Akbar Sana, Anjum Muzammil, Qadeer Samia, Nawaz Rab, Rao Zepeng, Ullah Habib, Alamri Abdulaziz, El-Tayeb Mohamed A
Department of Environmental Sciences, Institute of Soil and Environmental Sciences, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan.
Department of Environmental Sciences, Allama Iqbal Open University, Islamabad, Pakistan.
Front Microbiol. 2025 May 14;16:1551264. doi: 10.3389/fmicb.2025.1551264. eCollection 2025.
The high proportion of sludge generation worldwide has sparked interest in utilizing it for alternative purposes. Among different potential applications, using sludge as a substrate for oleaginous bacteria is a relatively novel approach. The study was conducted to harness sp. to produce bio-lipids and their further processing for biofuel through transesterification.
Sewage sludge was obtained from the I-9 treatment plant, Islamabad; after initial characterization the unprocessed sludge was optimized viz.: incubation time (24-96 h), inoculation rate (5-15%), pH levels (4-9), temperature (25-40°C), agitation (0-250 RPM), nitrogen sources (yeast, urea, ammonium chloride, and ammonium nitrate), and carbon sources (glucose, sucrose, starch, and dextrose). The qualitative analysis of the stored bio-lipids was performed using Fourier-transform infrared spectroscopy (FTIR) and Gas Chromatography Mass Spectrometry (GC-MS).
The maximum reactor performance was achieved with 40% lipid accumulation (gravimetric basis) in the dry cell biomass of sp. The results indicated the presence of C-H (Alkane), with additional phenolic and alcoholic bonds through FTIR, whereas the GC-MS results indicated the presence of palmitic acid and oleic acid as the most recurring compounds. This highlights the strong potential of sp. for biolipid based fuel production using sludge as a substrate. The contents of the extract (i.e., bio-lipids) were successfully transesterified to produce biofuels from the stored lipids. The findings indicated that the use of sp. potentially provides a dual benefit of reducing organic loading from the sludge along with biofuel production under optimized reactor conditions.
全球范围内污泥产生量的高比例引发了人们将其用于其他用途的兴趣。在不同的潜在应用中，利用污泥作为产油细菌的底物是一种相对新颖的方法。本研究旨在利用 菌生产生物脂质，并通过酯交换反应对其进行进一步加工以生产生物燃料。
从伊斯兰堡的 I-9 污水处理厂获取污水污泥；在初步表征后，对未处理的污泥进行了如下优化：培养时间（24 - 96 小时）、接种率（5 - 15%）、pH 值（4 - 9）、温度（25 - 40°C）、搅拌速度（0 - 250 转/分钟）、氮源（酵母、尿素、氯化铵和硝酸铵）以及碳源（葡萄糖、蔗糖、淀粉和右旋糖）。使用傅里叶变换红外光谱（FTIR）和气相色谱 - 质谱联用仪（GC - MS）对储存的生物脂质进行定性分析。
菌的干细胞生物质中脂质积累量达到 40%（重量基准）时，反应器性能达到最佳。FTIR 结果表明存在 C - H（烷烃）键，以及额外的酚类和醇类键，而 GC - MS 结果表明棕榈酸和油酸是最常见的化合物。这突出了 菌利用污泥作为底物生产基于生物脂质的燃料的巨大潜力。提取物（即生物脂质）的成分成功进行了酯交换反应，以从储存的脂质中生产生物燃料。研究结果表明，在优化的反应器条件下，使用 菌可能具有双重益处，即减少污泥中的有机负荷并同时生产生物燃料。
