This study evaluated the antimicrobial potentials of Citrus essential oils (CEOs) against spoilage microorganisms isolated from selected fruits. The fruits were randomly purchased from different markets in Akure, Nigeria. The microorganisms were isolated and identified using molecular tools. In vitro antimicrobial efficacies of CEOs and their synergistic potentials were tested against spoilage microorganisms using agar well diffusion. The bioactive compounds in CEOs were identified using gas chromatography–mass spectrometry (GC–MS). The highest bacterial count (5.84 × 105 cfu/g) was recorded in tomatoes, while African star apple had the highest fungal count of 3.04 × 105 sfu/g. Microorganisms isolated from fruits were Bacillus spp., Micrococcus luteus, Serratia marcescens, Aspergillus spp., Mucor piriformis, Fusarium oxysporum, Penicillium spp., Rhizopus spp., Alternaria alternata and others. Phytochemicals in the CEOs were anthraquinones, cardiac glycosides, tannins, alkaloids, terpenoids, saponins, steroids, flavonoids and phenol. The diameter zones of inhibition displayed by CEOs against tested microorganisms at 100 mg/ml ranged from 3.3 mm to 26.8 mm with B. muralis being the most susceptible bacteria. The minimum inhibitory concentration (MIC) against all the tested isolates ranged from 12.5 to 100 mg/ml, while the minimum bactericidal and fungicidal concentrations ranged from 25 to ≥ 100 mg/ml. The synergism between lime and lemon at ratio 1:1 had better antimicrobial activity than each essential oil when used singly. GC–MS revealed the presence of limonene, beta-pinene, alpha-phellandrene, terpinen-4-ol, alpha-terpineol and geraniol in EOs of lime and lemon. The inhibitory potential of CEOs could be attributed to their bioactive compounds, which can be exploited and used as preservatives by food industries.

中文翻译：

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柑橘精油（CEO）对某些水果变质相关微生物的生物活性

这项研究评估了柑橘精油（CEO）对从选定水果中分离出来的腐败微生物的抗微生物潜力。这些水果是从尼日利亚阿库雷的不同市场随机购买的。使用分子工具分离和鉴定微生物。使用琼脂井扩散，对CEOs的体外抗菌功效及其协同潜力进行了测试，以防腐败微生物。CEO中的生物活性化合物通过气相色谱-质谱法（GC-MS）鉴定。番茄中细菌计数最高（5.84×105 cfu / g），而非洲金星苹果的真菌计数最高，为3.04×105 sfu / g。从水果中分离出的微生物是芽孢杆菌，黄球微球菌，粘质沙雷氏菌，曲霉，梨形毛霉，尖孢镰刀菌，青霉菌，根霉属，链格孢和其他。CEO中的植物化学物质为蒽醌，强心苷，单宁，生物碱，萜类，皂苷，类固醇，类黄酮和苯酚。CEO对100 mg / ml的受测微生物表现出的直径抑制范围为3.3毫米至26.8毫米，其中村寨芽孢杆菌是最易感染的细菌。对所有测试分离物的最低抑菌浓度（MIC）为12.5至100 mg / ml，而最低杀菌和杀真菌浓度为25至≥100 mg / ml。当单独使用时，石灰和柠檬以1：1的比例产生的协同作用比每种精油具有更好的抗菌活性。GC-MS揭示了石灰和柠檬的EO中存在柠檬烯，β-pine烯，α-水芹烯，萜品四醇，α-萜品醇和香叶醇。