Purification, functional characterization and enhanced production of serratiopeptidase from Serratia marcescens MES-4: An endophyte isolated from Morus rubra.

Serratiopeptidase, a proteolytic enzyme serves as an important anti-inflammatory and analgesic medication. Present study reports the production and purification of extracellular serratiopeptidase from an endophyte, Serratia marcescens MES-4, isolated from Morus rubra. Purification of the enzyme by Ion exchange chromatography led to the specific activity of 13,030 U/mg protein of serratiopeptidase, showcasing about 3.1 fold enhanced activity. The catalytic domain of the purified serratiopeptidase, composed of Zn coordinated with three histidine residues (His 209, His 213, and His 219), along with glutamate (Glu 210) and tyrosine (Tyr 249). The molecular mass, as determined by SDS-PAGE was ∼51 kDa. The purified serratiopeptidase displayed optimal activity at pH 9.0, temperature 50°C. Kinetic studies revealed Vmax and Km values of 33,333 U/mL and 1.66 mg/mL, respectively. Further, optimized conditions for the production of serratiopeptidase by Taguchi design led to the productivity of 87 U/mL/h with 87.9 fold enhanced production as compared to the previous conditions.

Identification and taxonomy of Streptomyces justiciae strain RA-WS2: a novel setomimycin producing actinobacterium.

The taxonomic position of novel bianthraquinone antibiotic producer Streptomyces strain RA-WS2, a soil isolate from Shivalik region of NW Himalayas, India, has been described. The isolate produces Setomimycin as a major secondary metabolite under defined submerged fermentation conditions. 16S rRNA partial gene sequencing of the isolate indicated its closest similarity (99.4%) with Streptomyces cyaneochromogenes, followed by Streptomyces aquilus. However, the morphological characteristics i.e. colony colour, mycelium and spore chain arrangement were found to be close to Streptomyces aquilus. Therefore, a polyphasic approach was used for taxonomic positioning of the isolate. The Whole genome based similarity with 88.4% dDDH value, 98.65% ANI and 96.99% AAI value indicated its closest identity with Streptomyces justiciae. The taxonomic characteristics such as white colony with smooth surface, cylindrical spores arranged in straight chain, diffusible melanin production, high salt tolerance, 16S rRNA gene sequencing and phylogenomic studies, led to the identification of the strain as Streptomyces justiciae RA-WS2. The predicted biosynthetic gene clusters further confirmed the presence of the BGC for setomimycin biosynthesis in Streptomyces justiciae strain RA-WS2. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03459-5.

Purification and characterization of thermoactive serratiopeptidase from Serratia marcescens AD-W2.

Serratiopeptidase is a proteolytic enzyme extensively used as an anti-inflammatory and analgesic drug. Present work reports a thermoactive serratiopeptidase from Serratia marcescens AD-W2, a soil isolate from the North-Western Himalayan region of India. The extracellular metalloprotease has been purified by a simple two-step procedure resulting in a specific activity of 20,492 Units/mg protein with 5.28-fold purification. The molecular mass of the metalloprotease, as determined by SDS-PAGE was ~ 51 kDa. The purified serratiopeptidase presented optimum activity at pH 9.0, temperature 50 °C and stability in wide pH and temperature range. Critical temperature of 50 °C confirmed the thermoactivity of the purified serratiopeptidase. The kinetic studies of the purified serratiopeptidase revealed Vmax and Km of 57,256 Units/mL and 1.57 mg/mL, respectively, for casein. The purified serratiopeptidase from S. marcescens AD-W2 was found to be 100% identical to serralysin from Serratia marcescens ATCC 21074/E-15. The catalytic domain comprising of Zn coordinated with three histidine residues (His192, His196, His202), along with glutamate (Glu193) and tyrosine (Tyr232) residues, further confirmed that the purified protein is identical to serralysin.

Isolation and Characterization of Serratiopeptidase Producing Bacteria from Mulberry Phyllosphere.

Serratiopeptidase (EC 3.4.24.40), a proteolytic enzyme, is one of the most promising enzymes being used in biopharmaceutical industry. Mulberry phyllosphere, being an unexplored niche for exploration of protease production, was chosen for the present study. Protease producing bacteria were isolated from the tissues of mulberry plant as well as its rhizospheric soil. Two protease producing bacteria belonging to Serratia genus were found to be potential serratiopeptidase producers. Among them, the endophyte, i.e., Serratia marcescens MES-4 presented 95 Units/mL activity, while the soil isolate i.e., Serratia marcescens MRS-11 presented 156 Units/mL activity.