How long does r9370 mining cost
Publish: 2021-04-24 06:50:15
1. Yes, I'm similar to LZ, but I didn't practice enchantment and chose alchemy. In the project from 1-375, my materials are basically from ah. Up to now, I haven't made a big plane, which costs about 6000-7000g. The main reason is that after 350, I have to rely on a lot of money to develop it. If LZ has any problems in the process of developing the project, please let me know
2. R9370 graphics card can only meet the minimum requirements of Jedi survival, and can only eat chicken under low special effects.
3. X5550, quad core, eight thread, X58 motherboard, these are 2009 hardware. They are very old. If you buy them, you can't help it. If you don't buy them, don't buy them. The R9 370 4G graphics card is about 75000 to 80000 points. Although your configuration is old, you can use the R9 370 graphics card,
4.
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What's wrong with your R9 370 graphics card? It can be simply described or represented by map
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the explosion of graphics memory indicates that the graphics card is beyond the scope of use, or the running game software has exceeded the performance of the graphics card. You can try to update the driver to optimize the performance output or play low-end games< br />
5. Hello, landlord
R9 370 belongs to the middle end graphics card
generally, the overclocking ability of the middle end graphics card is not big, and if there are too many graphics cards, it will also cause hard damage to the graphics card
some of them can overclock with one key, which will increase by about 5-8%
but it is always the middle end graphics card, and it will be very difficult if there is no overclocking
R9 370 belongs to the middle end graphics card
generally, the overclocking ability of the middle end graphics card is not big, and if there are too many graphics cards, it will also cause hard damage to the graphics card
some of them can overclock with one key, which will increase by about 5-8%
but it is always the middle end graphics card, and it will be very difficult if there is no overclocking
6. 370 graphics card, mining? You make me laugh for a while
People's high-end cards are called mining. You can only play with mud.
People's high-end cards are called mining. You can only play with mud.
7. Your operation on the DNS server where your domain name is located can take effect immediately, but other DNS servers will not refresh the cache records of your domain name immediately in order to rece the load, which is one of the reasons why they can't synchronize quickly. What peanut shell does is need frequent and fast synchronization domain name, so it will try to overcome many factors, but this is at the expense of server performance.
8. DNS error is an error in your IP protocol. Method 1: shut down, check the network cable again, and check whether the network fee is e, No problem, and then restart method 2: if method 1 still doesn't work, right click broadband connection - properties - Network - stand alone protocol version - properties at the bottom right - use the DNS server address below - enter 255.255.255.0 in the preferred DNS server column - OK - connect broadband again
9. Try another DNS, use mine: 218.2.135.1, spare: 61.147.37.1
10. Study on the enzymatic properties of xylanase in feed enzyme preparation 2006-09-27 10:16 xylanase is one of the main enzymes in feed enzyme preparation. Through the study on the enzymatic properties of xylanase in a commercial enzyme preparation, the results showed that the optimal pH value of xylanase was 4.5, the optimal reaction temperature was 50 ℃, the dry heat stability was good, and Cu2 +, Zn2 +, Zn2 + were stable Mn2 + and Fe3 + could inhibit the xylanase activity, while Mg2 +, Na + and (NH4) 2SO4 could increase the xylanase activity
key words: feed xylanase; Enzymatic properties; Heat stability
Chinese Library Classification No. s816.3
in China's feed proction, in addition to the general corn soybean meal diet, in fact, it is more common to add 10% - 40% of unconventional feed materials such as barley or wheat, flour, wheat bran, wheat bran, cottonseed meal to the corn soybean meal diet Many antinutritional factors, such as xylan, are contained in by-procts such as grain and bran, which limits their extensive application in feed. Adding xylanase to feed can degrade non starch polysaccharides such as xylan, rece intestinal viscosity and improve feed utilization rate, so the market prospect of developing xylanase is broad [2-5]. In addition, the influx of foreign low price wheat and barley procts will further stimulate the market demand for xylanase. In order to understand the enzymatic properties of xylanase in common feed enzymes, we carried out experiments on the optimal pH value, optimal reaction temperature, substrate pertinence, thermal stability, and the effect of different metal ions on the enzyme activity of a certain xylanase in the market, in order to provide some reference for the preservation and Application of xylanase
1 materials and methods
1.1 experimental materials
precision pH meter ± 01), electronic balance, UV 200 spectrophotometer, constant temperature water bath, centrifuge; Xylanase was provided by a biological company in Sichuan
1.2 enzyme activity determination (modified DNS method [6-8])
1.2.1 enzyme activity unit definition
1.0% xylanase was released from 1.0% xylanase solution every minute at 50 ℃ and pH value of 5.0 μ The amount of enzyme required for recing sugar was defined as one enzyme activity unit (U)
1.2.2 1.0% substrate preparation
accurately weigh 1g oat xylan (sigma-x0627) and add it into acetic acid buffer solution, heat it and dissolve it with magnetic stirring, fix the volume to 100ml, and store it in refrigerator at 4 ℃ (valid for 3D)
1.2.3 preparation of DNS reagent
take 182.0g potassium sodium tartrate and dissolve it in 500ml water, heat it (no more than 60 ℃), add 6.3g 3,5-Dinitrosalicylic acid, 21.0g NaOH, 5.0g phenol and 5.0g sodium sulfite into the hot solution in turn, stir them to dissolve, cool them to a constant volume of 1000ml, store them in brown bottle, and use them after 2 weeks
1.2.4 activity determination steps
Add 0.1ml diluted enzyme solution to 0.1ml xylan substrate, react in 50 ℃ water bath for 10min, immediately add 0.6ml DNS reagent, boil in boiling water bath for 15min, add 4.2ml water, and then determine the od550 value
2 experimental design and results
2.1 the optimum pH value of xylanase was
0.1M citric acid and 0.2m disodium hydrogen phosphate solution were used to prepare citric acid disodium hydrogen phosphate buffer with pH value ranging from 3 to 7. The enzyme activity was determined under different reaction pH values. The maximum absorbance of the enzyme was 100%, The enzyme activity at other pH values is the maximum absorbance, and the percentage of enzyme activity is the relative enzyme activity at this pH value (see Figure 1)
the results showed that the xylanase activity was the highest when the pH value was 4.5, so the optimal pH value for xylanase activity determination was about 4.5. It can be seen from Fig. 1 that the relative activity of the enzyme is more than 91% at pH 4-5. When the pH value exceeds this range, the enzyme activity decreases. Fu wubing and others believe that this is related to the influence of pH value on the ionization state of proton transfer group in the active site of the enzyme protein and the stability of the enzyme to pH [9]
2.2 optimal reaction temperature of xylanase
under the optimal pH value, different reaction temperatures were set respectively, and the xylanase activity under this condition was determined. The maximum absorbance of the enzyme sample was 100%, and the percentage of the maximum enzyme activity at other temperatures was the relative enzyme activity at its temperature (see Figure 2)
it can be seen from Fig. 2 that the reaction temperature has a great influence on the determination of xylanase activity, and the maximum enzyme activity is at 50 ℃. Therefore, we determined that the optimal reaction temperature of the xylanase was 50 ℃
2.3 xylanase substrate specific experiment
under the optimal pH and temperature conditions, 1.0% birch xylan and 1.0% oat xylan were used as substrates to determine the enzyme activity under different substrates. When oat xylan was used as substrate, the enzyme activity was 100%. When birch xylan was used as substrate, the enzyme activity was 100%. When oat xylan was used as substrate, the percentage of enzyme activity was the relative enzyme activity
xylanase is a complex enzyme, containing a variety of enzyme protein components. From the existing research results, it can be found that there are at least 20 kinds of microorganisms that can proce xylanase, and different microorganisms usually proce different xylanase. In addition, the difference in the content and molecular structure of the active components in the substrate will inevitably lead to the inconsistency in the determination of xylanase activity. Studies have shown that the xylanase activity measured with different substrates is quite different [5]. Therefore, the xylanase activity on different substrates was tested. The experimental results showed that the enzyme activity with birch xylan as the substrate was 88.62% of that with oat xylan as the substrate, while the substrate specific experiment of xylanase studied by Li Lian and others showed that birch xylan was better than oat xylan [10]< The xylanase was precipitated with 30% (NH4) 2SO4, centrifuged for 15 min, and the supernatant was obtained; The supernatant was precipitated with 60% (NH4) 2SO4. After centrifugation, the precipitate was dissolved in 0.2mol/l acetic acid sodium acetate buffer (pH = 5.0). The supernatant was separated and purified on sephades-g100 column, and eluted with the same buffer. The components containing xylanase were collected and lyophilized to obtain pure enzyme. The purified enzyme was used to determine the reaction process as follows
according to the reaction time of 20, 40, 60, 70, 80, 90, 100 and 120 min, 0.02, 0.04, 0.06, 0.08 and 0.1 ml xylanase were added to each group, and the insufficient part was supplemented with acetic acid sodium acetate buffer (pH = 5.0) until the final volume was 0.1 ml, and 1.0% xylan was added according to the volume ratio of 1:1. Under the condition of 50 ℃ water bath, the reaction was carried out according to the corresponding reaction time, with the corresponding inactivated enzyme solution added with 0.6ml DNS reagent and 1.0% xylan 0.1ml as the control, and then the determination was carried out at od550. Taking the reaction time (min) as the horizontal axis and the absorbance value as the vertical axis, the reaction process curves with different enzyme dosage can be obtained (see Fig. 3)
it can be seen from the reaction process curve of xylanase in Fig. 3 that the reaction process curve is linear when the dosage of xylanase solution is 0.02-0.1ml and the reaction time is within 40min. Therefore, the reaction speed obtained from the determination within this range is the maximum initial reaction speed, which is concive to the correct determination of enzyme activity< The effect of dry heat treatment on xylanase activity
2.5.1 the samples were treated at 55, 65, 75, 85 and 95 ℃ for 10 min, extracted immediately, and the enzyme activity was determined, The enzyme activity after dry heat treatment is the percentage of enzyme activity before treatment, which is the remaining enzyme activity after dry heat treatment. The results are shown in Table 1
it can be seen from table 1 that the xylanase is not sensitive to dry heat treatment temperature, and it has strong resistance to dry heat treatment< 1.000 g sample was accurately weighed, 10% water was added (the total water content after adding water was about 17% ～ 20%), fully stirred and tightly covered, and then treated in 85 ℃ constant temperature drying oven for 2, 5, 10 and 30 min. the enzyme activity was immediately taken out and determined. The enzyme activity was 100% without wet heat treatment, The enzyme activity after hydrothermal treatment is the percentage of enzyme activity before treatment, which is the remaining enzyme activity after hydrothermal treatment. The results are shown in Table 2
it can be seen from table 2 that the effect of wet heat treatment on enzyme activity is much greater than that of dry heat treatment, because it is easier to denaturate protein under the condition of wet heat treatment [9]. The results showed that the enzyme had good thermal stability. It could retain 42.24% of the enzyme activity at 85 ℃ for 30 min with 17% water content. The enzyme activity would not be greatly reced e to the high temperature and humidity of pelleting ring feed processing
2.6 effects of different metal ions on xylanase activity
different metal ions were added to the 10 mg / ml oat xylan solution prepared with pH 5.0 buffer solution, and the final concentration of each ion in the reaction system was 5 mmol / L. When xylan solution without any ions is used as substrate, the measured enzyme activity value is 100%, and the enzyme activity measured under various metal ions conditions is its percentage, then the relative enzyme activity under its conditions can be obtained. The results are shown in Table 3
it can be seen from table 3 that the enzyme is not sensitive to 5mmol / L metal ions. Cu2 +, Mn2 +, Zn2 +, Fe3 + and Ca2 + have certain inhibitory effect on the activity of xylanase, among which Mn2 + and Fe3 + have the strongest inhibitory effect, and the loss of enzyme activity is about 26.53% - 29.71%, followed by Zn2 +, Cu2 +, and the loss of enzyme activity is about 3.73% - 12.56%. Ca2 + and K + have little effect on the activity of xylanase; In addition, Na +, Mg2 + and (NH4) 2SO4 can activate the enzyme activity. It indicates that the effect of metal ions on xylanase is less than some other reports, which may be e to the different sensitivity of xylanase from different sources to metal ions [10,11]. Therefore, the effect of metal ions added in feed on xylanase activity is not significant<
3 discussion
the optimal pH and temperature of xylanase studied in this paper are similar to those of other reported xylanases, and it has better heat resistance, which is the best one among the reported xylanases. The resial enzyme activity of xylanase is 42.24% after being treated at 85 ℃ for 30 min, while the resial enzyme activity of xylanase is 34.62% after being treated at 85 ℃ for 10 min [10], Because the enzyme has good thermal stability, it can rece the loss of enzyme activity in the pelletizing process of feed processing. In addition, Cu2 +, Zn2 +, Mn2 + and Fe3 + inhibited xylanase; Na +, Mg2 + and (NH4) 2SO4 can activate the enzyme activity
from the characteristics of the xylanase, the temperature and pH value in the animal intestine have little effect on its activity, and it can tolerate the high temperature in the granulation process, which makes it have unique advantages in the application of animal feed.
key words: feed xylanase; Enzymatic properties; Heat stability
Chinese Library Classification No. s816.3
in China's feed proction, in addition to the general corn soybean meal diet, in fact, it is more common to add 10% - 40% of unconventional feed materials such as barley or wheat, flour, wheat bran, wheat bran, cottonseed meal to the corn soybean meal diet Many antinutritional factors, such as xylan, are contained in by-procts such as grain and bran, which limits their extensive application in feed. Adding xylanase to feed can degrade non starch polysaccharides such as xylan, rece intestinal viscosity and improve feed utilization rate, so the market prospect of developing xylanase is broad [2-5]. In addition, the influx of foreign low price wheat and barley procts will further stimulate the market demand for xylanase. In order to understand the enzymatic properties of xylanase in common feed enzymes, we carried out experiments on the optimal pH value, optimal reaction temperature, substrate pertinence, thermal stability, and the effect of different metal ions on the enzyme activity of a certain xylanase in the market, in order to provide some reference for the preservation and Application of xylanase
1 materials and methods
1.1 experimental materials
precision pH meter ± 01), electronic balance, UV 200 spectrophotometer, constant temperature water bath, centrifuge; Xylanase was provided by a biological company in Sichuan
1.2 enzyme activity determination (modified DNS method [6-8])
1.2.1 enzyme activity unit definition
1.0% xylanase was released from 1.0% xylanase solution every minute at 50 ℃ and pH value of 5.0 μ The amount of enzyme required for recing sugar was defined as one enzyme activity unit (U)
1.2.2 1.0% substrate preparation
accurately weigh 1g oat xylan (sigma-x0627) and add it into acetic acid buffer solution, heat it and dissolve it with magnetic stirring, fix the volume to 100ml, and store it in refrigerator at 4 ℃ (valid for 3D)
1.2.3 preparation of DNS reagent
take 182.0g potassium sodium tartrate and dissolve it in 500ml water, heat it (no more than 60 ℃), add 6.3g 3,5-Dinitrosalicylic acid, 21.0g NaOH, 5.0g phenol and 5.0g sodium sulfite into the hot solution in turn, stir them to dissolve, cool them to a constant volume of 1000ml, store them in brown bottle, and use them after 2 weeks
1.2.4 activity determination steps
Add 0.1ml diluted enzyme solution to 0.1ml xylan substrate, react in 50 ℃ water bath for 10min, immediately add 0.6ml DNS reagent, boil in boiling water bath for 15min, add 4.2ml water, and then determine the od550 value
2 experimental design and results
2.1 the optimum pH value of xylanase was
0.1M citric acid and 0.2m disodium hydrogen phosphate solution were used to prepare citric acid disodium hydrogen phosphate buffer with pH value ranging from 3 to 7. The enzyme activity was determined under different reaction pH values. The maximum absorbance of the enzyme was 100%, The enzyme activity at other pH values is the maximum absorbance, and the percentage of enzyme activity is the relative enzyme activity at this pH value (see Figure 1)
the results showed that the xylanase activity was the highest when the pH value was 4.5, so the optimal pH value for xylanase activity determination was about 4.5. It can be seen from Fig. 1 that the relative activity of the enzyme is more than 91% at pH 4-5. When the pH value exceeds this range, the enzyme activity decreases. Fu wubing and others believe that this is related to the influence of pH value on the ionization state of proton transfer group in the active site of the enzyme protein and the stability of the enzyme to pH [9]
2.2 optimal reaction temperature of xylanase
under the optimal pH value, different reaction temperatures were set respectively, and the xylanase activity under this condition was determined. The maximum absorbance of the enzyme sample was 100%, and the percentage of the maximum enzyme activity at other temperatures was the relative enzyme activity at its temperature (see Figure 2)
it can be seen from Fig. 2 that the reaction temperature has a great influence on the determination of xylanase activity, and the maximum enzyme activity is at 50 ℃. Therefore, we determined that the optimal reaction temperature of the xylanase was 50 ℃
2.3 xylanase substrate specific experiment
under the optimal pH and temperature conditions, 1.0% birch xylan and 1.0% oat xylan were used as substrates to determine the enzyme activity under different substrates. When oat xylan was used as substrate, the enzyme activity was 100%. When birch xylan was used as substrate, the enzyme activity was 100%. When oat xylan was used as substrate, the percentage of enzyme activity was the relative enzyme activity
xylanase is a complex enzyme, containing a variety of enzyme protein components. From the existing research results, it can be found that there are at least 20 kinds of microorganisms that can proce xylanase, and different microorganisms usually proce different xylanase. In addition, the difference in the content and molecular structure of the active components in the substrate will inevitably lead to the inconsistency in the determination of xylanase activity. Studies have shown that the xylanase activity measured with different substrates is quite different [5]. Therefore, the xylanase activity on different substrates was tested. The experimental results showed that the enzyme activity with birch xylan as the substrate was 88.62% of that with oat xylan as the substrate, while the substrate specific experiment of xylanase studied by Li Lian and others showed that birch xylan was better than oat xylan [10]< The xylanase was precipitated with 30% (NH4) 2SO4, centrifuged for 15 min, and the supernatant was obtained; The supernatant was precipitated with 60% (NH4) 2SO4. After centrifugation, the precipitate was dissolved in 0.2mol/l acetic acid sodium acetate buffer (pH = 5.0). The supernatant was separated and purified on sephades-g100 column, and eluted with the same buffer. The components containing xylanase were collected and lyophilized to obtain pure enzyme. The purified enzyme was used to determine the reaction process as follows
according to the reaction time of 20, 40, 60, 70, 80, 90, 100 and 120 min, 0.02, 0.04, 0.06, 0.08 and 0.1 ml xylanase were added to each group, and the insufficient part was supplemented with acetic acid sodium acetate buffer (pH = 5.0) until the final volume was 0.1 ml, and 1.0% xylan was added according to the volume ratio of 1:1. Under the condition of 50 ℃ water bath, the reaction was carried out according to the corresponding reaction time, with the corresponding inactivated enzyme solution added with 0.6ml DNS reagent and 1.0% xylan 0.1ml as the control, and then the determination was carried out at od550. Taking the reaction time (min) as the horizontal axis and the absorbance value as the vertical axis, the reaction process curves with different enzyme dosage can be obtained (see Fig. 3)
it can be seen from the reaction process curve of xylanase in Fig. 3 that the reaction process curve is linear when the dosage of xylanase solution is 0.02-0.1ml and the reaction time is within 40min. Therefore, the reaction speed obtained from the determination within this range is the maximum initial reaction speed, which is concive to the correct determination of enzyme activity< The effect of dry heat treatment on xylanase activity
2.5.1 the samples were treated at 55, 65, 75, 85 and 95 ℃ for 10 min, extracted immediately, and the enzyme activity was determined, The enzyme activity after dry heat treatment is the percentage of enzyme activity before treatment, which is the remaining enzyme activity after dry heat treatment. The results are shown in Table 1
it can be seen from table 1 that the xylanase is not sensitive to dry heat treatment temperature, and it has strong resistance to dry heat treatment< 1.000 g sample was accurately weighed, 10% water was added (the total water content after adding water was about 17% ～ 20%), fully stirred and tightly covered, and then treated in 85 ℃ constant temperature drying oven for 2, 5, 10 and 30 min. the enzyme activity was immediately taken out and determined. The enzyme activity was 100% without wet heat treatment, The enzyme activity after hydrothermal treatment is the percentage of enzyme activity before treatment, which is the remaining enzyme activity after hydrothermal treatment. The results are shown in Table 2
it can be seen from table 2 that the effect of wet heat treatment on enzyme activity is much greater than that of dry heat treatment, because it is easier to denaturate protein under the condition of wet heat treatment [9]. The results showed that the enzyme had good thermal stability. It could retain 42.24% of the enzyme activity at 85 ℃ for 30 min with 17% water content. The enzyme activity would not be greatly reced e to the high temperature and humidity of pelleting ring feed processing
2.6 effects of different metal ions on xylanase activity
different metal ions were added to the 10 mg / ml oat xylan solution prepared with pH 5.0 buffer solution, and the final concentration of each ion in the reaction system was 5 mmol / L. When xylan solution without any ions is used as substrate, the measured enzyme activity value is 100%, and the enzyme activity measured under various metal ions conditions is its percentage, then the relative enzyme activity under its conditions can be obtained. The results are shown in Table 3
it can be seen from table 3 that the enzyme is not sensitive to 5mmol / L metal ions. Cu2 +, Mn2 +, Zn2 +, Fe3 + and Ca2 + have certain inhibitory effect on the activity of xylanase, among which Mn2 + and Fe3 + have the strongest inhibitory effect, and the loss of enzyme activity is about 26.53% - 29.71%, followed by Zn2 +, Cu2 +, and the loss of enzyme activity is about 3.73% - 12.56%. Ca2 + and K + have little effect on the activity of xylanase; In addition, Na +, Mg2 + and (NH4) 2SO4 can activate the enzyme activity. It indicates that the effect of metal ions on xylanase is less than some other reports, which may be e to the different sensitivity of xylanase from different sources to metal ions [10,11]. Therefore, the effect of metal ions added in feed on xylanase activity is not significant<
3 discussion
the optimal pH and temperature of xylanase studied in this paper are similar to those of other reported xylanases, and it has better heat resistance, which is the best one among the reported xylanases. The resial enzyme activity of xylanase is 42.24% after being treated at 85 ℃ for 30 min, while the resial enzyme activity of xylanase is 34.62% after being treated at 85 ℃ for 10 min [10], Because the enzyme has good thermal stability, it can rece the loss of enzyme activity in the pelletizing process of feed processing. In addition, Cu2 +, Zn2 +, Mn2 + and Fe3 + inhibited xylanase; Na +, Mg2 + and (NH4) 2SO4 can activate the enzyme activity
from the characteristics of the xylanase, the temperature and pH value in the animal intestine have little effect on its activity, and it can tolerate the high temperature in the granulation process, which makes it have unique advantages in the application of animal feed.
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