Screening of factors influencing exo-polygalacturonase production by Aspergillus niger ATCC 120120 using two-level fractional factorial design

Exo-polygalacturonase was produced by Aspergillus niger ATCC 120120 in a solid-state fermentation using Nephrolepis biserrata leaves. Factors affecting the production of exo-polygalacturonase were determined using a two-level fractional factorial design. The screening process for six factors; pH, incubation time, temperature, pectin concentration, inoculum size and moisture content, that influence the production of exo-polygalacturonase by A. niger was performed. The result of variance analysis (ANOVA) suggested that there were four statistically significant (P < 0.005) factors in the production of exo-polygalacturonase by A. niger. These factors were incubation time, temperature, pectin concentration and moisture content. The statistical analysis shows that the linear mathematical model is significant with coefficient of determination (R2) value of 0.9711. The optimum production of exo-polygalacturonase obtained using the model in this study was at 40.00 U/g

Comparative structural analysis of fruit and stem bromelain from Ananas comosus

Cysteine proteases in pineapple (Ananas comosus) plants are phytotherapeutical agents that demonstrate anti-edematous, anti-inflammatory, anti-thrombotic and fibrinolytic activities. Bromelain has been identified as an active component and as a major protease of A. comosus. Bromelain has gained wide acceptance and compliance as a phytotherapeutical drug. The proteolytic fraction of pineapple stem is termed stem bromelain, while the one presents in the fruit is known as fruit bromelain. The amino acid sequence and domain analysis of the fruit and stem bromelains demonstrated several differences and similarities of these cysteine protease family members. In addition, analysis of the modelled fruit (BAA21848) and stem (CAA08861) bromelains revealed the presence of unique properties of the predicted structures. Sequence analysis and structural prediction of stem and fruit bromelains of A. comosus along with the comparison of both structures provides a new insight on their distinct properties for industrial application

Expression, purification and characterization of extradiol dioxygenase carbb involved in carbazole degradation pathway

Extradiol dioxygenase is a family of enzymes essential for ring cleavage reactions in aromatic compounds degradation pathways. Extradiol dioxygenases belonging to the majority of aromatic compound degradation pathways are single peptide proteins, while a small subset of in this family was reported to be two subunits complex proteins. The extradiol dioxygenase CarB protein is a protein complex consisting of catalytic subunit CarBb with a smaller subunit CarBa. This enzyme was reported to show no ring cleavage activity without the expression of both peptides. However, to date, there was no specific study to confirm CarBb protein dependency on CarBa protein for its ring cleavage activity. In this study, we cloned, heterologously expressed and purified CarBb in E. coli. CarBb protein showed appreciable ring cleavage activity without expression of CarBa protein. The Km and Vmax values calculated were 163.68 μM and 1.19 μM/min. The effects of pH and temperature suggested that the CarBb protein was significantly unstable, suggesting that the CarBa protein may be responsible for the structural stability of the CarBb protein to function as an effective ring cleavage enzyme

Physicochemical properties and tenderness analysis of bovine meat using proteolytic enzymes extracted from pineapple (Ananas comosus) and jackfruit (Artocarpus heterophyllus) by-products

Present research investigation aimed to explore the pineapple and jackfruit by-products, the core and the seed, respectively, as a meat tenderizer. The effects of beef samples treated with bromelain and Artocarpus heterophyllus protease in four different concentrations (0, 1%, 2%, 3% and 4%) and combination (4% bromelain and 4% A. heterophyllus protease) were studied. The physicochemical treated beef samples showed a 13.30 ± 0.30 decrease in the water holding capacity (WHC), pH 5.47 ± 0.03, moisture content 63.86 ± 0.16 and cooking yield 75.78 ± 0.16 with the increased addition of crude enzyme extract (p < .05). The cooking loss increased significantly with the concentration of extracted proteolytic enzymes (p < .05). Microstructural analysis of the treated beef samples demonstrated the degradation of muscle fibers and the generation of numerous gaps or space. The sensory evaluation analysis also revealed the acceptance of the treated beef sample compared to the untreated sample. The results showed that the bromelain and A. heterophyllus protease extract from by-products could be used as an effective natural meat tenderizer. The core and seed as (pineapple and jackfruit) waste by-product could effectively improve the tenderization of tough muscle in beef without disturbing quality parameters, significantly contributing to the agricultural processing industry

Enhanced excretion of recombinant cyclodextrin glucanotransferase and cell stability of immobilized recombinant Escherichia coli by reducing tryptone concentration

BACKGROUND: Recombinant protein excretion has become a mainstream strategy in reducing downstream processing costs. However, recombinant protein excretion is often bottlenecked by cell lysis and plasmid stability. In the present study, recombinant Escherichia coli cell immobilization was performed on a hollow fiber membrane. Tryptone concentration in the expression medium (Super Optimal Broth), which was used as a nitrogen source, was varied between 5 and 20 g L−1 to enhance the excretion of recombinant cyclodextrin glucanotransferase (CGTase), plasmid stability, and resistance of cell lysis. RESULTS: The immobilized cells with 5 g L−1 concentration of tryptone improved the plasmid stability with 119% improvement and 69% reduction of cell lysis without remarkably altering the excretion of CGTase compared with the tryptone concentration of 20 g L−1. The immobilized cells showed a 2-fold increase in excretion of CGTase, a 45% reduction in cell lysis, and a 172% gain in plasmid stability in comparison with the free cells. Moreover, the doubling time increased to 58 and 5 h for the immobilized and free cells, respectively. The immobilized cells recorded 2301.62 U mL−1 of cumulative CGTase activity through seven fermentation cycles using the untreated membrane, marking their excellent reusability. CONCLUSION: This new technique of recombinant protein expression utilizing an immobilized cell system under low tryptone concentration is an outstanding approach to improve recombinant CGTase excretion and plasmid stability with low cell lysis

Rheological Stability, Enzyme Activity, and Incorporation of Pseudocereal Powder as an Alternative Ingredient in Health-Related Food

In response to the growing recognition of health issues, people are seeking products that are inexpensive, convenient, and health-related. The incorporation of pseudocereal powder in nutraceutical sector is currently increasing because of their high nutritional profile as well as health-promoting effects. The high nutritional profile includes low starch content, high in amino acid profile, high in mineral content, and low glycemic index. Moreover, it contains high levels of phytochemicals that contain considerable amounts of flavonoids, polyphenolic chemicals, and phytosterols, making them useful in the nutraceutical sector. These bioactive compounds offer antioxidant, anti-inflammatory, and reduced risk of obesity, prediabetes, and diabetic complications. With its tremendous potential and numerous food health-related uses, pseudocereal can serve as a low-cost alternative ingredient in health-related food products. Several pseudocereal processes via enzyme activity, as well as the high rheological stability of its starch, have made pseudocereal an attractive option for modern agriculture

Improved heterocyclic aromatic hydrocarbon compound adsorption using functionalised rice husk biochar

Carbazole (CBZ) is a hazardous heterocyclic aromatic hydrocarbon (HAH) that pollutes water bodies, and the treatment remains a challenge due to its high persistence in the environment. This study chemically modified rice husk biochar (RHB) with starch derivative (DS) to develop an effective adsorbent. Thus, functionalised RHB with starch derivative (RHBDS) was synthesised to remove CBZ from synthetic wastewater. Based on a Box-Behnken design, the DS functionalisation optimisation was successfully performed. The parameters, including RHB mass of (5–10) g, DS concentration of (1–5)% w/v, and sonication period of (1–5) min, were analysed using Design Expert. These parameters were then utilised to investigate the optimal conditions (removal rate response and adsorption capacity) for the adsorbent. The removal rate and the adsorption capacity ranged from 83.85 to 98.94 % and 335.41 to 395.76 mg/g, respectively. Consequently, the RHB mass of 6.50 g, DS concentration of 1 % w/v, and sonication period of 5 min within the experimental domain exhibited the best conditions with desirability of 1.0. The 92.67 % removal rate and adsorption capacity of 370.59 mg/g were also obtained under optimal conditions. Compared to RHB, RHBDS demonstrated four times the adsorption capacity for the CBZ removal from synthetic water, which were 23.03 mg/g and 98.01 mg/g, respectively. Therefore, the RHBDS compound could be a promising adsorbent in removing CBZ from wastewater

Development of organic porous material from pineapple waste as a support for enzyme and dye adsorption

The transformation of agricultural wastes such as pineapple waste into valuable product such as biochar will be of great advantage. Biochar is a black carbon produced by pyrolysis which can act as good adsorbent for organic substances due to the high porosity characteristic. Due to the instability and the non-recyclability factor of free enzymes, the use of immobilized enzyme is getting more attraction. Furthermore, biochar or activated carbon (AC) has been widely used in industries to adsorb pollution such as dye. In this study, process pyrolysis was used to convert pineapple waste biomass (PWB) into useful adsorbent such as biochar (BC) and activated carbon (AC) for lipase immobilization and RBBR dye adsorption. Several steps such as impregnation of PWbB with nitric acid, and process pyrolysis of pineapple waste at various temperatures and residence time have been performed. Studies of characterization of biochar such as Thermogravimetric analysis (TGA), Brunauer – Emmett – Teller (BET), Fourier Transform Infra-Red (FTIR) and Scanning Electron Microscopy (SEM) were accomplished to analyze the differences in performance. The performance of BC in lipase immobilization and RBBR dye adsorption were investigated by varying parameters i.e. initial concentration, physical size of PWB (grounded and non-grounded pineapple waste (PW) biomas) and physical size of BC (crushed and non-crushed BC). The achievements of generated BC were compared with commercial AC. The result shows the highest amount of protein adsorbed during immobilization was achieved at F500 1 h PWbB (92.99%). Meanwhile, the maximum dye removal was achieved at F 600.5 h PWbB (83.59%). Adsorption kinetics studies insinuate that the overall process follows the pseudo-first-order where the process was influenced by intraparticle and film diffusion while equilibrium isotherm studies is best described by Langmuir isotherm models. As a conclusion, the conventional liability burden of pineapple waste is possible to be transformed into valuable commodity especially for waste treatment