep liquor and betaine and positively correlated with potassium acetate. The PMLA production could be predicted using all different substrates’ concentrations with a Mean Absolute Error (MAE) of 4.164 g/L and with an MAE of 6.556 g/L by different secondary indexes. Finally, the convolutional neural network (CNN) was applied to predict the PMLA production by fermentation medium images, in which the collected images were categorized into three groups, 0–20 g/L, 21–40 g/L, and >41 g/L, based on the PMLA production. The CNN model could predict the production with high accuracy. The methods and results presented in this study provided new insight into evaluating different substrates concentration on PMLA production and demonstrating the possibility of using the convolutional neural network model in the PMLA fermentation industry.

β-poly(L-malic acid) (PMLA) is a highly water-soluble biopolymer used in medicine and other industries. PMLA is usually biosynthesized by Aureobasidium pullulans, but in low concentrations, which has restricted its further large-scale production. Here effects of surfactants on PMLA production were investigated. Of various surfactants examined, the addition of Tween 80 at the start of cell growth increased mycelial growth, PMLA production, PMLA productivity and the ratio of PMLA to cell biomass concentration (Y p/x ) of A. pullulans. Transmission electron microscopy and flow cytometry showed that cell membrane permeability was increased, improving the secretion of PMLA and uptake of nutrients and oxygen. Proteomic analysis showed that key pathways of PMLA synthesis, along with cellular energy metabolism, were enhanced. Moreover, glutathione (GSH) synthesis and anti-oxidation capacity were also improved. These results indicated that the addition of Tween 80 is an efficient approach for improving the production of PMLA.

Poly-[gamma]-glutamic acid ([gamma]-PGA) is biodegradable, water-soluble, environment-friendly, and edible. Consequently, it has a variety of industrial applications. It is crucial to control production cost and increase output for industrial production [gamma]-PGA. Here [gamma]-PGA production from sugarcane molasses by Bacillus licheniformis CGMCC NO. 23967 was studied in shake-flasks and bioreactors, the results indicate that the yield of [gamma]-PGA could reach 40.668 g/L in a 5L stirred tank fermenter. Further study found that [gamma]-PGA production reached 70.436 g/L, [gamma]-PGA production and cell growth increased by 73.20% and 55.44%, respectively, after FeSO.sub.4*7H.sub.2O was added. Therefore, we investigated the metabolomic and transcriptomic changes following FeSO.sub.4*7H.sub.2O addition. This addition resulted in increased abundance of intracellular metabolites, including amino acids, organic acids, and key TCA cycle intermediates, as well as upregulation of the glycolysis pathway and TCA cycle. These results compare favorably with those obtained from glucose and other forms of biomass feedstock, confirming that sugarcane molasses can be used as an economical substrate without any pretreatment. The addition of FeSO.sub.4*7H.sub.2O to sugarcane molasses may increase the efficiency of [gamma]-PGA production in intracellular.

Poly-γ-glutamic acid (γ-PGA) is biodegradable, water-soluble, environment-friendly, and edible. Consequently, it has a variety of industrial applications. It is crucial to control production cost and increase output for industrial production γ-PGA. Here γ-PGA production from sugarcane molasses by Bacillus licheniformis CGMCC NO. 23967 was studied in shake-flasks and bioreactors, the results indicate that the yield of γ-PGA could reach 40.668 g/L in a 5L stirred tank fermenter. Further study found that γ-PGA production reached 70.436 g/L, γ-PGA production and cell growth increased by 73.20% and 55.44%, respectively, after FeSO ·7H O was added. Therefore, we investigated the metabolomic and transcriptomic changes following FeSO ·7H O addition. This addition resulted in increased abundance of intracellular metabolites, including amino acids, organic acids, and key TCA cycle intermediates, as well as upregulation of the glycolysis pathway and TCA cycle. These results compare favorably with those obtained from glucose and other forms of biomass feedstock, confirming that sugarcane molasses can be used as an economical substrate without any pretreatment. The addition of FeSO ·7H O to sugarcane molasses may increase the efficiency of γ-PGA production in intracellular.

ß-poly (L-malic acid) (PMLA) is a polyester ligated by malate subunits. It has a wide prospective application as an anti-cancer drug carrier, and its malate subunits have a great application in the food industry. The strain Aureoabsidium melanogenum could produce a high amount of PMLA during fermentation, and different substrates addition could influence the production. In this study, we directly added potassium acetate, corn steep liquor, MgSO[sub.4] , MnSO[sub.4] , vitamin B1, vitamin B2, and nicotinamide as the fermentation substrate to the basic fermentation medium based on a generated random matrix that represented the added value. The PMLA production and four secondary indexes, pH, biomass, osmotic pressure, and viscosity were measured after 144 h fermentation. Finally, a total of 212 samples were collected as the dataset, by which the machine learning methods were deployed to predict the PMLA production by different substrates’ concentrations and the secondary indexes. The results indicated that PMLA production was negatively correlated with corn steep liquor and betaine and positively correlated with potassium acetate. The PMLA production could be predicted using all different substrates’ concentrations with a Mean Absolute Error (MAE) of 4.164 g/L and with an MAE of 6.556 g/L by different secondary indexes. Finally, the convolutional neural network (CNN) was applied to predict the PMLA production by fermentation medium images, in which the collected images were categorized into three groups, 0–20 g/L, 21–40 g/L, and >41 g/L, based on the PMLA production. The CNN model could predict the production with high accuracy. The methods and results presented in this study provided new insight into evaluating different substrates concentration on PMLA production and demonstrating the possibility of using the convolutional neural network model in the PMLA fermentation industry.

Extracting the polyphenol from the fruit of the Lycium barbarum L. by using a solvent method. On the basis of single factor test, the content of chlorogenic acid in polyphenol was the main factor, and the content of chlorogenic acid in polyphenol was the response value. The extraction conditions were optimized by three factors and three levels Box-Behnken test. The results showed that the relative effects of each factor on the extraction rate of Lycium barbarum L. polyphenols were as follows: extraction solvent, solid-liquid ratio and extraction times. Through the regression model analysis predicted by response surface method, the optimum extraction conditions of Lycium barbarum L. polyphenols can be predicted as follows: 72% methanol, the ratio of material to liquid is 1:19, the extraction times is 2.15 times, and the content of chlorogenic acid in Lycium barbarum is 0.0842 g/100g. In order to investigate the consistency between the test results and the real situation, the verification test was carried out. The extraction process was set to 2 times, and the content of chlorogenic acid was 0.0837 g / 100g. The predicted process conditions by regression equation are in good agreement with the actual situation, which proves that the model is effective and the process is stable and feasible.

ß-poly(L-malic acid) (PMLA) is a water-soluble biopolymer used in medicine, food, and other industries. However, the low level of PMLA biosynthesis in microorganisms limits its further application in the biotechnological industry. In this study, corn steep liquor(CSL), which processes high nutritional value and low-cost characteristics, was selected as a growth factor to increase the PMLA production in strain, Aureobasidium melanogenum, and its metabolomics change under the CSL addition was investigated. The results indicated that, with 3g/L CSL, PMLA production, cell growth, and yield (Yp/x) were increased by 32.76%, 41.82%, and 47.43%, respectively. The intracellular metabolites of A. melanogenum, such as amino acids, organic acids, and key intermediates in the TCA cycle, increased after the addition of CSL, and the enrichment analysis showed that tyrosine may play a major role in the PMLA biosynthesis. The results presented in this study demonstrated that the addition of CSL would be an efficient approach to improve PMLA production.