Investigation to identify paint coatings resistive to microorganism growth

All selected coatings contain nutrients that support microbial growth and survival. Incorporation of microbiocidal agents into coatings more susceptible to attack is recommended for improved inhibition of microorganism growth and for increased protection against deterioration of coatings by microorganisms

Biocidal effects of silver Final technical report

Elimination of microbial and viral agents from spacecraft water systems by silver ions from electrolytic ion generato

Contribution of Bacterial Infection to Male Infertility in Nigerians

There is disagreement as to the influence of certain microbial infection on male infertility and such agents are ignored. The incidence of these microbial agents in seminal fluid isolates is on the increase. This study therefore evaluates the prevalence of male factor infertility and contribution of microbial infection to male infertility in Kano, northern Nigeria. Seminal fluid analysis in five hundred males who were investigated for infertility was evaluated using the 5th generation SQ AII C-P sperm quality analyzer and the Neubaeur counting chamber. The result indicates that 58.2% had sperm density less than twenty million per millilitre. The oligospermic subjects (sperm density 2-19 millions/ml) were 27.6%, severe oligospermic (sperm density less than 2 million) 13.2% and azoospermia, 17.4%. Asthenospermia (motility less than 50%) decrease from 44.8% in oligospermia to 24.0% in severe oligospermia. Teratospermia (abnormal morphology greater than 50%) also deteriorated from 46.3% to 35.4% in oligospermic and severe oligospermic males respectively. Seminal fluid infection increases with decreasing sperm density, motility and morphology. The prevalence of abnormal sperm indices and bacterial infection is high and Staphylococcus aureus infection should be treated and no longer ignored in the management of male factor infertility

Microbial profiling of a suppressiveness-induced agricultural soil amended with composted almond shells lead to isolation of new biocontrol agents

Vida et al., 2016. Microbial profiling of a suppressiveness-induced agricultural soil amended with composted almond shells lead to isolation of new biocontrol agents. Biological and integrated control of plant pathogens IOBC-WPRS Bulletin Vol. 117, 2016 pp. 140-143This study focused on the microbial profile present in an agricultural soil that becomes suppressive after the application of composted almond shells (AS) as organic amendments. The role of microbes in the suppression of Rosellinia necatrix, the causative agent of avocado white root rot, was determined after heat-treatment and complementation experiments with different types of soil. Bacterial and fungal profiles based on the 16S rRNA gene and ITS sequencing, the soil under the influence of composted almond shells revealed an increase in Proteobacteria and Ascomycota groups, as well as a reduction in Acidobacteria and Xylariales (where R. necatrix is allocated). Complementary to these findings, functional analysis by GeoChip 4.6 confirmed the improvement of a group of specific probes included in the “soil benefit” category was present only in AS-amended soils, corresponding to specific microorganisms previously described as potential biocontrol agents, such as Pseudomonas spp., Burkholderia spp. or Actinobacteria. Based in such data, a model for the microbial-based suppressiveness is proposed and further isolation of representative microorganisms were performed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The Impact of Triclosan on the Spread of Antibiotic Resistance in the Environment

Triclosan (TCS) is a commonly used antimicrobial agent that enters wastewater treatment plants (WWTPs) and the environment. An estimated 1.1 × 105 to 4.2 × 105 kg of TCS are discharged from these WWTPs per year in the United States. The abundance of TCS along with its antimicrobial properties have given rise to concern regarding its impact on antibiotic resistance in the environment. The objective of this review is to assess the state of knowledge regarding the impact of TCS on multidrug resistance in environmental settings, including engineered environments such as anaerobic digesters. Pure culture studies are reviewed in this paper to gain insight into the substantially smaller body of research surrounding the impacts of TCS on environmental microbial communities. Pure culture studies, mainly on pathogenic strains of bacteria, demonstrate that TCS is often associated with multidrug resistance. Research is lacking to quantify the current impacts of TCS discharge to the environment, but it is known that resistance to TCS and multidrug resistance can increase in environmental microbial communities exposed to TCS. Research plans are proposed to quantitatively define the conditions under which TCS selects for multidrug resistance in the environment

Microbial biofilms: biosurfactants as antibiofilm agents.

Current microbial inhibition strategies based on planktonic bacterial physiology have been known to have limited efficacy on the growth of biofilm communities. This problem can be exacerbated by the emergence of increasingly resistant clinical strains. All aspects of biofilm measurement, monitoring, dispersal, control, and inhibition are becoming issues of increasing importance. Biosurfactants have merited renewed interest in both clinical and hygienic sectors due to their potential to disperse microbial biofilms in addition to many other advantages. The dispersal properties of biosurfactants have been shown to rival those of conventional inhibitory agents against bacterial and yeast biofilms. This makes them suitable candidates for use in new generations of microbial dispersal agents and for use as adjuvants for existing microbial suppression or eradication strategies. In this review, we explore aspects of biofilm characteristics and examine the contribution of biologically derived surface-active agents (biosurfactants) to the disruption or inhibition of microbial biofilms

Metabolism of soluble proteins by rumen microorganisms and the influence of condensed tannins on nitrogen solubility and degradation

The amino acid requirements of ruminants are met by two sources; microbes leaving the rumen and dietary protein escaping fermentation in the rumen. Much ruminant research has therefore focused on improving amino acid supply to the duodenum by increasing both microbial protein synthesis and escape of feed proteins from the rumen. The escape of dietary protein is dependent on the degradation characteristics and retention time in the rumen. The overall aims of this thesis were to increase the knowledge of ruminal degradation of buffer soluble proteins and to investigate the effect of condensed tannins on the degradation. The thesis examines the effect of trichloroacetic acid, perchloric acid, and tungstic acid on detection and recovery of feed peptides and chemically-defined peptides. Twenty-five feeds were screened for buffer soluble protein N. In vitro ruminal degradation rates of buffer soluble proteins were estimated in 11 of these feeds. Buffer soluble protein from peas or cold-pressed rapeseed cake was given as a pulse dose together with a liquid marker to lactating dairy cows, to investigate rumen in vivo degradation rates. The concentration of condensed tannins was determined for birdsfoot trefoil (Lotus corniculatus L.), big trefoil (L. uliginosus Schkur.) and sainfoin (Onobrychis viciifolia Scop.) and related to nitrogen solubility in fresh-frozen and ensiled material and ruminal in vitro degradation. The different protein precipitants did not alter detection of peptides formed in a ruminal in vitro system. The recovery of an eight-residue peptide was 0.66, 0.88, and 0.91 for tungstic acid, perchloric acid, and trichloroacetic acid, respectively. The content of soluble protein N in feeds ranged from 0 to 874 g/kg buffer soluble N with the highest contents for lupine, peas, and cold-pressed rapeseed cake. Fractional degradation rates determined in vitro for soluble protein ranged from 0.18 (linseed cake) to 1.0 /h (casein). Soluble protein from soybean meal, peas, and lupine were degraded at intermediate rates. Soluble proteins given as a pulse dose were rapidly degraded in vivo. Results were disturbed by slow mixing in the rumen. In several cases, concentration of the liquid marker was higher after 1 h than 0.5 h post dosing. Based on two experiments and a total of nine varieties of birdsfoot trefoil, the concentration of condensed tannins determined by a radial diffusion method ranged from 3 to 17 g/kg DM. The tannin content for sainfoin and big trefoil was 21.6 (maximum concentration) and 24.8 g/kg DM, respectively. Buffer N solubility and ruminal in vitro N degradability were negatively correlated to tannin content. Tannin content and wilting time cumulatively reduced buffer soluble nitrogen in birdsfoot trefoil silage. This thesis shows that there is no distinct cut-off for peptide size when using different protein precipitation agents. Soluble proteins degrade at different rates depending on source. As they are not instantly degraded, they must contribute to the dietary amino acid supply of the ruminant. The in sacco method, which assumes complete degradation of soluble proteins should not be used for feeds high in soluble proteins

Enhanced self-healing capacity in cementitious materials by use of encapsulated carbonate precipitating bacteria : from proof-of-concept to reality

In this study, two bacteria-based self-healing systems were developed for the proof-of-concept and approach to a realistic self-healing. A self-healing system with glass capillaries and silica sol gel carried bacterial cells was first built. The bio-CaCO3 formed in-situ (in silica gel) after glass capillaries breakage preliminarily showed the feasibility of this system. The investigation on the selfhealing efficiency demonstrated that the water permeability was decreased by about two orders of magnitude due to self-healing. However, practical application of this system was limited by the use of the un-mixable and expensive glass capillaries. A second self-healing system therefore was built in order to approach a realistic self-healing, by using hydrogel encapsulated bacteria. Great superiority in healing efficiency was obtained in this system. A maximum crack width of 0.5 mm could be healed within 7 days in the specimens of the bacterial series; while the maximum crack width can be healed in other series was in the range of 0.2~0.3 mm. Water permeability was greatly decreased (68%) in the bacterial series