Search results for "bacteria."
showing 10 items of 4757 documents
Insecticidal Activity of Strains of Bacillus thuringiensis on Larvae and Adults of Bactrocera oleae Gmelin (Dipt. Tephritidae)
1999
The olive fly, Bactrocera oleae, is the key pest on olives in the Mediterranean area. The pest can destroy, in some cases, up to 70% of the olive production. Its control relies mainly on chemical treatments, sometimes applied by aircraft over vast areas, with their subsequent ecological and toxicological side effects. Bacillus thuringiensis is a spore-forming soil bacterium which produces a protein crystal toxic to some insects, including the orders of Lepidoptera, Diptera, and Coleoptera and other invertebrates. The aim of this study was to search for isolates toxic to B. oleae. Several hundred B. thuringiensis isolates were obtained from olive groves and olive presses in different areas o…
Ecological Mysteries: is <i>Bacillus thuringiensis</i> a Real Insect Pathogen?
2012
Bacillus thuringiensis ( Bt ) can kill insects and multiply in their bodies, but it can also grow in semi-synthetic media; is found in environments were insects are absent; and has been reported to require midgut-associated bacteria for toxicity. We propose here a novel life cycle for Bt combining insect-based and insect-independent life cycles.
A comparison of infestation patterns by Ixodes ticks in urban and rural populations of the Common Blackbird Turdus merula
2002
Although spatial variation in the patterns of parasite infestations among host populations may have important ecological and epidemiological consequences, the causes underlying such variation are poorly known. In the context of a long-term study on the population biology of Common Blackbirds Turdus merula , we examined the prevalence and intensity of infestation by Ixodes ticks between birds living in rural vs. urban habitats. The overall prevalence of tick infestations was significantly higher in the rural habitat where 74% of individuals ( n = 130) were infested. This result contrasted markedly with the situation in the urban habitat where less than 2% of individuals ( n = 360) carried ti…
Culturable endophytic microbial communities in the circumpolar grass,Deschampsia flexuosain a sub-Arctic inland primary succession are habitat and gr…
2014
Summary Little is known about endophytic microbes in cold climate plants and how their communities are formed. We compared culturable putative endophytic bacteria and fungi in the ecologically important circumpolar grass, Deschampsia flexuosa growing in two successional stages of subarctic sand dune (68°29′N). Sequence analyses of partial 16S rRNA and internal transcribed spacer (ITS) sequences of culturable endophytes showed that diverse bacteria and fungi inhabit different tissues of D. flexuosa. A total of 178 bacterial isolates representing seven taxonomic divisions, Alpha, Beta and Gammaproteobacteria, Actinobacteria, Bacteroidetes, Firmicutes and Acidobacteria, and 30 fungal isolates …
An investigation of the bacteriocinogenic potential of lactic acid bacteria associated with wheat (triticum durum) kernels and non-conventional flours
2008
One hundred and thirty-seven lactic acid bacteria (LAB), previously isolated from wheat (Triticum durum) grains and non-conventional flour samples, were tested for the production of antibacterial substances. A total of 16 strains (5 Enterococcus faecium, 5 Enterococcus mundtii, 4 Pediococcus pentosaceus, 1 Lactobacillus coryniformis and 1 Lactococcus garvieae) were found to inhibit the growth of Listeria innocua. The antibacterial activities were preliminarily investigated for their general behaviour with proteolytic (proteinase K, protease B and trypsin), amylolytic (α-amylase) and lipolytic (lipase) enzymes, after heat treatment, and exposure to different pHs and ethanol concentrations. B…
Differential responses of bacterial and archaeal groups at high taxonomical ranks to soil management
2010
Little is known about abundances of the major bacterial taxa in agricultural soils and how they are affected by fertilization or other agricultural practices. Our aim was to determine the abundance and relative distribution of several bacterial phyla and one class, as well as the archaeal and crenarchaeal communities, and how they were affected by different fertilization regimes to examine whether specific responses of microorganisms could be identified at these high taxonomic ranks. We used real-time PCR with taxa specific primers to quantify the abundance of the Actinobacteria, Acidobacteria, Bacteriodetes, Firmicutes, Gemmatimonadetes, Verrucomicrobia, Alphaproteobacteria and Crenarchaeo…
Aerobic Endospore-forming Bacteria and Soil Invertebrates
2011
The intestinal microbiotas of only a few soil invertebrates such as collembola (springtails), earthworms, nematodes, isopods (woodlice and pill bugs), millipedes and termites have been studied by classical and molecular methods in the last decades. It became obvious that these lower members of the soil biota harbour complex microbial communities that sometimes reach counts of 1011 cells ml−1 in their intestinal tracts. The gut microbiotas of the soil fauna include a variety of microorganisms from all three domains of life (Bacteria, Archaea, Eucarya). The bacterial species can mainly be assigned to the Gram-positive phyla Firmicutes and Actinobacteria as well as the Gram-negative phyla Prot…
Gut Microbiome Analysis In Adult Tropical Gars (Atractosteus tropicus)
2019
AbstractTropical gar (Atractosteus tropicus), is freshwater and estuarine fish that has inhabited the Earth since the Mesozoic era, undergoing limited physiological variation ever since. This omnivorous fish is endemic to southern Mexico and part of Central America. Besides its recognized cultural and scientific relevance, the species has seen remarkable growth in its economic impact due to pisciculture. Previous studies have highlighted the role of microbial communities in fish, particularly those in the gut microbiome, in maintaining their host homeostasis or disease. In this study, we present the first report of the whole taxonomic composition of microbial communities in gut contents of …
Warm and wet: robust lipase-producing bacteria from the indoor environment
2017
Lipases are key biocatalysts with important biotechnological applications. With the aim of isolating robust lipolytic microbial strains, we have analyzed the bacterial communities inhabiting two domestic extreme environments: a thermophilic sauna and a dishwasher filter. Scanning electron microscopy revealed biofilm-forming and scattered microorganisms in the sauna and dishwasher sample, respectively. A culture-independent approach based on 16S rRNA analysis indicated a high abundance of Proteobacteria in the sauna sample; and, a large amount of Proteobacteria, Firmicutes, Cyanobacteria and Actinobacteria in the dishwasher filter. With a culture-dependent approach, we isolated 48 bacterial …
Draft Genome Sequences of Vibrio renopiscarius Strains CECT 8603T and CECT 8604, Two Marine Gammaproteobacteria Isolated from Cultured Gilthead Sea B…
2015
ABSTRACT Vibrio renopiscarius DCR 1-4-2 T (CECT 8603 T ) and DCR 1-4-12 (CECT 8604) were isolated from healthy gilthead sea bream ( Sparus aurata ) from Mediterranean fish farms (Castellón, Spain). Their draft genome sequences (30 and 44 contigs, respectively) have 4.3 Mbp and a G+C content of 45.2 mol% and contain almost 3,700 protein-encoding genes.