Submitted to: Journal of the Society of Leather Technologists and Chemists
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/1996
Publication Date: N/A
Citation: N/A Interpretive Summary: While brine curing is the most common commercial method of preserving cattle hides from bacterial damage, this process is not without its shortcomings. Under storage conditions of high temperature and humidity, hide damage can occur on even well cured hides. This is suspected by some to be caused by a particular species of bacteria, the halophiles, that are known to grow in saturated salt solutions. In this work halophilic organisms were isolated from commercially brine-cured hide samples and partially characterized. When grown at high temperature and humidity, seventy percent of the isolated organisms were found to be capable of degrading hide protein. This provides further evidence that halophilic organisms are capable of causing damage to salt- cured hides. Eliminating this damage by control of these organisms would save the leather industry considerable money annually.
Technical Abstract: Halophilic and halotolerant organisms found on brine cured hides were isolated and partially characterized. All of the halophilic bacteria isolated from the brine cured cattle hide samples used in these experiments were motile, Gram-negative, aerobic and extremely pleomorphic organisms. The colonies formed by these bacteria were either bright pink, red, or purple colonies on 27% and 30% salt- containing media. The halotolerant colonies on 20% salt media were all white. All of the isolated halophilic bacteria gave negative starch hydrolysis tests. Seventy percent of the isolates showed a positive gelatin test. The effect of the different salt solutions on the pH of brine cured hide samples was examined. When hide samples were placed into a variety of different salt solutions, a pH reduction was observed as the organisms grew. The growth rate of halophilic bacteria was examined at room conditions, 37 and 41 deg C. Growth was very slow at low temperatures. Halotolerant bacteria and halophilic bacteria grew best at 41 deg C. The original hide samples used as the source of these halophilic bacteria had a fishy odor and a large area of reddish discoloration on the flesh side typical of "red heat."