Much fundamental research has already been performed to understand the mechanism of microbial rubber degradation. Due to the increasing amount of rubber waste, biotechnical methods to degrade that particular waste are strongly needed. The present study evaluates whether a microbial or an enzymatic process is more suitable for efficient biodegradation, due to less sensitivity towards rubber additives. Therefore we investigated the impact of 15 different frequently used rubber additives on cells of the potent rubber degrader Gordonia polyisoprenivorans VH2 and the enzyme Lcp1_VH2. For this, cells were grown on poly(cis-1,4-isoprene) in presence of these rubber additives. Furthermore, the effect of those additives on the enzymatic cleavage of poly(cis-1,4-isoprene) by Lcp1_VH2 was determined by in vitro studies. It was observed that additives, used to accelerate the vulcanization process, like N-cyclohexyl-2-benzothiazolesulfenamide and zinc-bis(N,N-dibenzyl-dithiocarbamate), are diminishing the growth of the microorganism depending on their concentration—higher toxicity with increasing concentration. In contrast, sulfur prevents cell growth, but does not affect Lcp1_VH2. Stearic acid and paraffin wax were found to be consumed by G. polyisoprenivorans VH2. Plasticizers mainly prevent growth, but do not interfere with the enzyme activity. This study identified antioxidants as the most interfering group of additives for microbial and enzymatic rubber degradation. It was found that the in vitro degradation by Lcp1_VH2 is much more resistant and less sensitive towards the investigated rubber additives, when compared to the in vivo approach. Therefore, an enzymatic process might be a promising method to enhance rubber degradation.

中文翻译：

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商业橡胶化合物添加剂对聚（顺-1,4-异戊二烯）的微生物和酶降解的影响。

已经进行了许多基础研究来了解微生物橡胶降解的机理。由于橡胶废料的数量增加，因此强烈需要生物技术方法来降解该特定废料。由于对橡胶添加剂的敏感性较低，本研究评估了微生物或酶促工艺是否更适合有效的生物降解。因此，我们研究了15种不同的常用橡胶添加剂对强力降解橡胶Gordonia polyisoprenivorans _VH2和Lcp1 _VH2酶细胞的影响。为此，在这些橡胶添加剂的存在下，使细胞在聚（顺-1，4-异戊二烯）上生长。此外，这些添加剂对聚（通过体外研究确定了Lcp1 _VH2产生的顺式-1,4-异戊二烯）。据观察，用于加速硫化过程的添加剂，例如N-环己基-2-苯并噻唑亚磺酰胺和锌双（N，N-二苄基-二硫代氨基甲酸酯），正在根据其浓度而降低微生物的生长，具有更高的毒性。越来越集中。相反，硫阻止细胞生长，但不影响Lcp1 _VH2。发现硬脂酸和石蜡被聚异戊二烯食用。VH2。增塑剂主要防止生长，但不干扰酶的活性。这项研究确定了抗氧化剂是微生物和酶促橡胶降解的最大干扰物。已经发现，与体内方法相比，Lcp1 _VH2的体外降解对所研究的橡胶添加剂的耐受性更高，敏感性更低。因此，酶促工艺可能是增强橡胶降解的有前途的方法。