Microbial enhanced oil recovery makes a substantial contribution to the recovery of heavy oils; however, most methods use bacteria, with less attention paid to the potential of fungi. In this study, we investigated the efficiency of fungal extracellular enzymes in biotransformation of heavy oil fractions into light compounds. Two Aspergillus isolates (A. terreus and A. nidulans) with the ability to biodegrade heavy oil were isolated from bitumen. The extracellular enzymes from these Aspergillus isolates exhibited dehydrogenase and catechol 2,3‐dioxygenase activities. The biodegradation of heavy oil was coupled with abundant production of gases, mainly CO₂ and H₂. Gas chromatography analysis revealed a redistribution of n‐alkanes in heavy oil after treatment with crude enzyme extracts, which resulted in an increase in individual n‐alkanes. The viscosity of heavy oil was decreased considerably by enzymatic degradation. These results demonstrate the potential of fungal extracellular enzymes from Aspergillus spp. for applications in enhanced heavy oil recovery.

中文翻译：

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曲霉属真菌的细胞外酶对重油的生物降解作用。显示出提高石油采收率的潜力

微生物提高采油量对重油的采收做出了重大贡献；但是，大多数方法使用细菌，而很少关注真菌的潜力。在这项研究中，我们调查了真菌细胞外酶在将重油馏分生物转化为轻质化合物中的效率。两烟株（土曲霉和构巢曲霉）与生物降解重油的能力是从沥青中分离。这些曲霉菌分离物的细胞外酶表现出脱氢酶和邻苯二酚2,3-二加氧酶活性。重油的生物降解与大量气体的产生有关，主要是CO ₂和H ₂。气相色谱分析表明，用粗酶提取物处理后，正构烷烃在重油中的重新分布，这导致单个正构烷烃的增加。通过酶促降解，重油的粘度大大降低。这些结果证明了来自曲霉属的真菌细胞外酶的潜力。用于增强重油采收率的应用。