Solid-substrate fermentation of corn fiber by Phanerochaete chrysosporium and subsequent fermentation of hydrolysate into ethanol   总被引：2，自引：0，他引：2  

Shrestha P  Rasmussen M  Khanal SK  Pometto AL  van Leeuwen JH 《Journal of agricultural and food chemistry》2008,56(11):3918-3924

The goal of this study was to develop a fungal process for ethanol production from corn fiber. Laboratory-scale solid-substrate fermentation was performed using the white-rot fungus Phanerochaete chrysosporium in 1 L polypropylene bottles as reactors via incubation at 37 degrees C for up to 3 days. Extracellular enzymes produced in situ by P. chrysosporium degraded lignin and enhanced saccharification of polysaccharides in corn fiber. The percentage biomass weight loss and Klason lignin reduction were 34 and 41%, respectively. Anaerobic incubation at 37 degrees C following 2 day incubation reduced the fungal sugar consumption and enhanced the in situ cellulolytic enzyme activities. Two days of aerobic solid-substrate fermentation of corn fiber with P. chrysosporium, followed by anaerobic static submerged-culture fermentation resulted in 1.7 g of ethanol/100 g of corn fiber in 6 days, whereas yeast ( Saccharomyces cerevisiae) cocultured with P. chrysosporium demonstrated enhanced ethanol production of 3 g of ethanol/100 g of corn fiber. Specific enzyme activity assays suggested starch and hemi/cellulose contribution of fermentable sugar.  相似文献   

Estimating genetic differences in natural resistance in Rhön and Merinoland sheep following experimental Haemonchus contortus infection     

Gauly M  Kraus M  Vervelde L  van Leeuwen MA  Erhardt G 《Veterinary parasitology》2002,106(1):55-67

Genetic parameters of natural resistance were estimated in Rh?n and Merinoland (German Merino) sheep following experimental infection with Haemonchus contortus. A total of 133 Rh?n and 244 Merinoland lambs descending from 5 and 6 rams, respectively, were evaluated. Each helminth-naive lamb was orally infected with 5000 infective third-stage larvae (L(3)) of the nematode H. contortus at 12 weeks of age. Faecal egg counts (FEC) and haematocrit values were measured in all lambs at 16 and 20 weeks of age. Seventy-nine Merinoland and 29 Rh?n male lambs were slaughtered immediately after the second sampling and worms were collected. Mean worm burden was calculated and the length of adults worms from an aliquot was measured.FEC of Rh?n sheep was higher compared with Merinoland sheep (P<0.01). H. contortus L(3)-larvae specific antibody (IgL) level was higher in Rh?n sheep (P<0.05). However, no differences in haematocrit, worm burden and IgG antibody values could be found between the breeds. Heritabilities for log FEC (+/-S.E.) were 0.0 and 0.07 (+/-0.07) for the first sample in Rh?n and Merinoland sheep, respectively. Values for the second sample were higher in both breeds (Rh?n 0.35+/-0.14, P<0.05; Merinoland 0.17+/-0.07, P<0.05). Corresponding heritabilities for haematocrit were higher in Merinoland (0.56+/-0.20 and 0.51+/-0.27) compared with Rh?n (0.29+/-0.12 and 0.08+/-0.13). Heritabilities for worm burden were high in Rh?n (0.54+/-0.2) and low in Merinoland (0.06+/-0.14 and 0.11+/-0.15). Estimated values for IgL were between 0.13 (+/-0.11) for the first sample in both breeds and 0.30 (+/-0.18) for the second sample in Rh?n sheep. Corresponding heritabilities for IgG were not different from 0.0 in both breeds (P>0.05). Positive phenotypic correlations were estimated for IgG and IgL values in both breeds (P<0.01). IgG was significantly (P<0.05) and positively correlated with worm burden in male Merinoland and IgL with worm burden in male Rh?n sheep.  相似文献   

Assessment of health risks of large semi-wild herbivores in urbanized areas     

van Essen GJ  van Leeuwen JM 《The Veterinary quarterly》2000,22(2):112-116

The health risks for both domestic animals and humans caused by large herbivores in self-sustaining ecosystems are largely unknown. The aim of this article is to make an inventory of these risks, to explore ways to manage them in practice, and to make recommendations for the quantification of risks. Potential hazards from herbivores in and around Europe are listed using the data of the OIE (Office International des Epizooties). The desired health status and the implementation of control or surveillance measures are important factors when assessing the risks. Results indicate that a regular yearly system of health monitoring of herbivores is necessary. To get more insight into the importance of certain risks (Infectious Bovine Rhinotracheitis, biodegradation of carrion in the field) epidemiological investigations have to be carried out to assess the risk of transmission in different situations (with or without intervention). Analysing and managing risks enable decision-makers to formulate the conditions for the development of nature reserves. In Europe more has to be done to increase the quality of nature in terms of de-fragmentation and de-isolation, but regulations concerning the health of large herbivores also have to be improved.  相似文献   

Appropriate care for large grazers in nature     

van Leeuwen JM  Luten HA 《Tijdschrift voor diergeneeskunde》2000,125(9):293-295

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The complex II resistance mutation H258Y in succinate dehydrogenase subunit B causes fitness penalties associated with mitochondrial respiratory deficiency     

Christine Njiru  Corinna Saalwaechter  Konstantinos Mavridis  John Vontas  Sven Geibel  Nicky Wybouw  Thomas Van Leeuwen 《Pest management science》2023,79(11):4403-4413

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Innocent Cardiac Murmur in Puppies: Prevalence,Correlation with Hematocrit,and Auscultation Characteristics          下载免费PDF全文

V. Szatmári  M.W. van Leeuwen  E. Teske 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(6):1524-1528

Background

The aims of this study were to establish the prevalence of innocent cardiac murmurs in clinically healthy puppies, to investigate a possible correlation between the presence of an innocent murmur and hematocrit, and to describe the auscultation characteristics of innocent murmurs.

Hypothesis

Lower hematocrit contributes to the genesis of innocent murmurs.

Animals

Five hundred and eighty‐four client‐owned clinically healthy puppies, between 20 and 108 days old.

Methods

Two cross‐sectional surveys with a 1‐year (n = 389 pups) pilot and a half‐year (n = 195 pups) principal study periods. Cardiac auscultation was performed by a single, board‐certified cardiologist. Hematocrit was measured with an automatized hematology analyzer. Echocardiography was performed only on puppies with a cardiac murmur in the principal study.

Results

In the pilot study, 15% of the dogs had a murmur. Innocent murmur was diagnosed in 28% of the 195 dogs in the principal study. Innocent murmurs were systolic, mostly with a musical character and with a maximal intensity of 2 of 6, and mostly with the point of maximal intensity in the left cardiac base. The hematocrit was significantly lower in the group with a murmur compared to the group without (P = .023).

Conclusions and Clinical Importance

Innocent murmur was a common finding in puppies at the age when the first veterinary controls usually take place. Physiologic anemia contributes to the genesis of innocent murmurs in puppies. Rising hematocrit in growing puppies can explain the spontaneous disappearance of innocent murmurs with aging. Hematocrit did not differentiate innocent murmurs from abnormal murmurs.  相似文献   

Mutations in the mitochondrial cytochrome b of Tetranychus urticae Koch (Acari: Tetranychidae) confer cross‐resistance between bifenazate and acequinocyl     

Pieter Van Nieuwenhuyse  Thomas Van Leeuwen  Jahangir Khajehali  Bartel Vanholme  Luc Tirry 《Pest management science》2009,65(4):404-412

BACKGROUND: Resistance of Tetranychus urticae Koch to bifenazate was recently linked with mutations in the mitochondrial cytochrome b Q_o pocket, suggesting that bifenazate acts as a Q_o inhibitor (Q_oI). Since these mutations might cause cross‐resistance to the known acaricidal Q_oI acequinocyl and fluacrypyrim, resistance levels and inheritance patterns were investigated in several bifenazate‐susceptible and bifenazate‐resistant strains with different mutations in the cd1 and ef helices aligning the Q_o pocket. RESULTS: Cross‐resistance to acequinocyl in two bifenazate‐resistant strains was shown to be maternally inherited and caused by the combination of two specific mutations in the cytochrome b Q_o pocket. Although most investigated strains were resistant to fluacrypyrim, resistance was not inherited maternally, but as a monogenic autosomal highly dominant trait. As a consequence, there was no correlation between cytochrome b genotype and fluacrypyrim resistance. CONCLUSIONS: Although there is no absolute cross‐resistance between bifenazate, acequinocyl and fluacrypyrim, some bifenazate resistance mutations confer cross‐resistance to acequinocyl. In the light of resistance development and management, high prudence is called for when alternating bifenazate and acequinocyl in the same crop. Maternally inherited cross‐resistance between bifenazate and acequinocyl reinforces the likelihood of bifenazate acting as a mitochondrial complex III inhibitor at the Q_o site. Copyright © 2009 Society of Chemical Industry  相似文献   

Geographical distribution and molecular insights into abamectin and milbemectin cross‐resistance in European field populations of Tetranychus urticae     

Wenxin Xue  Simon Snoeck  Christine Njiru  Emre Inak  Wannes Dermauw  Thomas Van Leeuwen 《Pest management science》2020,76(8):2569-2581

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Implementation of an ISO 17025 flexible scope in the phytosanitary field at the National Reference Centre in the Netherlands     

G. C. M. van Leeuwen  S. Bosman  E. Souer  M. J. Edema  M. van der Blom  A. W. Werkman 《EPPO Bulletin》2020,50(3):549-556

Quality systems in plant health laboratories are common these days. Most of these laboratories are accredited under a fixed scope, but because of the high diversity of organism–matrix combinations tested yearly in phytosanitary laboratories, the National Reference Centre (NRC) of the National Plant Protection Organization in the Netherlands chose to implement a phytosanitary focused flexible scope, the Phytoflex scope. This allows for the inclusion of additional activities in its scope of accreditation, without prior evaluation by the accreditation body. One of the reasons to implement a flexible scope was the initiation of the Official Control Regulation by the European Union, which states that official laboratories in plant health should be accredited according to ISO/IEC 17025 for all methods used when working as an official laboratory. The quality management system of the NRC is the foundation of the Phytoflex scope. The results of diagnoses given are based on the pillars Validation, Expertise and Assurance. Before the implementation of the Phytoflex scope in 2014, the scope only covered six tests for a combination of organism and matrix. As a result of the introduction of the Phytoflex scope, the number of organisms that are covered under ISO 17025 accreditation at the NRC has increased from six to almost 90 in November 2019. Management of the Phytoflex scope demands high awareness of quality systems for personnel and management, and puts more responsibility on the laboratory. If the different aspects of management of the scope are not accurately organized, the flexible scope may be revoked by the accreditation body. The Phytoflex scope makes it possible to act more quickly to add tests for new and emerging risks to the accreditation. However, this is not possible for all tests and further discussions are required to fulfil the accreditation requirement from the Official Control Regulation.  相似文献   

Alternative routes to piscivory: Contrasting growth trajectories in brown trout (Salmo trutta) ecotypes exhibiting contrasting life history strategies     

Martin R. Hughes  Oliver E. Hooker  Travis E. Van Leeuwen  Alan Kettle‐White  Alastair Thorne  Paulo Prodhl  Colin E. Adams 《Ecology of Freshwater Fish》2019,28(1):4-10

Large and long‐lived piscivorous brown trout, Salmo trutta, colloquially known as ferox trout, have been described from a number of oligotrophic lakes in Britain and Ireland. The “ferox” life history strategy is associated with accelerated growth following an ontogenetic switch to piscivory and extended longevity (up to 23 years in the UK). Thus, ferox trout often reach much larger sizes and older ages than sympatric lacustrine invertebrate‐feeding trout. Conventional models suggest that S. trutta adopting this life history strategy grow slowly before a size threshold is reached, after which, this gape‐limited predator undergoes a diet switch to a highly nutritional prey source (fish) resulting in a measurable growth acceleration. This conventional model of ferox trout growth was tested by comparing growth trajectories and age structures of ferox trout and sympatric invertebrate‐feeding trout in multiple lake systems in Scotland. In two of the three lakes examined, fish displaying alternative life history strategies, but living in sympatry, exhibited distinctly different growth trajectories. In the third lake, a similar pattern of growth was observed between trophic groups. Piscivorous trout were significantly older than sympatric invertebrate‐feeding trout at all sites, but ultimate body size was greater in only two of three sites. This study demonstrates that there are multiple ontogenetic growth pathways to achieving piscivory in S. trutta and that the adoption of a piscivorous diet may be a factor contributing to the extension of lifespan.  相似文献