Indole-3-acetic acid production by rhizobacteria Bacillus spp. to various abiotic stress factors

Indole-3-acetic acid (IAA) phytohormone plays an essential role in forming and initiating main, lateral, and adventitious roots in vegetative propagation. Plants are receiving IAA naturally from a diverse group of soil-plant associated rhizobacteria. However, IAA synthesis by rhizobacteria is influenced by abiotic growth conditions. Three indigenous Bacillus isolates were subject to in vitro assay for the effects of abiotic factors (temperature, salinity and pH) on growth and IAA production. All isolates grew well between 25 - 40°C, and only B. megaterium UPMLH3 was capable of synthesising IAA (21.18 µg/ml) at 40°C. All three bacterial growth under saline stress were slightly dropped over control (0% NaCl), but still producing IAA up to 1% NaCl condition. B. cereus UPMLH24 revealed high resistance to salinity up to 5% NaCl. The optimum growth of all three Bacillus spp. was at pH 7. B. cereus UPMLH1 and UPMLH24 discovered higher IAA production in slightly alkaline conditions (pH 8). Each rhizobacterium shows different physiology trait against each abiotic factor. However, the multiple tolerance ability of PGPR against abiotic factors is an indication that its ability to survive under harsh soil and plant environments while delivering benefits to the plant. Thus, B. cereus UPMLH1, B. megaterium UPMLH3 and B. cereus UPMLH24 might serve as potential biofertiliser, enhancing the growth performance of test plants at various environmental conditions

Antagonistic activities of endophytic bacteria against Fusarium wilt of black pepper (Piper nigrum).

Fusarium wilt is a fungal disease, which affects a broad range of plants including black pepper (Piper nigrum). Fusarium solani f. sp. piperis is a common causal agent of root rots and stem blight in black pepper. F. oxysporum Schl. f. sp. piperis, a less common but an important pathogen of black pepper. The biological approach to control F. oxysporum is becoming popular in many crop plants however there is lack of scientific record in black pepper. Endophytic bacteria were isolated from black pepper roots and cultured on nutrient agar. The bacterial isolates were screened for in vitro antagonistic activity against F. oxysporum through dual culture, mycelial growth, spore germination and double plate tests. Five isolates with promising antifungal activity were further identified through 16S rDNA sequencing. Isolates EB1 and EB2 showed highest antagonism against F. oxysporum mycelia with the percentage of inhibition up to 43% and 41%, respectively. Isolated EB3, EB4 and EB5 produced clearing zones in spore germination test with radii measurements at 12.5-15.0 mm. The antifungal activities apparently involved the secretion of volatile and diffusible bioactive compounds. Analysis of the 16S rDNA sequences suggested the closest identities of the bacterial isolates as Bacillus megaterium, Bacillus cereus, Enterobacter sp. and Bacillus sp. Five endophytic bacteria isolates demonstrated significant control over both mycelia growth and spore germination of F. oxysporum. Some of these bacteria might possess additional beneficial plant growth promoting and insecticidal properties for the development of multi-function products in black pepper farming

Isolation of indigenous strains of Paecilomyces lilacinus with antagonistic activity Meloidogyne incognita.

Ten indigenous isolates of Paecilomyces lilacinus (PL), were isolated from two black pepper farms in Sarawak heavily infested with root-knot nematodes (RKN) as an initiative to control RKN problem. All isolates showed varying degree in colonizing female nematodes. In the female nematode bioassay on water agar, both indigenous strains of PL namely PLA, PLB, and a commercial strain, PLM (as positive control) demonstrated highly significant colonization (>90%, P≤0.01) on female. In egg parasitism test, spore suspension (105 spore/mL) of the strains PLA, PLB and PLM exhibited 78.8%, 66.0% and 73.4% parasitism on eggs, respectively. Meanwhile, hatching of nematode eggs incubated in spore suspension of PLA, PLB and PLM for seven days were significantly reduced; 88-89% of eggs were hatch-inhibited as compared to control (26%). This illustrated both local isolates, PLA and PLB are comparable with PLM as biological control agents for managing RKN infestation on black pepper vines

Spotted fever group rickettsiae in ticks collected from wild animals in Israel

We report molecular evidence for the presence of spotted fever group rickettsiae (SFGR) in ticks collected from roe deer, addax, red foxes, and wild boars in Israel. Rickettsia aeschlimannii was detected in Hyalomma marginatum and Hyalomma detritum while Rickettsia massiliae was present in Rhipicephalus turanicus ticks. Furthermore, a novel uncultured SFGR was detected in Haemaphysalis adleri and Haemaphysalis parva ticks from golden jackals. The pathogenicity of the novel SFGR for humans is unknown; however, the presence of multiple SFGR agents should be considered when serological surveillance data from Israel are interpreted because of significant antigenic cross-reactivity among Rickettsia. The epidemiology and ecology of SFGR in Israel appear to be more complicated than was previously believed. Copyright © 2011 by The American Society of Tropical Medicine and Hygiene

Development of a new class of stable and adaptable free-standing fibre mats with high room-temperature hydroxide-ion conductivity.

For alkaline anion-exchange membrane electrolysers and fuel cells to become a technological reality, hydroxide-ion (OH-) conducting membranes that are flexible, robust, affording high OH- conductivity, and synthesised in a low-cost and scalable way must be developed. In this paper, we engineer a stable, self-supporting, and flexible fibre mat using a low-cost ZIF-8 metal-organic framework composited with ionic liquid tetrabutylammonium hydroxide and widely used polyacrylonitrile as polymeric backbone. We obtain mats with a high intrinsic OH- conductivity for a metal-organic framework-based material already at room temperature, without added ion-conductor polymers. This approach will contribute to the development of low-cost and tuneable ion-conducting membranes

Origin of symbol-using systems: speech, but not sign, without the semantic urge

Natural language—spoken and signed—is a multichannel phenomenon, involving facial and body expression, and voice and visual intonation that is often used in the service of a social urge to communicate meaning. Given that iconicity seems easier and less abstract than making arbitrary connections between sound and meaning, iconicity and gesture have often been invoked in the origin of language alongside the urge to convey meaning. To get a fresh perspective, we critically distinguish the origin of a system capable of evolution from the subsequent evolution that system becomes capable of. Human language arose on a substrate of a system already capable of Darwinian evolution; the genetically supported uniquely human ability to learn a language reflects a key contact point between Darwinian evolution and language. Though implemented in brains generated by DNA symbols coding for protein meaning, the second higher-level symbol-using system of language now operates in a world mostly decoupled from Darwinian evolutionary constraints. Examination of Darwinian evolution of vocal learning in other animals suggests that the initial fixation of a key prerequisite to language into the human genome may actually have required initially side-stepping not only iconicity, but the urge to mean itself. If sign languages came later, they would not have faced this constraint

Does Income Mobility Equalize Longer-term Incomes? New Measures of an Old Concept

This paper develops a new class of measures of mobility as an equalizer of longer-term incomes – a concept different from other notions such as mobility as time-independence, positional movement, share movement, income flux, and directional income movement. A number of properties are specified leading to a class of indices, one easily-implementable member of which is applied to data for the United States and France. Using this index, income mobility is found to have equalized longer-term earnings among U.S. men in the 1970s but not in the 1980s or 1990s. In France, though, income mobility was equalizing throughout, and it has attained its maximum in the most recent period

Similarity solutions for unsteady shear-stress-driven flow of Newtonian and power-law fluids : slender rivulets and dry patches

Unsteady flow of a thin film of a Newtonian fluid or a non-Newtonian power-law fluid with power-law index N driven by a constant shear stress applied at the free surface, on a plane inclined at an angle α to the horizontal, is considered. Unsteady similarity solutions representing flow of slender rivulets and flow around slender dry patches are obtained. Specifically, solutions are obtained for converging sessile rivulets (0 < α < π/2) and converging dry patches in a pendent film (π/2 < α < π), as well as for diverging pendent rivulets and diverging dry patches in a sessile film. These solutions predict that at any time t, the rivulet and dry patch widen or narrow according to |x|3/2, and the film thickens or thins according to |x|, where x denotes distance down the plane, and that at any station x, the rivulet and dry patch widen or narrow like |t|−1, and the film thickens or thins like |t|−1, independent of N

Reconstructing ‘the Alcoholic’: Recovering from Alcohol Addiction and the Stigma this Entails

Public perception of alcohol addiction is frequently negative, whilst an important part of recovery is the construction of a positive sense of self. In order to explore how this might be achieved, we investigated how those who self-identify as in recovery from alcohol problems view themselves and their difficulties with alcohol and how they make sense of others’ responses to their addiction. Semi-structured interviews with six individuals who had been in recovery between 5 and 35 years and in contact with Alcoholics Anonymous were analysed using Interpretative Phenomenological Analysis. The participants were acutely aware of stigmatising images of ‘alcoholics’ and described having struggled with a considerable dilemma in accepting this identity themselves. However, to some extent they were able to resist stigma by conceiving of an ‘aware alcoholic self’ which was divorced from their previously unaware self and formed the basis for a new more knowing and valued identity

Prevalence of diabetes mellitus and impaired glucose tolerance in a rural community of Angola

<p>Abstract</p> <p>Background</p> <p>To determine the prevalence of diabetes mellitus (DM) and impaired glucose tolerance (IGT) in a rural community (Bengo) of Angola.</p> <p>Methods</p> <p>A random sample of 421 subjects aged 30 to 69 years (30% men and 70% women) was selected from three villages of Bengo province. This cross-sectional home survey was conducted using a sampling design of stage conglomerates. First, clinical and anthropometric data were obtained and fasting capillary glucose level was determined. Subjects who screened positive (fasting capillary glucose ≥ 100 mg/dl and < 200 mg/dl) and each sixth consecutive subject who screened negative (fasting capillary glucose < 100 mg/dl) were submitted to the second phase of survey, consisting of the 75-g oral glucose tolerance test. Data was analyzed by the use of SAS statistical software.</p> <p>Results</p> <p>The prevalence rates of diabetes mellitus and IGT were 2.8% and 8.1%, respectively. The age group with the highest prevalence of diabetes was 60 to 69 years (42%). Impaired glucose tolerance prevalence was 38% in the 40 to 49 year age group and it increased with age, considering that the 50 to 59 and 60 to 69 year age groups as a whole represent 50% of all subjects with impaired glucose tolerance. The prevalence of diabetes mellitus did not differ significantly between men (3.2%) and women (2.7%) (p = 0.47). On the other hand, the prevalence of impaired glucose tolerance among women showed almost twice that found in men (9.1% vs. 5.6%, respectively). Overweight was present in 66.7% of the individuals with diabetes mellitus and 26.5% of individuals with impaired glucose tolerance showed overweight or obesity.</p> <p>Conclusions</p> <p>Although the prevalence of diabetes mellitus was low, the prevalence of impaired glucose tolerance is considered to be within an intermediary range, suggesting a future increase in the frequency of diabetes in this population.</p