Marine enzyme biotechnology can offer novel biocatalysts with properties like high salt tolerance, hyperthermostability, barophilicity, cold adaptivity and ease in large scale cultivation. Exotic locations have been accessed for the search of novel enzymes. Scientists have isolated proteases and carbohydrases from deep sea hydrothermal vents. Cold active metabolic enzymes from psychrophilic marine microorganisms have received considerable research attention. Marine symbiont microorganisms growing in association with animals and plants were shown to produce enzymes of commercial interest. Microorganisms isolated from sediment and sea water have been the most widely studied; proteases, carbohydrases and peroxidases being noteworthy.

We purified and characterized a single salt, solvent, detergent and bleach tolerant alkaline serine protease produced by a truly marine bacterium. The isolate was classified as a new bacterium belonging to the gamma- Proteobacteria family. The enzyme is active over a broad range of pH (6.0–11.0), the optimum being at 9.0. This protease enzyme shows activity from 30 to 70 degree C. This enzyme exhibits appreciable activity in presence of up to 30% NaCl and is highly stable even after 18 h pre-incubation with 35% (w/v) NaCl. The enzyme is completely stable in presence of detergents, oxidizing agents, reducing agents and bleaches. Water miscible and immiscible organic solvents like ethylene glycol, ethanol, butanol, acetone, DMSO, xylene and perchloroethylene enhance as well as stabilize the enzyme activity. Our enzyme is capable of almost complete removal of recalcitrant blood and egg stains in both wet and dry wash operations.

High Performance Liquid Chromatography Separation and detection

High Performance Liquid Chromatography Separation and detection

A Bacillus sp. which can tolerate 10% (w/v) NaCl, produces esterase optimally in Marine Broth 2216 medium containing 1% (w/v) NaCl. The serine type esterolytic enzyme has a molecular weight of 35.0 kDa and is denatured into polypeptides of molecular weights 20 kDa and 15 kDa. The esterase was most active at pH 8.0, the pH of the seawater at the site of collection and is stable in the pH range 6.0–9.0.

The optimum temperature of activity of this esterase is 45 degree C and the enzyme is very stable at 50 degree C. Our esterase shows about 100% activity when incubated with 1 M NaCl. When incubated for a period of 10 days in the presence of 30–70% dimethylsufoxide (DMSO), the specific activity increased by approximately two–threefold compared to the enzyme in aqueous buffer throughout the period of study. High specific activity was maintained by our enzyme when incubated with 50% DMSO for 10 days. Extreme stability in DMSO could make this enzyme a potential immobilized biocatalyst for application in non-aqueous based continuous bioprocesses.

The first ribonuclease from the Cytophaga-Flavobacterium-Bacteroides phylum, dominant in the marine environment, and also from the first Bizionia species isolated from the tropics was purified and characterized. Extracellular ribonuclease production occurred when the culture medium contained 5% – 7% (w/v) NaCl. The pH and temperature optima are 6.5 and 35 degree C respectively and the enzyme retains more than half of its activity (relative to optimal assay conditions) after one hour pre-incubation separately with 5% (w/v) NaCl or from pH 5.0 to 8.5 or at 50 degree C. This ribonuclease degrades uracil containing nucleic acids only. Our isolate could be a novel renewable source of DNase free RNase enzyme.