Drug Radiation Research Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt.
Radiation Microbiology Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt.
Microb Cell Fact. 2022 Jul 30;21(1):151. doi: 10.1186/s12934-022-01877-3.
The complexity, toxicity and abundance of frying oil waste (FOW) render it difficult to be degraded biologically. The aim of the present work was to valorize FOW and investigate the potential use of the produced biosurfactant by Serratia marcescens N2 (Whole Genome sequencing accession ID SPSG00000000) as a biodetergent.
Serratia marcescens N2 demonstrated efficient valorization of FOW, using 1% peptone, 20% FOW and 8% inoculum size. Gene annotation showed the presence of serrawettin synthetase indicating that the produced biosurfactant was serrawettin. Zeta potential and Fourier Transform Infrared (FTIR) spectroscopy indicate that the biosurfactant produced was a negatively charged lipopeptide. The biosurfactant reduced the surface tension of water from 72 to 25.7 mN/m; its emulsification index was 90%. The valorization started after 1 h of incubation and reached a maximum of 83.3%. Gamma radiation was used to increase the biosurfactant yield from 9.4 to 19.2 g/L for non-irradiated and 1000 Gy irradiated cultures, respectively. It was noted that the biorecovery took place immediately as opposed to overnight storage required in conventional biosurfactant recovery. Both chemical and functional characteristics of the radiation induced biosurfactant did not change at low doses. The produced biosurfactant was used to wash oil stain; the highest detergency reached was 87% at 60 °C under stirring conditions for 500 Gy gamma assisted biorecovery. Skin irritation tests performed on experimental mice showed no inflammation.
This study was able to obtain a skin friendly effective biodetergent from low worth FOW using Serratia marcescens N2 with 83% efficient valorization using only peptone in the growth media unlike previous studies using complex media. Gamma radiation was for the first time experimented to assist biosurfactant recovery and doubling the yield without affecting the efficiency.
煎炸油废物（FOW）的复杂性、毒性和丰富性使其难以进行生物降解。本工作旨在对 FOW 进行增值利用，并研究蜡状芽孢杆菌 N2（全基因组测序访问号 SPSG00000000）产生的生物表面活性剂作为生物洗涤剂的潜力。
蜡状芽孢杆菌 N2 以 1%蛋白胨、20%FOW 和 8%接种量有效地利用 FOW。基因注释表明存在 serrawettin 合成酶，表明产生的生物表面活性剂是 serrawettin。Zeta 电位和傅里叶变换红外（FTIR）光谱表明，产生的生物表面活性剂是带负电荷的脂肽。生物表面活性剂将水的表面张力从 72 降低至 25.7 mN/m；其乳化指数为 90%。增值作用在孵育 1 小时后开始，达到 83.3%的最大值。伽马辐射分别将非辐照和 1000 Gy 辐照培养物的生物表面活性剂产量从 9.4 增加到 19.2 g/L。值得注意的是，与传统生物表面活性剂回收所需的过夜储存不同，生物回收立即发生。低剂量下，辐射诱导生物表面活性剂的化学和功能特性均未发生变化。所产生的生物表面活性剂用于清洗油污；在 60°C 搅拌条件下，经 500 Gy 伽马辅助生物回收后，去污率最高可达 87%。在实验小鼠上进行的皮肤刺激试验表明没有炎症。
与之前使用复杂培养基的研究不同，本研究仅使用蛋白胨作为生长培养基，使用蜡状芽孢杆菌 N2 以 83%的效率从低价值 FOW 中获得了一种对皮肤友好的有效生物洗涤剂。伽马辐射首次用于辅助生物表面活性剂回收，并在不影响效率的情况下将产量提高一倍。
