细菌代谢类型的特点

细菌代谢类型的特点钱留华（江苏省泰兴中学２２５４００）细菌的代谢类型之多，代谢能力之强，分布范围之广，是其它类生物所不及的。１各种代谢类型俱全１．１异养需氧型这类苗是细菌大家族中的主要成员，种类和数量最多，如枯草杆菌（Ｂａｃｉｌｌｕｓｓｕｂｔｉｌｉｓ...     

微生物挥发性代谢产物的产生途径及其质谱检测技术

微生物挥发性代谢产物（MVOCs）是微生物代谢产物的重要组成部分,是人类了解微生物生命活动本质规律的重要窗口,也是提高微生物利用价值的重要物质基础。MVOCs种类较多,按其化学结构不同可分为醇类、醛类、酸类、酯类和酮类等化合物。由于这些化合物的理化性质差异较大,在样品中含量低且浓度差异大,经常与大量的复杂基体共存,一般需要对其进行分离、富集后才能够进行分析测定。本文归纳了常见MVOCs的产生途径,综述了常规质谱分析方法在MVOCs分析检测中的应用,同时结合本课题组的研究工作,介绍了新兴的复杂基体样品快速质谱分析技术的原理,评述了它们在MVOCs检测中的优势,并展望了质谱技术在MVOCs检测方面的发展趋势。     

一株硅酸盐细菌抗生代谢产物分离和特性

对硅酸盐细菌CS2 9菌株的抗菌产物进行了分离、纯化 ,从其发酵液中得到的化合物FA对金黄色葡萄球菌等G+ 和G-菌具有显著抑制活性 ,对蜡样芽孢杆菌和枯草芽孢杆菌的最低抑菌浓度 (MIC)达到 7μg/ml。经核磁共振波谱、红外光谱和质谱数据分析 ,表明FA为多羟基黄酮类化合物 ,分子量30 2。     

海滨土壤粘细菌次级代谢产物的性质及产量调控的研究

从黄海边土壤中筛选到具有广谱抑菌活性白色粘细菌So ce cpu-1,次级代谢物活性组分在210nm紫外吸收值最大。研究了不同培养条件对次级代谢产物的产量影响。结果表明,So ce cpu-1在含10％w／vD312中性吸附树脂的M7培养基中,通氧量为总体积的70％,添加该粘细菌次级代谢产物的粗提物5μL作为诱导物,30℃,200r／min,培养6d,次级代谢产物产量可达到最大值。     

粘细菌次生代谢产物中大环类化合物的研究进展

粘细菌可以产生多种次生代谢产物,是继放线菌、芽胞杆菌之后的第3大类次级代谢产物产生菌。本文综述了粘细菌次生代谢产物中大环类化合物的研究进展。首先介绍了粘细菌中分离的主要大环类化合物种类、结构特征及来源菌株;然后分别从抗肿瘤、抗菌、抗病毒等几方面对其生物活性进行概述;最后对粘细菌次生代谢产物中大环类化合物的相关研究工作进行了展望。     

南海深海细菌Bacillus amyloliquefaciens GAS 00152抗菌代谢产物研究

采用多种色谱分离技术,从南海深海细菌Bacillus amyloliquefaciens GAS 00152发酵液中分离得到12个化合物,经波谱数据分析分别鉴定为4-苯基-3-丁烯酰胺(1)、苯乙酰胺(2)、苯乙酸-2-(4-羟苯基)乙酯(3)、对羟基苯乙醇(4)、环(甘氨酸-2-氨基丁酸)(5)、环(甘氨酸-亮氨酸)(6)、环(甘氨酸-L-脯氨酸)(7)、环(D-脯氨酸-L-缬氨酸)(8)、环(4-羟基脯氨酸-亮氨酸)(9)、环(N-甲基甘氨酸-苯丙氨酸)(10)、环(L-2-羟基脯氨酸-苯丙氨酸)(11)、环(2-哌啶酸-苯丙氨酸)(12)。其中,化合物1为新天然产物。测试化合物1~12对番木瓜炭疽菌和香蕉黑星菌的抑制活性,发现化合物9对两种热带水果致病菌显示出中等抗菌活性。     

棘孢木霉挥发性次级代谢产物检测及抑菌活性分析

木霉是一类具有重要生防价值的丝状真菌。文中首先对分离自浙江省绍兴市和广东省佛山市共12株棘孢木霉Trichoderma asperellum进行平板拮抗评价,然后采用顶空固相微萃取气质联用法(HS-SPME-GC-MS)检测拮抗性较好的两株菌的挥发性次级代谢产物。结果表明,棘孢木霉ZJSX5003和GDFS1009菌丝生长迅速,对尖孢镰孢菌Fusariumoxysporum抑制率分别达73%和74%。挥发性次级代谢产物主要是醇类和酮类,其中包含异丁醇、异戊醇、3-甲基-3-丁烯-1-醇、3-羟基-2-丁酮、2,3-丁二醇和6-正戊基-2H-吡喃-2-酮(6-PAP)。进一步通过体外抑菌试验,证实6-PAP具有较好的抑制尖孢镰孢菌的效果,为开发以木霉菌代谢产物如6-PAP为主要成分的生防制剂提供指导。     

植物次生代谢产物的应用

世界上有形形色色的植物,在它们的新陈代谢过程中产生了各种各样的化学物质,其中有些化合物是维持植物生命活动所必须的,通常称之为初生代谢产物,如糖、氨基酸、多肽、蛋白质等。而在新陈代谢过程中产生的绝大多数化合物对植物本身的生命活动似乎无关紧要,如生物碱、黄酮、香豆素、木脂素、挥发油、蒽醌、皂甙、强心甙等成分,这些化合物通常被称为次     

南海孔石藻可培养细菌多样性及代谢产物四溴吡咯研究

钙化藻和微生物在造礁石珊瑚幼虫的附着变态过程中扮演着重要角色,对珊瑚礁生态系统的健康具有重要意义。对南海珊瑚礁区钙化藻的共附生细菌进行分离培养,一方面有利于发掘南海珊瑚礁的微生物资源,另一方面有利于进行微生物与珊瑚、钙化藻等珊瑚礁框架生物的相互作用研究。本研究分离获得孔石藻(Porolithon onkodes)表面共附生细菌,基于16S rRNA基因序列进行系统发育分析,并通过高效液相色谱和质谱对分离得到的假交替单胞菌属菌株的代谢产物进行比较分析。从孔石藻分离获得的369株细菌菌株分别隶属于变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)的5纲12目22科47属的97个种级类群。在属级水平上,假交替单胞菌属(Pseudoalteromonas)的菌株数量最多,分属于7个种。在假交替单胞菌属的代谢产物分析中,发现3株在系统发育树中聚为一簇的假交替单胞菌的代谢产物中存在四溴吡咯,而其余没有。研究结果不仅表明了钙化藻中含有丰富的可培养微生物和潜在新物种资源,还首次发现四溴吡咯在南海珊瑚礁区特定类群菌株的代谢产物中的存在,为珊瑚幼虫附着变态的化学信号研究提供基础。     

单分子荧光检测技术的发展及其在植物生物学研究中的应用

单分子荧光检测技术是利用荧光基团对目的分子标记后,在单分子水平成像并追踪分子的构象变化、动力学特征以及分子之间相互作用的研究方法.相较于传统分子生物学和遗传学的研究手段,单分子检测技术可以对单个分子的动态和特性进行分析,特别是瞬时或偶发性的事件,从而更加深入地挖掘在群体测量中被掩盖的信息.该技术已广泛应用于动物细胞生物...     

Volatile Compounds of Bacterial Origin: Structure,Biosynthesis, and Biological Activity

Microbiology - Microorganisms produce various volatile compounds, including volatile organic compounds and complex combinations of volatile compounds. The ecological and functional role of these...     

Streptomyces Exploration: Competition,Volatile Communication and New Bacterial Behaviours

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侧柏挥发性次生代谢产物的提取及GC-MS分析

利用气相色谱-质谱联用技术对水蒸气蒸馏提取的侧柏挥发性次生代谢产物进行了分析,研究结果表明年轮低于6年和6～12年侧柏心材质量分数最高的挥发性次生代谢产物均为柏木醇(40.14%,41.13%),年轮12～20年侧柏心材和边材质量分数最高的挥发性次生代谢产物均为8-丙氧基-香松烷(49.71%,44.03%)。侧柏年轮低于6年、6～12年、12～20年心材和边材的挥发性共有次生代谢产物为罗汉柏烯、雪松烯和花侧柏烯,只有6～12年侧柏心材挥发性次生代谢产物中含有愈创木烯且不含有α-杜松醇。     

Enzymatic Conversion of Volatile Metabolites in Dry Seeds during Storage

Dry seeds can transform volatile metabolites via enzymes pre-existingin them. The interconversion between acetaldehyde and ethanoloccurred when they were applied gaseously to seeds of rice,lettuce, pea, cocklebur during storage at different relativehumidities (RH) at either 23°C or –3.5°C. Interconversionsbetween the compounds decreased with decreasing RH from 75%to 12% regardless of seed species and storage temperature, butit was still detectable even at 12% RH at –3.5°C.However, the conversion from acetaldehyde to ethanol did notoccur when seeds were killed by heating prior to storage. 2-Methoxyethanol,a competitive inhibitor of alcohol dehydrogenase (ADH) (EC 1.1.1.1 [EC] ),suppressed the transformation from ethanol to acetaldehyde inlettuce seeds. Therefore, ADH pre-existing in dry seeds maybe involved in the interconversion between ethanol and acetaldehydein dry seeds. Propanal, also a substrate of ADH, could be transformedto propanol during storage. However, methanol, which is nota substrate of this enzyme, was hardly converted to formaldehyde.Ethylacetate, applied to seeds during storage, was hydrolyzedby both lettuce and rice seeds, and the amount of hydrolysisincreased with increasing RH. Similarly, other carboxylic esters,such as methylacetate, ethylformate and ethylpropionate, couldbe hydrolyzed by rice, pea, and lettuce seeds. Little hydrolysisof ethylacetate occurred in the seeds killed by heating beforestorage, suggesting that ethylacetate may be hydrolyzed by carboxylic-esterhydrolase (EC 3.1.1.1 [EC] ). On the other hand, the production ofethylacetate through esterification was demonstrated by additionof gaseous acetate and ethanol in lettuce seeds, which occurredmore greatly at 12% RH than at 75% RH. These findings were discussedin relation to the mechanism of seed aging. (Received September 3, 1994; Accepted November 14, 1994)     

细菌人工染色体载体的发展和应用

细茵人工染色体(Bacterial artificial chromosome,BAC)是在大肠杆菌F质粒的基础上建成的高容量、低拷贝的质粒载体.BAC载体已广泛应用于基因组文库的构建及筛选、基因组测序、新基因的发现、图位克隆、BAC微阵列、转基因和动物品种资源保存等方面.本文综述了BAC载体的发展及其应用.     

An Investigation of Fecal Volatile Organic Metabolites in Irritable Bowel Syndrome

Diagnosing irritable bowel syndrome (IBS) can be a challenge; many clinicians resort to invasive investigations in order to rule out other diseases and reassure their patients. Volatile organic metabolites (VOMs) are emitted from feces; understanding changes in the patterns of these VOMs could aid our understanding of the etiology of the disease and the development of biomarkers, which can assist in the diagnosis of IBS. We report the first comprehensive study of the fecal VOMs patterns in patients with diarrhea-predominant IBS (IBS-D), active Crohn''s disease (CD), ulcerative colitis (UC) and healthy controls. 30 patients with IBS-D, 62 with CD, 48 with UC and 109 healthy controls were studied. Diagnosis of IBS-D was made using the Manning criteria and all patients with CD and UC met endoscopic, histologic and/or radiologic criteria. Fecal VOMs were extracted by solid phase microextraction (SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). 240 VOMs were identified. Univariate analysis showed that esters of short chain fatty acids, cyclohexanecarboxylic acid and its ester derivatives were associated with IBS-D (p<0.05), while aldehydes were more abundant in IBD (p<0.05). A predictive model, developed by multivariate analysis, separated IBS-D from active CD, UC and healthy controls with a sensitivity of 94%, 96% and 90%; and a specificity of 82%, 80% and 80% respectively (p<0.05). The understanding of the derivation of these VOMs may cast light on the etiology of IBS-D and IBD. These data show that fecal VOMs analyses could contribute to the diagnosis of IBS-D, for which there is no laboratory test, as well as IBD.     

细菌运载蛋白及在表面展示技术中的应用进展

细菌细胞表面展示技术是一项新的蛋白质应用技术,其体系由运载蛋白、靶蛋白和宿主菌三者构成,一般可将其分为革兰阴性菌展示体系和革兰阳性菌展示体系两大类。目前已证实多种具有锚定活性的运载蛋白,并用于不同靶蛋白的细胞表面展示体系。该技术现已被应用于活体重组疫苗的开发、蛋白质文库构建与筛选、生物传感器、全细胞生物催化剂、全细胞生物吸附与降解等多个研发领域。