Study of the Effect of Low-Temperature Plasma Exposure on Mould Fungi Colonizing Paper

The influence of radiofrequency cold plasma in ambient air at 200 Pa pressure on mould fungi of the genus Aspergillus was studied. It was shown that 20 min plasma treatment of paper with mould and contamination reduced the number of colony forming units but didn't lead to complete suppression of fungal viability. Strains of A. versicolor after plasma treatment lost the ability to excrete pink pigment to the environment. A. niger strains were more resistant and kept acidification ability. One of the possible plasma inactivation factors was formation of reactive hydroxyl (OH) radical

ВОЗДЕЙСТВИЕ НИЗКОТЕМПЕРАТУРНОЙ ГАЗОРАЗРЯДНОЙ ПЛАЗМЫ НА ГРИБЫ РОДА ASPERGILLUS, КОЛОНИЗИРУЮЩИЕ БУМАГУ

It was found that the exposure to low-temperature gas discharge plasma at atmospheric pressure is an effective way of paper cleaning from fungal spores. This effect is explained by the specific mechanisms of micro-discharges excitation and maintaining that ensure efficient (up to 90 %) reduction in the number of viable mould spores without local heating biopolymeric materials.Изучено влияние низкотемпературной плазмы ВЧ, СВЧ и барьерного разрядов на жизнеспособность грибов-колонизаторов бумаги рода Aspergillus. Выявлена высокая эффективность плазмы барьерного разряда по сравнению с другими типами разрядов для деконтаминации материалов на биополимерной основе

Going Solo: Discovery of the First Parthenogenetic Gordiid (Nematomorpha: Gordiida)

Despite the severe fitness costs associated with sexual reproduction, its persistence and pervasiveness among multicellular organisms testifies to its intrinsic, short-term advantages. However, the reproductive assurance hypothesis predicts selection favoring asexual reproduction in sparse populations and when mate finding is difficult. Difficulties in finding mates is especially common in parasites, whose life cycles involve multiple hosts, or being released from the host into the external environment where the parasite can find itself trapped without a sexual partner. To solve this problem and guarantee reproduction, parasites in numerous phyla have evolved reproductive strategies, as predicted by the reproductive assurance hypothesis, such as hermaphroditism or parthenogenesis. However, this type of strategy has not been reported from species in the phylum Nematomorpha, whose populations have often been described as sparse. A new Nematomorpha species, Paragordius obamai n. sp., was discovered from Kenya, Africa, and appears to have solved the problem of being trapped without a mate by eliminating the need for males. Paragordius obamai n. sp. represents the first and only known species within this phylum to reproduce asexually. To determine the mechanism of this mating strategy, we ruled out the involvement of reproduction manipulating endosymbionts by use of next generation sequencing data, thus suggesting that parthenogenesis is determined genetically and may have evolved as a means to assure reproduction. Since this new parthenogenetic species and a closely related gonochoristic North American congener, P. varius, are easy to propagate in the laboratory, these gordiids can be used as model systems to test hypotheses on the genetic advantages and disadvantages of asexual reproduction and the genetic determinants of reproductive strategies in parasites

Microbiomes of ant castes implicate new microbial roles in the fungus-growing ant Trachymyrmex septentrionalis

Fungus-growing ants employ several defenses against diseases, including disease-suppressing microbial biofilms on their integument and in fungal gardens. Here, we compare the phenology of microbiomes in natural nests of the temperate fungus-growing ant Trachymyrmex septentrionalis using culture-dependent isolations and culture-independent 16S-amplicon 454-sequencing. 454-sequencing revealed diverse actinobacteria associated with ants, including most prominently Solirubrobacter (12.2–30.9% of sequence reads), Pseudonocardia (3.5–42.0%), and Microlunatus (0.4–10.8%). Bacterial abundances remained relatively constant in monthly surveys throughout the annual active period (late winter to late summer), except Pseudonocardia abundance declined in females during the reproductive phase. Pseudonocardia species found on ants are phylogenetically different from those in gardens and soil, indicating ecological separation of these Pseudonocardia types. Because the pathogen Escovopsis is not known to infect gardens of T. septentrionalis, the ant-associated microbes do not seem to function in Escovopsis suppression, but could protect against ant diseases, help in nest sanitation, or serve unknown functions

The gut microbiota of Colombians differs from that of Americans, Europeans and Asians

ABSTRACT: The composition of the gut microbiota has recently been associated with health and disease, particularly with obesity. Some studies suggested a higher proportion of Firmicutes and a lower proportion of Bacteroidetes in obese compared to lean people; others found discordant patterns. Most studies, however, focused on Americans or Europeans, giving a limited picture of the gut microbiome. To determine the generality of previous observations and expand our knowledge of the human gut microbiota, it is important to replicate studies in overlooked populations. Thus, we describe here, for the first time, the gut microbiota of Colombian adults via the pyrosequencing of the 16S ribosomal DNA (rDNA), comparing it with results obtained in Americans, Europeans, Japanese and South Koreans, and testing the generality of previous observations concerning changes in Firmicutes and Bacteroidetes with increasing body mass index (BMI). Results: We found that the composition of the gut microbiota of Colombians was significantly different from that of Americans, Europeans and Asians. The geographic origin of the population explained more variance in the composition of this bacterial community than BMI or gender. Concerning changes in Firmicutes and Bacteroidetes with obesity, in Colombians we found a tendency in Firmicutes to diminish with increasing BMI, whereas no change was observed in Bacteroidetes. A similar result was found in Americans. A more detailed inspection of the Colombian dataset revealed that five fiber-degrading bacteria, including Akkermansia, Dialister, Oscillospira, Ruminococcaceae and Clostridiales, became less abundant in obese subjects. Conclusion: We contributed data from unstudied Colombians that showed that the geographic origin of the studied population had a greater impact on the composition of the gut microbiota than BMI or gender. Any strategy aiming to modulate or control obesity via manipulation of this bacterial community should consider this effect

Microbial analysis of in situ biofilm formation in drinking water distribution systems: implications for monitoring and control of drinking water quality.

Biofilm formation in drinking water distribution systems (DWDS) is influenced by the source water, the supply infrastructure and the operation of the system. A holistic approach was used to advance knowledge on the development of mixed species biofilms in situ, by using biofilm sampling devices installed in chlorinated networks. Key physico-chemical parameters and conventional microbial indicators for drinking water quality were analysed. Biofilm coverage on pipes was evaluated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The microbial community structure, bacteria and fungi, of water and biofilms was assessed using pyrosequencing. Conventional wisdom leads to an expectation for less microbial diversity in groundwater supplied systems. However, the analysis of bulk water showed higher microbial diversity in groundwater site samples compared with the surface water site. Conversely, higher diversity and richness were detected in biofilms from the surface water site. The average biofilm coverage was similar among sites. Disinfection residual and other key variables were similar between the two sites, other than nitrates, alkalinity and the hydraulic conditions which were extremely low at the groundwater site. Thus, the unexpected result of an exceptionally low diversity with few dominant genera (Pseudomonas and Basidiobolus) in groundwater biofilm samples, despite the more diverse community in the bulk water, is attributed to the low-flow hydraulic conditions. This finding evidences that the local environmental conditions are shaping biofilm formation, composition and amount, and hence managing these is critical for the best operation of DWDS to safeguard water quality

THE EFFECT OF LOW-TEMPERATURE GAS DISCHARGE PLASMA ON FUNGI OF THE GENUS ASPERGILLUS COLONIZING PAPER

It was found that the exposure to low-temperature gas discharge plasma at atmospheric pressure is an effective way of paper cleaning from fungal spores. This effect is explained by the specific mechanisms of micro-discharges excitation and maintaining that ensure efficient (up to 90 %) reduction in the number of viable mould spores without local heating biopolymeric materials

The effect of low-temperature gas discharge plasma on fungi of the genus Aspergillus colonizing paper

Изучено влияние низкотемпературной плазмы ВЧ, СВЧ и барьерного разрядов на жизнеспособность грибов-колонизаторов бумаги рода Aspergillus. Выявлена высокая эффективность плазмы барьерного разряда по сравнению с другими типами разрядов для деконтаминации материалов на биополимерной основе. It was found that the exposure to low-temperature gas discharge plasma at atmospheric pressure is an effective way of paper cleaning from fungal spores. This effect is explained by the specific mechanisms of micro-discharges excitation and maintaining that ensure efficient (up to 90 %) reduction in the number of viable mould spores without local heating biopolymeric materials