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81.
分离得到1株抑制烟草青枯病菌的内生拮抗菌B-001菌株.为确定其抗菌蛋白产生的最佳培养基和培养条件,用硫酸铵沉淀法从发酵液中提取抗菌蛋白质,测定其对烟草青枯病菌抗菌活性,确定产生抗菌蛋白的最佳培养基为BPY液体培养基,最佳发酵条件为pH7.0,30℃,装液量100 mL,200 r/min振荡培养96 h;抗菌蛋白在pH5.0,pH8.0时抑菌活性仍分别保持90%,96%;pH6.0,pH7.0时抑菌活性仍保持不变;对酸、碱稳定;经40~100℃处理20 min后抑菌活性保持不变,具有良好的热稳定性;对蛋白酶有一定的耐受性.在温室内,抗菌蛋白粗提液对烟草青枯病可取得83.8%的防效. 相似文献
82.
The effects of setting time, whey protein concentrate (WPC), and calcium chloride (CaCl2) on textural properties of silver carp surimi were investigated. Response surface methodology was used to evaluate and compare the effects of setting time (30–90 min), WPC (1–9% of protein ratio), and CaCl2 (1–59 mmol/kg) on the gel strength. Models for breaking force, breaking distance, and gel strength of surimi gel were established. The maximum gel strength was achieved at the setting time of 60 min, WPC and CaCl2 at 5% protein ratio, and 15–18 mmol/kg. CaCl2 was the most significant factor affecting the gel strength. 相似文献
83.
2003年夏季东海区带鱼资源状况及其秋冬汛渔况的分析 总被引:4,自引:0,他引:4
根据东海区渔业资源动态监测网调查资料,对2003年伏季休渔期间的带鱼资源状况进行了分析,并展望了秋冬汛带鱼生产前景。结果表明,2003年伏季休渔前期(6月),东海区带鱼资源重量密度、资源尾数密度及发生量均比常年偏低、产卵期个体重量较常年偏大,亲鱼量属低水平年份;伏季休渔中期(7月、8月),带鱼的产卵群体比例下降,个体平均肛长偏小。同时,海区的水温较2002年偏低,不利于带鱼生长和发育。预计伏季休渔结束后,渔获状况不容乐观,秋冬汛生产前景将差于2002年。 相似文献
84.
小球藻固定化培养的初步研究 总被引:11,自引:0,他引:11
用海藻酸钙作固定化载体,初步探讨了海藻酸钠浓度、CaCl2浓度、胶球密度、胶球直径等固定化条件对小球藻(Chlorella vulgaris)生长的影响。确定了优化的固定化条件为:4#针头、2%的海藻酸钠溶液和0.15mol/L的CaCl2溶液制备固定化小球藻,在含50mL培养液的150mL三角烧瓶内放置250个小球藻胶球时,其生长速度较高,生长周期较长。与游离的小球藻相比,固定化小球藻生长速率慢,但生长周期长。实验结果为微藻固定化技术的应用和发展提供了必要的实验数据和理论基础。 相似文献
85.
David G Ainley Nadav Nur Joseph T Eastman Grant Ballard Claire L Parkinson Clive W Evans Arthur L. DeVries 《Fish and Fisheries》2013,14(3):343-363
We report the analyses of a dataset spanning 39 years of near‐annual fishing for Dissostichus mawsoni in McMurdo Sound, Antarctica, 1972–2011. Data on total length, condition and catch per unit effort (CPUE) were derived from the > 5500 fish caught, the large majority of which were measured, tagged and released. Contrary to expectation, the length frequency of the McMurdo Sound catch was dominated by fish in the upper two‐thirds of the overall distribution exhibited in the industrial catch for the Ross Sea shelf. Fish length and condition increased from the early 1970s to the early 1990s and then decreased. Fish length positively correlated with Ross Sea ice extent in early spring, a relationship possibly caused by more ice encouraging larger fish to move farther south over the shelf and into the study area. Fish condition positively correlated with the amount of open water in the Ross Sea during the previous summer (Feb), perhaps reflecting greater availability of prey with the higher productivity that more open water brings. Decreasing fish size corresponds to the onset of the fishery, which targets the large individuals. CPUE was constant through 2001 and then decreased dramatically. We hypothesize that this decrease is related to the industrial fishery, which began in the 1996–97 austral summer, and concentrates effort over the ice‐free Ross Sea continental slope. As a result of limited prey choices and close coupling among mesopredators of the region, Antarctic toothfish included, the fishery appears to be dramatically altering the trophic structure of the Ross Sea. 相似文献
86.
87.
Interannual variations in abundance, timing of outmigration from rivers, growth rate and condition of juvenile chum salmon
(Oncorhynchus keta) were studied in the Nemuro Strait (eastern Hokkaido, Japan) during 1999–2002 to establish a possible relationship to zooplankton
abundance. The otolith microstructure of juveniles was examined each year in late June to determine their time and size at
sea entry (i.e., outmigration), and to estimate the early marine growth rates. Salmon outmigration peaked in mid- or late
May, which coincided, in three of the four study years, with the peak release of juveniles into rivers within the study area.
Abundance, growth rate and condition of fish were higher in 2001, when—compared to other years—smaller fish experienced higher
growth rates, coinciding with greater zooplankton abundance for that year. Our results suggest that high zooplankton abundance
positively influenced juvenile chum salmon growth and the condition of the fish during their early marine life despite their
small size at sea entry. 相似文献
88.
89.
根据2005-2010年南通近岸海域的水质监测,对该区域的水质状况和趋势作出分析和评价。结果表明:影响该海域水质的主要污染因子是磷酸盐,部分站位出现无机氮超标。近岸海域水质总体变化基本稳定,部分污染物略呈上升的趋势。 相似文献
90.