响应面法优化灵芝发酵三七渣产灵芝三萜工艺

通过单因素试验和Box-Behnken试验对三七渣固态发酵生产灵芝三萜的发酵条件进行优化。结果表明,各影响因素对于发酵培养物中灵芝三萜含量影响程度的排序为：培养基初始含水量＞酵母粉添加量＞磷酸盐添加量。优化发酵条件为：过60目筛的三七渣,酵母浸出粉添加量2.5%,磷酸二氢钾添加量0.15%,培养基初始含水量65%。在此优化条件下,发酵培养物中灵芝三萜含量为0.37%。     

灵芝和金针菇混和发酵提高锌产量的工艺研究

本实验采用混菌发酵技术,以信州灵芝和金针菇为出发株,探讨灵芝、金针菇混菌发酵高产锌元素的工艺条件,采用原子吸收分光度法测定胞内锌元素含量。结果表明:最佳培养基为2%山芋淀粉、2%马铃薯、1%蔗糖、2%玉米粉、1%黄豆粉;混菌发酵最佳培养条件为培养温度27℃,转速150 r/min,装液量100 mL/250 mL,培养时间8 d;在最佳条件下,混菌发酵胞内锌元素含量为45.6 mg/kg,比灵芝单独培养提高15.8%,比金针菇单独培养提高63.5%。说明混菌发酵更完全,对培养基中的营养物质吸收利用率高,菌丝体长势好,增加了胞内锌产量。     

纳豆芽孢杆菌固态发酵培养基的优化

为优化纳豆芽孢杆菌固态发酵培养基,采用微生物固态发酵技术,以固态发酵后的活茵数、芽孢教、蛋白酶及α-淀粉酶活力为指标,对纳豆芽孢杆茵固态发酵培养基组成及配比,添加碳源、氮源种类及浓度,培养基的含水量进行优化研究.试验结果表明,在玉米粉与麦麸配比3:7、葡萄糖2%、硝酸铵0.5%、本60%条件下发酵效果最好.     

枯草芽孢杆菌固态发酵玉米粉的研究

以玉米粉为原料,选用枯草芽孢杆菌进行固态发酵,研究适宜的发酵条件及发酵对玉米粉营养成分的影响。试验结果表明,适宜的发酵条件为:发酵时间72 h,接种量15%,料水比为1∶0.4,硫酸铵添加量为1.5%。发酵产物中淀粉含量显著下降,降解率达到37.76%(70.48%~43.87%)。淀粉相对分子质量显著下降(1.07×106~3.86×105)。可溶性糖含量提高了171.9%(11.96%~32.52%),其中还原糖含量提高了2.1倍(3.94%~12.22%),糊精含量提高了3.22倍(3.77%~15.94%)。枯草芽孢杆菌发酵玉米粉能显著提高可溶性糖的含量,从而改善饲用品质。     

培养方式对灵芝酸合成的影响及固态发酵条件的优化

先比较灵芝振荡培养、振荡-静置两阶段结合培养和固态发酵培养对总灵芝酸及灵芝酸Mk、灵芝酸S、灵芝酸T和灵芝酸Me合成的影响。并以玉米粉为主要的固态发酵基质,利用Plackett-Burman(PB)实验筛选影响总灵芝酸合成的主要因素,然后以最陡爬坡实验、中心组合设计和响应面法对影响灵芝酸合成的主要因素进行优化。确定最优培养条件为:39.0 g玉米粉(含水量38.0%)/瓶,1.08%蚕蛹粉,0.86%蔗糖,0.08%柠檬酸三铵,0.13%硫酸镁,0.22%KH2PO4,0.02%VB1,接种量20%,培养温度29.5℃,发酵时间为10 d。在此条件下,玉米灵芝菌丝体混合粉末中总灵芝酸含量到达了24.93 mg/g,灵芝酸Mk、灵芝酸S、灵芝酸T含量分别达到了0.86、0.69和3.69 mg/g。灵芝固态发酵法生产三种灵芝酸单体具有较好的应用前景。     

大米淀粉渣固态发酵生产饲料蛋白的研究

以大米、淀粉生产葡萄糖后的废渣为原料 ,固态发酵生产饲料蛋白 ,选用种子培养基 (% ) :葡萄糖 2 ,Na H2 PO4 　 0 .3,K2 SO4 1 .0 ,酵母粉 0 .2 ,筛选出啤酒酵母菌 ,并对其工艺条件进行了初步的研究。试验结果表明 :采用啤酒酵母单菌发酵时 ,培养基初始含水量为 6 5%、初始 p H6 .2、发酵温度为 2 8°C、接种量为 1× 1 0 8/ ml(1 2 % )、再加入适量的无机盐 ,固态发酵获得蛋白质含量最高为6 9% ,平均为 6 3% ,比对照提高 46 %     

培养基组成对灵芝多糖形态的影响及优化研究

在不同发酵培养基的条件下,灵芝胞外多糖形态有较大不同。在兼顾胞外多糖的形态与产量的同时,对其发酵培养基进行了优化,研究结果表明,最佳发酵培养基为:玉米粉2%,黄豆粉1%,FeSO4·7H2O0.02%,KH2PO40.1%,土豆汁30%,pH自然。最终所得到的胞外多糖形态外观良好,产量达到86.36mg/mL(湿重)。     

蛹虫草固态发酵对玉米粉加工性质及消化性的影响

利用蛹虫草固态发酵法对玉米粉性质进行改良。测定发酵前后玉米粉的理化性质,利用快速粘度分析仪和质构仪测定发酵前后玉米粉加工性质,来探究蛹虫草发酵对玉米粉性质的影响。研究结果表明,发酵0~2 d理化成分变化不显著（P>0.05）,2 d后发生明显变化,至发酵第3 d,总淀粉含量降低了11.7%,直链淀粉增加了29.8%;经固态发酵后,水溶指数增加了87.7%,吸水指数降低了28.2%;固态发酵可改善玉米粉的糊化特性和质构特性,到发酵的第3 d,峰值粘度降低了47.3%,回生值下降了34.9%,凝胶硬度和咀嚼性分别降低了45.4%和34.8%,提高了玉米主食制品适口性。蛹虫草固态发酵后的玉米粉具有更高的营养价值,到发酵的第3 d,可溶性蛋白、必需氨基酸,分别增加了52.3%和26%;慢消化淀粉及抗性淀粉分别提高至原来的1.83和1.41倍。通过本研究所得玉米粉的改良方法,可改善玉米粉的加工性能和淀粉消化性,为蛹虫草在玉米主食制品品质改良方面提供一定参考。     

不同品种灵芝固态发酵菌丝体多糖和三萜含量的比较

以多糖和三萜含量为指标,探讨了8种灵芝菌株固态发酵菌丝生物活性物质含量的差异。结果表明,不同菌株间固态发酵菌丝得率、多糖和三萜含量的差异较大,紫芝菌丝得率最高,达到了21.66%;云芝单位菌丝体多糖含量最高,为8.16%;赤芝和树舌灵芝单位菌丝体三萜含量最高,分别为1.13%和1.08%。8种灵芝菌株中紫芝单位培养基的多糖产量最高,达到了0.996%,赤芝单位培养基的三萜产量最高,为0.173%,因此紫芝适合于固态发酵生产灵芝多糖,而赤芝适合于固态发酵生产灵芝三萜。     

以活化硒矿为硒源的灵芝生物富硒研究

对以活化硒矿为硒源的灵芝(Ganoderma lucidum)液体培养条件进行了研究。考察了不同碳源和氮源对灵芝生长的影响,利用正交试验确定了最佳液体发酵培养基并对温度、转速、pH等发酵条件进行了优化。试验结果表明:灵芝液体培养的最佳发酵培养基是:2%玉米粉,4%葡萄糖,3%麸皮汁,0.2%磷酸二氢钾,0.1%七水硫酸镁;最佳发酵培养条件是:温度28℃,摇床转速180r/min,pH6,接种量15%,菌丝生物量高达23.59g/L。当添加的硒矿水溶硒含量为5μg/g时,灵芝富硒效果最好,其总硒含量和富硒率分别达302.2μg/g和60.0%。     

Solid-state fermentation of cornmeal with the basidiomycete Hericium erinaceum for degrading starch and upgrading nutritional value

The ability of the basidiomycete Hericium erinaceum to degrade starch and upgrade nutritional value of cornmeal during solid-state fermentation was studied. On the basal medium which consisted of cornmeal and salt solution, H. erinaceum produced a strong alpha-amylase on the 15th day after inoculation, which resulted in a 52% degradation of the starch. By supplementation with 5-15 g soybean meal per 100 g cornmeal the alpha-amylase activity and degradation rate of starch was raised significantly (P < 0.01). Prolongation of fermentation time from 15 to 30 days did not increase significantly the degradation rate of starch, though the alpha-amylase activity reached its maximum value of 179 U/g on the 20th day after inoculation. Under conditions close to the theoretical optimum fermentation conditions, that was after 25 days at 25 degrees C in the medium with added 15 g soybean meal per 100 g cornmeal, the starch content in the product decreased from 63% to 22% (P < 0.001) and protein content increased from 12% to 17% (P < 0.01). In the protein in the product, the lysine content was increased from 36 to 56 mg/ g and tryptophan from 9 to 13 mg/g. Using egg protein as a standard, an evaluation on the protein quality of the fermented product showed that it was superior to that of the nonfermented control and to other cereals, was close to that of soybean and chicken, but was inferior to that of milk and red meats.     

灵芝真菌液体发酵培养基优化研究

对灵芝真菌的发酵培养条件进行研究,选取了7种培养基成分进行研究,通过L18(37)正交试验确定出灵芝真菌的最佳发酵培养组(g/L)合为:葡萄糖30,玉米粉50,黄豆粉10,酵母膏1,KH2PO4 0.7,MgSO4·7H2O0.1,VB10.02,pH 6.0.     

Penicillium sp.X-1液态发酵生产生淀粉酶的优化

通过摇瓶发酵,研究了培养基成分对Penicillium sp.X-1液态发酵产生淀粉酶的影响。结果表明：碳源、氮源及MgCl2对产酶有较大的影响,经响应面优化得到的培养基组成为：玉米粉42 g/L,豆饼粉30 g/L,MgCl216 mmol/L,在最优条件下酶活达到239 U/mL,与采用基本培养基的相比,酶活提高了7.5倍.     

In vitro degradation of choline from selected feedstuffs and choline supplements

The objective of this experiment was to determine the extent of in vitro degradation of choline from barley, corn, corn gluten meal, cottonseed meal, fish meal, soybean meal, alfalfa hay, timothy hay, choline chloride, and choline stearate. During four individual fermentation runs, samples were incubated in vitro for .25, 1, 3, 6, 12, 18, 24, 36, and 48 h with an inoculum mixture containing rumen fluid obtained from a rumen-fistulated dairy cow fed 17.5% corn silage and 28.7% grass silage and 53.8% concentrate diet. Because of their low choline content (less than .68 mg/g) corn, corn gluten meal, alfalfa hay, and timothy hay gave erratic values for choline disappearance for different fermentation runs and times of incubation although disappearance tended to increase with time. Data for the rest of the feeds and choline supplements were analyzed using nonlinear regression procedure to obtain estimates of potentially degradable choline, rapidly degradable choline, and the rate of choline degradation in vitro. The mean estimates of rumen degradable choline (%) were 79.4, 84.7, 82.9, 83.8, 98.0, and 98.6 for barley, cottonseed meal, fish meal, soybean meal, choline stearate, and choline chloride, respectively. The results suggest that incorporating choline-rich feedstuffs in diets can only marginally increase the postruminal flow of choline in dairy cows.     

米曲霉固态发酵玉米胚芽粕制备玉米肽的研究

经过单因素试验和正交试验,确定了米曲霉发酵玉米胚芽粕生产玉米多肽的最佳发酵条件:玉米胚芽粕含量为40%(60%麸皮),培养基含水量为74%,培养基接种量为7%,培养温度30℃,发酵时间84h。在此条件下玉米肽转化率达到最大为36%。并对制得的玉米肽进行了初步的分离纯化,经截留分子质量104的中空纤维柱超滤,得到分子质量在104以下的超滤液,超滤液经SephadexG-25柱分离和相对分子质量分布的测定,共洗脱出2个峰。经过计算,其各级玉米肽组分相对分子质量分别大约为5128和1626 Da。为了进一步验证这两种组分的纯度,我们在实验中用Tricine-SDS-PAGE电泳进行了验证,并证明确实主要为两种组分,与葡聚糖凝胶柱分离结果相符。     

Effects of source of protein and carbohydrate on ruminal fermentation and passage of nutrients to the small intestine of lactating cows

Four early lactation multiparous Holstein cows were used in a 4 x 4 Latin square to investigate the effects of source of protein (fish meal or soybean meal) and carbohydrate (corn or barley) on ruminal fermentation, flow of nutrients to the small intestine, and animal performance. The treatments, arranged in a 2 x 2 (protein x carbohydrate) factorial were: 1) corn plus soybean meal; 2) corn plus fish meal; 3) barley plus soybean meal; and 4) barley plus fish meal. Dry matter and starch intakes were greater when corn was fed than when barley was fed. Barley-based diets were more extensively degraded in the rumen than corn-based diets and therefore provided more energy for microbial growth. However, passage of amino acids and starch to the duodenum was greater for corn-based diets than barley-based diets, because of the greater intake and lower ruminal degradability of the corn-based diets. Microbial protein constituted a larger portion of the total N and had a greater influence on the pattern and quantity of amino acids that passed to the duodenum than did protein from fish meal or soybean meal, which escaped ruminal degradation. Feeding corn-based diets increased production of milk and milk protein compared with feeding barley-based diets.     

灵芝菌液体发酵玉竹产水溶性多糖的工艺优化和抗氧化性研究

为探究灵芝菌发酵玉竹产水溶性多糖工艺及多糖的抗氧化能力,该研究利用灵芝菌液体发酵玉竹,以多糖提高率为评价指标,通过单因素试验及响应面试验对其发酵工艺进行优化,并测定发酵前后多糖的抗氧化能力。结果表明,最佳发酵条件为玉竹添加量6%、豆粕添加量为2%、KH₂PO₄添加量0.15%、Mg SO₄·7H₂O添加量0.15%、接种量8.7%、发酵时间4 d及发酵温度30℃。在此优化条件下,发酵液多糖含量达到5.91 mg/m L,较未发酵的培养基(3.41 mg/m L)提高了73.48%。抗氧化试验表明,在相同浓度下,发酵后多糖(PAF)对比发酵前多糖(PBF)的ABTS+·、DPPH·、OH·清除率均有所提高。其中,PAF对DPPH和OH·的半抑制浓度(IC50)值分别为2.77 mg/m L、0.54 mg/m L,PBF对DPPH·和OH·的IC₅₀值分别为7.94 mg/m L、1.57 mg/m L。结果表明,PAF具有更强的体外抗氧化能力。     

含水量对不同原料发酵参数的影响

试验旨在研究含水量对不同饲料原料发酵品质的影响,采用分组对照实验设计,以乳酸菌、酵母菌、枯草芽孢杆菌分别固态发酵玉米、豆粕和棉籽粕,设30%、40%、50%、60%四个含水量,以感官评价、pH和发酵后益生存留量为发酵品质评定指标。结果表明：随发酵时间延长,pH表现二次曲线的规律（P<0.01）;含水量显著影响玉米、豆粕和棉籽粕的发酵（P<0.05）,不影响原料初始pH（P>0.05）;pH达到稳定时,50%含水量的玉米、豆粕和棉籽粕的乳酸菌、枯草芽孢杆菌数量高于其它处理（P<0.05）。本试验条件下,乳酸菌、酵母菌、枯草芽孢杆菌分别发酵玉米,最佳含水量为50%;乳酸菌、枯草芽孢杆菌分别发酵豆粕和棉籽粕,最佳含水量为60%;酵母菌发酵豆粕和棉籽粕,最佳含水量为50%。     

米根霉高效利用玉米淀粉生产乳酸的发酵条件优化

研究米根霉HB12利用玉米淀粉生产乳酸的发酵条件优化。从土壤中新筛选得到一株以高浓度玉米淀粉为原料发酵生产乳酸的米根霉HB12。通过单因素及正交试验,得到最佳发酵培养基组成(g/L)为：玉米淀粉140、NH4Cl 2、KH2PO4 0.3、MgSO4·7H2O 0.3、ZnSO4·7H2O 0.05、CaCO3 80;最佳培养条件为：摇瓶装液量50mL/250mL,接种量为2.5×106个孢子,35℃、200r/min培养108h。该条件下,菌株最大产酸量为104.9g/L,产酸速率为0.97g/(L·h),对玉米淀粉的转化率达74.9%,产酸量提高了49.4%。此菌株能够直接高效利用价格低廉来源广泛的玉米淀粉发酵生产乳酸,具有很好的工业应用前景。     

米曲霉固态发酵降解大豆致敏原条件的优化

为了最大程度地降低甚至消除米曲霉固态发酵豆粕产品的免疫反应性,此研究利用响应面法对米曲霉固态发酵豆粕降解大豆致敏原的条件进行了优化。首先对影响米曲霉固态发酵豆粕降解大豆致敏原的几个因素(发酵时间、接种量、发酵温度、培养基初始pH、料水比)进行了单因素研究,确定了对结果有较大影响的料水比、发酵温度和培养基初始pH这三个因素。其后利用Box-Behnken设计,确定了固态发酵的最佳条件,即当料水比为1:1.21(g/mL)、发酵温度29.8℃、pH为6.63时,得到理论最低致敏原降解率为99.15%。最后,经验证实验,最佳条件下实际平均致敏原降解率为99.02%。验证实验结果与理论值相差0.13%,说明该方程与实际情况拟合较好。