Environmental chitinous materials as adsorbents for one-step purification of protease and chitosanase

Kinetic, Thermodynamic and Bio-applicable Studies on Aspergillus niger Mk981235 Chitinase

Chitinases have many applications in food, agricultural, medical, and pharmaceutical fields. This study succeeded in investigating Aspergillus niger MK981235 chitinase in the spot of its physiochemical, kinetic, thermodynamic, and application. The optimum temperature, pH and p-nitrophenyl-β-d-N-acetyl glucosaminide (PNP-β-GlcNAc) concentration to obtain the highest chitinase activity of 2334.79 U ml−1 were at 60 °C, 5 and 0.25%, respectively. The kinetic parameters, including Km and Vmax were determined to be 0.78 mg ml−1 and 2222.22 µmol ml−1 min−1, respectively. Furthermore, the thermodynamic parameters T1/2, D-values, ΔH, ΔG and ΔS at 40, 50 and 60 °C were determined to be (864.10, 349.45, 222.34 min), (2870.99, 1161.07, 738.74 min), (126.40, 126.36, 126.32 kJ mol−1), (101.59, 100.62, 100.86 kJ mol−1), (74.50, 76.17, 47.24 J mol−1 K−1), respectively. A. niger chitinase showed, insecticidal activity on Galleria mellonella by feeding and spraying treatments (72 and 52%, respectively), anti-lytic activity against Candida albicans, and effectiveness in improving the dye removal in the presence of crab shell powder as bio-absorbant. A. niger chitinase can be used in the pharmaceutical field for the bio-control of diseases caused by C. albicans and for the pretreatment of wastewater from the textile industry.

Graphical Abstract

In vitro antioxidant, antibacterial, in vivo immunomodulatory, antitumor and hematological potential of exopolysaccharide produced by wild type and mutant Lactobacillus delbureckii subsp. bulgaricus

Biological evaluation of exopolysaccharides (EPS) produced by wild type and mutant Lactobacillus delbureckii (EPSWLD and EPSMLD) was investigated. Varying degrees of functional groups associated with polysaccharides were present thus confirming the EPS. The EPSs had strong antioxidant potential in a dose dependent (0.5–10 mg/mL) manner. EPSWLD and EPSMLD exhibited the highest 1,1-diphemy 1-2-picryl-hydrazyl (DPPH) activity (73.4 % and 65.6 %), total antioxidant activity (1.80 % and 1.42 %), H₂O₂ scavenging activity (88.5 % and 78.6 %) and Ferric Reducing Antioxidant Power (FRAP) (1.89 % and1.81 %) at 10 mg/mL respectively. WLD and MLD were highly susceptible to chloramphenicol, cotrimoxazole, tetracycline, erythromycin and ceftazidine and resistant to cefuroxime, gentamicin and cloxacillin. The EPSs had antibacterial activity against the test pathogens. B. subtilis and S. aureus had the highest susceptibility (26.0 mm and 23.0 mm). EPSMLD modulate the highest IgG, IgA and IgM production (68–126 mg/dL and 67–98 mg/dL and 64–97 mg/dL) in the treated tumor induced mice (TTIM). EPSWLD and EPSMLD exhibited reduction capability on the CEA level (3.99–4.35 ng/L and 4.12–4.23 ng/L) of the TTIM. EPSWLD TTIM had the highest amount of RBC, WBC and PCV (5.6 × 10¹²%, 68000% and 42%). The EPS increased the lifespan of TTIM. In conclusion EPSWLD and EPSMLD had strong biological potential with pharmacological and neutraceutical activity.

Bromelain-loaded nanoparticles: A comprehensive review of the state of the art

Stem bromelain is a common available cysteine protease derived from pineapple (Ananas comosus L.). Bromelain finds widespread applications in several areas, such as medicine, health, food, and cosmetics, and its strong proteolytic activity supports its future application in many additional fields. However, most proteins and/or enzymes are fragile, leading to important considerations about increase storage and operational stability to enable their practical application. In this scenario, the use of nanoparticles to deliver proteins is increasing exponentially, given that these systems are capable of enhance active's stability, solubility and permeability, and decrease toxicity. In the pharmaceutical nanotechnology field, bromelain has played different roles and thus this paper aims to review the available literature for the use of nanoparticles and bromelain.

Exopolysaccharide production from Bacillus velezensis KY471306 using statistical experimental design

Exopolysaccharide (EPS) biopolymers produced by microorganisms play a crucial role in the environment such as health and bio-nanotechnology sectors, gelling agents in food and cosmetic industries in addition to bio-flocculants in the environmental sector as they are degradable, nontoxic. This study focuses on the improvement of EPS production through manipulation of different culture and environmental conditions using response surface methodology (RSM). Plackett–Burman design indicated that; molasses, yeast extract and incubation temperature are the most effective parameters. Box–Behnken RSM indicated that; the optimum concentration for each parameter was 12% (w/v) for molasses, 6 g/L yeast extract and 30 °C for incubation temperature. The most potent bacterial isolate was identified as Bacillus velezensis KY498625. After production, EPS was extracted, purified using DEAE-cellulose, identified using Fourier transform infrared (FTIR), gel permeation chromatography (GPC) and gas chromatography–mass spectroscopy (GC–MS). The result indicated that; it has molecular weight 1.14 × 10⁵ D consisting of glucose, mannose and galactose.

Production and Characterization of Antioxidant Properties of Exopolysaccharide(s) from Peanibacillus mucilaginosus TKU032

Natural polysaccharides have received much attention due to their wide range of applications. Although most microbial exopolysaccharides (EPSs) use sugars as the major carbon source, such as glucose or sucrose, in this study, EPSs were induced from a squid pen powder (SPP)-containing medium by Paenibacillus mucilaginosus TKU032, a bacterial strain isolated from Taiwanese soil. Under the optimal culture conditions, the maximum EPS yield (14.8 g/L) was obtained. MALDI-TOF MS analysis of an EPS fraction purified by gel filtration revealed two mass peaks with molecular weights of ∼1.05 × 10⁴ and ∼1.35 × 10⁴ Da, respectively. The analysis of the hydrolysates of TKU032 EPS with cellulase, pectinase or α-amylase indicated that the glycosidic bond of TKU032 EPS is most likely an α-1,4 glycosidic bond and the hydrolysates are similar to those of starch. In addition, the purified EPS demonstrated strong antioxidant abilities.

Chitinolytic Bacteria-Assisted Conversion of Squid Pen and Its Effect on Dyes and Pigments Adsorption

The aim of this work was to produce chitosanase by fermenting from squid pen, and recover the fermented squid pen for dye removal by adsorption. One chitosanase induced from squid pen powder (SPP)-containing medium by Bacillus cereus TKU034 was purified in high purification fold (441) and high yield of activity recovery (51%) by ammonium sulfate precipitation and combined column chromatography. The SDS-PAGE results showed its molecular mass to be around 43 kDa. The TKU034 chitosanase used for the chitooligomers preparation was studied. The enzyme products revealed that the chitosanase could degrade chitosan with various degrees of polymerization, ranging from 3 to 9, as well as the chitosanase in an endolytic manner. Besides, the fermented SPP was recovered and displayed a better adsorption rate (up to 99.5%) for the disperse dyes (red, yellow, blue, and black) than the water-soluble food colorants, Allura Red AC (R40) and Tartrazine (Y4). The adsorbed R40 on the unfermented SPP and the fermented SPP was eluted by distilled water and 1 M NaOH to confirm the dye adsorption mechanism. The fermented SPP had a slightly higher adsorption capacity than the unfermented, and elution of the dye from the fermented SPP was easier than from the unfermented. The main dye adsorption mechanism of fermented SPP was physical adsorption, while the adsorption mechanism of unfermented SPP was chemical adsorption.

Squid pen chitin chitooligomers as food colorants absorbers

One of the most promising applications of chitosanase is the conversion of chitinous biowaste into bioactive chitooligomers (COS). TKU033 chitosanase was induced from squid pen powder (SPP)-containing Bacillus cereus TKU033 medium and purified by ammonium sulfate precipitation and column chromatography. The enzyme was relatively more thermostable in the presence of the substrate and had an activity of 93% at 50 °C in a pH 5 buffer solution for 60 min. Furthermore, the enzyme used for the COS preparation was also studied. The enzyme products revealed various mixtures of COS that with different degrees of polymerization (DP), ranging from three to nine. In the culture medium, the fermented SPP was recovered, and it displayed a better adsorption rate (up to 96%) for the disperse dyes than the water-soluble food colorants, Allura Red AC (R40) and Tartrazne (Y4). Fourier transform-infrared spectroscopic (FT-IR) analysis proved that the adsorption of the dyes onto fermented SPP was a physical adsorption. Results also showed that fermented SPP was a favorable adsorber and could be employed as low-cost alternative for dye removal in wastewater treatment.