Laboratory of Treatment and Valorization of Water Rejects, Water Researches and Technologies Center, Borj-Cedria Technopark, University of Carthage, 8020, Soliman, Tunisia.
Laboratory of Environmental Science and Technologies, Higher Institute of Sciences and Technology of Environment, University of Carthage, 2050, Borj-Cedria, Tunisia.
Environ Sci Pollut Res Int. 2020 Sep;27(26):33127-33139. doi: 10.1007/s11356-020-09549-8. Epub 2020 Jun 11.
Kefir grains are a microbial consortium of different genera of bacteria and yeasts. In this study, the performance of Tunisian Kefir grains during the biological treatment of a mixture of Gouda cheese whey and white wastewaters (GCW) in ratio 1:1 with very high organic matter concentration is investigated. The biological process was evaluated and optimized through the response surface methodology. Under the optimum conditions, Kefir grains concentration of 1.02%, temperature at 36.68 °C, and incubation time of 5.14 days, the removal efficiencies of COD, PO, and NO were 87, 37.48, and 39.5%, respectively. Interestingly, the reusability tests of the grains proved not only their high resistance to harsh environmental conditions but also their great potential for more practical applications. Particularly, different strains were isolated from the grains and identified as Kluyveromyces marxianus, Lactoccocus lactis, Lactobacillus kefiri, and Bacillus spp. using 16S rDNA sequence analysis and rep-PCR fingerprinting. At the biological level, the raw GCW (RGCW) has a negative impact on the Hordeum vulgare both on seed germination, and on the growth parameters of seedlings. Interestingly, after Kefir grains treatment, the treated GCW (TGCW) allow a seedlings growth and germination rate similar to those soaked in water.
克菲尔粒是一种由不同属的细菌和酵母组成的微生物联合体。在这项研究中，研究了突尼斯克菲尔粒在处理高浓度有机物混合的古达干酪乳清和白水（GCW）混合物时的性能，GCW 与古达干酪乳清的比例为 1:1。通过响应面法评估和优化了生物过程。在最佳条件下，克菲尔粒浓度为 1.02%，温度为 36.68°C，孵育时间为 5.14 天，COD、PO 和 NO 的去除效率分别为 87%、37.48%和 39.5%。有趣的是，粒状物的可重复使用性测试不仅证明了它们对恶劣环境条件的高度抵抗力，而且还证明了它们在更实际应用中的巨大潜力。特别是，使用 16S rDNA 序列分析和 rep-PCR 指纹图谱，从粒状物中分离并鉴定出 Kluyveromyces marxianus、Lactoccocus lactis、Lactobacillus kefiri 和 Bacillus spp.。在生物学水平上，原始 GCW（RGCW）对大麦的种子发芽和幼苗生长参数都有负面影响。有趣的是，经过克菲尔粒处理后，处理后的 GCW（TGCW）允许幼苗生长和发芽率与在水中浸泡的相似。
