Isolation and screening of lipase producers
Lipases, also known as Triacyl glycerol acylhydrolases (EC 18.104.22.168) are a class of enzymes which catalyse the hydrolysis of long chain triglycerides. They belong to the class of Serine hydrolases. Lipases catalyse the hydrolysis of the ester bonds at the interpahse of the insoluble substrate phase and the aqueos phase where the enzyme remains dissolved. Industrial lipases are esterase enzymes that act on fats and oils and hydrolyse them in steps into substituted glycerides and fatty acids and finally into glycerol and fatty acids.
Bacterial lipases are glycoproteins, but some extracellular bacterial lipases are lipoproteins.Bacterial lipases are generally more stable than animal or plantlipases.Among bacteria, Achromobacter sp., Alcaligenes sp., Arthrobacter sp., Pseudomonas sp., Staphylococcus sp., Chromobacterium sp, and Burkholderia sp have been known to produce industrially viable lipases.
Fungal lipases are being exploited due to their low cost of extraction, thermal and pH stability, substrate specificity, and activity in organic solvents. The chief producers of commercial lipases are Aspergillus niger, Candidacylindracea, Humicola lanuginosa, Mucor miehei, Rhizopus arrhizus, R. delemar, R. japonicus, R. niveus and R. oryzae
As lipases act on ester bonds, they have been used in fat splitting, interesterification (transesterification), development of different flavours in cheese, improving pallatability of beef fat for making dog food, etc. In addition to their natural function of hydrolyzingcarboxylic ester bonds, lipases can catalyse esterification,interesterification, and transesterification reactions in nonaqueousmedia. This versatility makes lipases the enzymes of choicefor potential applications in the food, detergent, pharmaceutical,leather, textile, cosmetic, and paper industries.