Effect of continuous application of manures and fertilizers on rhizosphere microflora in arecanut palm

Summary The rhizosphere microflora of arecanut palm under continuous application of organic manures and inorganic fertilizers was studied. The nutrients applied are 100 g N, 40 g P₂O₅ and 140 g K₂O/palm/year in the form of organics and inorganics. The application of organic manure increased the microbial population. The increase in microbial population was observed between the rhizosphere samples collected at 0–30cm and 30–60 cm depths. The surface cultivation of soil increased the microbial population.Trichoderma sp. andAspergillus sp. dominated in therhizosphere of arecanut palm. Contribution No. 208. Central Plantation Crops Research Institute, Vittal-574243, Karnataka, India.     

Spatial and temporal changes in epibenthic communities at deep,hard bottom aquaculture sites in Newfoundland

This study explores spatio-temporal changes in epibenthic communities due to salmon aquaculture at deep (>30 m), hard-bottom dominated sites in Newfoundland (Canada). Using a drop-camera approach, we followed changes with production at two aquaculture sites, as well as potential recovery processes at two fallow sites, comparing their epibenthic composition with nearby non-production sites. Multivariate analysis revealed that aquaculture production led to rapid changes in epibenthic communities, as evidenced primarily by the presence of two visual indicators: bacterial mats and opportunistic polychaetes. Due to low taxon richness and abundances, as well as variability among sites, no clear intermediate successional stages were apparent. Beggiatoa-like mats and opportunistic polychaetes appeared rapidly once aquaculture production began; these indicators did not increase in spatial extent during the survey and were typically observed up to 100 m, and occasionally up to 160 m from cages. After 15 months of fallowing, Beggiatoa-like mats and opportunistic polychaetes remained present at sites and were occasionally accompanied by few other taxa, suggesting incomplete recovery.     

Murine splenocyte proliferation by porin of Shigella dysenteriae type 1 and inhibition of bacterial invasion of HeLa cell by anti-porin antibody

Abstract A highly sensitive nested polymerase chain reaction method was designed for the detection of a wide spectrum of strains from Borrelia burgdorferi sensu lato. This technique allows the detection of as little as 3 fg of total genomic DNA extracted and purified from pure cultures of the organism, this amount corresponds to less than 10 organisms. Two sets of primers homologous to conserved spots in the coding region of the hbb gene, encoding a conserved histone-like protein, were constructed. These were based on a multiple sequence alignment of 39 strains representing all the genomic groups described in B. burgdorferi sensu lato.     

Identification of sodC encoding periplasmic [Cu,Zn]-superoxide dismutase in Salmonella

Abstract sodC , encoding [Cu,Zn]-cofactored Superoxide dismutase, once thought to be virtually confined to eukaryotes, has now been described in many Gram-negative pathogens that have their primary niche of colonization in the upper respiratory tract. Their role in host-parasite interactive biology is unknown. We here show that members of the major human and animal enteric pathogenic species Salmonella harbour a version of sodC most closely resembling that found in Brucella abortus . The enzyme it encodes is a novel candidate determinant of virulence in Salmonella , an intracellular pathogen potentially exposed to toxic oxygen free radicals within its intracellular niche.     

Salinity-dependent copy number increase of a marine cyanobacterial endogenous plasmid

Listeria monocytogenes possessed glucose oxidase and NADH oxidase activities in whole cells and lysed protoplasts respectively. The NADH oxidase activity sedimented with the membrane fraction and was inhibited by the respiratory inhibitors rotenone, 2-heptyl-4-hydroxy-quinoline-N-oxide and cyanide, suggesting the presence of a membrane associated respiratory chain.     

Effect of the non-fertilizer N supply of grassland soils on the response of herbage to N fertilization under mowing conditions

I tested whether the non-fertilizer N supply of grassland soils (NFNS; N uptake on unfertilized plots) affects the relationships between N uptake and dry matter production, N application and N uptake, N application and dry matter production, as well as the optimum fertilizer application rate.At low N uptake rates the amount of dry matter production per kg of N uptake was negatively correlated with NFNS; at higher N uptake levels the correlation was not significant. The apparent nitrogen recovery of fertilizer N was not correlated with NFNS. The optimum fertilizer application rate was correlated positively with the maximum dry matter production (Max DM) and negatively with NFNS. The relationship optimum fertilizer application = –81–0.8 × NFNS + 0.0375 × Max DM accounted for 89% of the variance in optimum fertilizer application rate between soils at a marginal N effect of 7.5 kg dry matter per kg N applied. So an increase in NFNS of 100 kg N resulted in a decrease of the optimum N application rate of 80 kg N.     

Physicochemical and microbiological indicators of surface water body contamination with different sources of digestate from biogas plants

Transition from fossil energy sources to biogas production has resulted in a strong increase of leakage accidents from fermenters, but knowledge on the effects of fermentation product runoff into freshwater systems is currently restricted to direct toxicity due to oxygen depletion. This study provides first information about the influence of digestate runoff on the physicochemical habitat properties and the bacterial community composition of the hyporheic interstitial which is important in determining ecosystem functioning. We exposed natural stream beds to different concentrations of two different digestates from fermenters (corn and manure feedstock), hypothesizing that the digestate addition causes acute changes of the physicochemical parameters and has distinct effects on microbial community composition of the hyporheic interstitial depending on concentration and type of digestate. In line with the hypotheses, pH value, conductivity, redox potential and ammonium differed significantly from controls and among treatments after digestate addition, but only for a maximum of two days. pH values (controls: 7.8; corn: 7.9; manure: 7.9) and conductivity (controls: 813 μS/cm; corn: 969 μS/cm; manure: 1097 μS/cm) increased, the redox potential (controls: 153 mV; corn: 145 mV; manure: 144 mV) decreased the first two days. A high peak of ammonium-N was detected in the corn and manure treatments (controls: 5 mg/l, corn: 80 mg/l; manure: 60 mg/l) at day 1. In contrast, changes in bacterial community composition were detectable for longer periods of time (>5 days). Seventeen unique T-RF fingerprints of bacterial community response to each of the different digestate treatments (11 unique T-RFs in manure and 6 unique T-RFs in corn treatments) were found, suggesting that this approach provides a suitable ecological indicator for source tracking, e.g. in case of a biogas power plant leakage accident.