Ali Sameh Samir, Al-Tohamy Rania, Koutra Eleni, Kornaros Michael, Khalil Maha, Elsamahy Tamer, El-Shetehy Mohamed, Sun Jianzhong
Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Xuefu Rd. 301, Zhenjiang, 212013, China.
Botany Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt.
Biotechnol Biofuels. 2021 Mar 8;14(1):61. doi: 10.1186/s13068-021-01906-0.
Textile industry represents one prevalent activity worldwide, generating large amounts of highly contaminated and rich in azo dyes wastewater, with severe effects on natural ecosystems and public health. However, an effective and environmentally friendly treatment method has not yet been implemented, while concurrently, the increasing demand of modern societies for adequate and sustainable energy supply still remains a global challenge. Under this scope, the purpose of the present study was to isolate promising species of yeasts inhabiting wood-feeding termite guts, for combined azo dyes and textile wastewater bioremediation, along with biodiesel production.
Thirty-eight yeast strains were isolated, molecularly identified and subsequently tested for desired enzymatic activity, lipid accumulation, and tolerance to lignin-derived metabolites. The most promising species were then used for construction of a novel yeast consortium, which was further evaluated for azo dyes degradation, under various culture conditions, dye levels, as well as upon the addition of heavy metals, different carbon and nitrogen sources, and lastly agro-waste as an inexpensive and environmentally friendly substrate alternative. The novel yeast consortium, NYC-1, which was constructed included the manganese-dependent peroxidase producing oleaginous strains Meyerozyma caribbica, Meyerozyma guilliermondii, Debaryomyces hansenii, and Vanrija humicola, and showed efficient azo dyes decolorization, which was further enhanced depending on the incubation conditions. Furthermore, enzymatic activity, fatty acid profile and biodiesel properties were thoroughly investigated. Lastly, a dye degradation pathway coupled to biodiesel production was proposed, including the formation of phenol-based products, instead of toxic aromatic amines.
In total, this study might be the first to explore the application of MnP and lipid-accumulating yeasts for coupling dye degradation and biodiesel production.
纺织工业是全球一项普遍的活动，产生大量高污染且富含偶氮染料的废水，对自然生态系统和公众健康造成严重影响。然而，尚未实施有效且环保的处理方法，与此同时，现代社会对充足且可持续能源供应的需求不断增加，这仍是一项全球挑战。在此背景下，本研究的目的是分离出生活在以木材为食的白蚁肠道中的有前景的酵母菌种，用于联合偶氮染料和纺织废水的生物修复以及生物柴油生产。
分离出38株酵母菌株，进行分子鉴定，随后测试其所需的酶活性、脂质积累以及对木质素衍生代谢物的耐受性。然后将最有前景的菌种用于构建新型酵母联合体，并在各种培养条件、染料水平以及添加重金属、不同碳源和氮源的情况下，最后以农业废弃物作为廉价且环保的底物替代品，进一步评估该联合体对偶氮染料的降解情况。构建的新型酵母联合体NYC-1包括产锰依赖性过氧化物酶的产油菌株加勒比梅奇酵母、季也蒙梅奇酵母、汉逊德巴利酵母和腐殖瓦里酵母，表现出高效的偶氮染料脱色能力，且根据培养条件进一步增强。此外，还对酶活性、脂肪酸谱和生物柴油特性进行了深入研究。最后，提出了一条与生物柴油生产相关的染料降解途径，包括形成酚基产物而非有毒芳香胺。
总体而言，本研究可能是首次探索锰过氧化物酶和脂质积累酵母在耦合染料降解和生物柴油生产方面的应用。
