利用果渣产黄腐酸菌剂的筛选

以果渣发酵生产黄腐酸可实现农业有机固定废弃物的资源化利用。从腐植酸样品中分离获得4株耐高温菌,以果渣为基质发酵生产黄腐酸,通过测定黄腐酸产量和木质纤维素降解率,从中筛选出2株能够较好降解木质纤维素的黄腐酸生产菌株BFA02和BFA03,其黄腐酸产量分别为43.67、59.35 g/kg。经16S rDNA分类鉴定,初步确认BFA02为解淀粉芽孢杆菌,BFA03为地衣芽孢杆菌。选择季也蒙酵母、长枝木霉分别与BFA02、BFA03复配发酵生产黄腐酸。结果表明,复合菌剂发酵生产黄腐酸产量高于单菌发酵。其中,由BFA02、BFA03和长枝木霉组成的复合菌剂3实验组黄腐酸产量最高,达到103.19 g/kg,较BFA02、BFA03单菌发酵分别提高了136%和74%,其纤维素、半纤维素、木质素的降解率分别为46.25%、39.49%、37.5%,均高于单菌发酵。黄腐酸生产菌株与长枝木霉复配,能够有效促进木质纤维素降解率,提高黄腐酸产量,在果渣废弃物资源化利用领域有着极大的潜力。     

饲用微生物的分离鉴定及其对杏鲍菇菌糠发酵的效果

【目的】菌糠的营养素含量齐全,但纤维素含量过高是阻碍其饲料化利用的主要因素。故本研究筛选适合于发酵杏鲍菇菌糠的微生物菌株,以改善其饲用品质。【方法】首先,本研究采用纤维素-刚果红、苯胺蓝和MRS-Ca (De Man, Rogosa, Sharpe-Ca)筛选培养基,结合纤维素、木质素酶活力及抑菌活性的测定,从EM (effective microorganisms)原液发酵的杏鲍菇菌糠中分离筛选具有较强纤维素、木质素降解能力及抑菌能力的细菌/真菌。通过细菌16S rRNA和真菌18S rDNA基因序列分析确定菌株所属种属。其次,将筛选出的菌株菌液等体积混合制成复合菌剂用于固态发酵杏鲍菇菌糠。测定不同发酵时长菌糠营养成分含量以确定最佳发酵时间,并与相同工艺条件下EM原液发酵的杏鲍菇菌糠进行饲用品质比较。【结果】筛选并鉴定得到纤维素酶活性较高的特基拉芽孢杆菌(Bacillus tequilensis)菌株P11、发酵毕赤酵母(Pichia fermentans)菌株R8和马克斯克鲁维应变酵母(Kluyveromyces marxianus)菌株MU5;木质素酶活性较高的解淀粉芽孢杆菌(Bacillus amyloliquefaciens subsp.plantarum)菌株MU7;抑菌活性较高的类肠膜魏斯氏菌(Weissella paramesenteroides)菌株R4和乳酸片球菌(Pediococcus acidilactici)菌株R9。使用以上菌株复合发酵杏鲍菇菌糠7 d后,各项指标达到稳定。与EM原液发酵的杏鲍菇菌糠相比,复合菌剂发酵杏鲍菇菌糠的NDF和ADF分别显著降低了19.6%和21.44%(P0.05);CP (crude protein)、CA (crude ash)和EE (ether extract)含量分别显著提高了10.44%、5.26%和123.53%(P0.05)。【结论】本研究筛选得到的芽孢杆菌、酵母菌和乳酸菌优势菌株复合后用于发酵杏鲍菇菌糠可以很好地改善其饲用品质,效果优于生产中常用市售EM原液。     

微生物发酵对木薯渣营养成分的影响

[背景]将木薯渣作为饲料资源进行开发和利用能够减轻环境污染,实现资源就地转化,已成为国内外研究热点.微生物发酵可降低木薯渣的粗纤维含量,改善适口性,提高饲料转化率.[目的]筛选对木薯渣发酵效果较好的微生物发酵剂及其发酵时长.[方法]试验选用A(芽孢菌+乳酸菌+酿酒酵母菌)、B(戊糖片球菌+酿酒酵母菌)和C(植物乳杆菌+...     

金针菇菌渣和醋渣固态发酵的工艺研究

为了探索金针菇菌渣和醋渣2种农业废弃物资源化利用的方式,采用固态发酵法对金针菇菌渣和醋渣进行发酵。通过单菌发酵实验和多菌发酵实验探究其固态发酵的最佳方式及菌种组成,并摸索其最优的原料配比和发酵时间,随后通过单因素实验对发酵温度、接种量和pH进行优化,并在此基础上设计三因素三水平的正交实验以进一步优化发酵工艺。研究表明,金针菇菌渣和醋渣固态发酵的最佳发酵方式为多菌发酵,且混合菌种的组成及比例为枯草芽孢杆菌∶黄孢原毛平革菌∶热带假丝酵母=1∶1∶1;发酵原料金针菇菌渣和醋渣的配比为7∶3,发酵3 d,粗蛋白质含量达到峰值;单因素实验和正交实验的结果显示其最佳发酵条件为发酵温度26℃、接种量7%以及pH 7.5,在该条件下发酵3 d,发酵产物中的粗蛋白质含量为17.90%。研究结果为农业废弃物资源化高效利用提供了一种新途径。     

混合菌发酵转化纤维素生产单细胞蛋白

纤维素是自然界中存在的最丰富的天然资源 ,合理开发和利用纤维素是科学家们一直致力于研究的重点领域。尽管几十年来人们在纤维素及纤维素酶的理论研究和实践应用方面均取得了较大进步 ,迄今尚无一种微生物或一套酶系按传统方法用于大规模降解纤维素 ,并取得显著经济效益[1 3] 。利用微生物混合发酵 ,可使纤维素转化为单细胞蛋白。该方面研究不仅可以解决蛋白资源短缺 ,解决动物饲料需求上的短缺 ,而且还可以提高和改善饲料中的蛋白含量和营养价值。本文就混合菌发酵转化纤维素合成单细胞蛋白的应用研究进行概述。1　液态混合菌体系发酵纤…     

利用多菌种混合发酵转化玉米秸秆的研究

该文系统地研究了高产纤维素酶生产菌（ＴｒｉｃｈｏｄｅｒｍａｒｅｓｉＴＢ９７０１）与饲料酵母混合共发酵玉米秸秆粉对合成菌体蛋白质和利用纤维素的关系,优选出一条最佳的共发酵工艺途径和条件。研究表明在以氨法处理的玉米秸秆为底物的ＴＢ－９７０１与饲料酵母菌的混合菌共发酵正交实验中,于ｐＨ５．０,３０℃的条件下２００ｒ／ｍｉｎ的恒温、恒速摇瓶培养８ｄ,经测定发酵液终产物中粗蛋白（ＳＣＰ）的含量达到了２３．７０％,总秸秆纤维的转化率达到７０％以上。     

混合菌发酵转化纤维素生产单细胞蛋白

纤维素是自然界中存在的最丰富的天然资源,合理开发和利用纤维素是科学家们一直致力于研究的重点领域.尽管几十年来人们在纤维素及纤维素酶的理论研究和实践应用方面均取得了较大进步,迄今尚无一种微生物或一套酶系按传统方法用于大规模降解纤维素,并取得显著经济效益[1-3].利用微生物混合发酵,可使纤维素转化为单细胞蛋白.该方面研究不仅可以解决蛋白资源短缺,解决动物饲料需求上的短缺,而且还可以提高和改善饲料中的蛋白含量和营养价值.本文就混合菌发酵转化纤维素合成单细胞蛋白的应用研究进行概述. 1 液态混合菌体系发酵纤维素合成单细胞蛋白     

麦芽糖假丝酵母菌混合糖代谢的发酵特性

葡萄糖和木糖的混合糖共代谢是木质纤维素资源高效转化利用的关键环节。利用本实验室保藏的天然木糖利用酵母菌,麦芽糖假丝酵母(Candida maltosa)Xu316,本研究对该菌代谢利用不同比例的葡萄糖、木糖发酵特性进行了系统测试,总结了麦芽糖假丝酵母混合糖代谢的一般规律。研究结果表明麦芽糖假丝酵母菌具有较高的葡萄糖利用率和木糖醇积累能力。在糖浓度低于20%时,该菌可以共同利用葡萄糖和木糖,最大乙醇产量和木糖醇产量分别为0.43g·g-1和0.58g·g-1,具有工业应用生产生物基产品的潜力。     

菠萝渣纤维素降解菌的筛选及鉴定

为了加快菠萝渣快速发酵,通过利用多种选择性培养基,从自然发酵的菠萝渣中分离到多种纤维素分解菌,经过初筛和复筛,获得了降解菠萝渣纤维素的菌株c3b1-3,其最适合的培养基为蛋白纤维素培养基;通过形态、生理生化特征和分子综合鉴定得出c3b1-3为金黄杆菌属（Chryseobacterium sp.）。     

固态发酵玉米淀粉渣生产蛋白饲料的研究

本文对同化淀粉能力强的糖化酵母菌Ｙ９６０１株在固态发酵玉米淀粉渣生产蛋白饲料中的应用进行了研究,在合适的发酵条件下,３０℃发酵３６ｈ,发酵产物（干基）酵母达到７．４５×１０＾９个／ｇ,粗蛋白从２５．５％提高到３８．２％,增加１２．７％,粗蛋白增幅为４９．８％。     

利用微生物混合培养物生产沙棘果渣单细胞蛋白

以沙棘果渣作为唯一碳源进行了单细胞蛋白发酵研究。经过筛选,从４０多株霉菌、酵母菌和细菌中选育出Ｍｙ－９３１霉菌－酵母混合培养物能迅速地将沙棘果渣转变为单细胞蛋白。在最佳条件下,沙棘果渣经发酵后,其发酵产品粗蛋白含量达４４．１％。动物饲喂试验证明此发酵产品安全无毒,能部分替代鱼粉用作蛋白饲料。     

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％。     

Response surface optimization of mixed substrate solid state fermentation for the production of lovastatin by Monascus purpureus

The objective of this work is to enhance the production of lovastatin using Monascus purpureus MTCC 369 in mixed substrate solid state fermentation using various solid substrates and to optimize the combination of the solid substrates by response surface methodology. Solid state fermentation was conducted in a 250 mL Erlenmeyer flask at 30°C for 14 days with initial moisture content of 40% and inoculum size of 10% active culture. Barley, long grain rice and sago starch were found to be the suitable substrates producing maximum lovastatin of 193.7 mg, 190.2 mg and 180.9 mg/g of dry solids. These substrates were further used in various combinations as designed by the central composite design for enhancing the lovastatin production using Monascus purpureus. To the best of our knowledge this is the first report on the production of lovastatin using a mixed substrate solid state fermentation using Monascus purpureus.     

Solid state fermentation of banana wastes

Summary Using a strain ofAspergillus niger, the protein content of banana wastes was raised from 6 to 18 % by solid state fermentation. A meal of green bananas was obtained by solar drying, and fermentation was conducted in a 15 kg (dry weight) capacity stirred reactor. As the substrate consumption was 24 % of initial weight after 43 h. of fermentation, protein production was calculated to be 150 % of the initial content. According to its composition (50 % total sugars, 13 % reducing sugars, 18 % proteins) the fermented banana waste could be used as cattle feed.     

Comparative Study of Sugar Fermentation and Protein Expression Patterns of Two Lactobacillus plantarum Strains Grown in Three Different Media

A comparative study of two strains of Lactobacillus plantarum (REB1 and MLBPL1) grown in commercial medium (MRS broth), cucumber juice, and liquid pig feed was performed to explore changes to the metabolic pathways of these bacteria, using a proteomics approach (two-dimensional electrophoresis and liquid chromatography-tandem mass spectrometry) combined with analyses of fermentable sugars and fermentation end products. The protein expression showed that even with an excess of glucose in all media, both strains could metabolize different carbohydrates simultaneously and that hexoses could also be used via a phosphoketolase pathway with preferential expression in liquid feed. Sugar analyses showed that the fermentation of sugars was homolactic for all media, with some heterolactic activity in liquid feed, as shown by the production of acetate. Cucumber juice (the medium with the highest glucose content) showed the lowest hexose consumption (10%), followed by liquid feed (33%) and MRS broth (50%). However, bacterial growth was significantly higher in cucumber juice and liquid feed than in MRS broth. This discrepancy was due to the growth benefit obtained from the utilization of the malate present in cucumber juice and liquid feed. Despite different growth conditions, the synthesis of essential cellular components and the stress response of the bacteria were unaffected. This study has improved our understanding of the mechanisms involved in the growth performance of an appropriate lactic acid bacterium strain to be used for food and feed fermentation, information that is of crucial importance to obtain a high-quality fermented product.     

Lactic acid and animal feeds production from Sophora flavescens residues by Rhizopus oryzae fermentation

In this study, the feasibility of producing lactic acid and animal feeds from Sophora flavescens residues (SFR) by Rhizopus oryzae was explored. Results showed that the simultaneous saccharification and fermentation (SSF) is the optimal fermentation mode, which was simple and high-efficiency. When the inoculation volume of R. oryzae was 10 % and the pH value was adjusted by adding CaCO₃ in stages during SSF, the maximum concentration of lactic acid was 46.78 g/L, and the maximum lactic acid productivity reached 0.97 g/L/h. Results also showed that the protein content of the solid residues after fermentation of R. oryzae reached 12.15 %. This content was 46 times higher than that by the original SFRs and nearly 4.3 times the protein content of the solid residues after fermentation by Enterococcus faecium. In addition, the solid residues after fermentation rich in Fe and Zn could be used as animal feeds or feed additives. Thus, it is expected that this study may provide a novel approach for Chinese medicine residues treatment towards full resource recovery.     

Utilization of the white-rot fungus Sporotrichum pulverulentum for water purification and protein production on mixed lignocellulosic wastewaters

A process has been developed that allows a direct conversion of lignocellulosic materials into fungal biomass. The thermotolerant white-rot fungus Sporotichum pulverulentium has been used in continuous laboratory fermentations as well as in a 25 m³ batch fermentation. Fungal cell mass for feeding trials was produced and the economics of the process were estimated. The investigation shows that the process works satisfactorily on the small continuous scale as well as in the large batch culture. The process also seems easy to scale up. The economic evaluations show the conversion of solid lignocellulosic materials to protein feed is not feasible by our process unless the material to be fermented has a certain negative value. A mixed wastewater, such as the white water system in paper and fiber board mills, containing both water soluble mono- and oligosaccharides and solid lignocellulosic material, can, however, be fermented in an economically feasible way due to the combined effect of protein production and water purification. Data on the nutritional value of the product are presented in an accompanying paper.     

Bio-processing of agro-byproducts to animal feed

Agricultural and food-industry residues constitute a major proportion (almost 30%) of worldwide agricultural production. These wastes mainly comprise lignocellulosic materials, fruit and vegetable wastes, sugar-industry wastes as well as animal and fisheries refuse and byproducts. Agro-residues are rich in many bioactive and nutraceutical compounds, such as polyphenolics, carotenoids and dietary fiber among others. Agro residues are a major valuable biomass and present potential solutions to problems of animal nutrition and the worldwide supply of protein and calories, if appropriate technologies can be used for their valorization by nutrient enrichment. Technologies available for protein enrichment of these wastes include solid substrate fermentation, ensiling, and high solid or slurry processes. Technologies to be developed for the reprocessing of these wastes need to take account of the peculiarities of individual wastes and the environment in which they are generated, reprocessed, and used. In particular, such technologies need to deliver products that are safe, not just for animal feed use, but also from the perspective of human feeding. This review focuses on the major current applications of solid-state fermentation in relation to the feed sector.     

山梨糖发酵产生2—酮基—L—古龙酸氮源代谢规律

对山梨糖发酵产生2-酮基-L-古龙酸氮源代谢规律进行了初步研究。通过对这一混合发酵体系蛋白和尿素代谢的研究表明,氮源代谢与单一菌体发酵相比有其特殊性,主要表现在尿素的加入有两个作用,即作为生理碱性物质调节体系pH和为菌体代谢提供部分氮源,而体系的蛋白含量随发酵时间的延续不断增加,其增加的原因是巨大芽孢杆菌由营养体转变成芽孢所致,这是该发酵体系的特点。本文还对该发酵体系各种氨基酸变化规律进行了讨论,将一共17种氨基酸按其变化规律分成了三类,较好地解释了各种氨基酸的变化情况,为进一步深入研究该体系的动力学特性提供了数据基础。     

混合菌群发酵秸秆合成菌体蛋白及其动力学分析

混合菌群发酵秸秆可有效提高秸秆纤维的降解率及菌体蛋白的转化率,对拓广蛋白饲料来源、减少环境污染起到积极的作用。本研究以小麦秸秆为原料,在纤维素酶水解预处理的基础上,以米曲霉作为先导菌,进一步分解残留的粗纤维,为后期发酵提供充足的碳源。根据不同微生物的代谢特征和协同机理,试验确定了发酵阶段混合菌群的组成为:米曲霉、产朊假丝酵母和枯草芽胞杆菌;接种顺序为:先接种米曲霉,再接种产朊假丝酵母,最后接种枯草芽胞杆菌。正交试验表明,影响发酵主要因素的主次顺序为:秸秆与麸皮配比>接种比例>发酵时间>接种量>发酵温度;发酵的最适条件为:米曲霉的接种量2.5%,发酵12h后接入5%的产朊假丝酵母,继续发酵8h后接入2.5%的枯草芽胞杆菌,发酵温度为28℃,秸秆与麸皮的配比为4∶1,尿素添加量为1.2%;结合动力学分析,将混合菌群的发酵时间优化为35h,发酵产物中粗蛋白含量由原来的5.47%提高到25%左右。对最适发酵条件下的动力学过程进行了探讨,建立了以Logistic方程为基础的数学模型和动力学方程。本研究表明,混合菌群发酵秸秆提高了发酵产物中的粗蛋白含量。动力学分析对于了解发酵机理、掌握整个发酵过程中混合菌群生长的动态变化、优化发酵工艺具有重要的指导意义。