Fungal Competitors Affect Production of Antimicrobial Lipopeptides in <Emphasis Type="Italic">Bacillus subtilis</Emphasis> Strain B9–5

Bacillus subtilis has shown success in antagonizing plant pathogens where strains of the bacterium produce antimicrobial cyclic lipopeptides (CLPs) in response to microbial competitors in their ecological niche. To gain insight into the inhibitory role of these CLPs, B. subtilis strain B9–5 was co-cultured with three pathogenic fungi. Inhibition of mycelial growth and spore germination was assessed and CLPs produced by B. subtilis B9–5 were quantified over the entire period of microbial interaction. B. subtilis B9–5 significantly inhibited mycelial growth and spore germination of Fusarium sambucinum and Verticillium dahliae, but not Rhizopus stolonifer. LC-MS analysis revealed that B. subtilis differentially produced fengycin and surfactin homologs depending on the competitor. CLP quantification suggested that the presence of Verticillium dahliae, a fungus highly sensitive to the compounds, caused an increase followed by a decrease in CLP production by the bacterium. In co-cultures with Fusarium sambucinum, a moderately sensitive fungus, CLP production increased more gradually, possibly because of its slower rate of spore germination. With co-cultures of the tolerant fungus Rhizopus stolonifer, B. subtilis produced high amounts of CLPs (per bacterial cell) for the duration of the interaction. Variations in CLP production could be explained, in part, by the pathogens’ overall sensitivities to the bacterial lipopeptides and/or the relative growth rates between the plant pathogen and B. subtilis. CLP production varied substantially temporally depending on the targeted fungus, which provides valuable insight concerning the effectiveness of B. subtilis B9–5 protecting its ecological niche against the ingress of these pathogens.     

投资理财"小"赢家

--在美国这个资本主义社会,投资理财已经成为人们生活中的重要环节.这种观念的灌输日益低龄化,每一个美国家庭都非常重视培养小孩的理财观念,一切都从娃娃抓起,美国人深信:你懂不懂投资理财不是一朝一夕的,观念的潜移默化和经验的累积才是真理………     

墨比尔斯投资法则[三]——通往海外投资的致富之道

目前为富兰克林基金公司新兴市场最重要操盘人,素有新兴市场教父之称的马克·墨比尔斯(Mark Mobius),曾经荣获美国杂志评选的"全球十大投资大师"之一,并于1997年、1998年连续被路透社选为"年度最佳全球基金经理人".他所推出的著作<获利护照--通往海外投资致富之道>提出多项投资法则,值得投资人参考.法则共有三十多条,我们对其进行精选,并连续刊登,为你揭开墨比尔斯投资法则的神秘面纱.     

英国人怎样选择储蓄账户?

在英国的金融市场里,消费者可以选择的储蓄账户太多了,想存款的人几乎挑花了眼.其实挑选的原则并不是很复杂,主要根据以下这些因素进行选择:存款要存多久?什么时候想使用存款,以及存款是否要交税.但是不要小看这些储蓄账户,对它们进行详细的分析能帮助储蓄者处理他们的存款,同时也能获取令人满意的收益.以下介绍英国几种形式储蓄账户.     

富裕的理发师[3]

我是Cathy,一名普通的加拿大小镇居民,生活平静而安逸.每个月我都会到Roy的理发店去理发.Roy平常看起来就是一个老实、技术娴熟的理发师,可是去他那里理发,跟他海阔天空地聊天却总让我有许许多多意外的收获……     

Post-mining rehabilitation of coastal sand dunes in Zululand South Africa

In the process of dredge mining, employed since 1977 on the Zululand coast, heavy minerals are extracted from the dunes after the complete removal of the existing vegetation. The tailings are then reshaped to approximate their original contours, covered with topsoil and revegetated with a cereal cover crop, together with indigenous seeds of long-lived (woody) species. The existence of stands of different ages over a recorded period provided an opportunity to study changes in species composition and vegetation dynamics. Five random 10 × 10m quadrats were sampled in stands of age 4, 5, 7, 8, 9, 10, 11 and 12 years respectively, and cover data were used for multivariate analysis using TWINSPAN and DECORANA. Importance values of each species, and total and mean species richness were also calculated. Pre-mined and mined soil samples were analysed for trace elements, organic matter and pH. Recently rehabilitated areas of 4 to 5 years were dominated by Acacia karroo, but species richness showed a progressive increase with age of rehabilitated stands, with more woody species in the older stands and a slight decline in dominance of A. karroo. TWINSPAN classified older and younger stands into distinct groups which were related to a chronological succession gradient, also shown by the DECORANA ordination. Some soil nutrients of rehabilitated areas compared favourably with the pre-mined topsoil and subsoil, but percentage organic matter content was still higher in natural dune forests. Increases in soil nutrients suggest that nutrient retention and the establishment of substantial soil flora and fauna are occurring, providing evidence for the sustainability of the soils. From this study it appears that successional changes follow the facilitation pathway, and rehabilitation will eventually lead to the restoration of the dune forest.     

Socioeconomic status and HRT use

A two-month-old female German shepherd dog was presented with a history of ulcerated central pads of all four feet. On physical examination, the footpads were swollen, soft and ulcerated. On the nasal planum there was a partially depigmented nodule. Multiple biopsies were taken from the cutaneous lesions and histological examination revealed focal collagen degeneration and vasculitis. A diagnosis of familial cutaneous vasculopathy was made. Seven months later the nasal nodule had disappeared and the footpads were still swollen but non-ulcerated. At this time, the dog manifested a generalised pustular demodicosis.     

The development of a radioimmunoassay procedure for the estimation of Tamm-Horsfall glycoprotein in human serum

1. A quantitative radioimmunoassay was developed for the measurement of nanogram amounts of Tamm-Horsfall (TH) glycoprotein in the presence of serum proteins at concentrations above 30 mg/ml. 2. Specific anti-(TH-glycoprotein) antibodies were labelled with 125I and these were usable for a period of 8 weeks. 3. Agarose beads (Sepharose 4B), to which TH-glycoprotein had been coupled via cyanogen bromide activation of the Sepharose, were used as the solid phase in the assay. This proved stable upon storage at 4 degrees C for periods in excess of 4 months. 4. The dissociation of the glycoprotein in the presence of serum proteins that was necessary for quantification was achieved by subjecting the sample to ultrasonication. 5. Assays conducted on a small sample of normal serum produced evidence that normal serum contained amounts (50-180 ng/ml) of a substance that reacted similarly to TH-glycoprotein in the assay procedure and in a series of experiments conducted to confirm the presence of this substance in human serum.     

Pleasure, addiction, and habit: Factors in verbal report or factors in smoking behavior?

Presents findings of 3 experiments with 30 undergraduates that tested the validity of the Tomkins Reasons for Smoking Questionnaire and suggested that individual differences in reasons for smoking may be important in devising therapies for smoking reduction. Exp I compared the smoking rates of Ss who scored high and low on the Pleasure-Taste scale for adulterated and nonadulterated cigarettes; Exp II compared the rates of high- and low-scoring smokers on the Addict scale following deprivation or nondeprivation periods; Exp III comared the effects of increasing self-monitoring on smoking in Pleasure-Taste and Habit smokers. Adulteration of taste produced greater smoking reductions for high Pleasure-Taste smokers than for low Pleasure-Taste smokers, and increased self-awareness produced greater smoking reductions for Habit than for Pleasure-Taste smokers. Deprivation resulted in stronger reports of distress in addicted smokers but had no noticeable effects on smoking rates. In addition, data are reported on the effects of self-monitoring on self-perception and reasons for smoking (RFS) test scores. There are suggestions that the self-knowledge revealed by RFS scale scores is more accurate for factors closely linked to external cues and less accurate for reports of internally defined states. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)