固态发酵降低上部低次烟叶中淀粉及蛋白质的含量

利用固态发酵的方法降低上部低次烟叶中淀粉和蛋白质的含量,并对发酵过程中的厌氧细菌和酵母的数量进行检测。采用单因素和正交试验对固态发酵的条件进行优化,结果表明:各因素对发酵上部低次烟叶影响显著性主次次序依次为发酵时间(C)、发酵温度(A)和发酵水分质量分数(B),固态发酵的最佳条件为A2B2C3,即温度45℃、水分质量分数50%、发酵时间9 d。在该发酵条件下,上部低次烟叶的淀粉降解率为20.41%,蛋白质降解率为12.35%。通过固态厌氧发酵的方法可取得较好的、短期内快速降解上部低次烟叶中淀粉和蛋白质含量的效果。     

对虾加工副产品自然发酵虾酱对T-2毒素的消减作用及其降解菌的筛选与鉴定

利用对虾加工副产品自然发酵法制备虾酱,在掌握制备工艺的基础上,探索了不同发酵时间(1、5、10、15、20 d)的虾酱对T-2毒素的消减效应,解析了毒素消减作用与细菌总数的相关性,筛选出降解菌并分析其生化特性,利用分子生物学技术确定其分类地位。结果表明,利用对虾加工副产品自然发酵(3.5±0.5)周即可制备成虾酱。随着自然发酵时间的延长,虾酱对T-2毒素的消减能力逐渐增加,但对质量浓度为10 ng/mL的T-2消减能力最强,达77.24%,效果优于5 ng/mL(最高降解率达70.1%)和15 ng/mL(最高降解率达67.11%)。虾酱在发酵4周时细菌总数最高达3.5×10~6 cfu/g,对T-2毒素的降解率最高达77.24%。通过比较34株分离株对T-2毒素的降解效果,发现1株(编号CAMT25481)对T-2毒素有明显的降解作用。经生化特性分析和16S rDNA鉴定确定,该菌株为潮间带微小杆菌(Exiguobacterium aestuarii)。     

豆渣对平菇和灵芝发酵产生木质素酶系的影响

研究了不同浓度的豆渣(1%~5%)对平菇和灵芝固态发酵油菜秸秆产生木质素降解酶系的影响。结果表明:与对照(无豆渣)相比,浓度为3%、4%的豆渣显著提高平菇产生的锰过氧化物酶(MnP)和木质素过氧化物酶(LiP)活性;漆酶(Lac)的活性也在豆渣浓度为2%~4%时得到显著提高。灵芝发酵基质中,3%的豆渣显著提高了MnP和LiP的活性;浓度为3%~5%的豆渣也可显著提高灵芝发酵基质中Lac的活性,其中豆渣浓度为3%时,平菇与灵芝单菌发酵中Lac的活性都达到峰值,分别为对照的2.3倍、1.67倍。     

解淀粉芽孢杆菌3-2发酵羽毛产氨基酸

【目的】建立废弃羽毛液体发酵工艺,优化发酵条件,提高羽毛降解率及氨基酸产量,研发新型、高效复合氨基酸肥料。【方法】利用解淀粉芽孢杆菌3-2发酵羽毛,探究温度、发酵时间、羽毛含量、单一碳源、复合碳氮源、金属离子等对废弃羽毛降解效果以及发酵液中氨基酸种类和含量的影响。【结果】废弃羽毛降解率与氨基酸总产量呈负相关。随着发酵时间延长,羽毛降解率增加,当发酵温度为37°C、羽毛添加量为1%、以乳糖为外加碳源、添加Mg2+时,羽毛降解率最高,达到81.92%。随着羽毛添加量增加,氨基酸总含量也增加(在20%范围以内),当发酵温度为37°C、降解时间为108 h、羽毛添加量为10%、乳糖添加量为0.5%、不添加复合碳氮源、不添加金属离子时,氨基酸的种类最全(富含17种氨基酸),总含量最高,达到20.861 g/kg。【结论】利用解淀粉芽孢杆菌3-2发酵废弃羽毛生产氨基酸复合肥料是一种可靠、环保、经济的方法,获得的氨基酸肥料营养齐全。研究结果为新型复合氨基酸肥料的研发提供技术支撑。     

加工番茄污水污泥生物好氧发酵对有机污染物的降解及其影响因素

通过研究加工番茄污水污泥的有机污染物降解变化和好氧发酵条件(含水量、p H、C/N、含氧量和CO2)来确定番茄污水中有机污染物降解情况,从而优化加工番茄废水处理。结果表明:最佳生物好氧发酵条件为含水量60%~80%,C/N范围为5~10,氧气浓度10%,p H=6.5,污泥发酵15 h后,有机物降解速率达到平衡。     

复合固态发酵棉粕中盐类物质的优化

通过Plackett-Burman试验设计方法和DPS v7.05统计软件中的均匀设计方法研究了盐类物质对棉粕发酵底物中游离棉酚降解率的影响。Plackett-Burman试验结果表明只有生物素对降解率的影响是极显著的,其他因素均不显著,进而不能进一步通过Box-Behnken(BBD)实验来验证此试验结果。因此选出对降解率具有正效应的因素利用DPS v7.05统计软件中的均匀设计方法来研究这些因素对降解率的影响。最后得出各个因子的最佳组合:X_1(尿素)1.44%,X_2(柠檬酸三铵)0.20%,X_3(氯化胆碱)0.20%,X_4(磷酸氢二钾)0.34%,X_5(硫酸镁)1.00%,X_6(硫酸铜)1.00%,X_7(硫酸锰)1.00%,X_8(硫酸锌)0.10%。     

城市污泥中邻苯二甲酸酯(PAEs)的厌氧微生物降解

邻苯二甲酸酯(PAEs)是城市污泥中普遍存在的一类具有内分泌干扰性作用的有机污染物.研究污泥厌氧生物处理过程中PAEs的微生物降解对保障污泥农用的安全性十分必要.本文以污泥中两种主要的PAEs——邻苯二甲酸二丁酯(DBP)和邻苯二甲酸(2-乙基己)酯(DEHP)为研究对象,通过比较PAEs在污泥厌氧消化系统与发酵产氢系统中降解过程的差异及系统污泥特性的变化,分析不同污泥厌氧生物处理系统中影响PAEs降解的可能因素.结果表明: 在污泥厌氧发酵系统中,DBP在6 d内降解率达99.6%, DEHP在整个14 d的培养期间也降解了46.1%;在发酵产氢系统中,在14 d培养过程DBP的降解率仅为19.5%,DEHP则没有明显的降解.与厌氧消化系统相比,PAEs在发酵产氢系统中的降解受到明显抑制,这与发酵产氢过程中微生物量下降、革兰氏阳性菌/革兰氏阴性菌(G⁺/G^-)和真菌/细菌变小及挥发性脂肪酸(包括乙酸、丙酸及丁酸)浓度升高有关.     

耐高温菌的分离及在固态发酵上部烟叶中的应用

从上部低次烟叶中筛选出耐高温淀粉酶产生菌GW-2和耐高温蛋白酶产生菌GW-3,通过对菌落的形态观察、16S rRNA的鉴定和同源性分析,初步确定GW-2为解淀粉芽胞杆菌,GW-3为枯草芽胞杆菌。对上部低次烟叶进行双菌种固态发酵,并优化发酵条件,最佳发酵条件:GW-2菌悬液(OD600=1)接种量为7.5 m L/g,GW-3菌悬液(OD600=1)接种量为10 m L/g,物料填充度为500 m L三角瓶中装50 g烟叶干基,当烟叶发酵水分质量分数为45%时,48℃发酵5 d。在该发酵条件下,上部低次烟叶的淀粉降解率为22.33%,蛋白质降解率为16.74%。烟叶淀粉和蛋白质的质量分数较大幅度下降,其含量指标接近优等烟叶的含量。该发酵方式比传统的贮存式烟叶发酵大大缩短了发酵时间。     

秸秆降解菌的筛选及对秸秆的降解效果

作物秸秆作处置不当可能严重影响农村生态环境。目前东北地区的秸秆处置方式主要为直接打碎还田,但秸秆在自然环境中不易腐化,影响春耕。从添加外源微生物促进秸秆原位腐化角度开发新型可培养秸秆降解菌,具有重要意义。本实验通过菌种富集培养、刚果红培养基初筛和滤纸条崩解试验复筛的方法,从腐烂的秸秆和牛肠道中分离筛选潜在的高效纤维素降解菌,测定其最适生长温度和pH,在液态发酵培养条件下考察菌株实际降解能力,共获得具有较高玉米秸秆降解能力的降解菌5株。5种菌株的生长峰值均出现在温度20～30℃,pH值7.5～8.5范围内。液态发酵培养15天后,秸秆失重率为菌株NX9(53.88%)NF6(51.36%)JF3(46.97%)JZ8(45.2%)JX4(35.79%)CK(23.88%)。其中,菌株NX9(温度30℃、pH 7.5)对秸秆半纤维素和木质素的降解能力最强,15天降解率分别为48%和37.7%;筛选出的NF6和JF3属于耐冷微生物,特别是菌株NF6在4℃条件下也能生长繁殖,为北方开展"外源微生物促进秸秆原位腐化"技术提供了基础。     

环境保护上的应用

870438海水中原油在连续培养中的发酵〔英〕/Rontani,J.F.…// Appl.Mierobiol.Bioteehnol一1986,23(3~4)。一3Q2、304〔译自CBA,2986,(4),1438〕, 利用混合细菌群体在连续培养和非消毒条件下使原油降解(80%),     

Sphingobacterium bambusaue及其紫外诱变菌株的石油降解功能

【目的】研究Sphingobacterium bambusaue及其紫外诱变菌株的石油降解功能。【方法】紫外诱变后筛选石油降解高效菌株; 以不同石油浓度、pH值及盐浓度优化培养条件, 用重量法检测高效菌株石油降解率。【结果】发现菌株S. bambusaue在石油降解培养基中培养5 d的石油降解率为25.86%, UV诱变高效菌株IBFC2009-S3培养5 d的石油降解为42.85%, 比始发菌株提高65.7%; UV诱变菌株IBFC2009-S3的优化培养条件为石油浓度0.5 g/L、pH值7.0以及NaCl质量浓度为10 g/L, 其石油降解率可达50.51%。【结论】首次报道S. bambusaue具有石油降解功能; 紫外诱变获得的菌株S3的石油降解能力较强。     

In situ ruminal degradation of amino acids and in vitro protein digestibility of undegraded CP of dried distillers’ grains with solubles from European ethanol plants

The objectives of this study were to compare the in situ ruminal degradation of CP and amino acids (AAs) of dried distillers’ grains with solubles (DDGS), and to estimate intestinal digestibility (ID) of undegradable crude protein (UDP) with the in vitro pepsin–pancreatin solubility of CP (PPS), using either DDGS samples (DDGS-s) or DDGS residues (DDGS-r) obtained after 16 h ruminal incubation. Thirteen samples originating from wheat, corn, barley and blends were studied. Lysine and methionine content of DDGS-s varied from 1.4 to 4.0 and 1.3 to 2.0 g/16 g N, respectively. The milk protein score (MPS) of DDGS-s was low and ranged from 0.36 to 0.51, and lysine and isoleucine were estimated to be the most limiting AAs in DDGS-s and DDGS-r. DDGS-r contained slightly more essential AAs (EAAs) than did the DDGS-s. Rumen degradation after 16 h varied from 44% to 94% for CP, from 39% to 90% for lysine and from 35% to 92% for methionine. Linear regressions showed that the ruminal degradation of individual AAs can be predicted from CP degradation. The PPS of DDGS-s was higher than that of DDGS-r and it varied from 70% to 89% and from 47% to 81%, respectively. There was no significant correlation between the PPS of DDGS-s and PPS of DDGS-r (R²=0.31). The estimated intestinally absorbable dietary protein (IADP) averaged 21%. Moderate correlation was found between the crude fibre (CF) content and PPS of DDGS-r (R²=0.43). This study suggests an overestimation of the contribution of UDP of DDGS to digestible protein supply in the duodenum in some currently used protein evaluation systems. More research is required and recommended to assess the intestinal digestibility of AAs from DDGS.     

Amino Acid Profile of Escaped Feed Protein After Rumen Incubation and Their Intestinal Digestibility

The crude protein content and amino acid profile of seven feedstuffs (linseed meal, maize gluten meal, rapeseed meal, rapeseed meal protected, soybean meal, fullfat soybean extruded and sunflower meal) were determined before and after ruminal incubation for 16h in three bulls with large rumen cannulas. The intestinal disappearance of amino acids was measured using mobile bag technique. Ruminal incubation affected amino acid profile of all experimental feedstuffs. Crude protein degradation varied from 29.3% for maize gluten meal to 86.4% for rapeseed meal. A tendency towards increased disappearance was observed for glutamic acid, histidine, lysine and proline and decreased disappearance for branched-chain amino acids. The intestinal crude protein digestibility was higher than >80%, except rapeseed meal (66.4%) and sunflower meal (77.8%). The least digestible individual amino acids were methionine and isoleucine in rapeseed meal, histidine and methionine in rapeseed meal protected and arginine in sunflower meal. In general, the lowest amino acid digestibilities were found in feedstuffs with the highest fibre content. The feedstuffs show that they have different potential for supplying of limiting amino acids. Of particular value are the feedstuffs with low crude protein degradability in the rumen and high intestinal digestibility of amino acids.     

高效降解石油细菌的分离鉴定及降解能力的研究

目的:为获得高效降解原油的菌株,从石油污染严重的土壤中采样,富集分离得到原油降解菌,并初步考察它们降解原油的能力。方法:通过富集培养、多次筛选分离得到三株优势菌,编号为SWH-1、SWH-2和SWH-3。通过16S rDNA序列分析和NCBI数据库的Blast比对分析,对其鉴定到种。通过差量法测定它们在室内摇瓶中对原油的降解率。结果:经鉴定,这三株菌分别为枯草芽孢杆菌(Bacillus subtillus)、多食鞘氨醇杆菌(Sphingobacterium multivorum)和嗜温鞘氨醇杆菌(Sphingobacterium thalpophi-lum)。在0.5g/L的原油培养基内培养1w,SWH-1和SWH-2的降解率较高,分别为33.89%和46.31%。将这两株菌进行混合培养降解原油,降解率高达51.73%。结论:所筛选到的枯草芽孢杆菌和多食鞘氨醇杆菌在生物修复方面具有很好的应用潜力,而且多食鞘氨醇杆菌在石油降解方面的报道尚属首次。     

Operating conditions of a 200l staged vertical reactor for bioconversion of wheat straw by Phanerochaete chrysosporium

Bioconversion of wheat straw using Phanerochaete chrysosporium was carried out in a 200l staged vertical reactor. The bioconversion process was characterized by measuring the percentage degradation of lignin and cellulose, and increment in crude protein content. The effect of airflow rate, inoculum amount and wheat straw loading on bioconversion was investigated using a statistical experimental design. An analysis of variance was performed to determine response surfaces. The quality of bioconversion indicated by an optimization index called the desirability coefficient had the highest value of 0.75 for the fifth day of cultivation. This corresponded to an operating condition of 1.5kg wheat straw per stage using an inoculum amount of 0.38g (100g dry wheat straw)(-1) and an airflow rate of 15lmin(-1). The lignin and cellulose degradation achieved at this operating condition was 27% and 29%, respectively. A ratio of 3 for the weight of wheat straw to inoculum amount gave the highest crude protein of 5.9% on dry weight basis. Among the variables investigated, the airflow rate exhibited a significant effect on the quality of bioconversion. Our results indicate that the quality of bioconversion may be controlled by implementing a predetermined airflow rate schedule.     

Evaluation of alkali treatment for biodegradation of corn cobs byAspergillus niger

Anstract Effect of NaOH pretreatment on the biodegradation of corn cobs for the production of cellulase and protein was studied usingAspergillus niger. Delignification of cobs with NaOH remarkaby increased the production of cellulase and protein. Treatment of cobs with 2% NaOH was found to be the best with respect to their susceptibility to biodegradation for maximum production of cellulose 1,4-β-cellobiosidase, cellulase, β-glucosidase soluble protein and crude protein; this also led to the highest protein recovery, maximum cellulose utilization and also for the maximum degradation of substrate.     

高效石油降解菌群的构建及对芳香烃化合物萘的协同降解性能

【背景】石油作为一类混杂有机化合物,一旦产生污染就会对人类和环境造成严重的危害。【目的】从新疆石油污染土壤中分离筛选石油降解菌,为石油污染土壤的生物修复提供数据支持及技术参考。【方法】以石油为唯一碳源,通过富集培养、筛选分离得到123株单菌,根据菌落形态挑选出30个不同形态菌株,通过16S rRNA基因序列确定其种属,构建系统发育树;通过原油降解实验筛选出高效石油降解菌,以芳香烃的标志化合物萘为唯一碳源筛选出高效降解菌株,并分别筛选可降解水杨酸、邻苯二酚的菌株。【结果】分离筛选出5株高效石油降解菌,降解率高于85%;萘、水杨酸和邻苯二酚降解菌株各获得一株,将3种菌株按照1:1:1的接种比例对萘进行降解,萘的降解率从单菌60.74%提升到89.40%,菌株间的分工协作可以提高有机物的降解效率。【结论】筛选得到的菌株丰富了石油降解微生物菌种库,不同微生物菌株之间的分工协作为石油污染物的降解提供了新思路,为进一步研究石油污染治理提供参考。     

Protein enrichment of corn cob heteroxylan waste slurry by thermophilic aerobic digestion using Bacillus stearothermophilus

Thermophilic aerobic digestion (TAD) of heteroxylan waste was implemented at waste load of 30gL(-1) with mineral nitrogen supplementation to study effect of the process on waste degradation, protein accretion and quality. Digestions were carried out at 45 50, 55, 60 and 65 degrees C using Bacillusstearothermophilus in a CSTR under batch conditions at 1.0vvm aeration rate, pH 7.0 for a maximum of 120h. Amylase and xylanase activities appeared rapidly in the digest, while basal protease activity appeared early in the digestion and increased towards end of the processes. Highest degradation of volatile suspended solid, hemicellulose and fibre occurred at 55 degrees C while highest degradation of total suspended solid occurred at 60 degrees C. Highest protein accretion (258.8%) and assimilation of mineral nitrogen and soluble protein occurred at 55 degrees C. The % content of amino acids of digest crude protein increased relative to raw waste and with digestion temperature. Quality of digest protein was comparable to the FAO standard for feed use. TAD has potentials for use in the protein enrichment of waste.     

Protein turnover and proliferation. Turnover kinetics associated with the elevation of 3T3-cell acid-proteinase activity and cessation of net protein gain.

1. At least 95% of the total protein of A31-3T3 cell cultures undergoes turnover. 2. First-order exponential kinetics were used to provide a crude approximation of averaged protein synthesis, Ks, degradation, Kd, and net accumulation, Ka, as cells ceased growth at near-confluent density in unchanged Dulbecco's medium containing 10% serum. The values of the relationship Ka = Ks - Kd were : 5%/h = 6%/h - 1%/h in growing cells, and 0%/h = 3%/h - 3%/h in steady-state resting cells. 3. As determined by comparison of the progress of protein synthesis and net protein accumulation, the time course of increase in protein degradation coincided with the onset of an increase in lysosomal proteinase activity and decrease in thymidine incorporation after approx. 2 days of exponential growth. 4. After acute serum deprivation, rapid increases in protein degradation of less than 1%/h could be superimposed on the prevailing degradation rate in either growing or resting cells. The results indicate that two proteolytic mechanisms can be distinguished on the basis of the kinetics of their alterations. A slow mechanism changes in relation to proliferative status and lysosomal enzyme elevation. A prompt mechanism, previously described by others, changes before changes in cell-cycle distribution or lysosomal proteinase activity. 5. When the serum concentration of growing cultures was decreased to 1% or 0.25%, then cessation of growth was accompanied by a lower steady-state protein turnover rate of 2.0%/h or 1.5%/h respectively. When growth ceased under conditions of overcrowded cultures, or severe nutrient insufficiency, protein turnover did not attain a final steady state, but declined continually into the death of the culture.     

Disappearance of protein supplements and their fractions in sacco

The rumen degradability of animal and plant protein supplements (eight of each) was assessed in sacco under two feeding regimens. The supplements as such and those obtained after in sacco degradability were fractionated into soluble (albumin and globulin) and insoluble (prolamin and glutehn) proteins. Skimmed milk powder had the highest ratio of soluble to insoluble fractions, followed by cotton seed cake, deoiled mustard cake and blood meal. The casein and soybean meal had a similar but relatively low ratio compared with the above protein supplements. However, these were completely degraded. Corn gluten meal had the lowest ratio of soluble to insoluble fractions, which was reflected in the lowest dry matter and crude protein degradability. Similarly, bone meal and meatcum-bone meal, having low ratios, showed poor degradation of dry matter, crude protein and their fractions. The feeding regimens of the animals had significant (P < 0.05) influence on the degradation of some of the protein supplements. Further, irrespective of the feeding system and the source of protein, albumin was degraded the most and prolamin the least. It was concluded, therefore, that the solubility of protein supplements is an important factor for determining the susceptibility or resistance of protein supplements to rumen degradation.