interfaces, changes in solvent-exposed surface areas, increase in the extent of
secondary structure formation and truncated amino and carboxyl termini [37].
6 Application of Protease in Cleaner Leather Processing
Pre-tanning operations in conventional leather processing generate significantly
high pollution problems as compared to the post-tanning operation. Responsible
chemicals for pollution in the pre-tanning processes include lime, detergents, sodium
sulphide, caustic soda, sodium chloride, inorganic salt, acids and degreasing solvents. In addition, pre-tanning operations consume large amounts of energy and
huge quantities of water. The sludge generated from flashings, fat waste and digested
hair results in further environmental pollution. In addition, tanneries incur high costs
in treatment of the waste as well in purchasing the same chemicals. Significant
efforts have been made in the past decades to render pre-tanning operations in
tanneries cleaner. The best strategy in reducing or eliminating pollution problems
in leather industry is by targeting and replacing toxic polluting chemicals by
eco-friendly chemicals and recycling some of the waste such as water.
7 Enzymatic Leather Processing
The following section summarizes the major operations performed in beam house,
tanyard, post-tanning and finishing areas in leather production. All the progressive
steps in the ongoing processing of hides and skins involve application of enzyme
either directly or indirectly to facilitate the processing and production of desired
quality. Enzymes are mainly applied in soaking, dehairing, bating, degreasing and
waste treatment in effort to avert negative effect associated with use of chemicals.
7.1 Hide and Skin Sorting, Trimming and Storage
7.1.1 Sorting and Trimming
Hides and skins of good quality are sorted into different grades, types and weight.
This procedure may be performed at the tannery or slaughterhouse. Unsuitable
materials may be sold to other tanners or if in extremely poor conditions, discarded
as waste. Selected hides/skins are then trimmed to remove spoiled parts such as
edges, legs, tails, face, udders, etc. from the raw skin. This stage generates huge
putrescible wastes, which require to be discarded following the set regulation on
animal by-products/waste disposal. Proteolytic and lipolytic enzymes can be applied
Alkaliphilic Enzymes and Their Application in Novel Leather Processing. . .
205
secondary structure formation and truncated amino and carboxyl termini [37].
6 Application of Protease in Cleaner Leather Processing
Pre-tanning operations in conventional leather processing generate significantly
high pollution problems as compared to the post-tanning operation. Responsible
chemicals for pollution in the pre-tanning processes include lime, detergents, sodium
sulphide, caustic soda, sodium chloride, inorganic salt, acids and degreasing solvents. In addition, pre-tanning operations consume large amounts of energy and
huge quantities of water. The sludge generated from flashings, fat waste and digested
hair results in further environmental pollution. In addition, tanneries incur high costs
in treatment of the waste as well in purchasing the same chemicals. Significant
efforts have been made in the past decades to render pre-tanning operations in
tanneries cleaner. The best strategy in reducing or eliminating pollution problems
in leather industry is by targeting and replacing toxic polluting chemicals by
eco-friendly chemicals and recycling some of the waste such as water.
7 Enzymatic Leather Processing
The following section summarizes the major operations performed in beam house,
tanyard, post-tanning and finishing areas in leather production. All the progressive
steps in the ongoing processing of hides and skins involve application of enzyme
either directly or indirectly to facilitate the processing and production of desired
quality. Enzymes are mainly applied in soaking, dehairing, bating, degreasing and
waste treatment in effort to avert negative effect associated with use of chemicals.
7.1 Hide and Skin Sorting, Trimming and Storage
7.1.1 Sorting and Trimming
Hides and skins of good quality are sorted into different grades, types and weight.
This procedure may be performed at the tannery or slaughterhouse. Unsuitable
materials may be sold to other tanners or if in extremely poor conditions, discarded
as waste. Selected hides/skins are then trimmed to remove spoiled parts such as
edges, legs, tails, face, udders, etc. from the raw skin. This stage generates huge
putrescible wastes, which require to be discarded following the set regulation on
animal by-products/waste disposal. Proteolytic and lipolytic enzymes can be applied
Alkaliphilic Enzymes and Their Application in Novel Leather Processing. . .
205