Purification and characterization of 60 kD lipase linked with chaperonin from Pseudomonas aeruginosa BN-1

An extracellular lipase from Pseudomonas aeruginosa BN-1 was purified to 42.99 fold. N-terminal sequence of purified enzyme was AAKEVKFGDS identical to sequence of a chaperonin and enzyme may be linked to it. It has an estimated molecular weight of 60 kD, while temperature and pH optima were 37°C and 8.0,  respectively. The enzyme obtained has considerable thermostability retaining 70% of activity at 50°C for 1 h. The enzyme was stable at pH 9.5 for 1 h having 70% of the residual activity. Long acyl chains were preferred as substrate and highest hydrolytic activity was observed against C-16 and C-18 4-nitrophenyl esters. Mustard oil was found to be the preferred substrate as lipolytic activity was 2.75 fold higher when compared with the activity with olive oil as the substrate. The enzymatic activity declined in the presence of Al3+, Hg2+, Co2+ and Mn2+, while Ca2+ and Ba2+ ions enhanced the activity. Non ionic detergents, Tween 80 and sodium deoxycholate, increased the activity by 1.2 and 2.5 fold, respectively. Ethylenediaminetetraacetic acid (EDTA), 2-mercaptoethanol and 1,4-dithio-DL-threitol (DTT) had no effect on lipolytic activity. Sodium dodecyl sulfate (SDS) and phenylmethylsulfonyl fluoride (PMSF) inhibited the enzyme activity by 90 and 98%, respectively. The lipase showed stability in organic solvents.Key words: Pseudomonas aeruginosa BN-1, chaperonin, mustard oil, organic solvent, phenyl methyl sulfonylfluoride, sodium deoxycholate, Swiss Prot Accession # P 30718

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Effect of Metal Ions, Solvents and Surfactants on the Activity of Protease from Aspergillus niger KIBGE-IB36

Metal ions greatly impact on the enzymatic activity, they may form strong interaction by forming coordinate bond with enzyme-substrate at the catalytic site which may activate, inhibit or stabilized the enzyme molecules. In this study, extracellular protease from Aspergillus niger KIBGE-IB36 was precipitated with 40% ammonium sulfate. It was revealed that K+, Ba2+, Na+, Mg2+ Zn2+, Ca2+ boosted the protease activity whereas, Cs+, Mn2+, Cu2+, Ni2+, V2+, Co2+, Hg2+ and Al3+ showed to be inhibitor of protease. Dimethyl sulfoxide (5.0 mM) and methanol (5.0 mM) showed catalytic activity while ethanol at same concentration exhibited inhibitory effect. Protease activity augmented with Tween 80, while SDS, Triton X-100, EDTA and PMSF exhibited inhibitory effect

Utilization of corncob xylan as a sole carbon source for the biosynthesis of endo-1,4-β xylanase from Aspergillus niger KIBGE-IB36

Abstract Background Xylan is a hemicellulose polysaccharide which is composed of β-1,4-linked d-xylosyl residues. Endo-1,4-β xylanase has the ability to cleave xylan back bone chains to release xylose residues. They are produced by a number of prokaryotic and eukaryotic organisms. Among them, filamentous fungi are attracting great attention due to high secretion of xylanolytic enzymes. Endo-1,4-β xylanase has wide industrial applications such as in animal feed, bread making, food and beverages, textile, bleaching of wood pulp, and biofuel production. Results In this study, different Aspergillus species were screened for the production of endo-1,4-β xylanase, and Aspergillus niger KIBGE-IB36 was selected for optimum production of enzyme in submerged fermentation technique. Influence of various fermentation conditions was investigated to produce high titer of endo-1,4-β xylanase. The results indicated that A. niger KIBGE-IB36 showed optimum production of endo-1,4-β xylanase at 30 °C, pH 8 after 6 days of incubation. Different macro- and micronutrients were also amalgamated in the fermentation medium to increase the enzyme production. The parametric optimization of endo-1,4-β xylanase resulted in tenfold increase after hydrolysis of 20 g L−1 corncob xylan. Conclusions The use of low-cost substrate approach for high production of endo-1,4-β xylanase has been developed successfully that can be consumed in different industrial applications especially in paper and pulp industry. Graphical abstract Production of Xylanase from Aspergillus niger KIBGE-IB36

Effect of Metal Ions, Solvents and Surfactants on the Activity of Protease from Aspergillus niger KIBGE-IB36

Metal ions greatly impact on the enzymatic activity, they may form strong interaction by forming coordinate bond with enzyme-substrate at the catalytic site which may activate, inhibit or stabilized the enzyme molecules. In this study, extracellular protease from Aspergillus niger KIBGE-IB36 was precipitated with 40% ammonium sulfate. It was revealed that K+, Ba2+, Na+, Mg2+ Zn2+, Ca2+ boosted the protease activity whereas, Cs+, Mn2+, Cu2+, Ni2+, V2+, Co2+, Hg2+ and Al3+ showed to be inhibitor of protease. Dimethyl sulfoxide (5.0 mM) and methanol (5.0 mM) showed catalytic activity while ethanol at same concentration exhibited inhibitory effect. Protease activity augmented with Tween 80, while SDS, Triton X-100, EDTA and PMSF exhibited inhibitory effect

Immobilization of Dextranase Using Anionic Natural Polymer Alginate as a Matrix for the Degradation of a Long-Chain Biopolymer (Dextran)

Alginate is an inexpensive, nontoxic, valuable biopolymer utilized in the study for the immobilization of commercially applicable biocatalyst dextranase. Dextranase was immobilized by an entrapment method, and alginate hydrogel spheres were synthesized after optimizing several parameters. A sodium alginate concentration of 4.0% was noticed to be suitable along with a calcium chloride concentration of 0.2 molar after providing a curing time of 20 minutes. After comparing the characteristics of the entrapped enzyme with those of the soluble one, it was observed that the characteristics were more or less the same except for the change in reaction time which was noticed to be prolonged in the case of entrapped dextranase while the change in temperature and pH optima was not observed. The variation in Vmax and Km values of dextranase after entrapment was also noted. However, after extensive stability examination studies, it was found that dextranase became more stable after entrapment; as a result, it retained more than 50% of its original activity at elevated temperature even after exposure for about 2.0 hours. The reusability of dextranase was up to 7.0 cycles after performing catalytic activity under constant condition

Molecular and Biochemical Characterization of a Salt Tolerant α-Amylase Producing Isolate NH-25

Halophiles are considered as important sources of extremozymes that are not only salt tolerant but can catalyze reactions efficiently under harsh conditions of various industrial processes. Among industrially important enzymes alpha amylase is used in many industries such as starch, pharmaceutical, detergent, paper, food, and textile. Due to wide applications there is a continuous need for novel sources of the enzyme to be discovered. One of the new variant from various amylase producing isolates of marine samples of Arabian Sea, an industrial dumping site and a rich natural source, particularly for microbes, a salt tolerant α-amylase producer was studied. This isolate based on cultural characteristics, biochemical tests and molecular characterization inferred from 16s rDNA sequencing identified as Bacillus subtilis NH-25

Role of Metal Ions, Surfactants and Solvents on Enzymatic Activity of Partial Purified Glucoamylase from Aspergillus niger ER05

The glucoamylase requirement of different industries should vary in their physiochemical and functional properties, so the investigation of new sources for the novel enzymes is the only solution. The current study describe the production of glucoamylase from Aspergillus niger ER05 in a submerged fermentation. The enzyme then partially purified and then effect of thirteen different metal ions (Cs+, K+, Na+, Ba2+, Ca2+ Co2+, Cu2+ , Hg2+, Mg2+, Mn2+, Ni2+, Zn2+ , Fe3+), surfactant as well as organic solvent on catalytic performance of glucoamylase was studied. A newly isolated Aspergillus niger ER05 is hyper producing strain of glucoamylase. Specific activity for the crude enzyme was found to be 6.87 KU/mg. The crude enzyme was partially purified via fractional ammonium sulphate precipitation. Ammonium sulphate saturation from 40-80% was found suitable to precipitate the enzyme. After dialyzing precipitates, the specific activities were found to be 66.33KU/mg with percent yield of 26.5. The inhibitory influence of all metal studies was interestingly found on glucoamylase activity. The strong inhibition was demonstrated in presence of Hg2+, Ni2+, Zn2+, Cu2+, Fe3+. Only Na+ ions were able to maintain the 101% relative activity at 1mM concentration. The SDS completely inhibits the enzyme activity and in presence of tween-80 and triton X-100 glucoamylase exhibited less than 45% relative activity. Furthermore, formaldehyde, isopropanol, ethanol, methanol, and DMSO stabilized the enzyme activity while chloroform inhibits enzyme activity by 48%