Description: Andisol in farmland located in Hokkaido, Japan, is known to actively flux nitrous oxide (N 2 O) during the spring to summer seasons. Using a culturing system which mimics farm soils, nitrous oxide (N 2 O) emission potentials of the soils or soil microorganisms were investigated. A total of thirty-three soil samples from the farmland showed high N 2 O production potential, of which the maximum level of N 2 O emission was 3.69 μg per ml of the cultured medium per day (ml –1 d –1 ) in the assay system. However, only three eubacteria ( Leptothrix sp., Paenibacillus sp., and Streptomyces sp.) were isolated as culturable N 2 O emitters among a total of 92 bacterial isolates and 2 fungi obtained from the assayed soil suspensions. N 2 O production from all the isolated N 2 O emitters was more active within a weakly acidic region (pH 4.5–5.0) than neutral regions. However, unlike N 2 O emitters isolated from tropical peat soils, they did not respond to supplemental 0.5% sucrose. In the acetylene inhibition assay for the evaluation of complete denitrification, Leptothrix sp. P3-15D and Streptomyces sp. M2-0C indicated that these culturable N 2 O emitters are not effective denitrifiers but weak N 2 O emitters in the Andisol. Conversely, Rhodococcus sp. that was isolated from the Andisol collected in another season using a KNO 3 -enriched plate, showed 3.2-fold higher N 2 O emission with 10% C 2 H 2 . Instead of the culturable bacteria, it is probable that the N 2 O emitters in viable but non-culturable (VBNC) state or obligately anaerobic denitrifiers are the major contributors to N 2 O emission from the vitric Andisol. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Description: As well as for chemical and environmental reasons, acrylamide is widely used in many industrial applications. Due to its carcinogenicity and toxicity, its discharge into the environment causes adverse effects on humans and ecology alike. In this study, a novel acrylamide-degrading yeast has been isolated. The isolate was identified as Rhodotorula sp. strain MBH23 using ITS rRNA analysis. The results showed that the best carbon source for growth was glucose at 1.0% (w/v). The optimum acrylamide concentration, being a nitrogen source for cellular growth, was at 500 mg l –1 . The highest tolerable concentration of acrylamide was 1500 mg l –1 whereas growth was completely inhibited at 2000 mg l –1 . At 500 mg l –1 , the strain MBH completely degraded acrylamide on day 5. Acrylic acid as a metabolite was detected in the media. Strain MBH23 grew well between pH 6.0 and 8.0 and between 27 and 30 °C. Amides such as 2-chloroacetamide, methacrylamide, nicotinamide, acrylamide, acetamide, and propionamide supported growth. Toxic heavy metals such as mercury, chromium, and cadmium inhibited growth on acrylamide. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Description: A biosurfactant producing Pseudomonas aeruginosa RS29 (identified on the basis of 16S rDNA analysis) with good foaming and emulsification properties has been isolated from crude oil contaminated sites. Optimization of different environmental factors was carried out with an objective to achieve maximum production of biosurfactant. Production of biosurfactant was estimated in terms of surface tension reduction and emulsification (E24) index. It was recorded that the isolated strain produced highest biosurfactant after 48 h of incubation at 37.5 °C, with a pH range of 7–8 and at salinity 〈0.8% (w/v). Ammonium nitrate used in the experiment was the best nitrogen source for the growth of biomass of P. aeruginosa RS29. On the other hand sodium and potassium nitrate enhanced the production of biosurfactant (Surface tension, 26.3 and 26.4 mN/m and E24 index, 80 and 79% respectively). The CMC of the biosurfactant was 90 mg/l. Maximum biomass (6.30 g/l) and biosurfactant production (0.80 g/l) were recorded at an optimal C/N ratio of 12.5. Biochemical analysis and FTIR spectra confirmed that the biosurfactant was rhamnolipid in nature. GC-MS analysis revealed the presence of C 8 and C 10 fatty acid components in the purified biosurfactant. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Description: Bacillus thuringiensis ( Bt ) strains were isolated from 94 samples from different geographical regions. Novel types of crystalline inclusion bodies were observed from some of the isolates. Crystalline inclusions of bipyramidal, spherical and cuboidal morphology were found produced by most of the isolates. Isolate GS12 showed crystal on one side of spore while isolate GM108 formed crystals on both termini of spore. Isolate GN31 produced large sized bipyramidal crystals. SDS-PAGE analysis of the spore crystal suspension showed major protein bands in the range of 29 and 140 kDa. Two new serovars of Bt viz. GS4 and GN24 having H3abce and H3ab serotype respectively were isolated. Toxicity comparable to the reference strain Bacillus thuringiensis subs. kurstaki ( Btk ) HD-1 was observed for the isolates GM20, GM17 and MP3 against larvae of Helicoverpa armigera . Some of the isolates harboring cry genes like cry1Ac and cry2 did not show any toxicity towards H. armigera while most of the isolates were harboring cry1, cry1Ac and cry2 gene. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Description: NMR solution structure of the antifungal protein PAF (pdb code: 2kcn). (The figure was generated by Ádám Fizil and Gyula Batta, Debrecen, Hungary)

Description: Ergosterol is the main component of the fungal membrane and is not found in plants or other microbial cells. Therefore, it can be a useful biomarker for the quantification of fungal biomass. We are now reporting the first isolation and characterisation of ergosterol from the mycelium of G. boninense . The ergosterol structure was detected by Thin Liquid Chromatography (TLC) and Ultra Performance Liquid Chromatography (UPLC) and confirmed with Gas Chromatography coupled with Mass Spectrometry (GCMS) and Nuclear Magnetic Resonance (NMR) analysis. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Description: Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia, and adherence to host cells is a key step in the pathogenic process. Although trimeric autotransporter adhesins (TAAs) were identified in many pathogenic bacteria in recent years, none in A. pleuropneumoniae have been characterized. In this study, we identified a TAA from A. pleuropneumoniae , Apa, and characterized the contribution of its amino acid residues to the adhesion process. Sequence analysis of the C-terminal amino acid residues of Apa revealed the presence of a putative translocator domain and six conserved HsfBD1-like or HsfBD2-like binding domains. Western blot analysis revealed that the 126 C-terminal amino acids of Apa could form trimeric molecules. By confocal laser scanning microscopy, one of these six domains (ApaBD3) was determined to mediate adherence to epithelial cells. Adherence assays and adherence inhibition assays using a recombinant E. coli- ApaBD3 strain which expressed ApaBD3 on the surface of E. coli confirmed that this domain was responsible for the adhesion activity. Moreover, cellular enzyme-linked immunosorbent assays demonstrated that ApaBD3 mediated high-level adherence to epithelial cell lines. Intriguingly, autoagglutination was observed with the E. coli- ApaBD3 strain, and this phenomenon was dependent upon the association of the expressed ApaBD3 with the C-terminal translocator domain. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Description: The yeast strains VKM Y-2977 and VKM Y-2978, derived from the isolate Pa-202, were examined for their physiological properties and mycocin sensitivities and studied by light, phase-contrast, fluorescence, transmission and scanning electron microscopy. The cells of the first strain produced long stalk-like conidiophores, whereas the cells of the second one had the appearance of a typical budding yeast under the light microscope. Transmission and scanning electron microscopy showed the formation of stalk-like conidiophores and long necks in VKM Y-2977, similar in appearance to Fellomyces fuzhouensis . The actin cytoskeleton, microtubules and nuclei were similar as well, but due to presence of a capsule, they were not clearly visible. The second isolate, VKM Y-2978, had very short stalk-like conidiophores, and the neck, microtubules and actin cables were shorter as well. The actin patches, actin cables, and microtubules were similar in VKM Y-2977 and VKM Y-2978 and not clearly visible. The physiological characteristics and mycocin sensitivity patterns, together with the microscopic structures and ultrastructures, led us to conclude that both strains belong to Fellomyces penicillatus , even though they differ in the lengths of their stalk-like conidiophores and necks. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Description: Bacteria in a biofilm have a co-dependent lifestyle resulting in a harmonized and complex coordination of the bacterial cells within an exopolysaccharide (EPS) matrix. We hypothesized that biofilm formation and EPS production in salt-tolerant bacteria are helpful for plant growth improvement in saline soil, but that they are influenced differently. To investigate this hypothesis, we tested the effect of different salinity levels on the biofilm formation of the bacterial strains PAa6 ( Halomonas meridiana ), HT2 ( Kushneria indalinina ) and ST2 ( Halomonas aquamarina ) on different abiotic and biotic surfaces. Maximum biofilm formation was established at 1 M salt concentration. However, EPS production was maximal at 0–1 M NaCl stress. We also studied the effect of salt stress on EPS produced by the bacterial strains and confirmed the presence of EPS on Cicer arietinum var. CM 98 roots and in soil at different salinity levels, using Alcian blue staining. Overall, the strain PAa6 was more effective in biofilm formation and EPS production. Under saline and non-saline conditions, this strain also colonized the plant roots more efficiently as compared to the other two strains. We conclude that the strain PAa6 has the potential of biofilm formation and EPS production at different salinity levels. The presence of EPS in the biofilm helped the bacterial strains to better colonize the roots. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)