排序方式： 共有46条查询结果，搜索用时 15 毫秒
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Abbas Zamani Rasool Madani Mehran Habibi Rezaie 《Journal Of Aquatic Food Product Technology》2013,22(3):237-252
The purification of trypsin from the common kilka (Clupeonella cultriventris caspia) viscera (pyloric caeca) resulted in a 28.3-fold increase and 12% yield by ammonium sulfate precipitation (30–60%), Sephadex G-75, and DEAE-cellulose chromatography. Trypsin showed a molecular weight of 23.2 kDa and appeared as a single band on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), native-PAGE, and zymography. The trypsin had optimal activity at pH 8.0 and 60°C for the hydrolysis of α-N-benzoyl-DL-arginine-ρ-nitroanilide hydrochloride (BAPNA) substrate. Trypsin was stable up to 50°C and at pH range of 7.0–10.0. Activity was significantly inhibited by soybean trypsin inhibitor (SBTI) and N-ρ-tosyl-L-lysine-chloromethylketone (TLCK) inhibitors (p < 0.05). The enzyme was relatively stable toward oxidizing agents, retaining 59.7 and 98.0% of its initial activity after 1 h incubation in the presence of 15% H2O2 and 1% sodium perborate, respectively. Trypsin was significantly activated by surfactants and Ca2+, Mg2+, and Mn2+ and inactivated by Fe2+, Zn2+, Cu2+, Al3+, Ba2+, and Co2+ (p < 0.05). Nevertheless, Na+ and K+ had no significant effect on trypsin activity (p > 0.05). The purified trypsin showed significantly higher catalytic efficiency (kcat/Km) than porcine pancreatic trypsin against BAPNA and N-α-p-Tosyl-L-arginine methyl ester hydrochloride (TAME) substrates (p < 0.05). 相似文献
33.
Sohrab Moini Amir Mojtaba Sotoodeh Alireza Haghoo Mehran Moslemi Seyed Vali Hosseini Joe M. Regenstein 《Journal Of Aquatic Food Product Technology》2013,22(2):147-155
Changes in the content of biogenic amines (BA; e.g., putrescine, tyramine, and histamine) and the mesophilic and psychrotrophic bacterial counts of tiger-tooth croaker (Otolithes ruber) were monitored during ice storage for 18 days. BA and bacterial loads gradually increased (p < 0.05) with storage time. On the first day of storage, no amines were detected, and no histamine was detected up to 6 days. The best linear regressions between BA and bacterial counts were found between putrescine and psychrotrophic bacteria. Furthermore, it was found that psychrotrophs were the dominant microorganisms during storage and showed significant (p < 0.05) differences with storage time. The initial concentration of putrescine was 1.27 μg g?1 and reached 18.8 μg g?1 when the psychrotrophic bacterial load was over 108 CFU g?1. The results suggest that the level of putrescine is a suitable indicator of freshness for O. ruber, and the shelf life of O. ruber stored in ice as determined by BA content and microbiological data was 10 days. 相似文献
34.
Abdolmohammad Abedian Kenari Ebrahim Sotoudeh Mehran Habibi Rezaei 《Aquaculture Research》2011,42(5):655-663
The effects of supplemental dietary phosphatidylcholine (PtCho) on the growth performance, survival and digestive enzyme activity of Caspian brown trout (Salmo trutta caspius Kessler 1877) alevins were investigated in this study. Alevin (initial weight 0.8 ± 0.12 g) was fed for 5 weeks with an isoproteic‐ and isolipidic‐formulated diet with increased levels of PtCho from 0 to 60 g kg?1 dry matter and decreasing levels of soybean oil. The increase in dietary PtCho up to 4% led to an increase in alevin final weight, suggesting that moderate PtCho levels are needed during this stage of Caspian brown trout. Survival was not affected by the dietary PtCho level. Phosphatidylcholine incorporation into the diet caused higher phospholipase A2‐specific activity. Phosphatidylcholine did not show a beneficial effect on the specific activity of amylase and protease. Lipase‐specific activity was significantly higher in the PtCho groups compared with the control group. The hepatosomatic index (HSI) was significantly influenced by the dietary PtCho level. The results of the present study indicated that the dietary supplementation of PtCho in the diet of Caspian brown trout alevin improved growth and lipolytic enzyme activity. 相似文献
35.
Ebrahim Sotoudeh Abdolmohammad Abedian Kenari Mehran Habibi Rezaei 《Aquaculture International》2011,19(4):611-623
We investigated the effects of soybean phosphatidylcholine (PtCho) on the growth, fatty acid (FA) profile, and body composition
of juvenile Caspian brown trout. Juvenile trout, initial average weight 0.8 ± 0.12 g, were fed semi-purified formulated diets
supplemented with 2, 4, and 6% PtCho for 5 weeks. Results showed that fish with diets containing 4 or 6% PtCho had significantly
greater growth. The FA profiles of both the polar lipids (PL) and neutral lipids (NL) in juvenile tissues were influenced
by dietary FA, although the effects of PtCho supplementation were more marked for PL than for NL. Fish fed PtCho in the diet
also had higher levels of 18:2n-6, 20:4n-6 and n-6, and significantly lower levels of docosahexaenoic acid and eicosapentaenoic
acid in both PL and NL. The lipid contents of whole-body tissues and liver were positively affected by PtCho percentage in
the diet. Specific growth rate, hepatosomatic index, visceralsomatic index, and protein efficiency ratio were also significantly
influenced by dietary PtCho. The results of our study indicate that dietary PtCho has a growth-promoting effect and that juvenile
Caspian brown trout have a relatively moderate PtCho requirement (at least 4% dry weight of the diet). 相似文献
36.
Zahirian Mehdi Seidavi Alireza Solka Magdalena Nosrati Mehran Corazzin Mirco 《Tropical animal health and production》2019,51(8):2263-2268
Tropical Animal Health and Production - This study investigated the effect of different levels and consumption periods of Aspergillus oryzae meal on performance, carcass characteristics, blood... 相似文献
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Erfani Amir Mehdi Bakhshesh Mehran Fallah Mohammad Hosein Hashemi Majid 《Tropical animal health and production》2019,51(2):313-319
Tropical Animal Health and Production - Bovine viral diarrhea virus (BVDV) and bovine herpes virus-1 (BHV-1) remain as the major pathogens with heavy economic consequences in Iran. The prevalence... 相似文献
38.
Zahra Hatami Alireza Rashki Mehdi Nasiri Mahallati Behnam Habibi Khaniani 《Archives of Agronomy and Soil Science》2018,64(10):1446-1458
In order to study the effects of desert dust on yield and yield components of cowpea, two field experiments were conducted in the factorial layout based on randomized complete block design with three replicates in Dezful and Mashhad, Iran in 2015. The experimental treatments were combinations of desert dust in three levels (0, 500 and 1500 µg m?3), numbers of desert dust application (once, twice and thrice) and two types of desert dust. The desert-dust particles were collected during dust storms occurred in Dezful and Zabol, which are the main sources of dust in Iran. The results showed that the biological yield and the grain yield were significantly decreased in both studied sites (Dezful and Mashhad) when the plants exposed to 500 µg m?3 desert dust treatment compared to normal conditions. Total soluble sugar and proline contents in plant leaf tissues increased significantly when they affected by 1500 µg m?3 of desert dust, while the plant height was significantly decreased by increasing the desert-dust concentrations at both sites. Biological yield, grain yield, and 100-seed weight were also significantly affected by the desert dust. Overall, the desert dust has adverse effects on yield of cowpea. 相似文献
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Hossein Asadi Mohammad Ghorbani Mehran Rezaei-Rashti Sepideh Abrishamkesh Elnaz Amirahmadi Chen Chengrong Manouchehr Gorji 《水稻科学》2021,28(4):325-343
This paper critically reviewed the current knowledge and challenges of rice husk biochar(RHB) production and its effects on soil properties, plant growth, immobilization of heavy metals, reduction of nutrient leaching and mitigation of greenhouse gas emissions. The characteristics of RHBs produced at various pyrolysis temperatures were discussed and compared to biochars derived from other agroindustrial wastes. RHBs produced at higher pyrolysis temperatures show lower hydrogen/carbon ratio, which suggests the presence of higher aromatic carbon compounds. The increase of pyrolysis temperature also results in production of RHBs with higher ash content, lower yield and higher surface area. RHB usually has higher silicon and ash contents and lower carbon content compared to biochars derived from other feedstocks at the same pyrolysis conditions. Although it depends on soil type, RHB application can improve soil organic carbon content, cation exchange capacity, available K concentration, bulk density and microbial activity. The effect of RHB on soil aggregation mainly depends on soil texture. The growth of different crops is also enhanced by application of RHB. RHB addition to soil can immobilize heavy metals and herbicides and reduce their bioavailability. RHB application shows a significant capacity in reduction of nitrate leaching, although its magnitude depends on the biochar application rate and soil biogeochemical characteristics. Use of RHB, especially in paddy fields, shows a promising mitigation effect on greenhouse gas(CH_4, CO_2 and N_2 O) emissions. Although RHB characteristics are also related to other factors such as pyrolysis heating rate and residence time, its performance for specific applications(e.g. carbon sequestration, p H amendment) can be manipulated by adjusting the pyrolysis temperature. More research is needed on long-term field applications of RHB to fully understand the advantages and disadvantages of RHB as a soil amendment. 相似文献
40.
利用杨树人工林剩余物生产刨花板可行性研究 总被引：1，自引：0，他引：1
The composite board industry in Iran is obliged to use residues from forest operation as well as wood industry for competing
with paper industry because of shortage of wood. In the present study we investigated the residues from poplar plantation
used for particleboard production. Three kinds of wood materials, poplar branches, small diameter poplar wood (3–8 cm) and
beech wood, were used in the experiment of particleboard production. The results demonstrated that the characteristic of particleboard
made from poplar branches and small diameter wood is comparable to that made from mature beech wood. To avoid too much residual
acid in the final board, the properties of boards produced with 1.5% hardener at 175°C press temperature are acceptable, although
the properties of particleboard produced with 2% hardener were higher than were higher than that of the board produced with
lower hardener (1% or 1.5%).. The MOR, MOE and IB of particleboard made from branches were measured as 14.57, 2015, and 1.32
MPa, respectively, while The MOR, MOE and IB of particleboard produced from small diameter poplar wood were 19.90, 2199, and
1.86 MPa, respectively. The thickness swelling of boards made from branches after 2 and 24 h immersion in water was 20.14%
and 31.26%. The utilization of branches and very small diameter wood of poplar is recommended for the survival and developments
of particleboard industry in Iran. 相似文献