Phenazine carboxylic acid production and rhizome protective effect of endophytic Pseudomonas aeruginosa isolated from Zingiber officinale

Ginger (Zingiber officinale) is cultivated commercially in most parts of the world especially in India for its culinary and medicinal applications. One of the major challenges that limit the yield of ginger is rhizome rot disease caused by organisms including Pythium myriotylum. A feasible ecofriendly method is yet to be devised to prevent the plant from this threatening disease. Recent studies on plant microbiome show the possibility of having endophytic organisms with plant protective characteristics associated with the plants. Because of the uniquely evolved underground nature of the ginger rhizome and its peculiar survival in soil for a long time, many interesting endophytic microbes with plant protective characters can be well expected from it. In the current study, previously isolated endophytic Pseudomonas aeruginosa from ginger was investigated in detail for its effect on Pythium myriotylum. The rhizome protective effect of the organism was also studied by co-inoculation studies, which confirmed that Pseudomonas aeruginosa has very potent inhibitory effect on Pythium myriotylum. On further studies, the active antifungal compound was identified as phenazine 1-carboxylic acid.     

Seasonal variation of fungal spore populations in the atmosphere of Zarqa area,Jordan

Fungi are among the most important aeroallergens. The aim of this study was to provide aeromycological baseline information about Zarqa area, Jordan, for the first time. During the entire survey and from 170 settle plate exposures, a total of 735 mould- and 274 yeast colony-forming units (CFU) were collected. mould colonies were assigned to 35 genera and 59 species. The highest abundance was attributed to Cladosporium with a percentage of 29.1% of the total colony count followed by Fusarium 20%, Alternaria 7.7%, Ulocladium 6.5% Penicillium 4.2% and then Aspergillus 3.6%. Cladosporium showed one peak in October while Aspergillus and Penicillium peaked in September. Fusarium peaked in May and August and Alternaria in March and July. However, Ulocladium showed almost the same abundance from March to June and then in September and December. A double peak in total colony count and fungal diversity was found, the first was in March and the second in November–December. Significant differences of total fungal colony counts favouring the 1500 hours collection time over that at 1000 hours were found between November and January while no such significant differences were obtained between February and April. Our results also indicated differences in species composition between the two periods in different months. Spores of the three abundant species, Cladosporium, Fusarium and Alternaria, might favour high release in the 1500 hours period during winter while having a similar incidence during the two periods in the spring months.     

Online column preconcentration for speciation and selective determination of Cr(III) in natural water samples using flow injection with chemiluminescence detection

A simple, rapid, sensitive and inexpensive approach is described in this work based on a combination of solid-phase extraction of 8-hydroxyquinoline (8HQ), for speciation and preconcentration of Cr(III) and Cr(VI) in river water, and the direct determination of these species using a flow injection system with chemiluminescence detection (FI–CL) and a 4-diethylamino phenyl hydrazine (DEAPH)–hydrogen peroxide system. At different pH, the two forms of chromium [Cr(III) and Cr(VI)] have different exchange capacities for 8HQ, therefore two columns were constructed; the pH of column 1 was adjusted to pH 3 for retaining Cr(III) and column 2 was adjusted to pH 1 for retaining of Cr(VI). The sorbed Cr(III) and Cr(VI) species were eluted from columns using 3.0 ml of 0.1 N of HCl and 3.0 ml of 0.1 N of NaOH, respectively. The flow injection–chemiluminescence (FI–CL) method is based on light emitted due to the oxidation of DEAPH by the H₂O₂ in the presence of Cr(III), which catalyzes the reaction. The flow cell is a transparent coiled tube made from glass (2.0 × 4.0, inner and outer diameter) and located close to the photodetector. The flow parameters: flow rate, sample volume, flow cell length, and distance to the CL detector were studied and optimized. Under optimum flow conditions, the Cr(III) concentration can be determined over the range 5–350 μg L⁻¹ with a limit of detection of 1.2 μg L⁻¹, as the Cr(III) concentration is proportional to the intensity of the CL signal. The relative standard deviations (%) for 10 and 50 μg L⁻¹ Cr(III) were 1.2% and 3.2%, respectively. The effects of Al(III), Cd(II), Zn(II), Hg(II), Pb(II), Co(II), Cu(II), Ni(II), Mn(II), Ca(II), and Fe(III) were investigated. The proposed method is highly selective and sensitive, enabling a rapid determination of the Cr(III) amount in the presence of other interfering metals. Finally, the FI–CL method was examined in five river water samples with excellent recoveries.     

Plant growth promoting potential of endophytic bacteria isolated from Piper nigrum

Piper nigrum is an interesting plant to study the endophytic microbial factors affecting plant growth because of its unique features. Endophytic bacterial isolation from the plant resulted in the isolation of twelve bacterial isolates which were screened for various plant growth promoting properties like phosphate solubilization, ACC deaminase production, siderophore production etc. Interestingly, seven isolates were found to have IAA biosynthetic potential. Bacterial isolates with multiple plant growth promoting properties were studied for their growth promoting effect on Vigna radiata seedlings. This resulted in the identification of Klebsiella sp. (PnB 10) and Enterobacter sp. (PnB 11) as the isolates with excellent growth promoting properties. The results confirm promising applications of the endophytic bacterial isolates obtained in the study and also their possible growth promoting effect in P. nigrum.     

Serum level of prostate-specific antigen (PSA) in women with breast cancer

ObjectiveTo identify the diagnostic role of total and free prostate-specific antigen (TPSA and FPSA) in breast cancer in women.MethodsBlood samples of 55 women with breast cancer were prospectively analyzed for PSA before and after breast surgery, with a control group of 82 healthy women.ResultsTotal and free PSA levels were significantly higher in women with breast cancer (preoperatively) than in healthy women (P < 0.001). Both serum TPSA and FPSA showed a significant decline in their pre-surgical values after surgical removal of the tumor (P < 0.001). A significant proportion of breast cancer patients (83.6%) had free PSA as the predominant molecular form in serum as compared to 0% of controls and 1.8% of postoperative groups (P < 0.001). TPSA and FPSA levels were significantly associated with younger age and earlier cancer stage, whereas no significant association was found between these two variables and FPSA as a predominant molecular form.ConclusionsThis study indicated a clinical significance of preoperative measurement of serum TPSA and FPSA in the diagnosis of women with breast cancer, and may be a useful marker for monitoring the response to treatment.     

Alterations in sucrose metabolizing enzyme activities and total phenol content of Curcuma longa L. as affected by different triazole compounds

Changes in the sucrose metabolism of Curcuma longa L. plants were studied under treatment with different triazole compounds viz., triadimefon (TDM) and propiconazole (PCZ). Plants were treated with TDM at 15 mg/L and PCZ at 10 mg/L separately by soil drenching on 80, 110, and 140 days after planting (DAP). The plants were harvested randomly on 90, 120, and 150 DAP to determine the effect of both the triazoles on sucrose metabolizing enzymes and phenol content. The sucrose metabolism was studied by analyzing sucrose metabolizing enzymes like sucrose synthase and sucrose phosphate synthase. All the analyses were assayed in leaves and tubers of both control and treated plants. It was found that both of the triazole compounds had profound effects on these parameters.