Fermentation of Feedlot Waste Filtrate by Fungi and Streptomycetes

The soluble and dispersed nitrogen and carbon components in the filtrate fraction of cattle feedlot waste are a potential nutrient source from which single-cell protein could be produced for animal feeds. The ability of more than 200 fungi and streptomycetes to grow in this liquid was determined; these included isolates from the waste and associated sources, as well as organisms maintained in the Culture Collection of the Agricultural Research Service in Peoria, Ill. Utilization of waste nutrients was measured by changes in nitrogen content and chemical oxygen demand. Only 20% of the organisms were able to grow appreciably in the filtrate. Of these, dry-weight yields varied from 0.6 to 2.7 g of mycelium per liter; from 21 to 50% of the nitrogen in the filtrates was used during growth, whereas chemical oxygen demand levels diminished from 4 to 60%. In general, streptomycetes isolated from the feedlot used nutrients from the filtrates better than fungi did. Addition of readily available carbon sources such as glucose or whey significantly increased (as much as sixfold) cell yields of selected organisms and promoted better utilization of nitrogen (from two- to threefold); the effect on chemical oxygen demand varied (0 to 33% increase).     

利用纤维素废弃物发酵生产纤维素酶的研究

以纤维素废弃物为原料利用黑曲霉LN0402菌株发酵生产纤维素酶。分别考察培养时间、碳源用量、装液量、摇床转速及孢子悬液体积分数等因素对该菌株利用不同碳源生产纤维素酶能力的影响。确立了黑曲霉LN0402利用不同纤维素废弃物产纤维素酶的最适条件。     

甘蔗糖蜜酒精废液混菌发酵菌体蛋白的研究

本文报导利用甘蔗糖蜜酒精废液混菌发酵高质量菌体蛋白的研究,通过热带假丝酵母Ｃａｎｄｉｄａ ｔｒｏｐｉｃａｌｉｓ种合融合株Ｃｔ－３配伍其他菌株,混菌发酵时间缩短２￣４ｈ,生物量可达２０ｇ／Ｌ,粗蛋白质含量５０￣５３％,灰份≤１０％,水分为５￣８％,与Ｃｔ－３单菌发酵相比,蛋白质提高４￣６％。     

休哈塔假丝酵母发酵木糖制乙醇过程研究

木质纤维素原料水解产物的主要成分是葡萄糖和木糖,其中葡萄糖很容易发酵,致使木糖成为木质纤维素发酵的关键,休哈塔假丝酵母(Candida shehatae)1766是自然界木糖发酵性能较好的天然酵母之一。研究了发酵温度、发酵时间、接种量、初始pH值、摇床转速等因素对休哈塔假丝酵母1766发酵木糖生产乙醇的影响,由正交试验初步确定了休哈塔假丝酵母发酵木糖制乙醇工艺的适宜条件为好氧条件,发酵时间为2d,发酵温度为28℃,摇床转速为150r/min,初始pH值为5,此时乙醇收率最高可达68.62%。     

Biochar as a Biocompatible Mild Anti-Inflammatory Supplement for Animal Feed and Agricultural Fields

Biochar is an organic material and high in carbon content, besides its use for energy purposes, it is also a material that serves the purpose of improving soil fertility, organic matter content of soils and removing heavy metals from water and soil. This study aims to investigate the antimicrobial effects of biochar whose beneficial effects on agricultural productivity has been proven by different studies. Scientific literature concerning the antibacterial, antifungal, and antiviral effects of the apricot seed and olive seed biochar is limited. Biochar applications may help to alter the microbial diversity by modifying biological environment either in agriculture or in animal husbandry. Moreover, biochar has been used in animal husbandry to improve animal health especially by regulating the intestinal flora and inflammation in the intestines. Hence, in our study, we investigated the effect of biochar on the growth of Aspergillus niger, Cryphonectria parasitica, Phytophthora cinnamomi, Plenodomus tracheiphilus, Enterococcus casseliflavus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and two different bacteriophage strains. Biochar did not have any direct effect on the growth of either Gram-positive or Gram-negative bacteria, bacteriophages, and fungi. In order to test their direct effects on the immune cells, mammalian macrophages were used and biochar directly reduced the inflammatory cytokine levels produced by the in vitro activated macrophages.     

Whey Fermentation by Anaerobiospirillum succiniciproducens for Production of a Succinate-Based Animal Feed Additive

Anaerobic fermentation processes for the production of a succinate-rich animal feed supplement from raw whey were investigated with batch, continuous, and variable-volume fed-batch cultures with Anaerobiospirillum succiniciproducens. The highest succinate yield, 90%, was obtained in a variable-volume fed-batch process in comparison to 80% yield in a batch cultivation mode. In continuous culture, succinate productivity was 3 g/liter/h, and the yield was 60%. Under conditions of excess CO₂, more than 90% of the whey-lactose was consumed, with an end product ratio of 4 succinate to 1 acetate. Under conditions of limited CO₂, lactose was only partially consumed and lactate was the major end product, with lower levels of ethanol, succinate, and acetate. When the succinic acid in this fermentation product was added to rumen fluid, it was completely consumed by a mixed rumen population and was 90% decarboxylated to propionate on a molar basis. The whey fermentation product formed under excess CO₂, which contained mainly organic acids and cells, could potentially be used as an animal feed supplement.     

Protoplast Fusion between Geotrichum candidium and Phanerochaete chrysosporium to Produce Fusants for Corn Stover Fermentation

Lignin impedes the digestion of corn stover when used as an animal feed. Phanerochaete chrysosporium is an efficient lignindegrader. Geotrichum candidum can be used to produce single-cell protein. In this study, protoplasts of the two fungi were prepared and fused. After screening, one of the fusants, Fusant R1, was selected for corn stover fermentation. It decreased lignin from 109 to 54 g/kg and increased protein from 48 to 67 g/kg in corn stover. Comparison with their parental strains indicated that the fusant obtained the lignin-degrading ability from P. chrysosporium and the protein-accumulating ability from G. candidium.     

米曲霉发酵玉米秸秆产纤维素酶饲料条件的优化

目的:研究米曲霉发酵玉米秸秆产富含纤维素酶的饲料的最优条件.方法:采用响应面法对发酵条件进行了优化.对Plackett-Burman设计筛选出的麸皮与秸秆比值、固液比和发酵时间三个主要因素再利用Box-Behnken设计进行优化.结果:确定了以上三个因素的最佳值分别为秸秆:麸皮比值为1.32,固液比为0.68,发酵时间为6.1d.在优化的培养基中,纤维素酶活力为522.36U/g,比优化前的469.13U/g高了11.35%.结论:利用响应面法获得了米曲霉发酵玉米秸秆产纤维素酶饲料的最佳发酵条件.     

悬浮培养CHO 细胞生产重组人促红细胞生成素条件的优化*

目的:通过对贴壁培养CHO细胞筛选驯化,得到高表达的细胞后进行悬浮培养生产重组人促红细胞生成素(rHuEPO)。方法:利用96孔板和24孔板对CHO细胞进行筛选,得到高表达细胞株后进行驯化,使其适合悬浮培养,经过摇瓶扩增后接种到生物反应器中无血清培养,每天监测葡萄糖含量,测rHuEPO表达量。结果:悬浮培养CHO细胞生产rHuEPO,生产周期短,表达量比贴壁培养高出很多,操作方便,减少污染,易于放大,并建立了适合悬浮培养的CHO细胞株,为工业化悬浮培养CHO细胞生产rHuEPO提供了技术基础。结论:经过工艺优化后利用无血清悬浮培养生产促红细胞生成素平均表达量较贴壁培养高,生产周期短,有利于降低生产成本。     

Bioconversion of Gibberellin Fermentation Residue into Feed Supplement and Organic Fertilizer Employing Housefly (Musca domestica L.) Assisted by Corynebacterium variabile

The accumulation of a considerable quantity of gibberellin fermentation residue (GFR) during gibberellic acid A3 (GA3) production not only results in the waste of many resources, but also poses a potential hazard to the environment, indicating that the safe treatment of GFR has become an urgent issue for GA3 industry. The key to recycle GFR is converting it into an available resource and removing the GA3 residue. To this end, we established a co-bioconversion process in this study using house fly larvae (HFL) and microbes (Corynebacterium variabile) to convert GFR into insect biomass and organic fertilizer. About 85.5% GA3 in the GFR was removed under the following optimized solid-state fermentation conditions: 60% GFR, 40% rice straw powder, pH 8.5 and 6 days at 26°C. A total of 371g housefly larvae meal and 2,064g digested residue were bio-converted from 3,500g raw GFR mixture contaning1, 400g rice straw in the unit of (calculated) dry matter. HFL meal derived from GFR contained 56.4% protein, 21.6% fat, and several essential amino acids, suggesting that it is a potential alternative animal feed protein source. Additionally, the digested GFR could be utilized as an organic fertilizer with a content of 3.2% total nitrogen, 2.0% inorganic phosphorus, 1.3% potassium and 91.5% organic matter. This novel GFR bio-conversion method can mitigate potential environmental pollution and recycle the waste resources.     

右旋糖酐发酵液酶解制备右旋糖酐40中氮的控制

右旋糖酐发酵液经过吸附除杂和陶瓷膜过滤后处理,在右旋糖酐酶的作用下降解制备右旋糖酐40,对氮进行过程控制,达到右旋糖酐40国家标准。首先以蛋白质作为检测目标,对右旋糖酐发酵液进行吸附条件研究,利用最佳吸附条件进行右旋糖酐发酵液的吸附除杂,氮的去除率达到57%以上,氮含量降至0.09%以下;然后通过陶瓷膜过滤将右旋糖酐与果糖等杂糖分离,并进一步去除氮,氮的去除率达到45%以上,氮含量降至0.040%以下;最后利用右旋糖酐酶对右旋糖酐发酵液处理液进行酶解,右旋糖酐酶解液经过乙醇分级沉淀分离制备右旋糖酐40,氮的去除率达到89%以上,氮含量降至0.003%以下,达到≤0.007%的国家标准。右旋糖酐发酵液酶解制备右旋糖酐40工艺过程氮的控制可以使氮去除率达到98%以上,产品氮含量达到国家标准(≤0.007%),分子量分布有所改善,重均分子量35 000以上,10%小分子＞7 000。     

食药用菌酸乳制作中深层发酵滤液添加量的比较

利用深层发酵培养基对两种食药用菌（香菇、猴头菌）进行深层发酵培养,然后分别将香菇（猴头菌）发酵滤液、奶粉、无菌水按不同比例配制成相应的复原奶,并接种乳酸菌制成酸乳。同时检测不同比例发酵滤液添加量所制得的酸乳的营养和理化特性,选择出了最佳比例的滤液添加量,即香菇滤液添加量以3份较好,而猴头菌则以4份滤液添加量最佳。     

基于遗传算法的麦角固醇分批发酵动力学参数估算

把遗传算法应用于求解麦角固醇分批发酵动力学模型参数,能进一步提高麦角固醇分批发酵过程状态变量的计算值与实验值的吻合程序,在计算机上对动力学模型进行了拟合,模拟值与实验值对比显示,该动力学模型能很好地反映麦角固醇分批发酵过程。     

固态发酵木薯酒精渣生产生物饲料菌种的筛选

目的:筛选获得能混合固态发酵木薯酒精渣生产生物饲料的真菌组合.方法:利用木薯酒精渣堵养基,初筛能在其上良好生长的植物内生真菌菌株,再将这些菌株两两组合进行固态混菌发酵、添加酵母混菌发酵,测定产物中粗蛋白和粗纤维的含量,获得能有效降低木薯酒精渣中粗纤维、提高粗蛋白含量的菌株组合.结果:菌株G4与C15、Q4与C32混菌发酵效果最好,可将粗蛋白质含最从底物的1.42%分别提高到产物的16.08%与18.54%(于基),粗纤维含量从底物的32.41%降低到27.57%与26.59%.添加酵母培养后,两个组合产物中粗蛋白质含量可进一步提高到21.79%与23.56%,而粗纤维含量几乎无变化.结论:菌株G4(黑曲霉)、C15(白地霉)与郎比可假丝酵母,Q4(黑曲霉)、C32(青霉)与季也蒙假丝酵母可用作混菌固态发酵木薯酒精渣生产生物饲料的菌种.     

Purification and Characterization of a Bacterial Phytase Whose Properties Make it Exceptionally Useful as a Feed Supplement

A periplasmatic phytase from a bacterium isolated from Malaysian waste water was purified about 173-fold to apparent homogeneity with a recovery of 10% referred to the phytase activity in the crude extract. It behaved as a monomeric protein with a molecular mass of about 42 kDa. The purified enzyme exhibited a single pH optimum at 4.5. Optimum temperature for the degradation of phytate was 65°C. The kinetic parameters for the hydrolysis of sodium phytate were determined to be K _M = 0.15 mmol/l and k _cat = 1164 s⁻¹ at pH 4.5 and 37°C. The purified enzyme was shown to be highly specific. Among the phosphorylated compounds tested, phytate was the only one which was significantly hydrolysed. Some properties such as considerable activity below pH 3.0, thermal stability and resistance to pepsin make the enzyme attractive for an application as a feed supplement.     

基于遗传算法的谷氨酸发酵动力学参数估计

把遗传算法应用于求解谷氨酸分批发酵动力学模型参数,取交叉概率Pc=0．8、变异概率Pm=0．06、初始种群为20、遗传世代数为200代,能进一步提高谷氨酸分批发酵过程状态变量的计算值与实验值的吻合程度。模拟值与实验值对比显示,该动力学模型能很好地反映谷氨酸分批发酵过程。     

温度对谷胱甘肽分批发酵的影响及动力学模型

研究了24～32℃范围内产朊假丝酵母生产谷胱甘肽的分批发酵过程,发现较高温度对细胞生长有促进作用,而较低温度则更有利于谷胱甘肽产量的提高。应用改进的Logistic和LuedekingPiret方程分别对细胞生长动力学和谷胱甘肽合成动力学进行了模拟,得到不同温度下各种动力学参数。在此基础上,进一步研究了温度同细胞生长动力学参数之间的内在联系,得到谷胱甘肽分批发酵过程中细胞浓度的变化同温度以及底物浓度之间的一般关系式：dX-dt＝［0.0224(T+1.7)］2X(1-X/X_max)1+S｛8.26×10.6×exp［-31477/R/(T+273)］｝。验证实验结果表明,该模型具有很好的适用性。     

绿色木霉在啤酒糟基质上产纤维素酶条件的优化

对绿色木霉接种到啤酒糟固态发酵产纤维素酶的培养基和培养条件进行优化,考察发酵物料起始含水量、发酵时间、起始pH值等发酵条件,以及啤酒糟培养基中添加麸皮、氮源种类对产酶的影响。结果表明,以啤酒糟为发酵基质接种绿色木霉生产纤维素酶是可行的。经单因素和正交试验获得最适固态发酵的培养条件为:起始pH 5~6,培养温度28~30℃,发酵4 d;最佳发酵培养基组合为:麸皮比例30%,培养基起始含水量50%,(NH₄)₂SO₄添加量为2.0%~2.5%。     

洋葱伯克霍尔德菌发酵产抗菌物质CF66I温度控制策略

在3.7 L发酵罐中考察了不同温度23℃～33℃对洋葱伯克霍尔德菌CF-66发酵产抗菌物质CF66I的影响,并对不同温度下的发酵过程进行了动力学特性分析。在此基础之上,提出抗菌物质CF66I合成的分阶段控制策略：发酵过程0～20 h控制温度在30℃,20 h后温度控制在25℃至发酵结束。采用此温度控制策略进行了CF66I的发酵,CF66I的活性达到了3.783 u/mL,比采用单一温度下的最大值提高了26.1%。     

灵芝胞外多糖分批发酵动力学模型

利用分批发酵研究了灵芝（Ganoderma lucidum）胞外多糖的合成特性,结果表明Ganoderma lucidum多糖合成和菌体生长呈部分生长关联型。菌体干重、胞外多糖分别达到15.56g·L^-1<、3.02g·L^-1<,胞外多糖对细胞干重得率系数(Y_p/x）为0.19。根据分批发酵试验结果采用Logistic方程、Luedeking-Piret方程和类似Luedeking-Piret方程,得到了描述灵芝生长、胞外多糖以及葡萄糖底物消耗分批发酵动力学模型。同时在初始葡萄糖变化较大范围内,试验数据与模型预测值进行了比较拟合,平均相对误差小于5％,表现出很好的适用性。表明该动力学模型对指导灵芝胞外多糖的发酵生产具有实际意义。