reported to have properties similar to that of gelatin derived from porcine [58]. Use
of enzymes to extract gelatin should be targeted in enzymatic tannery processing.
The proposed gelatin production method produces gelatin with very low colour and
high gel strength over a very wide range of viscosities. If further improvement in gel
strength is needed, transglutaminase may be used for cross-linking some smaller
molecules, thereby improving the gel strength. The high purity, enzyme-extracted
gelatin is produced with a dramatic reduction in gelatin production cycle due to
elimination of liming step. Further, the low-temperature enzyme method of producing gelatin results in reduction of unit production costs due to increased yield,
reduced chemical cost, reduced water usage, reduced utility cost and reduced
emission of greenhouse gases and climate change.
Gelatin is an attractive molecule to be used in cultivation of mammalian cells. Use
of bovine or porcine gelatin is nowadays restricted, and there seems to be great
potential for other sources of gelatin material including fish-skin-derived gelatin.
The gelatin produced should be evaluated with respect to this area of application.
Furthermore, the gelatin can be modified with cross-linking functional groups for the
preparation of chirally pure hydroxyalkanoic to be used as carriers of bioactive
agents in various forms (hydrogels, capsules, microspheres, films, etc.). Addition of
functional groups and blending with other biopolymers containing polysaccharides
and lipids will confer to the gelatin buffering capacity and hydrophobicity, thus
protecting the sensitive bioactive agents during gastric transit.
Tannery waste biomass is an abundant feedstock globally and has the potential to
be exploited as a rich source of fatty acids for use in the biosynthesis of wax esters and
lipid-based biopolymers. Wax esters are esters of long-chain aliphatic alcohols and
fatty acids and are used as high-performance lubricants for engines, transmission and
hydraulic systems. They are also used in cosmetics, foods and pharmaceuticals.
Currently, these compounds are produced at a scale of 3 million tons per year from
mineral oils. The last few years have seen a push towards the production of biodegradable lubricants from renewable sources. However, so far, the only natural sources
of wax esters are whale sperm oil and jojoba oil, which are too expensive for wide
range use. As an alternative, researchers have recently begun to explore lipid sources
for the synthesis of bio-WEs. Synthesis of jojoba oil-like wax esters such as palmityl
oleate, palmityl palmitoleate and oleyl oleate from oleate requires first the CoA
activation of a fatty acid catalysed by an acyl-CoA synthetase and in a second step
esterification with a fatty alcohol catalysed by a WE synthase (WS). Genes encoding
these two enzyme functions have only recently been identified [59]. Both WSs not
only catalyse esterification of fatty acids with long-chain alcohols but also esterification of diacylglycerol which results in the production of both triacylglycerols (TAGs)
and WEs. The ratio of produced WEs (the desired product) and TAGs depends on the
fatty acids used.
Despite several reports indicating more valuable products can be obtained from
such by-products, there is no information on an integrated approach of recovery oil,
omega-3 fatty acids, biodiesel, protein hydrolysate, amino acids, enzymes, gelatin,
biofertilizer, etc. at large scale from such by-products globally. Such an approach is
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W. C. Wanyonyi and F. J. Mulaa
of enzymes to extract gelatin should be targeted in enzymatic tannery processing.
The proposed gelatin production method produces gelatin with very low colour and
high gel strength over a very wide range of viscosities. If further improvement in gel
strength is needed, transglutaminase may be used for cross-linking some smaller
molecules, thereby improving the gel strength. The high purity, enzyme-extracted
gelatin is produced with a dramatic reduction in gelatin production cycle due to
elimination of liming step. Further, the low-temperature enzyme method of producing gelatin results in reduction of unit production costs due to increased yield,
reduced chemical cost, reduced water usage, reduced utility cost and reduced
emission of greenhouse gases and climate change.
Gelatin is an attractive molecule to be used in cultivation of mammalian cells. Use
of bovine or porcine gelatin is nowadays restricted, and there seems to be great
potential for other sources of gelatin material including fish-skin-derived gelatin.
The gelatin produced should be evaluated with respect to this area of application.
Furthermore, the gelatin can be modified with cross-linking functional groups for the
preparation of chirally pure hydroxyalkanoic to be used as carriers of bioactive
agents in various forms (hydrogels, capsules, microspheres, films, etc.). Addition of
functional groups and blending with other biopolymers containing polysaccharides
and lipids will confer to the gelatin buffering capacity and hydrophobicity, thus
protecting the sensitive bioactive agents during gastric transit.
Tannery waste biomass is an abundant feedstock globally and has the potential to
be exploited as a rich source of fatty acids for use in the biosynthesis of wax esters and
lipid-based biopolymers. Wax esters are esters of long-chain aliphatic alcohols and
fatty acids and are used as high-performance lubricants for engines, transmission and
hydraulic systems. They are also used in cosmetics, foods and pharmaceuticals.
Currently, these compounds are produced at a scale of 3 million tons per year from
mineral oils. The last few years have seen a push towards the production of biodegradable lubricants from renewable sources. However, so far, the only natural sources
of wax esters are whale sperm oil and jojoba oil, which are too expensive for wide
range use. As an alternative, researchers have recently begun to explore lipid sources
for the synthesis of bio-WEs. Synthesis of jojoba oil-like wax esters such as palmityl
oleate, palmityl palmitoleate and oleyl oleate from oleate requires first the CoA
activation of a fatty acid catalysed by an acyl-CoA synthetase and in a second step
esterification with a fatty alcohol catalysed by a WE synthase (WS). Genes encoding
these two enzyme functions have only recently been identified [59]. Both WSs not
only catalyse esterification of fatty acids with long-chain alcohols but also esterification of diacylglycerol which results in the production of both triacylglycerols (TAGs)
and WEs. The ratio of produced WEs (the desired product) and TAGs depends on the
fatty acids used.
Despite several reports indicating more valuable products can be obtained from
such by-products, there is no information on an integrated approach of recovery oil,
omega-3 fatty acids, biodiesel, protein hydrolysate, amino acids, enzymes, gelatin,
biofertilizer, etc. at large scale from such by-products globally. Such an approach is
216
W. C. Wanyonyi and F. J. Mulaa