Petroleum contamination of marine environments due to exploitation and accidental spills causes serious harm to ecosystems. Bioremediation with immobilized microorganisms is an environmentally friendly and cost-effective emerging technology for treating oil-polluted environments. In this study, Bacillus licheniformis was entrapped in Ca alginate beads using the electrospray technique for light crude oil biodegradation. Three important process variables, including inoculum size (5–15% v/v), initial oil concentration (1500–3500 ppm), and NaCl concentration (0–30 g/L), were optimized to obtain the best response of crude oil removal using response surface methodology (RSM) and Box–Behnken design (BBD). The highest crude oil removal of 79.58% was obtained for 1500 ppm of crude oil after 14 days using immobilized cells, and it was lower for freely suspended cells (64.77%). Our result showed similar trends in the effect of variables on the oil biodegradation rate in both free cell (FC) and immobilized cell (IC) systems. However, according to the analysis of variance (ANOVA) results, the extent of the variables’ effectiveness was different in FC and IC systems. In the immobilized cell system, all variables had a greater effect on the rate of light crude oil degradation. Moreover, to evaluate the effectiveness of free and immobilized B. licheniformis in bioremediation of an actual polluted site, the crude oil spill in natural seawater was investigated. The results suggested the stability of beads in the seawater, as well as high degradation of petroleum hydrocarbons by free and immobilized cells in the presence of indigenous microorganisms.

由于开采和意外泄漏造成的海洋环境石油污染对生态系统造成了严重损害。固定化微生物的生物修复技术是一种环保且经济高效的新兴技术，可用于处理油污染的环境。在这项研究中，地衣芽孢杆菌使用电喷雾技术将藻类捕获在藻酸钙珠粒中，以进行轻质原油生物降解。优化了三个重要的过程变量，包括接种量（5-15％v / v），初始油浓度（1500-3500 ppm）和NaCl浓度（0-30 g / L），以获得最佳的原油响应使用响应面方法（RSM）和Box–Behnken设计（BBD）进行去除。使用固定化池14天后，对于1500 ppm的原油，去除率最高，为79.58％，而对于自由悬浮的池，去除率则较低（64.77％）。我们的结果表明，变量对游离细胞（FC）和固定细胞（IC）系统中的油生物降解率的影响具有相似的趋势。但是，根据方差分析（ANOVA）结果，变量有效程度在FC和IC系统中有所不同。在固定化细胞系统中，所有变量对轻质原油的降解速率都有较大的影响。此外，评估自由和固定化的有效性在地衣芽孢杆菌的生物修复中，实际污染了一个地点，对天然海水中的原油泄漏进行了调查。结果表明在海水中珠粒的稳定性，以及在存在本地微生物的情况下游离和固定化细胞对石油烃的高度降解。