Hemicellulase production in Chrysosporium lucknowense C1     

Sandra W.A. Hinz  Laurice Pouvreau  Rob Joosten  Jeffrey Bartels  Meliana C. Jonathan  Jan Wery  Henk A. Schols 《Journal of Cereal Science》2009

Filamentous fungi are widely used for enzyme production for the biofuel industry. The ascomycetous fungus Chrysosporium lucknowense C1 was isolated as a natural producer of neutral cellulases. It is at present an attractive alternative to well known fungi like Aspergillus sp. and Trichoderma reesei for protein production on a commercial scale. Besides many cellulases, a large number of hemicellulases (particularly xylanases and arabinofuranosidases) and esterases (acetyl xylan esterases and ferulic acid esterases) encoding genes have also been identified in the C1 genome. Many of these extracellular enzymes have been selectively expressed in C1 and then purified and characterized. Four arabinofuranosidases, two acetyl xylan esterases, two ferulic acid esterases, an α-glucuronidase and four xylanases have been purified and characterized. All these enzymes were found to be active towards arabinoxylans, demonstrating the high potential of C1 as a producer of hemicellulolytic enzymes.  相似文献   

Evaluation of brook trout production in a coldwater recycle aquaculture system     

Gregory J. Fischer  James Held  Christopher Hartleb  Jeffrey Malison   《Aquacultural Engineering》2009,41(2):109-113

Brook trout (Salvelinus fontinalis) are a commercially important coldwater species reared in Wisconsin and the Midwestern United States. Brook trout are raised by private, tribal, state, and federal fish hatchery facilities in Wisconsin. Approximately 10% of private coldwater aquaculture operations are presently raising brook trout of various strains for stocking uses and a limited amount for food markets. Growing brook trout to a larger size, if they can be reared in a shorter time span, may present a potential new sector for the aquaculture market in the Midwestern US. The present study reports hatchery production attributes, i.e., growth, survival, fin condition, feed efficiency, water chemistry requirements and general husbandry of Lake Superior strain (Nipigon) brook trout reared in a recirculating aquaculture system (RAS), operated at an average temperature of 13 °C. The recycle system at NADF reared 1379 kg of brook trout over a 10-month period from fingerling (9 g) to market size (340–454 g). The trout grew faster (0.84 g/day and 0.64 mm/day) in the RAS than fish cultured in traditional flow-through tank culture utilizing ground water at 7.6 °C (0.14 g/day and 0.35 mm/day). Final average weight of RAS fish was 260 g, while the flow-through fish averaged 65 g. Final tank densities for the RAS averaged 40.4 kg/m³ while flow-through tanks averaged 31.2 kg/m³. Throughout the project, feed conversions in the RAS ranged from 0.9 to 1.3. Water quality variables such as TAN, nitrite, DO, temperature, TSS, CO₂, ph, etc. were within safe limits for brook trout and will be discussed. It does appear from this initial research project that market size brook trout can be raised successfully in a recycle system within a similar time frame as a rainbow trout produced in a Wisconsin typical flow-through facility.  相似文献   

Toxic and excitatory effects of the molluscicide metaldehyde on the biofouling bivalve Dreissena polymorpha Pallas     

Sashi M Putchakayala  Jeffrey L Ram 《Pest management science》2000,56(1):39-42

The zebra mussel, Dreissena polymorpha Pallas, is a biofouling freshwater pest for which alternative control methods to the use of chlorine are sought. Metaldehyde, a molluscicide used primarily for control of terrestrial slugs, has also been shown to have efficacy and specificity in the control of aquatic snails. To test its potential for zebra mussel control, we investigated its effects on zebra mussel viability and on contractility of siphon/mantle muscle preparations in vitro. Metaldehyde caused zebra mussel mortality within 48 h at concentrations of approximately 0.1 and 0.2 g litre⁻¹. The same concentrations of metaldehyde activated a complex, excitatory response in previously quiescent siphon/mantle preparations but did not modify the contractile responses of the preparations to acetylcholine. The relatively low level of toxicity of metaldehyde to zebra mussels, compared to its toxicity to snails and slugs, and the difficulty of applying this relatively insoluble molluscicide in the aqueous environment suggest that metaldehyde would not be an effective zebra mussel control agent. © 2000 Society of Chemical Industry  相似文献   

Silvicultural treatment effects on oak seed production and predation by acorn weevils in southeastern Ohio     

Jeffrey A. Lombardo  Brian C. McCarthy 《Forest Ecology and Management》2008

Oak regeneration failure in the hardwood forests of eastern North America has been well documented. Silvicultural treatments of prescribed burning and canopy thinning (fire surrogate) are being studied as possible management tools to promote oak regeneration in oak dominated forests. We examined oak seed production and predation by acorn weevils (Coleoptera: Curculionidae) from two experimental forests in southeastern Ohio, under four different silvicultural treatments. Treatments consisted of replicate stands that received a prescribed burning, thinning, and thinning followed by a prescribed burn, in addition to an untreated control. Initial thinning and prescribed burning treatments were conducted in winter/spring of 2000–2001, with a second prescribed burn in spring 2005. Within each treatment unit, nine black oak and nine chestnut oak trees were selected for study and two 0.25 m² seed fall traps were placed beneath each tree. Seed collections were completed for five seasons from 2001 to 2005. Data were analyzed using a randomized complete block design, utilizing a mixed-model repeated measures analysis. Overall, stand level treatments resulted in only a slight increase in acorn production (in the burn and thin + burn stands) relative to the control; however, this response was species specific. Masting, the intermittent production of large seed crops, was evident in our study though occurrence of a mast event was not influenced by the treatments. Chestnut oak displayed greater yearly, as well as individual variation in seed production than did black oak. Treatments had no effect on predation by acorn weevils. Predation percentages were lowest during mast years for chestnut oak; however, percentages were mostly stable for black oak across all 5 years. Our data suggest that variation due to climate and genotype are more influential in affecting seed production and masting cycles than are stand level disturbances. Thus, stand level management activities are not likely to have a large influence on oak seed production and oak regeneration must be more strongly influenced at other stages of its life history.  相似文献   

Data quality and quantity for invasive species: A case study of the lionfishes     

Timothy J. Lyons  Quenton M. Tuckett  Jeffrey E. Hill 《Fish and Fisheries》2019,20(4):748-759

Predicting invasion risk involves inherent uncertainty when data on biological and ecological characteristics are lacking. To combat data gaps, assessors are required to use information from secondary sources, further reducing predictive accuracy. Lionfish in the subfamily Pteroinae have invasion history in the Western Atlantic Ocean and Mediterranean Sea, raising concern that other species of globally traded lionfish may pose risks similar to the invasive complex comprised of the red lionfish (Pterois volitans, Scorpaenidae) and devil firefish (Pterois miles, Scorpaenidae). We conducted a standardized literature review of 18 species in the genera Pterois, Dendrochirus, and Parapterois to (a) characterize the volume and composition of literature addressing the invasive complex pre‐establishment and pre‐spread, and compare it to the body of literature that has been generated post‐spread and impact, (b) compare the volume and composition of literature addressing other members of Pteroinae to the invasive complex, and (c) evaluate data quality addressing the Pteroinae by characterizing literature used to generate biological profile reports during a risk screening protocol. Little data were available for the invasive complex prior to introduction and focused primarily on the composition or effects of venom. Following introduction, there was a considerable time lag in research effort. Post‐spread, research effort increased rapidly. We identify similar data deficiencies for other species of lionfish that have not been reported outside of their native ranges. While proactive management is gaining support as an effective framework, it is important to understand data limitations and their resulting uncertainties, which leads to more informed proactive management.  相似文献   

The role of sand lances (Ammodytes sp.) in the Northwest Atlantic Ecosystem: A synthesis of current knowledge with implications for conservation and management     

Michelle D. Staudinger  Holly Goyert  Justin J. Suca  Kaycee Coleman  Linda Welch  Joel K. Llopiz  David Wiley  Irit Altman  Andew Applegate  Peter Auster  Hannes Baumann  Julia Beaty  Deirdre Boelke  Les Kaufman  Pam Loring  Jerry Moxley  Suzanne Paton  Kevin Powers  David Richardson  Jooke Robbins  Jeffrey Runge  Brian Smith  Caleb Spiegel  Halley Steinmetz 《Fish and Fisheries》2020,21(3):522-556

The American sand lance (Ammodytes americanus, Ammodytidae) and the Northern sand lance (A. dubius, Ammodytidae) are small forage fishes that play an important functional role in the Northwest Atlantic Ocean (NWA). The NWA is a highly dynamic ecosystem currently facing increased risks from climate change, fishing and energy development. We need a better understanding of the biology, population dynamics and ecosystem role of Ammodytes to inform relevant management, climate adaptation and conservation efforts. To meet this need, we synthesized available data on the (a) life history, behaviour and distribution; (b) trophic ecology; (c) threats and vulnerabilities; and (d) ecosystem services role of Ammodytes in the NWA. Overall, 72 regional predators including 45 species of fishes, two squids, 16 seabirds and nine marine mammals were found to consume Ammodytes. Priority research needs identified during this effort include basic information on the patterns and drivers in abundance and distribution of Ammodytes, improved assessments of reproductive biology schedules and investigations of regional sensitivity and resilience to climate change, fishing and habitat disturbance. Food web studies are also needed to evaluate trophic linkages and to assess the consequences of inconsistent zooplankton prey and predator fields on energy flow within the NWA ecosystem. Synthesis results represent the first comprehensive assessment of Ammodytes in the NWA and are intended to inform new research and support regional ecosystem‐based management approaches.  相似文献   

Characterization 3333 of tomato (Solanum lycopersicum) accessions for resistance to phylotype I and phylotype II strains of the Ralstonia solanacearum species complex under high temperatures     

Sanju Kunwar  Yun-Che Hsu  Shu-Fen Lu  Jaw-Fen Wang  Jeffrey B. Jones  Samuel Hutton  Mathews Paret  Peter Hanson 《Plant Breeding》2020,139(2):389-401

Bacterial wilt of tomato caused by Ralstonia solanacearum species complex (RSSC) causes substantial yield losses in the tropics and subtropics. Disease management options by chemicals are limited, and host resistance is the cheapest and easiest means of control. However, sources of bacterial wilt resistance in tomato are limited. The disease often coincides with higher temperatures in the tropics, and resistance sources that are more heat stable are particularly valuable for breeding of tropically adapted tomato cultivars. The objectives of this study were to identify tomato accessions that demonstrate relatively high bacterial wilt resistance under high temperatures and to identify accessions that may possess QTLs other than Bwr-6 and Bwr-12 (two major disease resistance QTLs against bacterial wilt), which could be exploited in future breeding. Sixty-seven tomato entries reported as bacterial wilt resistant were evaluated in a greenhouse against one strain each of phylotype I (Pss4) and phylotype IIB (Pss1632) of the RSSC (average temperature ≥29°C). Of those, five and 19 were homozygous for Bwr-6 and Bwr-12, respectively, and six were homozygous for both QTLs. Bwr-12 contributed to resistance against phylotype I strain but not against the phylotype II strain. Bwr-6 contributed to resistance against both phylotype strains. Entries with both QTLs as a group performed relatively better against the phylotype I strain. Entry “94T765-24-79”, which lacked Bwr-6 and Bwr-12, demonstrated relatively high resistance against the phylotype II strain and may carry new QTL/s. As new bacterial wilt resistance QTLs are mapped and markers designed, pyramiding multiple bacterial wilt resistance QTLs into new varieties should be straightforward, thereby increasing the chances of obtaining stable resistance.  相似文献   

Effects of elevated CO2 and temperature on survival and wing dimorphism of two species of rice planthoppers (Hemiptera: Delphacidae) under interaction     

Caiyun Wang  Minghui Fei  Ling Meng  Jeffrey A Harvey  Baoping Li 《Pest management science》2020,76(6):2087-2094

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Chronic toxicity of clothianidin,imidacloprid, chlorpyrifos,and dimethoate to Apis mellifera L. larvae reared in vitro     

Pingli Dai  Cameron J Jack  Ashley N Mortensen  Tomas A Bustamante  Jeffrey R Bloomquist  James D Ellis 《Pest management science》2019,75(1):29-36

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Chemical inhibition of Kir channels reduces salivary secretions and phloem feeding of the cotton aphid,Aphis gossypii (Glover)     

Zhilin Li  Jeffrey A Davis  Daniel R Swale 《Pest management science》2019,75(10):2725-2734

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