The Experts below are selected from a list of 669 Experts worldwide ranked by ideXlab platform
M Koohmaraie - One of the best experts on this subject based on the ideXlab platform.
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effect of chemical Dehairing on the prevalence of escherichia coli o157 h7 and the levels of aerobic bacteria and enterobacteriaceae on carcasses in a commercial beef processing plant
Journal of Food Protection, 2003Co-Authors: Xiangwu Nou, Mildred Riverabetancourt, Joseph M Bosilevac, T L Wheeler, S D Shackelford, Bucky L Gwartney, James O Reagan, M KoohmaraieAbstract:The objective of this experiment was to test the hypothesis that cleaning cattle hides by removing hair and extraneous matter before hide removal would result in improved microbiological quality of carcasses in commercial beef processing plants. To test this hypothesis, we examined the effect of chemical Dehairing of cattle hides on the prevalence of Escherichia coli O157:H7 and the levels of aerobic bacteria and Enterobacteriaceaeon carcasses. Samples from 240 control (conventionally processed) and 240 treated (chemically dehaired before hide removal) hides (immediately after stunning but before treatment) and preevisceration carcasses (immediately after hide removal) were obtained from four visits to a commercial beef processing plant. Total aerobic plate counts (APC) and Enterobacteriaceae counts (EBC) were not (P > 0.05) different between cattle designated for chemical Dehairing (8.1 and 5.9 log CFU/100 cm2 for APC and EBC, respectively) and cattle designated for conventional processing (8.0 and 5.7 l...
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effect of chemical Dehairing on the prevalence of escherichia coli o157 h7 and the levels of aerobic bacteria and enterobacteriaceae on carcasses in a commercial beef processing plant
Journal of Food Protection, 2003Co-Authors: Xiangwu Nou, Mildred Riverabetancourt, Joseph M Bosilevac, T L Wheeler, S D Shackelford, Bucky L Gwartney, James O Reagan, M KoohmaraieAbstract:The objective of this experiment was to test the hypothesis that cleaning cattle hides by removing hair and extraneous matter before hide removal would result in improved microbiological quality of carcasses in commercial beef processing plants. To test this hypothesis, we examined the effect of chemical Dehairing of cattle hides on the prevalence of Escherichia coli O157:H7 and the levels of aerobic bacteria and Enterobacteriaceae on carcasses. Samples from 240 control (conventionally processed) and 240 treated (chemically dehaired before hide removal) hides (immediately after stunning but before treatment) and preevisceration carcasses (immediately after hide removal) were obtained from four visits to a commercial beef processing plant. Total aerobic plate counts (APC) and Enterobacteriaceae counts (EBC) were not ( P . 0.05) different between cattle designated for chemical Dehairing (8.1 and 5.9 log CFU/100 cm 2 for APC and EBC, respectively) and cattle designated for conventional processing (8.0 and 5.7 log CFU/100 cm 2 for APC and EBC, respectively). However, E. coli O157:H7 hide prevalence was higher ( P , 0.05) for the control group than for the treated group (67% versus 88%). In contrast to hides, the bacterial levels were lower ( P , 0.05) on the treated (3.5 and 1.4 log CFU/100 cm 2 for APC and EBC) than the control (5.5 and 3.2 log CFU/100 cm 2 for APC and EBC) preevisceration carcasses. Prevalence of E. coli O157:H7 was lower ( P . 0.05) on treated than on control preevisceration carcasses (1% versus 50%). These data indicate that chemical Dehairing of cattle hides is an effective intervention to reduce the incidence of hide-to-carcass contamination with pathogens. The data also imply that any effective hide intervention process incorporated into beef processing procedures would signie cantly reduce carcass contamination by E. coli O157:H7.
C Shanthi - One of the best experts on this subject based on the ideXlab platform.
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enzymatic Dehairing a comprehensive review on the mechanistic aspects with emphasis on enzyme specificity
International Journal of Biological Macromolecules, 2018Co-Authors: Parthiban Sujitha, Sundararajan Shakilanishi, Sundar Kavitha, Narasimhan Kannan Chandra Babu, C ShanthiAbstract:Abstract Enzymatic Dehairing as a part of the efforts for greener leather processing has reached progressive advancement with the tradition-bound tanning industry being now more receptive to cleaner processing methods due to increasing pressure from environmental groups. The Dehairing mechanism is vaguely understood at present from the point of view of the enzyme specificity, which is needed for consistent and satisfactory hair removal without deleterious effect on the leather quality. Gaining insight into the Dehairing specificity would help in designing efficient Dehairing process. This paper attempts to review the literature pertaining to all the relevant and critical issues in detail to clearly delineate the right kind of substrate specificity required to attack only the potential targets for hair removal, and for making fine quality leather without adverse effect on other desired leather making components of the skin matrix. The gap in understanding of these critical issues is discussed with recommendation for further scientific studies in the area.
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specificity studies on proteases for Dehairing in leather processing using decorin as model conjugated protein
International Journal of Biological Macromolecules, 2017Co-Authors: Sundararajan Shakilanishi, C ShanthiAbstract:Enzyme based Dehairing of animal skins in leather processing is considered a greener alternative to conventional chemical based Dehairing process. The specificity based screening of proteases would be an important criterion as it would help in removing hairs by acting particularly on the proteoglycans holding the hair to the bulb without damaging the other proteins. The present paper describes a comparative study of the specificity of a Dehairing protease with non-Dehairing one isolated from Bacillus sps. Dehairing protease was found to be trypsin-like, non-collagenolytic and non-keratinolytic enzyme whereas non-Dehairing one was a metalloprotease with non-collagenolytic activity but specificity for soluble keratin. Substrate specificity was studied using decorin as model proteoglycan. The Dehairing enzyme was effective in digesting the core protein of the decorin as confirmed by high performance liquid chromatography analysis and SDS-polyacrylamide gel electrophoresis. The histochemical studies on dehaired skins also confirmed preservation of skin matrix with no visible damage to collagen. This study emphasizes the importance of screening proteases based on their specificity characteristics for effective and safer enzyme-only Dehairing process. The acquired knowledge can be employed in formulating bacterial growth media to produce Dehairing proteases that would help in commercial exploitation of this greener option.
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exploration of chrome shaving hydrolysate as substrate for production of Dehairing protease by bacillus cereus vitsn04 for use in cleaner leather production
Journal of Cleaner Production, 2017Co-Authors: Sundararajan Shakilanishi, Narasimhan Kannan Chandra Babu, C ShanthiAbstract:Abstract Chrome shavings (chromium complexed collagenous waste scrapings), one of the major proteinous solid wastes of leather industry are posing a pollution threat. Recovery and reuse of protein component of the waste can prevent their disposal as landfills. In the present work, the collagen hydrolysate derived from chrome shavings was screened as an inexpensive protein source in comparison with agro based protein wastes for the cost-effective production of Dehairing protease. The chrome shavings used in the study were obtained during processing of goat skins. Maximum enzyme production of 203 ± 0.07 U/mL by Bacillus cereus VITSN04 was observed with the formulated medium (pH 8.0) containing, 12 g/L of collagen hydrolysate from chrome shavings, 15 g/L of molasses, 3 g/L of K 2 HPO 4 , 2 g/L of NaCl and 0.04 g/L of CaCl 2 . Fluorescence spectral analysis confirmed that collagen hydrolysate stabilized the protease and prolonged its activity. The protease was purified with a yield of 88.1% using 22% (w/v) of 2-propanol and 14% (w/v) of K 2 HPO 4 aqueous two phase system. The purification and activity of the enzyme was confirmed by native-polyacrylamide gel electrophoresis. The purification yield of protease with aqueous two phase system was much higher than that with ultrafiltration system. Thus, approach made in the present study provides an attractive option for recycling chrome shavings waste as a cheaper protein source in the production of Dehairing enzyme for use in cleaner leather processing.
Xiangwu Nou - One of the best experts on this subject based on the ideXlab platform.
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effect of chemical Dehairing on the prevalence of escherichia coli o157 h7 and the levels of aerobic bacteria and enterobacteriaceae on carcasses in a commercial beef processing plant
Journal of Food Protection, 2003Co-Authors: Xiangwu Nou, Mildred Riverabetancourt, Joseph M Bosilevac, T L Wheeler, S D Shackelford, Bucky L Gwartney, James O Reagan, M KoohmaraieAbstract:The objective of this experiment was to test the hypothesis that cleaning cattle hides by removing hair and extraneous matter before hide removal would result in improved microbiological quality of carcasses in commercial beef processing plants. To test this hypothesis, we examined the effect of chemical Dehairing of cattle hides on the prevalence of Escherichia coli O157:H7 and the levels of aerobic bacteria and Enterobacteriaceaeon carcasses. Samples from 240 control (conventionally processed) and 240 treated (chemically dehaired before hide removal) hides (immediately after stunning but before treatment) and preevisceration carcasses (immediately after hide removal) were obtained from four visits to a commercial beef processing plant. Total aerobic plate counts (APC) and Enterobacteriaceae counts (EBC) were not (P > 0.05) different between cattle designated for chemical Dehairing (8.1 and 5.9 log CFU/100 cm2 for APC and EBC, respectively) and cattle designated for conventional processing (8.0 and 5.7 l...
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effect of chemical Dehairing on the prevalence of escherichia coli o157 h7 and the levels of aerobic bacteria and enterobacteriaceae on carcasses in a commercial beef processing plant
Journal of Food Protection, 2003Co-Authors: Xiangwu Nou, Mildred Riverabetancourt, Joseph M Bosilevac, T L Wheeler, S D Shackelford, Bucky L Gwartney, James O Reagan, M KoohmaraieAbstract:The objective of this experiment was to test the hypothesis that cleaning cattle hides by removing hair and extraneous matter before hide removal would result in improved microbiological quality of carcasses in commercial beef processing plants. To test this hypothesis, we examined the effect of chemical Dehairing of cattle hides on the prevalence of Escherichia coli O157:H7 and the levels of aerobic bacteria and Enterobacteriaceae on carcasses. Samples from 240 control (conventionally processed) and 240 treated (chemically dehaired before hide removal) hides (immediately after stunning but before treatment) and preevisceration carcasses (immediately after hide removal) were obtained from four visits to a commercial beef processing plant. Total aerobic plate counts (APC) and Enterobacteriaceae counts (EBC) were not ( P . 0.05) different between cattle designated for chemical Dehairing (8.1 and 5.9 log CFU/100 cm 2 for APC and EBC, respectively) and cattle designated for conventional processing (8.0 and 5.7 log CFU/100 cm 2 for APC and EBC, respectively). However, E. coli O157:H7 hide prevalence was higher ( P , 0.05) for the control group than for the treated group (67% versus 88%). In contrast to hides, the bacterial levels were lower ( P , 0.05) on the treated (3.5 and 1.4 log CFU/100 cm 2 for APC and EBC) than the control (5.5 and 3.2 log CFU/100 cm 2 for APC and EBC) preevisceration carcasses. Prevalence of E. coli O157:H7 was lower ( P . 0.05) on treated than on control preevisceration carcasses (1% versus 50%). These data indicate that chemical Dehairing of cattle hides is an effective intervention to reduce the incidence of hide-to-carcass contamination with pathogens. The data also imply that any effective hide intervention process incorporated into beef processing procedures would signie cantly reduce carcass contamination by E. coli O157:H7.
Rengarajulu Puvanakrishnan - One of the best experts on this subject based on the ideXlab platform.
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mechanism of enzymatic Dehairing of skins using a bacterial alkaline protease
Chemosphere, 2008Co-Authors: S Sivasubramanian, Murali B Manohar, Rengarajulu PuvanakrishnanAbstract:In the conventional Dehairing process of leather manufacture, animal skins are subjected to a drastic chemical treatment using lime and sodium sulfide. Sulfide reduces disulfide bonds in keratin present in hair and epidermis and thereby detaches them from skin. Lime, being an alkali, contributes to opening up of collagen fiber structure by cleaving a major portion of the glycosaminoglycans from proteoglycans, the interfibrillar elements of skin connective tissue. Currently, as an alternative to chemical Dehairing, enzyme based Dehairing processes using proteases avoiding the use of lime and sulfide are being developed because of their environmental benefits. Though both chemical as well as enzymatic Dehairing processes are aimed at removing noncollagenous proteins and proteoglycans in addition to fiber opening, the mechanism of enzymatic process is distinct from that of the chemical process. In this study, we attempt to study in detail the mechanism of hair saving enzymatic Dehairing process for skins using a bacterial protease against the customary hair burn chemical Dehairing process. Quantitative analysis shows that the collagen content remains unaffected in both treatments but there is a marked reduction of proteoglycan constituents from dehaired pelts in the enzymatic process when compared to lime-sulfide process. This is further substantiated by histochemical examination of the sections of dehaired pelts using different stains as well as immunohistochemical studies on the removal of decorin. HPLC profile shows that decorin is extensively degraded by the bacterial protease. This study conclusively demonstrates that proteolytic degradation of decorin and subsequent removal of proteoglycan aggregates play an important role in the opening up of the collagen fiber bundles during enzymatic Dehairing.
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ecofriendly lime and sulfide free enzymatic Dehairing of skins and hides using a bacterial alkaline protease
Chemosphere, 2008Co-Authors: S Sivasubramanian, Murali B Manohar, A Rajaram, Rengarajulu PuvanakrishnanAbstract:The ever-increasing attention to the environmental impact of leather industry has necessitated the development of enzyme-based processes as potent alternatives to pollution causing chemicals. In this study, a hair saving process is developed for Dehairing of skins and hides using a bacterial alkaline protease preparation, completely eliminating the use of lime and sulfide. To evaluate the efficacy of the enzymatic process, comparative studies have been carried out with two controls; a conventional lime-sulfide process and enzyme-assisted process using commercial Dehairing enzyme with reduced quantities of lime and sulfide. The developed process requires a shorter duration of 6h for complete Dehairing of skins and hides than control groups and also, it avoids the use of silicate carriers since the enzymatic Dehairing is carried out by dip method. Histological and scanning electron microscopic analyses of the dehaired pelts obtained from enzymatic process reveal complete removal of hair and epidermis with moderate opening up of fiber structure in both dermis and corium. Moreover, the collagen is not damaged and resulting in a leather of good quality. The developed process has resulted in a remarkable reduction of effluent load in terms of biochemical oxygen demand, chemical oxygen demand, total dissolved solids and total suspended solids. Physicochemical studies conclusively show that the leathers produced by enzymatic process are equivalent to or better than that obtained by control systems. Thus, the developed enzymatic process offers immense potential for greener mode of Dehairing of skins and hides in leather industry coupled with environmental excellence.
Naveen Gupta - One of the best experts on this subject based on the ideXlab platform.
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approach to ecofriendly leather characterization and application of an alkaline protease for chemical free Dehairing of skins and hides at pilot scale
Journal of Cleaner Production, 2014Co-Authors: Nancy George, Prakram Singh Chauhan, Neena Puri, Vivek Kumar, Naveen GuptaAbstract:Abstract The objective of this work was to purify and characterize alkaline protease from Vibrio metschnikovii NG 155 and to study its applicability as a Dehairing agent at pilot scale in leather industry. Relative molecular weight of the purified protease was found to be 45 kDa with optimum temperature and pH of 65 °C and 10 respectively. Stability of enzyme in wide range of pH (7–11) and temperature (10–50 °C) makes it suitable for industrial applications. The protease efficiently removed hair from goat skins and buffalo hides, completely eliminating the use of lime and sulphide within short process duration of 8 h. Efficacy of the developed process is supported by histology, scanning electron microscopic analysis and quantification of different skin components. In addition, better physicochemical properties of dyed crusts and lesser pollution load in Dehairing process, further affirms the potential of this enzyme for ecofriendly Dehairing of animal skins in leather industry.
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Lime and Sulphide-Free Dehairing of Animal Skin Using Collagenase-Free Alkaline Protease from Vibrio metschnikovii NG155
Indian Journal of Microbiology, 2014Co-Authors: Nancy George, Sonica Sondhi, Sanjeev Kumar Soni, Naveen GuptaAbstract:The objective of this work was to isolate a microorganism producing alkaline protease that can be used as an ecofriendly alternative to chemicals in Dehairing process of leather manufacture. Alkaline protease producing bacterium Vibrio metschnikovii NG155 was isolated from soil samples of leather industry. The protease was highly effective in Dehairing of goat skin, completely eliminating the use of lime and sulfide. Histological studies of the skin after Dehairing showed that the enzyme did not damage the collagen layer and brought good fiber opening. Absence of collagenase activity was confirmed by reacting pure collagen with the enzyme and analyzing it on SDS PAGE, which showed no degradation of collagen. The enzyme was stable in a wide range of pH (7-11) and temperature (10-50 °C), which makes it suitable for industrial application.
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statistical optimization of process parameters for production of alkaline protease from vibrio metschnikovii ng155 having application in leather industry
International journal of pharma and bio sciences, 2014Co-Authors: Nancy George, Prakram Singh Chauhan, Neena Puri, Naveen GuptaAbstract:Alkaline protease producing microorganism Vibrio metschnikovii NG155, isolated from the soil samples of leather industry, having potential application in Dehairing of animal skin was used in this study. To enhance the production of protease by this strain, various physical and nutritional factors were optimized using statistical methods like Plackett Burman and Response Surface Methodology. In accordance with the Plackett Burman design three nutritional variables soyabean meal, wheat gluten meal and cotton seed flour having a significant positive effect on protease production were selected and optimized by Response Surface Methodology. Production of protease was increased considerably (200 Uml -1 ) in the optimized medium containing 2.46 (%) wheat gluten meal, 2.45 (%) soyabean meal and 1.46 (%) cotton seed flour, leading to an overall 13 fold increase from the unoptimised medium.