Abstract:

The antibacterial role of needle aqueous extract of Picea asperata (NAEPA) from Zoige in Qinghai-Tibetan Plateau was evaluated on 6 pathogenic bacteria, and its active compounds were investigated by gas chromatograph-mass spectrometry (GC-MS). In vitro antibacterial assay showed that NAEPA inhibited effectively both against Gram-positive and Gram-negative bacteria including Staphylococus aureus, Bacillus cereus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Hafnia alvei, with minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) being 3.8~15 and 7.5~30 mg/mL, respectively. The antibacterial compounds were stable even after being heated to 121℃ for 15 min. Antibacterial activity was the highest in acidic environment, but decreased when pH increased. The chemical composition of NAEPA assay revealed that organic acids were the main components. Benzoic acid, m-hydroxybenzoic acid, pyrocatechol, squalene and myrtenol were the main antibacterial compounds. In addition, NAEPA had antioxidant, lipid-lowering and antithrombotic compounds. Those results suggested that NAEPA might be a new potential source as natural antimicrobial agent applied in food and feed industries.

Key words: Qinghai-Tibetan Plateau, Picea asperata, Antibacterial activity, Organic acid

摘要：

研究青藏高原若尔盖云杉针叶水提物(NAEPA)的抗菌作用并初步分析其活性成分。NAEPA抗菌活性显著，对供试六种常见的革兰氏阳性和革兰氏阴性病原菌都有较强的抑菌作用和杀菌作用，最小抑菌浓度(MIC)和最小杀菌浓度(MBC)分别为3.8~15 mg/mL和7.5~30 mg/mL。抑菌物质在酸性环境中活性最强，对中性和碱性环境敏感；对121℃高温比较稳定。GC-MS分析表明，有机酸是NAEPA的主要成分；苯甲酸、间羟基苯甲酸、邻苯二酚、角鲨烯和桃金娘烯醇是主要抑菌物质。NAEPA中还含有抗氧化、降血脂以及抗血栓成分。NAEPA具有有效的抑菌物质和各种保健成分，是一种可应用于食品和饲料工业的潜在天然植物防腐剂资源。

关键词: 青藏高原；云杉；抑菌作用；有机酸