Enzymes, Industrial (overview)

B.C. Saha , ... R.J. Bothast , in Encyclopedia of Microbiology (Third Edition), 2009

Enzymes in the Leather Industry

Animal pare is composed of lx–65% h2o, 30–32% protein, approximately x% fat, and 0.5–1% minerals. Skins are soaked initially to clean them and to allow rehydration. Proteolytic enzymes effectively facilitate the soaking process. In improver, lipases have also been used to deliquesce and remove fat. Dehairing is and so carried out using element of group i protease, such equally subtilisin, in an alkaline bath. Alkaline weather neat the hair roots, easing removal of the hair past allowing proteases to selectively assail the protein in the hair follicle. Conventional dehairing processes require harsh chemicals such equally slaked lime and sodium sulfide which substantially slap-up the hide and loosen and impairment the hair. Enzyme-based dehairing has led to much lower pollution emissions from tanneries.

Tanning wastes, consisting primarily of the so-chosen glue stock, cannot be discarded at waste product dump sites and must be completely processed. All proteins are solubilized at a loftier alkaline pH with bacterial proteases in society to partition the fat from the hydrolyzate. Subsequently concentration, the protein is dried and used as a nutritional supplement in animal feed.

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Animal Attributes Exploited by Humans (Nonfood Uses of Animals)

Colin G. Scanes , in Animals and Man Society, 2018

ii.2.one Introduction

Fauna skins take long been valued particularly as raw materials for vesture (leather and wool), gloves (leather), shoes (leather), furniture (leather), blankets (wool), and other uses.

Leather in Protective Clothing

Leather is used as protective clothing for motorcyclists (bikers), such every bit protective jackets, gloves, pants, and boots. Leather was integral to armor for soldiers in the medieval period.

Tabular array 2.2 summarizes the global production of hides and skin. Hides represent half dozen% of body weight in cattle and pigs simply 9% for sheep (Jayathilakan et al., 2012). Hides or skins are made upwardly of iii layers:

Table 2.ii. Global Production of Beast Cobweb-Based Products in 2013

Production Product (million metric tons)
Sheep skins 9.19
Cattle hides viii.12
Wool, greasy two.13
Goat skins 1.26
Buffalo hides 0.96
Horse pilus 0.14

Data from FAOStats (Un Food and Agriculture Organization Statistics), 2015. Production/Livestock Main. Available from: http://faostat3.fao.org/scan/Q/*/E.

•

Epidermis: i% of the skin with hair formed predominantly of the protein, keratin. The major production is wool or hair or feathers and related products.

•

Dermis: 85% of the pare composed largely of the protein, collagen. The major product is leather after tanning.

•

Subcutaneous layer (or mankind): 14% of the pare, which is removed during leather- or fur-making.

According the Economic Research Service of the U.s.a. Department of Agronomics (USDA), "The drop value reflects the wholesale price that packers receive from the animal's byproducts that 'drop' off an creature'due south carcass when information technology is dressed, on a dollar per hundredweight ground" (ARS, 2017) and "Hides account for 30–75% of the byproduct drop value for cattle just very little of the driblet value for hogs" (Marti et al., 2011).

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By-PRODUCTS | Hides and Skins

H.W. Ockerman , 50. Basu , in Encyclopedia of Meat Sciences (Second Edition), 2014

Introduction

Humans have utilized animal skins throughout recorded history, and nomadic people still utilize them for shelter, vesture, weapons, and food containers. In spite of competition from synthetic materials, many quality items still demand the wearing ability, wet–vapor transfer, and insulating backdrop of leather.

Fauna hide is a very significant proportion (4–12%) of the live weight of an animal (Table 1) and is 1 of the nearly valuable by-products that can be converted into a variety of items. A few examples are shown in Table 2. Other uses of animal skin include food, cosmetics, and medical prosthetics.

Table i. Hide yield weights and yields every bit a percentage of animals' live weights

Type of animate being Range of hibernate yield (lbs) Pct of alive weight (%)
Cattle v.1–five.8 Average 7.0
Average using hide stripper 4.0–6.0 Average decrease of 2% or v%
Herford 8.5
Angus vii.5
Shorthorn 6.5
Charolais, bull, xv months onetime viii.5
Charolais, bull, xx months erstwhile eight.3
Charolais, bull, 30 months one-time six.vii
Proficient stear 6.6–7.6
Poor stear half-dozen.4–7.viii
Good heifer five.1–vii.ix
Branded cow 6.6–vii.7
Canner, cutter 5.7–6.8
Bull half dozen.7–7.five
Bologna balderdash 7.0–eight.1
Sheep
Sheep and lamb (wool+pare) 11.0–11.vii
Swine
Pig, vertical drum skinner 3.0–eight.0
Boar 10.0–12.0

Source: Reproduced from Bengtsson, O., Holmqvist, O., 1984. By-products from slaughtering. Fleischwirtschaft 64 (3), 334–336; Judge, M.D., Salm, C.P., Okos, R.M., 1978. Hog Skinning Versus Scalding. Arlington, VA: AMI Foundation, pp. 155–164; Lawrie, R., 1981. Development in Meat Science – 2. London: Practical Scientific discipline Publishers; Minnoch, J.K., Minnoch, R.M., 1979. Hides and Skins. Ithaca, NY: National Hide Clan; Romans, J.R., Ziegler, P.T., 1974. The Meat We Consume. Danville, IL: Interstate; and Ockerman, H.W., Hansen, C.50., 2000. Animal By-Product Processing and Utilization. Lancaster, PA: Technomic Publishing Co.

Table 2. Examples of some cured and tanned uses of hides, skins, or pelts and their past-products

Portion of hide, peel, or pelt Examples of finished products
Cattle hide by-products
Cured and tanned hides Sole, upper, linings and heels for leather shoes, rawhide, bags, athletic equipment, belting, upholstery, harness, saddles, etc.
Corium layer Picking bands, textile shuttle holders and passers, reconstituted collagen sausage, casings, cosmetics products, and collagen products
Tail hair Paint brushes and upholstery padding (no longer used much)
Body hair Felting, plaster retardant, etc.
Within of ear hair Imitation camel hair brushes
Hibernate trimmings Tankage, fertilizer, glue, and inedible gelatin
Hide fatty Tallow
Calf skin Low-cal-weight leather, fabric trimmings, drumheads, gloves, etc.
Hog peel by-products
Pig skin Gloves, belts, razor straps, shoe uppers, inner-soles, upholstery, shoe counters, sausage, pork rinds, edible gelatin, gum, etc.
Trimmings Dog chews
Pilus Upholstery padding (not used much anymore), felting, and plaster retardant
Bristles Brushes
Sheep pelt, by-products
Wool Blankets, gloves, vesture, carpets, upholstery fabric, lanolin, etc.
Slats (skin after wool or fleece is removed) Shoe and slipper uppers and lining, hat sweat bands, fancy shoes, gloves, garments, sporting goods, chamois, book bindings, diplomas, etc.
Hair sheep Small pneumatics, diaphragms, and bellows
Pelts (wool or fleece left on) and trimmings Heavy coat textile, moutons, shearlings, glue, and tankage
Horse hide by-products
Cured and tanned hides Shoe sole and uppers, gloves, sporting goods, luggage, belts, harness, saddles, etc.
Domesticated country and water buffalo hide by-products
Cured and tanned hides Shoe sole and uppers, fancy leather appurtenances, luggage, handbags, and buffing wheels
Goat and kid
Cured and tanned hides Shoe uppers and linings, gloves, fancy leather, handbags, and book bindings
Deer and elk hide by-products
Cured and tanned hides Shoe uppers, clothing, gloves, moccasins, and mukluks
Kangaroo hibernate by-products
Cured and tanned hides Shoe uppers, diaphragms, and bellows
Exotic and fancy leathers
Aquatic group Frog, seal, shark, walrus, and turtle leather
Land grouping Camel, elephant, ostrich, emu, rabbit, and pangolin leather
Reptile group Alligator, crocodile, lizard, and snake leather

Source: Adjusted from Clemen, R.A., 1927. Past-products in the Packing Manufacture. Chicago, IL: Academy of Chicago Press; Ockerman, H.W., 1996. Chemistry of Meat Tissue. Columbus, OH: Section of Animal Scientific discipline; Tanners' Council of America, 1983. Dictionary of Leather Terminology. Washington, DC: Tanners Council of America; Leather Industries of America Enquiry Laboratories, 1991. Lexicon of Leather Terminology. Cincinnati, OH: University of Cincinnati; and Ockerman, H.W., Hansen, C.Fifty., 2000. Animal By-Product Processing and Utilization. Lancaster, PA: Technomic Publishing Co.

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Relationships between Diet and Diseases1

In Horse Feeding and Nutrition (2d Edition), 1991

3. DISEASE Defense

Mucous membranes and the animal'southward skin are a get-go line of defense. Many nutrients are of import in keeping epithelial tissue in a healthy condition. Poly peptide, sure B-complex vitamins, and other nutrients are essential for the product of antibodies and phagocytes which serve as secondary defenders confronting infectious agents entering the animal'south torso. Adequate nutrition also enables an animal to reply properly to vaccination.

Sure diseases increase the demand for various nutrients by animals. This tin can be due to: a reduced appetite, which causes an inadequate feed and consequent nutrient intake; fever; an infection which causes diarrhea or vomiting and thus a loss of nutrients from the intestinal tract; decreased absorption or utilization of nutrients; or other causes. A deficiency of nutrients can cause abnormality of the epithelial tissue and consistent penetration past various organisms. Boosted food supplementation may prevent this.

Diseases may destroy tissues, red blood cells, vital organs, and other parts of the body system. This increases the need for nutrients required for the repair and restoration of damaged cells. Therefore, extra food supplementation may exist helpful to the horse that is sick and in poor condition, provided that irreparable damage has non occurred in some vital surface area of the body organization.

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Production and Utilization of Natural Phospholipids

Willem van Nieuwenhuyzen , in Polar Lipids, 2015

Leather

The production of leather from beast skins involves a series of processes, from the slating of fresh skins to tanning and fatting. The tanning is performed with various vegetable, constructed, and mineral tanning agents. After the tanning, the pare has to be greased to produce supple leather suitable for manufacturing goods. Fat liquors consist of sulfonated and sulphated oils with polar groups in the triglycerides. Natural lecithins can be added to the fatty blend as raw material sources for the sulfonation and sulphating processes. The hydroxylated lecithins are also used because these products fulfill the requirements for a skillful fatting agent: (1) deep penetration into the skin, (2) fixation in the leather, (three) expert lightfastness (resistance), and (iv) low residual fat content in the used liquor. In particular, the very hydrophilic combined hydrolyzed and hydroxylated lecithins give deep penetration and practiced fixation, resulting in leathers with firm grain, good tear, and tensile forcefulness.

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Collagen Derived Materials

P.B. van Wachem , Chiliad.J.A. van Luyn , in Encyclopedia of Materials: Science and Engineering science, 2001

ii Reconstituted Collagens

Collagen, usually originating from fauna skins or tendons, can be solubilized with acids. In this form, together with the denatured form, gelatin, it has widespread use in tissue culture. The full general advantages of reconstituted collagen are that information technology can be prepared in a highly purified form and can be molded to whatever shape or prepared as gels, filaments, membranes, tubes, tapes, powders, or sponges. It does, however, suffer from low physical strength and more rapid biodegradation. I example of such a collagen device is an umbrella-shaped sealant used in arterial puncture holes remaining after coronary angiography and angioplasty.

The longest and well-nigh widely employed reconstituted product in the clinic is the noncross-linked sponge used as a hemostatic amanuensis. Collagen and gelatin are also used as sealants with large bore vascular prostheses. Combinations of collagen with growth factors and heparin to promote endothelialization of the grafts whilst preserving blood compatibility are under investigation. Reconstituted collagens have been used as soft tissue replacement materials in urinary tract surgery and as a matrix for nerve regeneration. Bovine and autologous collagen are the most common substances used in nonsurgical soft tissue augmentation, e.g., every bit a filler in cosmetic imperfections.

Both collagen and gelatin are used in controlled drug delivery systems, for case, with the controlled release of substances to forbid biomaterial-related infections. In improver, collagen in combination with other extracellular matrix components such as glycosaminoglycans has been used to decrease inflammatory reactions in tissues. Reconstituted collagen sponges have found employ in certain tissue engineering science applications. For example, one collagen sponge product is seeded with human foreskin keratinocytes or fibroblasts.

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Muscle proteins

Y.Fifty. Xiong , in Proteins in Food Processing (Second Edition), 2018

five.5.2 Collagen poly peptide

Collagen tin be obtained from animal skins, hides, bone extracts, offal meats, and skeletal muscle. Native collagen tissue from animal carcasses is of little usefulness in nutrient. Withal, past means of denaturation followed by fractional hydrolysis, collagen tin exist converted into a highly functional protein ingredient known every bit gelatin. Gelatin derived from young collagen, such equally the peel of the squealer, chicken, and some fish, is termed "Type A gelatin" and is suitable for a broad range of food applications. A mild acid treatment is generally sufficient to excerpt gelatin from the collagen textile. In contrast, gelatin extracted from mature (highly cantankerous-linked) collagen sources, such as cattle hides, bones, and cartilage, is called "Type B gelatin," and it is of limited use in food but more in nonfood applications. This blazon of gelatin requires more vigorous treatments for solubility, for example, pretreated in an brine-lime solution for a few days. Blazon A gelatin has a high isoelectric point (pH   6–9) and thus carries a net positive accuse in about food uses, whereas Type B gelatin has an isoelectric indicate close to pH   5.0 and thus carries a net negative or positive charge depending on the acerbity of the food (Stainsby, 1987). Chemically, peel contains a mixture of types I and Three collagen, while os and cartilage have a preponderance in types I and Three collagen, respectively (Weiss, 1984).

The relative independence of pH (four–9) for gelation makes gelatin particularly useful for a broad range of applications. Yet, the single largest food application of gelatin is cold desserts because of the unique cold-prepare gelling and melt-in-rima oris property of the poly peptide. A typical gelation process will involve heating the gelatin solution to laissez passer its denaturation bespeak so cooling rapidly to permit renaturation and interaction of gelatin molecules to form a protein gel matrix. Because hydrogen bonding is the predominant force that stabilizes the gel and no interpeptide covalent linkages are present, the gelatin gel is thermoreversible and readily melts at torso temperature. Rapid gel setting is essential to immobilization and an fifty-fifty distribution of fruit bits and other particles in the gel matrix. Gelatin is also used in frozen dairy products, such as frozen desserts, to inhibit ice crystal growth and recrystallization (graininess) every bit well as lactose recrystallization (sandiness) during frozen storage (Jones, 1977). In confectionery, gelatin is used in soft candies, such as Gummy Bears, to stabilize sucrose, corn syrup, and other ingredients through its gelling belongings.

In meat products, collagen is used to make edible casing and equally an ingredient in sausage products to increase the product poly peptide content. For skeletal muscle collagen, it is full-bodied by mechanical desinewing or past fractional defatting through a low-temperature rendering procedure. Collagen added to emulsified meats, such as turkey and beef frankfurters, improves the raw meat emulsion stability. However, on cooking, significant product shrinkage due to loss of water and collapse of emulsified fat droplets can occur, resulting in an increased meat toughness (Gillett, 1987). This is because collagen denaturation and ensuing abrupt shrinkage occur at around the final cooking temperature (65–75°C) (Davey and Gilbert, 1974), which disrupts the fat globule membrane (where collagen serves every bit a constituent) every bit well as the gel matrix made of myosin and suspended collagen fibrils.

To ameliorate the functional functioning of collagen in muscle foods, native collagen has been treated to increment its solubility and to eliminate cooking-induced shrinkage. Oestrus-predenatured collagen, when added at a level of no more than x% of the product weight, was found to improve bind forcefulness and juiciness in restructured low-fat, low-common salt beef (Kenney et al., 1992). Recent industrial developments include low-temperature processing to make gelatin-rich protein. Extracted rough collagen from pork trimmings and poultry (chicken and turkey) skins can course a business firm, rubberband common cold-set gel when formulated into emulsified muscle foods. The gel serves as a matrix for fat entrapment and h2o immobilization also as for adhesion of meat particles, and is used in frankfurters, bologna, craven nuggets, and boneless hams (Prabhu, 2003). With careful control of time and temperature of moist heating and express enzyme hydrolysis, it is now possible to make gelatin that remains liquid at room temperature, which can exist pumped into restructured meat to bind water and to class a cohesive gel when chilled to the fridge temperature.

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Biochemistry of Glycoconjugate Glycans; Carbohydrate-Mediated Interactions

K. Takagaki , I. Kakizaki , in Comprehensive Glycoscience, 2007

three.10.3.2.2.2.ii Hyaluronidase from parasites

The genus Ancylostoma, which includes common parasites of animal skin, besides possess hyaluronan-degrading activeness. 159 The optimal pH of hyaluronidase from the Ancylostoma caninum developed worm is 6 and the enzyme is agile at neutral pH. By contrast, the optimal pH of hyaluronidase from A. simplex larvae is iv and the enzyme is inactive at neutral pH. Both these hyaluronidases likewise depolymerize chondroitin 4-sulfate. 160 Hyaluronidase from A. braziliense hookworm larvae has action over a broad pH optimum between 6.0 and viii.0 and does not hydrolyze chondroitin sulfate. Therefore, the enzymatic backdrop and substrate specificities of these enzymes vary depending upon the species. 161 Information technology is anticipated that these enzymes from parasites more closely resemble leech hyaluronidase than testicular hyaluronidase. Further studies are required to verify this hypothesis.

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MOTHS AND BUTTERFLIES (Lepidoptera)

GARY R. MULLEN , in Medical and Veterinary Entomology, 2002

WOUND-FEEDING AND SKIN-PIERCING MOTHS

The merely lepidopterans known to exist capable of piercing animal peel are members of the noctuid genus Calyptra in Southeast Asia. Like many geometrids and other zoophilous moths, they tend to be attracted to wounds, open sores, cuts, scratches, scabs, and other pare lesions (Figs. eighteen.20, 18.21). However, while these other moths imbibe only exposed wound fluids, Calyptra spp. are capable of piercing the underlying tissue to draw fresh blood. Only the males are hematophagous. Females are believed to feed almost exclusively on fruits and are able to pierce the outer layers of ripening fruit to achieve the sugar-rich juices within. Other moths closely related to Calyptra are fruit piercers, suggesting that blood-feeding is a relatively recent development in this group, derived from such fruit-piercing beliefs.

FIGURE 18.21. 2 wound-feeding moths, Hypochrosis pyrrhophaeata and Zythos sp. (Geometridae), feeding at site of host injury.

 (Photo past Hans Bänziger.)

Figure eighteen.22. Hypochrosis hyadaria (Geometridae) feeding at open wound of zebu.

 (Photograph by Hans Bänziger.)

A number of Calyptra species take been observed piercing mammalian skin under natural weather condition. Five Calyptra species are known to feed on humans: Calyptra bicolor, C. fasciata, C. ophideroides, C. parva (Fig. 18.23), and C. pseudobicolor. Calyptra species as well have been observed piercing the skin of elephants, h2o buffalo, zebu, Malayan tapir, rhinoceros, deer, antelope, mules, and pigs. The feeding times typically range from 3 to 15 min. The reaction to the proboscis penetrating the pare varies from being barely felt to causing locally intense pain accompanied by a burning sensation. The latter has been attributed to saliva which is introduced as the moth feeds, whereas the amount of pain is believed to depend on the number of hurting receptors which are hit by the piercing stylets. Other associated reactions include localized swelling which may persist for several hours, slight numbness or itching, pressure sensitivity at the bite site, and mild induration the following day.

Figure 18.23. Peel-piercing moth, Calyptra parva (Noctuidae), feeding on human.

 (Photo past Hans Bänziger.)

For further details on the biology and beliefs of lachryphagous, wound-feeding and peel-piercing moths, run across the references past Bänziger.

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Moths and Butterflies (Lepidoptera)

Gary R. Mullen , Jennifer One thousand. Zaspel , in Medical and Veterinarian Entomology (Tertiary Edition), 2019

Wound-Feeding and Skin-Piercing Moths

The only lepidopterans known to exist capable of piercing beast skin are members of the erebid genus Calyptra in Southeast Asia. Like many geometrids and other zoophilous moths, they tend to be attracted to wounds, open up sores, cuts, scratches, scabs, and other pare lesions (Fig. 21.22). However, while these other moths imbibe just exposed wound fluids, Calyptra spp. are capable of piercing the underlying tissue to feed on claret (Fig. 21.23). Just males are hematophagous. Both males and females are believed to feed nearly exclusively on fruits and are able to pierce the outer layers of ripening fruit to reach the sugar-rich juices within. Other moths closely related to Calyptra are fruit piercers, suggesting that blood feeding is a relatively recent development in this group, derived from fruit-piercing behavior (Zaspel et al., 2012).

Effigy 21.22. Two wound-feeding moths, Hypochrosis pyrrhophaeata and Zythos sp. (Geometridae), feeding at site of host injury.

 Photograph past H. Bänziger.

Figure 21.23. A peel-piercing moth, Calyptra thalictri (Erebidae), feeding on human claret at the base of the fingernail on pollex, Vladivoskok, Russian federation.

 Photograph by Jennifer K. Zaspel.

A number of Calyptra spp. has been observed piercing mammalian skin nether natural atmospheric condition. Five Calyptra spp. are known to feed on humans: C. bicolor, C. fasciata, C. ophideroides, C. parva, and C. pseudobicolor. Calyptra spp. as well have been observed piercing the skin of elephants, water buffalo, zebu, Malayan tapir, rhinoceros, deer, antelope, mules, and pigs. Not surprisingly, they are often referred to as "vampire moths." At least iii additional species take been observed piercing human skin and feeding on blood under experimental weather: C. eustrigata, C. fletcheri, and C. thalictri (Figs. 21.23 and 21.24). The feeding times typically range from iii to fifteen   min. The reaction to the proboscis penetrating the pare varies from existence barely felt to causing locally intense hurting accompanied by a burning sensation. The latter has been attributed to saliva that is introduced as the moth feeds, whereas the amount of pain is believed to depend on the number of pain receptors that are encountered by the piercing stylets. Other associated reactions include localized swelling that may persist for several hours, slight numbness or itching, pressure sensitivity at the seize with teeth site, and mild induration the following day.

Effigy 21.24. Distal tip of the proboscis of Calyptra thalictri (Erebidae); lateral view. Annotation the erectile barbs and tearing hooks that are adjusted for piercing fruit and brute tissues; confocal microscope image.

 Photograph by Matthew S. Lehnert.

For further details on the biology and behavior of center-frequenting and wound-feeding moths, encounter references by Bänziger and Zaspel.

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