Process engineering studies to investigate the effect of temperature and pH on kinetic parameters of alkaline protease production

Production and characterization of protease enzyme from Acinetobacter pittii using peanut meal as substrate

A significantly high protease enzyme yield of 617 U/ml was achieved with Acinetobacter pittii as the microorganism and peanut oil meal as the substrate. Peanut oil meal, which consists of proteins (40-60%) and carbohydrates (22-30%), serves as a sufficient source of nitrogen and carbon necessary for microbial growth and production of enzymes. Moreover, peanut meal offers the advantages of being affordable and available in large quantities, making the meal suitable for cost-effective enzyme production. In the present study, two bacterial strains and one fungal strain were selected to produce proteases utilizing peanut oil meal as the substrate. The experimental conditions during the enzyme production, including pH and temperature, were optimized. In addition, the substrate was enriched with various carbon and nitrogen sources. The microbial strains were streaked on nutritional agar (for bacteria) and potato dextrose agar (for fungus). Following an incubation period, the plates were stored at 4°C for further studies. The molecular weight of partially purified proteases of Acinetobacter pittii was found to be ≅ 95.5 kDa. Potassium nitrate was the most ideal nitrogen source (up to 411% increase in activity) and fructose was the best carbon source (425% increase). These enzymes exhibited excellent temperature tolerance and were capable of functioning over a wide pH range. Furthermore, the obtained proteases demonstrated ability to coagulate milk effectively, indicating their potential for various food-related applications.

Biodegradation of 4-chlorophenol in batch and continuous packed bed reactor by isolated Bacillus subtilis

In present work, biodegradation of 4-Chlorophenol (4-CP) has been successfully achieved using bacteria i.e. Bacillus subtilis (MF447841.1), which was isolated from the wastewater of a nearby drain of Hyundai Motor Company service centre, Agartala, Tripura (India). Geonomic identification was carried out by 16 S rDNA technique and phylogenetic processes. Both, batch and column mode of experiments were performed to optimize various parameters (initial concentration, contact time, dosages etc.) involved in the significant biodegradation of 4-CP. Based on R² value (0.9789), the Levenspiel's model was found to be best fit than others. The kinetic parameters; specific growth rate (μ), yield of cell mass (Y_X/S), and saturation constant (KS), were obtained as 0.6383 (h^-1), 0.35 (g/g), and 0.006884 (g/L), respectively. The isolated strain has shown the ability of degrading 4-CP up to 1000 mg/L initial concentration within 40 h. Bacterial strain was immobilized via developing calcium alginate beads along by optimizing weight proportion of calcium chloride and sodium alginate and size of the bead for further experiments. Various process parameters i.e. initial feed concentration, bed height, rate of flow of were optimized during packed bed reactor (PBR) study. Maximum biodegradation efficiency of 4-CP was observed as 45.39% at initial concentration of 500 mg/L within 105 min, using 2 mm size of immobilized beads which were formed using 3.5% w/v of both calcium chloride and sodium alginate within. Thus, Bacillus subtilis (MF447841.1) could be used for biological remediation of 4-CP pollutant present in wastewater. Moreover, because of affordable and eco-friendly nature of water treatment, relatively it has the better scope of commercialization.

Production of β-glucanase and protease from Bacillus velezensis strain isolated from the manure of piglets

In this study, a strain producing β-glucanase and protease, identified as Bacillus velezensis Y1, was isolated from the manure of piglet. We attempted to produce β-glucanase and protease after optimization of various process parameters with the submerged fermentation. The effects of each factor on producing β-glucanase and protease were as follows: temperature > time > pH > loaded liquid volume. The properties of the β-glucanase showed that the most suitable reaction temperature was 65 °C and pH was 6.0. However for protease optimum reaction temperature was 50 °C, and pH was 6.0. The amplified PCR fragments of β-glucanase and protease were 1434 bp containing an open reading frame of 1413 bp encoding a protein with 444 amino acids and 1752 bp containing an open reading frame of 1521 bp encoding a protein with 506 amino acids, respectively. So, the study demonstrated a viable approach of using newly identified B. velezensis Y1 strain for the maximum yield of two industrially important enzymes.

Optimization of Process Parameters for Production of Pectinase using Bacillus Subtilis MF447840.1

BACKGROUND

Pectinase enzyme has immense industrial prospects in the food and beverage industries.

OBJECTIVE

In our investigation, we find out the optimum process parameters suitable for better pectinase generation by Bacillus subtilis MF447840.1 using submerged fermentation.

METHOD

2% (OD600 nm = 0.2) of pure Bacillus subtilis MF447840.1 bacterial culture was inoculated in sterile product production media. The production media components used for this study were 1 g/l of pectin, 2 g/l of (NH4)2SO4, 1 g/l of NaCl, 0.25 g/l of K2HPO4, 0.25 g/l of KH2PO4 and 1 g/l of MgSO4 for pectinase generation. We reviewed all recent patents on pectinase production and utilization. The various process parameters were observed by changing one variable time method.

RESULTS

The optimum fermentation condition of different parameters was noticed to be 5% inoculums, 25% volume ratio, temperature (37°C), pH (7.4) and agitation rate (120 rpm) following 4 days incubation.

CONCLUSION

Maximum pectinase generation was noticed as 345 ± 12.35 U following 4 days incubation.

Optimization of physical and morphological regime for improved cellulase free xylanase production by fed batch fermentation using Aspergillus niger (KP874102.1) and its application in bio-bleaching

The physiological and morphological changes were extensively studied during fed batch fermentation using newly isolated Aspergillus niger (KP874102.1). Significantly higher xylanase production was possible through optimization of environmental stresses by fed batch process. The fed batch fermentation was carried out for improved xylanase production (2524 U) where initial xylan was kept 1.5 g/L in the production medium. However, 3 g/L of xylan with 50 mM K₂HPO₄ having pH-7 was consecutively fed at 72 and 120 h of fermentation. K₂HPO₄ showed significant role both the morphology of the microorganism and produces enzymes in fed batch fermentation. During feeding phase, the pH was found in the range of 6.5 to 7 which was used as marker for the fed batch process. The crude enzyme was used for the bio-bleaching of banana pulp.

High purity recombinant human growth hormone (rhGH) expression in Escherichia coli under phoA promoter

ABSTACT Recombinant human Growth Hormone (rhGH) is an important protein for human growth and is in high demand in clinics. Hence, it is necessary to develop an efficient fermentation process to produce highly pure rhGH. In this study, rhGH was expressed in Escherichia coli under alkaline phosphatase (phoA) promoter. The cultivation conditions for high expression level and purity of rhGH were investigated. The best initial phosphate concentration for rhGH expression, out of the 4 levels of initial phosphate concentration tests performed, was 12.6 mmol/L. Subsequently, 2 fed-batch cultivations under low dissolved oxygen (DO) (0% - 10%) and high DO (20% - 30%) conditions were carried out. High purity rhGH (92%) was obtained from 20% - 30% DO-stat cultivation, although the biomass did not show any significant difference. In summary, this research provided an efficient fermentation process for high purity rhGH production from E. coli under phoA promoter, which can lower the production and purification costs for large-scale production of rhGH.