Development of PCR-based molecular marker for screening of disease-suppressive composts against Fusarium wilt of tomato (Solanum lycopersicum L.).

The present study was carried out to develop a PCR-based molecular marker suitable for screening of disease-suppressive composts against Fusarium wilt of tomato. An effective uncultured bacterial community was screened from our previous study on investigation of microbial communities in composts for their potential for biocontrol of Fusarium wilt. Based on available sequence information (Accession no. HQ388491) of selective community, PCR-based molecular markers were designed and tested for their specificity in different compost sample. To confirm specificity of designed marker, real-time reverse transcription-PCR (qRT-PCR) analysis was performed. Selective marker efficacy was further tested for different set of composts and results were cross-verified by conducting bioassay of same composts against Fusarium wilt in tomato crop. Results showed that out of two designed set of primers (i.e., PAC1F/PAC1R and PAC4F/PAC4R), primer set PAC4F/PAC4R resulted in successful amplification of 199 bp in highly disease-suppressive compost (i.e., CPP); however, no/below detection level amplification was observed in non-suppressive compost (JC). qRT-PCR analysis confirmed the specificity of selective marker by representing single peak in melting curve. A clear difference was observed in relative population of selective community in different set of composts. It was observed maximum in the most effective compost, i.e., CPP followed by other disease-suppressive composts. Cross-examination of results with bioassay confirmed that composts with presence of selective bacterial community having no/very less disease incidence of Fusarium. It is clearly evident from the study that such kind of molecular markers can be developed and used in future research focusing on compost-based disease suppression.

Impact assessment of silver nanoparticles on plant growth and soil bacterial diversity.

The present study was carried out to investigate the impact of silver nanoparticles (AgNPs) on the growth of three different crop species, wheat (Triticum aestivum, var. UP2338), cowpea (Vigna sinensis, var. Pusa Komal), and Brassica (Brassica juncea, var. Pusa Jai Kisan), along with their impact on the rhizospheric bacterial diversity. Three different concentrations (0, 50 and 75 ppm) of AgNPs were applied through foliar spray. After harvesting, shoot and root parameters were compared, and it was observed that wheat was relatively unaffected by all AgNP treatments. The optimum growth promotion and increased root nodulation were observed at 50 ppm treatment in cowpea, while improved shoot parameters were recorded at 75 ppm in Brassica. To observe the impact of AgNPs on soil bacterial community, sampling was carried out from the rhizosphere of these crops at 20 and 40 days after the spraying of AgNPS. The bacterial diversity of these samples was analyzed by both cultural and molecular techniques (denaturing gradient gel electrophoresis). It is clearly evident from the results that application of AgNPs changes the soil bacterial diversity and this is further influenced by the plant species grown in that soil. Also, the functional bacterial diversity differed with different concentrations of AgNPs.

Phosphate solubilizing and indole-3-acetic acid producing bacteria from the soil of Garhwal Himalaya aimed to improve the growth of rice.

In the present study, soil bacteria from rainfed agriculture field of Garhwal Himalaya, just prior to sowing of summer crop, were isolated and initially tested for solubilization of inorganic phosphate, production of indole acetic acid (IAA) and siderophore. Two bacterial isolates, having efficient P- solubilizing activity in solid medium, were identified using 16S rRNA sequence analysis as Pseudomonas koreensis strainYB1 Arthrobacter nitroguajacolicus strainYB3 and three bacterial isolates, producing high amount of IAA in liquid medium, were identified as Klebsiella oxytoca strainYB2 and two strain of Arthrobacter nitroguajacolicus, strainYB4 and YB5, respectively. In culture medium supplemented with L-Tryptophan, Klebsiella oxytoca produced high amount of IAA (337.44 µg l(-1)). The selected five bacterial strains were further tested for tricalcium phosphate (TCP) solubilizing abilities at three different incubation temperature viz., 4 degrees C, 10 degrees C and 28 degrees C, under in vitro conditions. At 28 degrees C, three bacterial strains Pseudomonas koreensis, Arthrobacter nitroguajacolicus strainYB4 and Klebsiella oxytoca solubilized the phosphate efficiently. At 10 degrees C only two strains, Pseudomonas koreensis and Arthrobacter nitroguajacolicus strainYB4 solubilized phosphate efficiently as compared to other strains. These five bacterial strains were tested for nitrogen, catalase activity, starch and cellulose hydrolysis as well as growth promotion activity on rice, under controlled conditions. All the five bacterial strains efficiently increased the biomass and phosphorus uptake in Swama and Swarna sub1 varieties of rice.

Platforms for energy and nutrient recovery from domestic wastewater: A review.

Alternative domestic wastewater treatment processes that recover energy and nutrients while achieving acceptable nutrient limits (<5mgNL(-1)) are a key challenge. Major drivers are value and availability of phosphorous, nitrogen, and potassium, and increasing energy costs. The two major platforms that can achieve this are (a) low energy mainline (LEM), with low strength anaerobic treatment, followed by mainline anaerobic nitrogen removal and chemical or adsorptive phosphorous removal and (b) partition-release-recover (PRR), in which carbon and nutrients are partitioned to solids through either heterotrophic or phototrophic microbes, followed by anaerobic digestion of these solids and recovery from the digestate. This paper reviews practical application of these processes, with a focus on energy costs. Compared to conventional processes which require 0.5kWhkL(-1) electricity (500mgCODL(-1) influent concentration), PRR requires only 0.05kWhkL(-1) electricity. LEM offers the possibility to recover 0.1kWhkL(-1) as electricity with net energy generation above 400mgCODL(-1)influent, while PRR becomes energy generating at >650mgCODL(-1). PRR offers the possibility for recovery of nitrogen and other nutrients (including potassium) through assimilative recovery. However, the energetic overhead of this is substantial, requiring 5kWhkgN(-1) as electricity, which compares to ammonia fixation costs. The lower energy costs, and near to market status of LEM treatment make it likely as a recovery platform in the shorter term, while ability to recover other elements such as nitrogen and potassium, as well as enhance favourability on concentrated wastewaters may enhance the desirability of partitioning in the longer term.

Compost: its role, mechanism and impact on reducing soil-borne plant diseases.

Soil-borne plant pathogens are responsible for causing many crop plant diseases, resulting in significant economic losses. Compost application to agricultural fields is an excellent natural approach, which can be taken to fight against plant pathogens. The application of organic waste products is also an environmentally friendly alternative to chemical use, which unfortunately is the most common approach in agriculture today. This review analyses pioneering and recent compost research, and also the mechanisms and mode of action of compost microbial communities for reducing the activity of plant pathogens in agricultural crops. In addition, an approach for improving the quality of composts through the microbial communities already present in the compost is presented. Future agricultural practices will almost definitely require integrated research strategies to help combat plant diseases.

"Sex isn't something you do with someone you don't care about": young women's definitions of sex.

STUDY OBJECTIVE: How young women define sexual intercourse has implications for their sexually transmitted infection (STI) risk. This study investigated young women's (1) definitions of sex, (2) understanding of a unique sex event, and (3) definitions of when a sex event begins and ends. DESIGN: Using semi-structured interviews, young women were asked to define sex, define when a sex event began and ended, and were asked whether they thought their partners would agree. Interview transcripts were analyzed using thematic analysis. SETTING: Participants were recruited from an urban adolescent health clinic in the Northeastern United States. PARTICIPANTS: Twenty-four heterosexual, sexually active young women contributed data for analysis. INTERVENTIONS: None. RESULTS: Young women's definitions of sex varied. Some included anal and oral sex while others did not. Time between sex events, new condom use, and new erection were used to define unique sex events. Some believed sex began with foreplay. Others believed sex began when the penis entered the vagina. Some believed sex ended when the penis was withdrawn from the vagina. Others believed sex ended with orgasm for one or both partners. Young women talked about the influence of relationship type on their definitions of sex. CONCLUSIONS: Variations in young women's definitions of sex may influence their responses to clinical questions about sexual activity and their understanding of their STI risk. As such, our findings have important implications for clinical counseling regarding sexual behavior and correct condom use and for researchers investigating young women's sexual behavior.

Dose-response studies on tolerance to multiple doses of secobarbital and methaqualone in a polydrug abuse population.

Patients from a polydrug abuse treatment program were titrated with either secobarbital or methaqualone, their primary drug of abuse, to a state of mild intoxication, consisting of lateral and vertical nystagmus, ataxia, slurred speech, and drownsiness. The mean dose required to produce each sign was compared to that determined in a similarly treated control group. Tolerance to secobarbital was more easily demonstrated than tolerance to methaqualone, and nystagmus was the least sensitive indicator of patient tolerance. The individual signs were also cumulated into a graded rating scale of central nervous system depression which would be related to the dose administered. Tolerence was easily demonstrated at the higher stages of toxicity for secobarbital in the overall patient population, but tolerance to methaqualone was only unequivocal in the subjects indicating a relatively high frequency of abuse. Tolerance to methaqualone occurred at the lower stages of toxicity, suggesting that there is a difference between tolerance to secobarbital and tolerance to methaqualone. There was no indication that patients who also abuse alcohol are more tolerant than their patient counterparts. The patients who also had a history of amphetamine abuse, however, were less tolerant than the nonusers of these drugs.