82 research outputs found
Pseudovibrio denitrificans strain Z143-1, a heptylprodigiosin-producing bacterium isolated from a Philippine tunicate
Microbial isolate Z143-1 found to be associated with an unidentified tunicate was characterized due to its significant antimicrobial activity. Z143-1 is similar to Pseudovibrio ascidiaceicola and Pseudovibrio denitrificans in morphological, physiological and biochemical characteristics, except for its ability to ferment glucose and produce a characteristic red pigment. Fatty acid methyl ester analysis revealed a predominance of the fatty acid 18:1 ω7c at 80.55%, at levels slightly lower than the Pseudovibrio denitrificans type strain DN34T (87.7%). The mol% G+C of Z143-1 is 54.02, relatively higher than the Pseudovibrio denitrificans type strain DN34T and Pseudovibrio ascidiaceicola with mol% G+C of 51.7 and 51.4, respectively. However, phylogenetic analysis of the 16S rRNA gene sequence of Z143-1 showed 100% similarity with the Pseudovibrio denitrificans type strain DN34T. In this study, the bacterium Z143-1 is reported as a new strain of Pseudovibrio denitrificans. While there is no report of a secondary metabolite for Pseudovibrio denitrificans, Z143-1 produces the red pigment heptylprodigiosin, also known as 16-methyl-15-heptyl-prodiginine, which shows anti-Staphylococcus aureus activity
Assessment of Chemical Inhibitor Addition to Improve the Gas Production from Biowaste
The coexistence of sulphate-reducing bacteria and methanogenic archaea in the reactors during the anaerobic digestion from sulphate-containing waste could favor the accumulation of sulfide on the biogas, and therefore reduce its quality. In this study, the effect of sulphate-reducing bacteria inhibitor (MoO−2
4 ) addition in a two phase system from sulphate-containing municipal solid waste to improve the quality of the biogas has been investigated. The results showed that although SRB and sulphide production decreased, the use of inhibitor was not effective to improve the anaerobic digestion in a two phase
system from sulphate-containing waste, since a significant decrease on biogas and organic matter removal were observed. Before MoO−2 4 addition the average values of volatile solid were around 12 g/kg, after 5 days of inhibitor use, those values did exceed to 28 g/kg. Molybdate caused acidification in the reactor and it was according to decrease in the pH values. In relation to microbial consortia, the effect of inhibitor was a decrease in Bacteria (44%; 60% in sulphate-reducing bacteria) and Archaea (38%) population
Microbial Community and Chemical Characteristics of Swine Manure during Maturation
Swine diet formulations have the potential to lower animal emissions, including odor and ammonia (NH3). The purpose of this study was to determine the impact of manure storage duration on manure chemical and microbial properties in swine feeding trials. Three groups of 12 pigs were fed a standard corn–soybean meal diet over a 13-wk period. Urine and feces were collected at each feeding and transferred to 12 manure storage tanks. Manure chemical characteristics and headspace gas concentrations were monitored for NH3, hydrogen sulfide (H2S), volatile fatty acids, phenols, and indoles. Microbial analysis of the stored manure included plate counts, community structure (denaturing gradient gel electrophoresis), and metabolic function (Biolog). All odorants in manure and headspace gas concentrations were significantly (p \u3c 0.01) correlated for length of storage using quadratic equations, peaking after Week 5 for all headspace gases and most manure chemical characteristics. Microbial community structure and metabolic utilization patterns showed continued change throughout the 13-wk trial. Denaturing gradient gel electrophoresis species diversity patterns declined significantly (p \u3c 0.01) with time as substrate utilization declined for sugars and certain amino acids, but functionality increased in the utilization of short chain fatty acids as levels of these compounds increased in manure. Studies to assess the effect of swine diet formulations on manure emissions for odor need to be conducted for a minimum of 5 wk. Efforts to determine the impact of diets on greenhouse gas emissions will require longer periods of study (\u3e13 wk)
Measuring emission rates of particulate matter from fan ventilated swine barns
Methods for measuring concentrations and
emission rates of particulate matter (PM) from mechanically ventilated livestock buildings were evaluated in a laboratory facility and in a swine-finishing barn. Concentrations of PM were measured inside the room (room sampling) and at the exhaust duct (exhaust sampling). Concentrations at the exhaust duct were determined using high-volume traverse downstream of the exhaust fan, low-volume traverse downstream of the fan, and fixed sampling upstream and downstream of the fan. The traverse methods, which served as the reference, were conducted under isokinetic conditions; fixed sampling was done under both isokinetic and sub-isokinetic conditions. Compared to the traverse method, both room sampling and exhaust sampling under subisokinetic
conditions overestimated PM concentrations.
Fixed sampling under isokinetic conditions, on the other hand, did not differ
significantly (P>0.05) from the high-volume
traverse method. Thus, isokinetic fixed sampling can be an alternative to the more expensive and time-consuming high-volume PM
traverse method to measure PM concentrations
and emission rates at the exhaust
Air quality in swine-finishing barns
Air quality was assessed in two commercial swine-finishing barns: one naturally
ventilated (NV) and one mechanically ventilated (MV). The concentrations of inhalable dust (IDC), respirable dust (RDC), airborne viable particles, carbon dioxide (CO2), and ammonia (NH3), as well as the air temperature and relative humidity (RH) inside the barns were monitored for 41 weeks. The two barns did not differ significantly (P>0.05) in IDC, RDC, and bioaerosol concentration. Overall mean levels for IDC, RDC, CO2, and NH3 were below the threshold limit values specified by the American Conference of Governmental Industrial Hygienists (ACGIH). However, some measurements exceeded the exposure limits suggested by previous researchers, especially during cold days. In general, the air quality in the two types of buildings was acceptable except under certain conditions (e.g., low ventilation rates during cold weather). In such case, workers and producers may need help or further training to ensure adequate air quality. In addition, under these conditions, workers should wear respiratory protective devices to minimize risk of inhalation of dust, gases, and bioaerosols
Comparison of bioaerosol sampling methods for swine barns
Two bioaerosol sampling methods (Andersen sampler and filtration sampler) were compared. The two samplers were used to assess the bioaerosol loads in two swine
finishing barns. They were similar in terms
of the species of microorganisms sampled.
The persistent strains of microorganisms
were various species of the following genera:
Staphylococcus, Pseudomonas, Bacillus,
Listeria, Enterococcus, Nocardia, Lactobacillus, and Penicillium. However, the
use of Andersen sampler resulted in significantly higher bioaerosol concentrations than the filtration sampler. Thus, it appears that filtration sampling can be used for a qualitative survey of bioaerosols in swine barns while the Andersen sampler is suitable for both quantitative and qualitative assessments
The role of Ran-binding protein 3 during influenza A virus replication
Influenza A virus vRNP nuclear export is CRM1-dependent. Ran-binding protein 3 (RanBP3) is a Ran-interacting protein that is best known for its role as a cofactor of CRM1-mediated cargo nuclear export. In this study, we investigated the role of RanBP3 during the influenza A virus life cycle. We found that RanBP3 was phosphorylated at Ser58 in the early and late phases of infection. Knockdown of RanBP3 expression led to vRNP nuclear retention, suggesting that RanBP3 is involved in vRNP nuclear export. Moreover, we demonstrated that the function of RanBP3 during vRNP nuclear export is regulated by phosphorylation at Ser58, and that RanBP3 phosphorylation is modulated by both PI3K/Akt and Ras/ERK/RSK pathways in the late phase of viral infection.</jats:p
The role of Ran-binding protein 3 during influenza A virus replication
Influenza A virus (family Orthomyxoviridae) is one of the most important human pathogens, causing annual epidemics with significant worldwide mortality, and sporadic but potentially devastating pandemics. The influenza A viral genome encodes 14 proteins and consists of 8 segments of negative-stranded RNA. During infection, the virus exploits the host cell signaling machinery to ensure efficient replication. The PI3K/Akt and Ras/ERK are two of the signaling cascades that are induced for virus survival.
Influenza A virus replicates in the nucleus, hence the newly synthesized RNPs must be exported from the nucleus and exported to the cell membrane. Although the detailed mechanism of vRNP nuclear export is not yet fully elucidated, several studies on this process have begun to emerge. Influenza A virus nucleoprotein nuclear export is CRM1-dependent. Ran-binding protein 3 (RanBP3) is a Ran-interacting protein that is best known for its role as a cofactor of CRM1-mediated cargo nuclear export. In this study, we investigated the role of RanBP3 during the influenza A virus life cycle. We found that RanBP3 was phosphorylated at Ser58 in early and late phases of infection. Knockdown of RanBP3 expression led to a vRNP nuclear retention, suggesting that RanBP3 is involved in vRNP nuclear export. Moreover, we demonstrated that RanBP3’s function during vRNP nuclear export is regulated by phosphorylation at Ser58, and the RanBP3 phosphorylation is modulated by both PI3K/Akt and Ras/ERK/RSK pathways in the late phase of viral infection. In conclusion, this study has shown that RanBP3 is a host factor that has a vital role during the late stage of influenza A virus replication, specifically as a co-factor in CRM1-mediated nuclear export. Identifying this host factor will contribute to the understanding of the mechanism of vRNP transport
Control of Gas and Odor Levels in Swine Facilities Using Filters with Zinc Oxide Nanoparticles
Abstract. The effectiveness of zinc oxide (ZnO) nanoparticles as filtering media for controlling the levels of hydrogen sulfide (H2S), ammonia (NH3), and odor in swine facilities was evaluated in this study. Semi-pilot scale tests were done to determine basic operational factors, the results of which showed that the fluidized bed air filtration system (FBAFS), loaded with ZnO nanoparticles at a rate of 0.28 g cm-2 of filter area, and a gas flow rate equivalent to 0.5 m s-1 face velocity achieved significant reduction in target gas levels. The performance of this filter system was further investigated in a room-scale environmental chamber representative of normal swine production conditions. When installed as part of the ventilation air recirculation system of the room, the FBAFS with ZnO nanoparticles achieved about 65% H2S and 42% NH3 reductions in the human-occupied zones but had no significant impact on pig performance as well as odor levels in the chamber. Keywords: Ammonia, Face velocity, Filtration, Hydrogen sulfide, Nanoparticles, Odor, Swine, Ventilation, Zinc oxide.</jats:p
Proceedings of the Asian-French workshop on food industry: strategic linkages with education and research, 11-14 November 1997, Bangkok, Thaïland
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