15 research outputs found
STUDY OF THE CONTAMINATING MICROBIOTA OF OLD PAPER SUPPORTS
Biodeterioration has drawn the attention of different specialists who started to cooperate and to understand the need of joint research to have a picture as comprehensive as possible of the degradation agents and the measures that can be taken to salvage the heritage assets. This paper contains a description of the microbiota identified in two types of old paper supports part of a private collection from North Moldavia (Romania), namely a church book from the end of the 19th century for which the paper was obtained manually from textile fibres, and a book from 1870 with paper from cellulose pulp derived from wood. To the purpose of identifying the types of bacteria and fungi present on the supports examined, several comments were made related to the morphology of the colonies developed on the growth medium, which provided important indications for the determination based on the microscopical examination as well. Bacterial contamination (of the genera Bacillus, Clostridium, Pseudomonas and Micrococcus) was detected in most samples collected. The diversity of the fungi isolated from the paper supports (the genera Penicillium, Alternaria) is the result of the fact that since they are highly hygroscopic materials, they have the capability to retain water more easily, which stimulates fungal growth. The investigations made to determine the presence of microorganisms responsible for degradation and their identification allowed the discovery and acertainment of the real and justified need to find ways to prevent biodeterioration or to inactivate and destroy biodeteriogens by non-invasive, eco-friendly chemical and physical treatments
Illustration of different modalities of Role-Play for Medical Communication Skills at Undergraduate Level
Role-play is commonly used as a learning method for teaching communication in medical institutions and there two types of role-play i.e. Round Robin and Relay`s methods. This study among our students and trainers to identify which role-play has better effect on students learning at college of Medicine, King Faisal University, Al Ahsa. All the first year students and trainers were included in the study. Students are divided into different groups and each group contains 9 – 11 students. Different scenarios are provided to the students with each physician and patient role. A pre-structured questionnaire was distributed among students and trainers to compare between the Role-play methods. The questionnaire included 15 statements related to the role-play methods based on Likert scale. Wilcoxon signed-rank test was applied to compare different items for both methods and to obtain p-value. The results showed that 221 students and 25 trainers filled the questionnaire. The Round Robin was found to have more influence on students` perception as compared to that for Relay`s except for item 4 i.e. role-play builds a team work where majority of participants agreed for Relay`s method. Similar results were found while checking perception of trainers. The results of statistical test for comparing both methods suggest that there is a significant difference in Round Robin and Relay`s method for most of the questions P- value < 0.05. We found that both methods of role-play used in communication skills sessions are helpful however, Round robin method has better outcome on learning as compared to Relay`s metho
Lignicolous Basidiomycetes as Valuable Biotechnological Agents
Lignicolous basidiomycetes are highly specialized organisms that are capable of degrading lignin, one of the most abundant and resistant organic compounds. Through their enzymes and secondary metabolites, these fungi have a great potential that can be successfully used in various biotechnological processes, ranging from mycoremediation of different pollutants and isolation of bioactive molecules with applications in the pharmacological industry and agriculture, as biocontrol agents of phytopathogens
Lipopeptides produced by Bacillus subtilis as new biocontrol products against fusariosis in ornamental plants
National audienceIn this study, we have investigated the effects of three lipopeptides (fengycin, surfactin and mycosubtilin) produced by different strains of Bacillus subtilis against the phytopathogenic fungi Fusarium oxysporum f. sp. iridacearum, which affects the ornamental bulb plant populations of Iris sp. The antifungal effects were tested using minimum inhibitory concentration assay, determination of mycelium growth and spore germination inhibition rates. Also, in vivo tests on infected rhizomes and scanning electron microscopy were employed. Mycosubtilin alone and in combination with fengycin or/and surfactin showed potent inhibitory activity at concentrations as low as 5gml(-1) which is 100 times lower compared to Topsin M, a common chemical fungicide frequently used against fusariosis in ornamental plants. An enhancement of mycosubtilin antifungal activity was observed when it was used in combination with surfactin due to a synergistic effect. At a concentration of 20gml(-1), mycosubtilin inhibited the growth of the mycelium up to 49% and the spore germination ability up to 26% in comparison to control. In addition, significant changes on the macro- and micro-morphology have been observed. The antifungal activity is related to the inhibition of spore germination and the irreversible damage of the hyphae cell wall. To the best of our knowledge, this is the first attempt to propose the lipopeptides as biopesticides against the fusariosis of ornamental plants
SPATIAL DISTRIBUTION OF SOME ECTOMYCORRHIZAL FUNGI (RUSSULACEAE, FUNGI, BASIDIOMYCOTA) IN FOREST HABITATS FROM THE NORTH-EAST REGION (ROMANIA)
Ectomycorrhizal macromycetes are, generally, an important ecological component for forest habitats, and a valuable resource in the context of sustainable development of rural communities in the North-East Region of Romania. The woody species distribution is an extremely important factor for the ECM macromycetes presence. The purpose of this study was to elaborate maps of potential distribution for some ECM edible macromycetes from Russula and Lactarius genera, based on chorological information, ICAS Forest Types Map, vegetation tables and bibliographical sources. These information allowed the elaboration of 15 potential maps of distribution for 15 edible species of Russula and Lactarius. The study was based entirely on the plant – fungal associations. The results highlighted that in the North-East Region of Romania there is a noteworthy potential for Russulaceae species. As expected, there is a large amplitude of species presence in the field depending on the fungal specificity for tree host and tree species distribution