June 2017 Abstracts

A Reexamination of the Aging of Organ Leather

by Kevin Carr, Gabriel J. Ratcliff, Brian P. Grady and Jeremy D. Wance

Based on two papers that appeared almost 30 years ago, chrome tanning became more commonly used to tan leathers used for pipe organs because accelerated aging tests indicated that chrome tanning was more effective at retaining tensile strength. Anecdotal evidence over the last 30 years has indicated that the chrome tanned leathers have not lasted as long as hoped. Further, the atmosphere used in the accelerated testing used sulfur dioxide; and with the improvements in air quality in many parts of the world and the removal of many coal-burning ovens in American churches and their buildings, the reason for using sulfur dioxide enriched air is less justified. The work described in this paper reproduced the results of the tests done ~30 years ago, but we have also shown that using an atmosphere that is not enriched with sulfur dioxide yields very different results, namely that vegetable tanning performs superior to chrome tanning in terms of tensile strength retention.

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An Investigation on Chicken Leg Skin for the Preparation of Fashionable Leather and Leather Products

by R. Karthikeyan and N.k. Chandra Babu

Chicken leg is available in enormous quantity as a by-product from poultry industry. Due to lack of awareness and technology, most of the chicken legs are wasted by the poultry producers and the skins are not utilized by the tanners. Hence, an attempt has been made in the present study to investigate the feasibility of turning chicken leg skins into leather and products. The raw skin was characterised and converted into finished leather by using suitable tanning methodology and the resultant chicken leg leather with attractive grain pattern has been utilized for the preparation of highly fashionable leather products. Histological examination was carried out on the chicken leg skin at different stages of processing. The leathers were characterized by differential scanning colorimetry and scanning electron microscopic analysis. The strength properties of the crust leathers were also tested and reported in the paper. Visual assessment reveals that vegetable tanning followed by chrome tanning produces fuller and softer leathers with exquisitely raised grain pattern compared to chrome tanning method and the same is corroborated by SEM study.

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Adsorption Isotherm and Kinetics of Tannic Acid on to Carbonized Chrome Tanned Leather Solid Waste

by Rubina Chaudhary and Anupama Pati

The disposal of chrome tanned leather shavings (CTLS) waste is a serious concern for the environment due to the presence of chromium. In this study, an attempt has been made to prepare adsorbent from CTLS through carbonization process. Carbonization of CTLS at temperature 600°C had provided surface area of 620 m2 g-1 and total pore volume of 0.49 cm3 g-1. The adsorption study is conducted by employing adsorbent prepared from CTLS on adsorbate tannic acid. The effects of various experimental parameters have been investigated using a batch adsorption technique to obtain information on treating wastewater containing tannic acid. The extent of tannic acid removal was studied by varying parameters such as pH, contact time, initial concentration of the tannic acid and amount of adsorbent. The removal efficiency of tannic acid in aqueous solution is found to be about 95%. The experimental equilibrium data for this system has been analyzed using the linearized forms of Langmuir and Freundlich isotherms. The Langmuir isotherm was found to provide the best theoretical correlation of the experimental data for the adsorption of tannic acid. The adsorption of tannic acid on adsorbent increased from 57 to 63 mg g-1, when the temperature was increased from 30 to 60°C. The adsorption was found to follow pseudo-second order kinetics. In short, this study provides a greener solution for CTLS and tannin containing wastewater.

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Screening of Industrially Important Enzymes Produced by Moderately Halophilic Bacteria Isolated from Salted Sheep Skins of Diverse Origin

by P. Caglayan, M. Birbir, C. Sánchez-Porro and A. Ventosa

Moderately halophilic bacteria have received attention in several industries due to their industrial enzymes which are stable at high temperatures, various salt concentrations and different pH values. Therefore, this study was conducted to isolate and identify moderately halophilic bacteria found on salted sheep skin samples and to detect the isolates producing industrially important enzymes. These skin samples were from Australia, Bulgaria, Dubai, Greece, Israel, Kuwait, South Africa, Turkey and U.S.A. Phenotypic characteristics and comparative partial 16S rRNA gene sequence analysis were used to characterize these microorganisms. According to the test results, 77 isolates representing 13 genera and 29 species were identified. These moderately halophilic bacteria, which were able to mostly grow in the media containing 3-15% salts and in some cases, up to 20-25% salts, were closely related to species of genera Staphylococcus, Salimicrobium, Bacillus, Salinicoccus, Planococcus, Alkalibacillus, Gracilibacillus, Oceanobacillus, Marinococcus, Halomonas, Salinivibrio, Chromohalobacter, and Idiomarina. A fairly high percentage of the isolates (79%) produced a great variety of industrially important enzymes. Protease, lipase, β-galactosidase, amylase, caseinase, DNase, urease, cellulase, and lecithinase enzymes were produced respectively by 46, 33, 30, 20, 18, 13, 9, 9, and 8 isolates. None of the isolates produced pullulanase, xylanase and phospholipase enzymes. Combined enzymatic activities have been detected among the isolates. While 12% and 27% of isolates produced six and four different enzymes, respectively, 1% of isolates produced three different enzymes. Furthermore, 39% of the isolates produced one and two enzymes. These enzymes were produced by isolates belonging to all genera detected in this study except genus Alkalibacillus. The findings of this study demonstrated that moderately halophilic bacteria on the skins produced industrially important enzymes which may have potential applications in different industries.

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