Purification and biochemical characterization of pullulanase produced from Bacillus sp. modified by ethyl-methyl sulfonate for improved applications

Strain improvement via chemical mutagen could impart traits with better enzyme production or improved characteristics. The present study sought to investigate the physicochemical properties of pullulanase produced from the wild Bacillus sp and the mutant. The pullulanases produced from the wild and the mutant Bacillus sp. (obtained via induction with ethyl methyl sulfonate) were purified in a-three step purification procedure and were also characterized. The wild and mutant pullulanases, which have molecular masses of 40 and 43.23 kDa, showed yields of 2.3% with 6.0-fold purification and 2.0% with 5.0-fold purification, respectively, and were most active at 50 and 40 °C and pH 7 and 8, respectively. The highest stability of the wild and mutant was between 40 and 50 °C after 1 h, although the mutant retained greater enzymatic activity between pH 6 and 9 than the wild. The mutant had a decreased Km of 0.03 mM as opposed to the wild type of 1.6 mM. In comparison to the wild, the mutant demonstrated a better capacity for tolerating metal ions and chelating agents. These exceptional characteristics of the mutant pullulanase may have been caused by a single mutation, which could improve its utility in industrial and commercial applications.

Production of herbal toothpaste: Physical, organoleptic, phyto-compound, and antimicrobial properties

Objective

To investigate the possibility of producing dental antimicrobial toothpaste from Allium cepa L skin chaff, Azadirachta indica A. seed, and Tetrapleura tetraptera pod extracts.

Methods

Ethanolic extracts of the three plant materials were obtained. These were subjected to phytochemical and GC-MS analyses. The different extract combinations were used for the production of various toothpaste. The toothpaste's physical, organoleptic, and antimicrobial properties were determined.

Results

From the phytochemical analysis, Allium cepa has the highest phenolic (1.20 mgGAE/g), saponin (14.80%), tannin (0.11 mg/g) and DPPH (82.80%), Tetrapleura tetraptera has the highest flavonoid (0.33 mg RE/g), and alkaloid (20.50 mg/g) while, Azadirachta indica has the highest oxalate (77.50 mg/g). The GC-MS revealed significant chemical components of Allium cepa as 1-heptatriacotanol, germacra-1(10),4,11(13)-trien-12-oic acid, 6-alpha-hydroxy-,gamma-lactone, (E,E)-, 11H-Indeno [1,2b] quinoxaline, 2-methyl- while Azadirachta indica have butyl benzoate, benzoic acid, hexyl ester, hexadecanoic acid, methyl ester and Tetrapleura tetraptera have the following 15-hydroxypentadecanoic acid, cis-9-hexadecenal, and 11,13-dimethyl-12-tetradecen-1-ol acetate. All the produced toothpaste has a brown colour and a pleasant smell, with pH from 7.30 to 8.10 and foamability from 19.23% of stand-alone toothpaste to 44.44% of Allium cepa-based. Amongst the produced toothpaste Allium cepa-based toothpaste has the best antimicrobial activities against the tested bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca) and fungi (Candida albicans and Candida parapsilosis). The stand-alone toothpaste has the lowest minimum inhibitory concentration of 1.25 mg/mL against bacteria and fungi.

Clinical significance

The study provides information on the production of human health-friendly dental antimicrobial toothpaste from plant materials.