Optimization of medium for the production of a novel aquaculture probiotic,Micrococcus MCCB 104 using central composite design

Enhanced antimicrobial and antioxidant properties of Nano chitosan and pectin based biodegradable active packaging films incorporated with fennel (Foeniculum vulgare) essential oil and potato (Solanum tuberosum) peel extracts

Active packaging materials are generally prepared by incorporating antimicrobial agents. The main objective of the present research is the development and characterization of active packaging with Nano chitosan and pectin. Active packaging film was prepared by incorporating essential oil of Fennel (EOF) along with potato peel extract (PPE) to improve the antioxidant and antimicrobial property of the film. Incorporation of EOF into Nano chitosan and pectin-based films increased antimicrobial activity, whereas; PPE increased the antioxidant property of the films. In the present study, thickness, optical property, mechanical property, antioxidant and antimicrobial property, total soluble matter, morphological study, FTIR analysis, and microbial degradation study of the prepared active packaging material was done. The addition of the PPE and EOF together improved the surface, optical, mechanical, antimicrobial and antioxidant properties of the packaging film. Enhanced antimicrobial and antioxidant property of the Nano chitosan-PPE-PVA-EOF and pectin-PPE-PVA-EOF-based packaging films can extend the shelf life of the packed food; hence it is suggested for the active packaging for perishable food commodity. In short, the prepared active packaging film with biodegradable property is suggested as an effective packaging material to replace synthetic plastic packages for food and hence reduce plastic pollution.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-021-05333-9.

Freeze dried probiotic carrot juice powder for better storage stability of probiotic

Probiotic strains isolated from Gundruk- a traditional Indian fermented food-and fermented carrot juice, were evaluated for their probiotic properties and analyzed probiotic properties such as lactic acid production, NaCl tolerance, and acid tolerance for all the isolated strains. Most isolated strains were susceptible to antibiotics, and cell-free extracts showed potential antioxidant activity and observed antagonistic properties against foodborne pathogens such as Salmonella typhi ATCC 6539, Escherichia coli ATCC 25922, Shigella ATCC 12022, and Staphylococcus ATCC 29213. The isolate Enterococcus faecalis(K13), was incorporated in carrot juice and microencapsulated by freeze-drying and spray drying. Gum Arabic and maltodextrin were used as coating materials. The physicochemical properties, such as bulk density, moisture content, water activity and color of the powders, and the survivability of probiotic bacteria, were studied on storage. The freeze-dried probiotic formulation is suggested over spray-dried formulation for further use, since it had good storage stability up to one month (6-7 Log CFU/g).

A refined medium to enhance the antimicrobial activity of postbiotic produced by Lactiplantibacillus plantarum RS5

Postbiotic RS5, produced by Lactiplantibacillus plantarum RS5, has been identified as a promising alternative feed supplement for various livestock. This study aimed to lower the production cost by enhancing the antimicrobial activity of the postbiotic RS5 by improving the culture density of L. plantarum RS5 and reducing the cost of growth medium. A combination of conventional and statistical-based approaches (Fractional Factorial Design and Central Composite Design of Response Surface Methodology) was employed to develop a refined medium for the enhancement of the antimicrobial activity of postbiotic RS5. A refined medium containing 20 g/L of glucose, 27.84 g/L of yeast extract, 5.75 g/L of sodium acetate, 1.12 g/L of Tween 80 and 0.05 g/L of manganese sulphate enhanced the antimicrobial activity of postbiotic RS5 by 108%. The cost of the production medium was reduced by 85% as compared to the commercially available de Man, Rogosa and Sharpe medium that is typically used for Lactobacillus cultivation. Hence, the refined medium has made the postbiotic RS5 more feasible and cost-effective to be adopted as a feed supplement for various livestock industries.

Optimization of fermentation conditions for an Escherichia coli strain engineered using the response surface method to produce a novel therapeutic DNA vaccine for rheumatoid arthritis

BACKGROUND

Fermentation condition optimization and nutrients screening are of equal importance for efficient production of plasmid DNA vaccines. This directly affects the downstream purification and final quality and yield of plasmid DNA vaccines. The present study aimed to optimize the fermentation conditions for high-throughput production of therapeutic DNA vaccine pcDNA-CCOL2A1 by engineered Escherichia coli DH5α, using the response surface method (RSM).

RESULTS

We hypothesized that optimized fermentation conditions significantly increase the yield of pcDNA-CCOL2A1 therapeutic DNA vaccine, a novel DNA vaccine for treating rheumatoid arthritis (RA). Single-factor analysis was performed to evaluate the optimal basal culture medium from LB, 2 × YT, TB, M9 (Glycerol) and M9 (Glucose), respectively. Thereafter, the Plackett-Burman design (PBD) was used to ascertain the three most significant factors affecting the vaccine yields, followed by the paths of steepest ascent to move to the nearest region of maximum response. Initial screening through the PBD revealed that the most key factors were peptone, mannitol, and inoculum concentration. Subsequent use of RSM was further optimized for the production of therapeutic DNA vaccine pcDNA-CCOL2A1 through Box-Behnken design (BBD). The final optimized fermentation conditions were as follows: peptone, 25.86 g/L; mannitol, 8.08 g/L; inoculum concentration, OD = 0.36. Using this statistical experimental design, the yield of therapeutic DNA vaccine pcDNA-CCOL2A1 markedly increased from 223.37 mg/L to339.32 mg/L under optimal conditions, and a 51.9% increase was observed compared with the original medium.

CONCLUSIONS

The present results provide a basis for further production of high-quality and high-yield therapeutic DNA vaccine pcDNA-CCOL2A1 in pilot-scale and even industrial-scale.

Characterization of ethanol fermentation waste and its application to lactic acid production by Lactobacillus paracasei

In this study, an ethanol fermentation waste (EFW) was characterized for use as an alternative to yeast extract for bulk fermentation processes. EFW generated from a commercial plant in which ethanol is produced from cassava/rice/wheat/barley starch mixtures using Saccharomyces cerevisiae was used for lactic acid production by Lactobacillus paracasei. The effects of temperature, pH, and duration on the autolysis of an ethanol fermentation broth (EFB) were also investigated. The distilled EFW (DEFW) contained significant amounts of soluble proteins (2.91 g/l), nitrogen (0.47 g/l), and amino acids (24.1 mg/l). The autolysis of the EFB under optimum conditions released twice as much amino acids than in the DEFW. Batch fermentation in the DEFW increased the final lactic acid concentration, overall lactic acid productivity, and lactic acid yield on glucose by 17, 41, and 14 %, respectively, in comparison with those from comparable fermentation in a lactobacillus growth medium (LGM) that contained 2 g/l yeast extract. Furthermore, the overall lactic acid productivity in the autolyzed then distilled EFW (ADEFW) was 80 and 27 % higher than in the LGM and DEFW, respectively.