1.Genetic analysis of plant endophytic Pseudomonas putida BP25 and chemo-profiling of its antimicrobial volatile organic compounds.
Sheoran N1, Valiya Nadakkakath A2, Munjal V1, Kundu A3, Subaharan K4, Venugopal V4, Rajamma S2, Eapen SJ2, Kumar A5. Microbiol Res. 2015 Apr;173:66-78. doi: 10.1016/j.micres.2015.02.001. Epub 2015 Feb 17.
Black pepper associated bacterium BP25 was isolated from root endosphere of apparently healthy cultivar Panniyur-5 that protected black pepper against Phytophthora capsici and Radopholus similis - the major production constraints. The bacterium was characterized and mechanisms of its antagonistic action against major pathogens are elucidated. The polyphasic phenotypic analysis revealed its identity as Pseudomonas putida. Multi locus sequence typing revealed that the bacterium shared gene sequences with several other isolates representing diverse habitats. Tissue localization assays exploiting green fluorescence protein expression clearly indicated that PpBP25 endophytically colonized not only its host plant - black pepper, but also other distantly related plants such as ginger and arabidopsis. PpBP25 colonies could be enumerated from internal tissues of plants four weeks post inoculation indicated its stable establishment and persistence in the plant system.
2.Hydrocarbon biodegradation and dynamic laser speckle for detecting chemotactic responses at low bacterial concentration.
Nisenbaum M1, Sendra GH, Gilbert GA, Scagliola M, González JF, Murialdo SE. J Environ Sci (China). 2013 Mar 1;25(3):613-25.
We report on the biodegradation of pure hydrocarbons and chemotaxis towards these compounds by an isolated chlorophenol degrader, Pseudomonas strain H. The biochemical and phylogenetic analysis of the 16S rDNA sequence identified Pseudomonas strain H as having 99.56% similarity with P. aeruginosa PA01. This strain was able to degrade n-hexadecane, 1-undecene, 1-nonene, 1-decene, 1-dodecene and kerosene. It grew in the presence of 1-octene, while this hydrocarbons is toxic to other hydrocarbons degraders. Pseudomonas strain H was also chemotactic towards n-hexadecane, kerosene, 1-undecene and 1-dodecene. These results show that this Pseudomonas strain H is an attractive candidate for hydrocarbon-containing wastewater bioremediation in controlled environments. Since the classical standard techniques for detecting chemotaxis are not efficient at low bacterial concentrations, we demonstrate the use of the dynamic speckle laser method, which is simple and inexpensive, to confirm bacterial chemotaxis at low cell concentrations (less than 10(5) colony-forming unit per millilitre (CFU/mL)) when hydrocarbons are the attractants.
3.The potential impact of washing machines on laundry malodour generation.
Stapleton K1, Hill K, Day K, Perry JD, Dean JR. Lett Appl Microbiol. 2013 Apr;56(4):299-306. doi: 10.1111/lam.12050. Epub 2013 Feb 22.
A multidisciplinary approach has been adopted to investigate and identify the source of malodour in washing machines and the potential for cross-contamination of laundry. Four washing machines were olfactively graded, and the number of colony-forming units (CFUs) bacteria was determined in four specific locations. Then, samples of terry-towel and fleece were washed, without the use of detergent, in the machines, and the occurrence of malodour over a 52-h period was assessed. Analysis of the scrapings from the four locations in the two malodorous machines identified a plethora of volatile organic compounds (VOCs) by either olfactory detection or mass spectral identification post-gas chromatographic separation. In addition, microbiological analysis from the swabs from the four locations within all four washing machines was carried out. Quantitative analysis of VOCs from 66 microbiological isolates from either the washing machines or fabrics was carried out.
4.Development of semiochemical attractants for monitoring bean seed beetle, Bruchus rufimanus.
Bruce TJ1, Martin JL, Smart LE, Pickett JA. Pest Manag Sci. 2011 Oct;67(10):1303-8. doi: 10.1002/ps.2186. Epub 2011 May 2.
BACKGROUND: Bruchus rufimanus is a serious pest of field beans. The objective here was to develop a semiochemical-baited trapping system to facilitate monitoring of the pest.