Dpt. Fisiología, Genética y Microbiología, Universidad de Alicante, Spain.
Hide Consultant, Dpt. Fisiología, Genética y Microbiología, Universidad de Alicante, Spain.
Syst Appl Microbiol. 2023 Jul;46(4):126421. doi: 10.1016/j.syapm.2023.126421. Epub 2023 May 18.
The leather-making industry is an age-old industry and desiccation with salt has been one of the most used methodologies for obtaining valuable skins. However, halophiles may proliferate and affect the integrity of the hide-collagen structure, as well as leading to undesirable red colorations or less-frequent purple stains. To understand the basis of these industrial hide contaminations, the microbial community from raw hide samples, salt-cured samples and four different industrial salts, was analyzed by 16S rRNA gene metabarcoding together with standard cultivation methods. Comparison of raw hides and correctly cured hides revealed a core microbiome that was absent from contaminated hides. In addition, archaea were missing from well-cured hides, whereas Psychrobacter and Acinetobacter were highly represented (23 % and 17.4 %, respectively). In damaged hides, only a few operational taxonomic units (OTUs), from among the hundreds detected, were able to proliferate and, remarkably, a single Halomonas OTU represented 57.66 % of the reads. Halobacteria, mainly Halovenus, Halorubrum and Halovivax, increased by up to 36.24-39.5 % in the red- and purple-affected hides. The major contaminants were isolated and hide infections, together with collagenase activity, were evaluated. The results showed that hides enriched with the non-pigmented isolate Halomonas utahensis COIN160 damaged the collagen fibers similarly to Halorubrum, and together they were considered to be one of the major causes. Putative degrading inhibitors were also identified from among the Alkalibacillus isolates. It was concluded that hide contaminations were driven by clonal outbreaks of a few specific microbes, which may have been non-pigmented collagen degraders. Acinetobacter and Alkalibacillus, members of the core microbiome of raw and well-cured salted hides, are suggested as hide contaminant inhibitors that need further analysis.
制革业是一个古老的行业，盐干法是获取有价值皮革的最常用方法之一。然而，嗜盐微生物可能会大量繁殖，影响皮革胶原蛋白结构的完整性，并导致不理想的红色着色或较少出现的紫色污渍。为了了解这些工业皮革污染的基础，通过 16S rRNA 基因代谢组学分析以及标准培养方法，对生皮样本、盐腌样本和四种不同工业盐中的微生物群落进行了分析。与生皮和正确腌制的生皮进行比较，发现核心微生物组不存在于污染的生皮中。此外，古细菌从腌制良好的生皮中缺失，而 Psychrobacter 和 Acinetobacter 则高度代表（分别为 23%和 17.4%）。在受损的皮革中，只有少数（在数百个中检测到的）操作分类单元（OTUs）能够繁殖，值得注意的是，单个 Halomonas OTU 占读数的 57.66%。在红色和紫色受影响的皮革中，嗜盐菌（主要是 Halovenus、Halorubrum 和 Halovivax）增加了 36.24-39.5%。主要污染物被分离出来，并评估了与胶原蛋白酶活性相关的皮革感染情况。结果表明，富含非色素分离株 Halomonas utahensis COIN160 的皮革与 Halorubrum 相似地损坏胶原蛋白纤维，它们被认为是主要原因之一。在 Alkalibacillus 分离株中还鉴定出了潜在的降解抑制剂。结论是，皮革污染是由少数特定微生物的克隆爆发引起的，这些微生物可能是非色素胶原蛋白降解剂。建议将生皮和腌制良好的盐皮的核心微生物群的成员 Acinetobacter 和 Alkalibacillus 作为皮革污染物抑制剂进行进一步分析。
