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1.
Saving camels from straws: how propagule pressure-based prevention policies can reduce the risk of biological invasion 总被引:1,自引:0,他引:1
Nonnative species that harm or have the potential to cause harm to the environment, economy, or human health are known as
invasive species. Propagule pressure may be the most important factor in establishment success of nonnative species of various
taxa in a variety of ecosystems worldwide, and strong evidence is emerging that propagule pressure determines both the scale
of invasion extent and impact. In a limited way, the US government is applying a “propagule pressure approach” in a variety
of prevention policy contexts aimed at minimizing the impact of harmful organisms. However, there are also readily apparent
opportunities for enacting propagule pressure-based measures to fill current gaps in invasive species prevention and control
at national, state, and local levels. An explicit focus on propagule pressure-based policies could substantially increase
the effectiveness of US efforts to prevent the introduction of invasive species through by intentional and unintentional introductions.
The views expressed in this paper are solely those of the authors and do not necessarily reflect those of the US government.
“As the last straw breaks the laden camel’s back...”
-Charles Dickens, Dombey and Son 相似文献
2.
The molecular biology of barophilic bacteria 总被引:3,自引:1,他引:3
Many microorganisms from the deep-sea display high-pressure-adapted — also described as barophilic or piezophilic — growth
characteristics. Phylogenetic studies have revealed that a large proportion of the barophilic bacteria currently in culture
collections belong to a distinct subgroup of the genus Shewanella, referred to as the “barophile branch.“ Many of the basic properties of barophiles that enable their survival at extremes
of pressure remain to be elucidated. However, several genes whose expression is regulated by pressure, or which appear to
be critical to baroadaptation, have been uncovered. One such operon, whose presence appears to be restricted to the “barophile
branch,” has been identifed in DNA samples obtained from sediments recovered in the deepest ocean trench. In the case of another
set of pressure-regulated genes, regulatory elements required for pressure signaling have been uncovered. The nature and regulation
of these genes is discussed.
Received: February 19, 1997 / Accepted: March 3, 1997 相似文献
3.
Minetaka Sugiyama Kazuo Yamagishi Yeon-Hee Kim Yoshinobu Kaneko Masafumi Nishizawa Satoshi Harashima 《Applied microbiology and biotechnology》2009,84(6):1045-1052
A fundamental issue in biotechnology is how to breed useful strains of microorganisms for efficient production of valuable
biomaterials. On-going and more recent developments in gene manipulation technologies and chromosomal and genomic modifications
in particular have facilitated important contributions in this area. “Chromosome manipulation technology” as an outgrowth
of “gene manipulation technology” may provide opportunities for creating novel strains of organisms with a variety of genomic
constitutions. A simple and rapid chromosome splitting technology called “PCR-mediated chromosome splitting” (PCS) that we
recently developed has made it possible to manipulate chromosomes and genomes on a large scale in an industrially important
microorganism, Saccharomyces cerevisiae. This paper focuses on recent advances in molecular methods for altering chromosomes and genome in S. cerevisiae featuring chromosome splitting technology. These advances in introducing large-scale genomic modifications are expected to
accelerate the breeding of novel strains for biotechnological purposes, and to reveal functions of presently uncharacterized
chromosomal regions in S. cerevisiae and other organisms. 相似文献
4.
Gülhan Vardar-Ünlü Sibel Silici Mehmet Ünlü 《World journal of microbiology & biotechnology》2008,24(7):1011-1017
The antibacterial activity of propolis has been widely investigated. Since reports dealing with antimicrobial activity of
the origin of propolis are not available, this study was carried out aiming to analyse the in vitro antimicrobial activity
of the methanol extracts of poplar type propolis and Populus (Populus nigra, P. alba, P. tremuloides) buds as its sources against standard strains of a panel of microorganisms by determining the minimum inhibitory concentration
(MIC) and minimum bactericidal concentration (MBC). The concentrations of the “poplar” phenolics were relatively high (4.5%)
and some compounds typical for P. nigra such as pinobanksin and 4,3 acetyloxycaffeate were found in the propolis sample by GC-MS. The poplar type propolis and Populus
bud exudates were found to inhibit most clinically important microorganisms in a wide spectrum including pathogenic yeasts
but not Gram-negative bacteria. 相似文献
5.
Wang X Schlossmacher U Wiens M Schröder HC Müller WE 《Marine biotechnology (New York, N.Y.)》2009,11(1):99-108
Polymetallic/ferromanganese nodules (Mn-nodules) have been assigned a huge economic potential since they contain considerable
concentrations of manganese, copper, nickel, iron, and cobalt. It has been assumed that they are formed by, besides hydrogenous,
nonbiogenic processes, biogenic processes based on metabolic processes driven by microorganisms. In the present study, we
applied the techniques of digital optical microscopy and high-resolution scanning electron microscopy to search for microorganisms
in Mn-nodules. They were collected from the Clarion-Clipperton Zone in the Eastern Pacific Ocean and are composed of Mn (23.9%),
Cu (0.69%), Ni (1.02%), Fe (10.9%), and Co (0.29%). These Mn-nodules, between 2.3 and 4.8 cm, show a distinct lamination;
they are composed of small-sized micronodules, 100 to 450 μm in size, which are bound together by an interstitial whitish
material. In the micronodules, a dense accumulation of microorganisms/bacteria could be visualized. Only two morphotypes exist:
(1) round-shaped cocci and (2) elongated rods. The cocci (diameter: ≈3.5 μm) are arranged in bead-like chains, while the rods
(≈2 × 0.4 μm) are arranged either as palisades or in a linear row. Energy-dispersive X-ray spectroscopy analyses showed that
the areas rich in microorganisms/bacteria are also rich in Mn, while in regions where no microorganisms are found, the element
Si is dominant. We suggest that growth of the Mn-nodules starts with the formation of “micronodules.” The formation of micronodules
is assumed to be mediated by microorganisms. After accretion of biogenic and additional nonbiogenic minerals, the micronodules
assemble to large nodules on the sea floor through additional inclusion of nonbiogenic material. 相似文献
6.
S. Even B. Thouvenin N. Bacq G. Billen J. Garnier L. Guezennec S. Blanc A. Ficht P. Le Hir 《Hydrobiologia》2007,588(1):13-29
Within the framework of the European Water Framework Directive, the Seine-Normandie Water Agency has defined prospective scenarios
describing possible trends of evolution of the pressures on water resources. In order to evaluate the resulting water quality
improvement or degradation of water bodies in the Seine river basin, an integrated modelling was proposed. The approach consisted
in coupling three models, the seneque model for upstream sub-basins, the ProSe model for the Seine river and main tributaries and finally the s
i
am1d model for the downstream estuary. After consistency verification, the integrated model was applied to scenarios proposed
by the Seine-Normandie Water Agency. As a result of improvement in the nitrogen treatment by waste water treatment plants,
the annual load of ammonia at the basin scale will be reduced by 65%. The oxygen and ammonia criteria in the estuary will
improve from “bad” to “good”. However the nitrate criteria will remain “poor”, given the strong influence of non-point sources.
Despite a 70–75% drop of the point orthophosphate loads, the criteria for this variable will also remain “poor”. The nutrient
levels will be high enough to maintain eutrophication in the system; a general trend to a shift from N-limitation to P-limitation
will be accentuated. 相似文献
7.
Atmospheric culturable bacteria associated with meteorological conditions at a summer-time site in the mid-Willamette Valley,Oregon 总被引:1,自引:0,他引:1
Bruce Lighthart Brenda T. Shaffer A. Shelby Frisch Dorothea Paterno 《Aerobiologia》2009,25(4):285-295
A set of simultaneously collected quantitative measurements of 12 meteorological and 6 culturable atmospheric bacterial (CAB)
variables was made over a grass seed field during several early, mid, and late summer days. The observation site was located
between the Cascade and Coastal Mountain Ranges near Corvallis in the Willamette Valley, Oregon. Principal component analysis
identified those meteorological variables that had the highest loadings in six eigenvectors that account for 95.9% of variation
in the data factors, i.e., temperature @ 6.3 m above ground level (AGL), wind velocity @ 10.0 m AGL, wind velocity difference
@ 1.7–10.0 m, barometric pressure, wind direction standard deviation, and wind direction. When these variables were used in
a cluster analysis, they formed three statistically distinct meteorological variable clusters with means at ca. “midnight”,
ca. “midday”, and ca. “evening.” The highest mean density of CAB (i.e., 153.4 ± 162.5 CFU/m3) was associated with the “midday” meteorological Cluster-1 that had warm, dry “gentle breezes” from the southeast, in the
relatively bacteria loaded Willamette Valley air. The lowest mean density of CAB (i.e., 35.5 ± 24.1 CFU/m3) was associated with meteorological Cluster-3 in the late afternoon and “evening” occurring during the hottest and driest
part of the day with “fresh breezes” coming from the north northwest in air off the Pacific Ocean. Finally, the last cluster,
Cluster-2 occurred about midnight and had an intermediate density of CAB (74.2 ± 76.2 CFU/m3) in “light air” coming from the northwest, perhaps off the Pacific Ocean. The CAB associated with each of the three meteorological
clusters was only partially statistically distinct. Partially because the CAB in both the Pacific Ocean derived air masses
of the “evening” Cluster-3 and “midnight” Cluster-2 were not statically separable, though both were statistically separable
from the midday, Willamette Valley derived Cluster-1. Further indicating their common source, both Pacific Ocean derived air
masses had very similar percentages of pigmented bacteria, which were dissimilar to the pigmented bacterial population density
in the Willamette Valley air masses. In short, it is speculated that “midnight” atmosphere may simply contain the settling
concentrated residual bacterial particles in the abated fresh Pacific Ocean breezes after sundown. It is clearly shown that
with the methods employed, it is possible to associate the uniqueness of the quantity, and to a lesser extent the quality,
of the CAB population with the atmospheric conditions reported herein. From this project comes speculation that the strategies
relating the quasi-conservative bacterial populations associated with distinct but nonconservative air mass properties can
help to better understand more of the bacterial dynamics found in such situations. And to a further extent, molecular biological
methods could be applied to identify bacterial taxa in specific air masses. 相似文献
8.
A. M. Semenov 《Microbial ecology》1991,22(1):239-247
Three groups of physiological processes in microorganisms are considered the physiological basis of oligotrophy: the greater
substrate affinity of the oligotrophs' transport systems, efficient or “economical” metabolism, and existence of a “master
reaction” or “rate-determining steps” controlling the rate of metabolism. Heterotrophic microorganisms are divided into three
unequal groups according to “reaction norma.” Two groups representing the extremes are small groups with the “narrow” reaction
norma, regarding the concentrations and structure of the assimilated organic compounds and variability limits of the physiological
characteristics mentioned above. The third, intermediate group includes the majority of microorganisms with the “wide” reaction
norma. 相似文献
9.
Peter Alpert 《Biological invasions》2006,8(7):1523-1534
Introduced species, those dispersed outside their natural ranges by humans, now cause almost all biological invasions, i.e.,
entry of organisms into habitats with negative effects on organisms already there. Knowing whether introduction tends to give
organisms specific ecological advantages or disadvantages in their new habitats could help understand and control invasions.
Even if no specific species traits are associated with introduction, introduced species might out-compete native ones just
because the pool of introduced species is very large (“global competition hypothesis”). Especially in the case of intentional
introduction, high initial propagule pressure might further increase the chance of establishment, and repeated introductions
from different source populations might increase the fitness of introduced species through hybridization. Intentional introduction
screens species for usefulness to humans and so might select for rapid growth and reproduction or carry species to suitable
habitats, all which could promote invasiveness. However, trade offs between growth and tolerance might make introduced species
vulnerable to extreme climatic events and cause some invasions to be transient (“reckless invader hypothesis”). Unintentional
introduction may screen for species associated with human-disturbed habitats, and human disturbance of their new habitats
may make these species more invasive. Introduction and natural long-distance dispersal both imply that species have neither
undergone adaptation in their new habitats nor been adapted to by other species there. These two characteristics are the basis
for many well-known hypotheses about invasion, including the “biotic resistance”, “enemy release”, “evolution of increased
competitive ability” and “novel weapon” hypotheses, each of which has been shown to help explain some invasions. To the extent
that biotic resistance depends upon local adaption by native species, altering selection pressures could reduce resistance
and promote invasion (“local adaptation hypothesis”), and restoring natural regimes could reverse this effect. 相似文献
10.
Microrheological properties (aggregation and deformability) of erythrocytes separated by centrifugation at 30000×g density gradient into “young” and “old” (the upper and lower fractions, respectively) were studied. The erythrocytes were
taken from physically active persons (PAP) and from those with elevated arterial pressure (EAP). A significant difference
in microrheological properties of the “young” and “old” erythrocytes was found. The aggregation degree of “old” cells was
nearly twice that of “young” cells. The deformability of the erythrocyte subpopulations was significantly different, though
the difference was not so pronounced as in the case of aggregation. The aggregation of “young” and “old” erythrocytes in the
PAP group was the least (28% lower than in the control). Note, that “old” erythrocytes in the PAP group had better microrheological
properties than in the other groups. All erythrocyte populations in the EAP group were characterized by higher aggregation,
decreased deformability, and decreased capacity for oxygen transport. 相似文献
11.
Habitat fragmentation is a process involving splitting of continuous habitats into smaller, and more isolated habitat patches.
To assess the effects of small-scale habitat patchiness and isolation without the confounding effect of habitat loss on benthic
macrofauna, two field experiments were conducted in the Archipelago Sea, SW Finland. Using artificial seagrass units (ASUs)
we contrasted continuous patches (“C”) with fragmented patches (“F”) of the same combined area as the continuous patches.
The fragmentation treatment involved two isolation distances (0.5 and 3.0 m) between the ASUs (“F 0.5”) and (“F 3.0”). This
design was repeated in two consecutive experiments where the patch area was 0.25 and 0.0625 m2, respectively. Mobile epifauna were allowed to colonize patches for 12 days in both experiments. In both experiments, the
total epifaunal density was significantly higher in the “F 0.5” treatment than in the “C” treatment, and the three dominant
taxa showed positive or neutral responses to the habitat configuration. No fragmentation effect on the number of species was
detected in either of the experiments, but fragmentation had a negative effect on the epifaunal diversity (Shannon’s H′) in the experiment with the largest patch area. Epifaunal diversity was significantly lower in “F 3.0” treatment than in
“C” or “F 0.5” treatments in the first experiment, indicating stronger effect of isolation instead of fragmentation per se.
Edge effects were indirectly tested by comparing epifaunal densities with patch edge:area ratios. The results suggest that
edge effects may have a more important role than patch size for the total densities of epifaunal taxa, and that small, isolated
patches have equal or higher habitat value compared to larger fragments. 相似文献
12.
Kenji Konishi Tsutomu Tamura Ryoko Zenitani Takeharu Bando Hidehiro Kato Lars Walløe 《Polar Biology》2008,31(12):1509-1520
The annual trend in energy storage in the Antarctic minke whale was examined using catch data from all 18 survey years in
the Japanese Whale Research Program (JARPA). Regression analyses clearly showed that blubber thickness, girth and fat weight
have been decreasing for nearly 2 decades. The decrease per year is estimated at approximately 0.02 cm for mid-lateral blubber
thickness and 17 kg for fat weight, corresponding to 9% for both measurements over the 18-year period. Furthermore, “date”,
“extent of diatom adhesion”, “sex”, “body length”, “fetus length”, “latitude”, “age” and “longitude” were all identified as
partially independent predictors of blubber thickness. The direct interpretation of this substantial decline in energy storage
in terms of food availability is difficult, since no long-term krill abundance series is available. However, an increase in
the abundance of krill feeders other than minke whales and a resulting decrease in the krill population must be considered
as a likely explanation. 相似文献
13.
Iron is an essential element for oceanic microbial life but its low bioavailability limits microorganisms in large areas of
the oceans. To acquire this metal many marine bacteria produce organic chelates that bind and transport iron (siderophores).
We have previously shown that algal-associated heterotrophic bacteria belonging to the γ-proteobacterial Marinobacter genus release the siderophore vibrioferrin (VF). The iron-VF complex was shown to be both far more photolabile than all previously
examined photolabile siderophores and to generate a photoproduct incapable of re-chelating the released iron. Thus, the photo-generated
iron was shown to be highly bioavailable both to the producing bacterium and its algal partner. In exchange, we proposed that
algal cells produced dissolved organic matter that helped support bacterial growth and ultimately fueled the biosynthesis
of VF through a light-dependent “carbon for iron mutualism”. While our knowledge of the importance of light to phototrophs
is vast, there are almost no studies that examine the effects of light on microbial heterotrophs. Here, we characterize iron
uptake mechanisms in “algal-associated” VF-producers. Fe uptake by a VF knock-out mutant mimics the wild-type strain and demonstrates
the versatility of iron uptake mechanisms in Marinobacter VF-producers. We also show that VF-producers selectively regulate a subset of their siderophore-dependent iron uptake genes
in response to light exposure. The regulation of iron uptake and transport genes by light is consistent with the light driven
algal–bacterial “carbon for iron mutualism” hypothesis in the marine environment. 相似文献
14.
The notion of “pressure” as an evolutionary “force” that “causes” evolution is a pervasive linguistic feature of biology textbooks,
journal articles, and student explanatory discourse. We investigated the consequences of using a textbook and curriculum that
incorporate so-called force-talk. We examined the frequency with which biology majors spontaneously used notions of evolutionary
“pressures” in their explanations, students’ definitions and explanations of what they meant when they used pressures, and
the structure of explanatory models that incorporated evolutionary pressures and forces. We found that 12–20 percent of undergraduates
spontaneously used “pressures” and/or “forces” as explanatory factors but significantly more often in trait gain scenarios
than in trait loss scenarios. The majority of explanations using “force-talk” were characterized by faulty evolutionary reasoning.
We discuss the conceptual similarity between faulty notions of evolutionary pressures and linguists’ force-dynamic models
of everyday reasoning and ultimately question the appropriateness of force-talk in evolution education. 相似文献
15.
The inheritance of resistance to Plum pox virus (PPV) has been studied in 1,178 apricot hybrids. Seven hundred and eighteen F1 hybrids, obtained from controlled crosses
between the susceptible Greek cultivar “Bebecou” and the resistant PPV cultivars of American origin (“Stark Early Orange,”
‘NJA2,” ‘Veecot,” “Sunglo,” “Harlayne,” and “Orangered”) were evaluated for resistance to the PPV-M (Marcus) strain, 8 years
after artificial inoculation. The inheritance of resistance to PPV has been additionally studied for the first time in a BC1 population of 95 apricot hybrids for four vegetative periods. Reaction of each hybrid to PPV-M was scored through visual
symptoms, indexing onto GF-305 and double-antibody sandwich enzyme-linked immunosorbent assay tests. Segregation within the
hybrids, determined by Chi-squared analysis, fits a 1:1 ratio (P ≤ 0.05) of the resistant vs susceptible, indicating that resistance to PPV is controlled by a single dominant gene locus
and that the above six resistant cultivars are heterozygous for the trait. Plants carrying this gene may initially develop
disease symptoms on leaves but eventually recover and no virus can be detected in leaves. Susceptible plants show similar
symptoms initially but remain symptomatic. Inheritance of resistance to PPV also has been studied in 365 F1 hybrids by crossing
the resistant cultivar “Stella” with the susceptible “Bebecou” and the resistant cultivars “Sunglo” and “NJA2,” for 8 years
after inoculation. The segregation ratio was 1:0 (resistant/susceptible) suggesting that “Stella” is homozygous for the resistance
trait. The purpose of this work was the enhancement of the knowledge of inheritance of resistance to PPV for the selection
of new cultivars. 相似文献
16.
The microflora inhabiting the intestinal mucosa of the pike and the tegument surface of the intestinal parasite Triaenophorus nodulosus is investigated. By means of electron microscopy, the ultrastructural features of bacteria and pattern of their interaction
with the colonized surfaces are estimated. Specific distribution of microorganisms belonging to different morphotypes and
subdivided into subpopulations on the colonized surfaces is found. Predominance of gram-negative bacteria in all studied microbiocenoses
and abundance of nanobacteria in the “superficial” subpopulations are observed. The bacteria of “a deep population” associated
with the basal parts of microtrichiae and microvilli are described. It is concluded that the helminthes, the fish parasites
possess the normal microflora characterized by specific composition, by ultrastructural features of cells, and by patterns
of interaction with the helminth surface. The obtained data characterize the mechanisms of symbiotic interaction of prokaryotes
and eukaryotes in the system parasite-host-symbiotic microflora. 相似文献
17.
Keith Johnson 《Journal of biological physics》2012,38(1):85-95
Water nanoclusters are shown from first-principles calculations to possess unique terahertz-frequency vibrational modes in
the 1–6 THz range, corresponding to O–O–O “bending,” “squashing,” and “twisting” “surface” distortions of the clusters. The
cluster molecular-orbital LUMOs are huge Rydberg-like “S,” “P,” “D,” and “F” orbitals that accept an extra electron via optical
excitation, ionization, or electron donation from interacting biomolecules. Dynamic Jahn–Teller coupling of these “hydrated-electron”
orbitals to the THz vibrations promotes such water clusters as vibronically active “structured water” essential to biomolecular
function such as protein folding. In biological microtubules, confined water-cluster THz vibrations may induce their “quantum
coherence” communicated by Jahn–Teller phonons via coupling of the THz electromagnetic field to the water clusters’ large
electric dipole moments. 相似文献
18.
We recently classified 23 bacteria into two types based on their complete genomes; “S-type” as represented by Staphylococcus aureus and “E-type” as represented by Escherichia coli. Classification was characterized by concentrations of Arg, Ala or Lys in the amino acid composition calculated from the
complete genome. Based on these previous classifications, not only prokaryotic but also eukaryotic genome structures were
investigated by amino acid compositions and nucleotide contents. Organisms consisting of 112 bacteria, 15 archaea and 18 eukaryotes
were classified into two major groups by cluster analysis using GC contents at the three codon positions calculated from complete
genomes. The 145 organisms were classified into “AT-type” and “GC-type” represented by high A or T (low G or C) and high G
or C (low A or T) contents, respectively, at every third codon position. Reciprocal changes between G or C and A or T contents
at the third codon position occurred almost synchronously in every codon among the organisms. Correlations between amino acid
concentrations (Ala, Ile and Lys) and the nucleotide contents at the codon position were obtained in both “AT-type” and “GC-type”
organisms, but with different regression coefficients. In certain correlations of amino acid concentrations with GC contents,
eukaryotes, archaea and bacteria showed different behaviors; thus these kingdoms evolved differently. All organisms are basically
classifiable into two groups having characteristic codon patterns; organisms with low GC and high AT contents at the third
codon position and their derivatives, and organisms with an inverse relationship. 相似文献
19.
Maialen Garmendia Marta Revilla Juan Bald Javier Franco Aitor Laza-Martínez Emma Orive Sergio Seoane Victoriano Valencia Ángel Borja 《Biogeochemistry》2011,106(2):243-263
Eutrophication is a major threat to coastal ecosystems. Within Europe, the Water Framework Directive (WFD) has established
the need of developing methods of assessment. Bulk chlorophyll “a” is used world-wide as an indicator of eutrophication. However,
the size structure of the phytoplankton communities has not been investigated, in detail, in relation to eutrophication pressures.
This study investigates the suitability of fractionated chlorophyll “a” (<10 and >10 μm), as an indicator of eutrophication.
Along the Basque coast (northern Spain) several water bodies, ranging from offshore waters to the heads of the estuaries,
were surveyed during 2008. Physico-chemical conditions and chlorophyll “a” showed a distinct spatial gradient. Trophic richness
increased towards the middle and inner parts of the estuaries, where nutrient inputs, from natural or anthropogenic sources,
together with the residence time of the water are usually higher. In summer, phytoplankton biomass and abundance decreased,
generally, in offshore and coastal waters; in estuaries, they tended to increase. The chlorophyll distribution within the
two size fractions was coherent with the phytoplankton taxonomic composition. In summer, the relative abundance of small-sized
cells (diatoms and non-siliceous taxa) increased. The relationships between size-fractionated chlorophyll and physico-chemical
variables differed, when comparing the offshore and coastal waters, with the estuaries. In the offshore and coastal waters,
a strong seasonality was observed; in estuaries, an important spatial component was found. Fractionated chlorophyll provided
complementary useful information on anthropogenic pressures. However, more research is necessary to utilise this variable
as a tool for ecological status assessment, within the WFD. 相似文献
20.
Cheng X Imai T Teeka J Yamaguchi J Hirose M Higuchi T Sekine M 《Applied microbiology and biotechnology》2011,90(4):1493-1500
Little information is available regarding the effectiveness of water disinfection by CO2 at low pressure. The aim of this study was to evaluate the use of high levels of dissolved CO2 at 0.3–0.6 MPa for the inactivation of microorganisms. Bacteriophage T4 was chosen as the model virus and Escherichia coli was selected as the representative bacterium. The results of the study showed a highly effective log inactivation of E. coli and bacteriophage T4 at low and medium initial concentrations by high levels of dissolved CO2 at 0.3 MPa with a treatment time of 20 min. When the pressure was increased to 0.6 MPa, inactivation of both microorganisms
at high initial concentrations was improved to different extents. Neither pressurized air nor O2 effectively inactivated both E. coli and bacteriophage T4. The pH was not a key factor affecting the inactivation process by this method. The results of scanning
electron microscopy of E. coli and transmission electron microscopy of bacteriophage T4 suggested that “CO2 uptake at high pressure and bursting of cells by depressurization” were the main reasons for lethal effect on microorganisms.
This technology has potential for application in the disinfection of water, wastewater, and liquid food in the future. 相似文献