942 resultados para Cassava flour


Relevância:

10.00% 10.00%

Publicador:

Resumo:

An experiment was carried out in farmers' gher (shrimp farm) at Bagerhat sadar upazilla, Bagerhat to ascertain the effects of three different types of feeds on the production and economics of brackishwater shrimp, Penaeus monodon for a period of 120 days. There were three treatments such as T1 (BFRI dough feed containing of 30% fish meal, 10% protein conc., 10% soya meal, 15% mustard oil cake, 18% rice bran, 5% maize, 10% wheat flour, 1% oyster shell powder and 1% vitamin premix), T2 (Commercial diet Saudi-Bangla grower) and T3 (Saudi-Bangla special feed). Each treatment had two replicates and the stocking of shrimp in each gher was 3 nos/m². Water quality parameters did not differ significantly among the treatments except water depth. Average production and net return of shrimp in different treatments varied from 404.0 to 509.0 kg/ha and Tk. 56,493.99-Tk. 84,209.60, respectively. T2 showed significantly (p<0.05) the highest production and economic return. The result of the study implied that T2 is more suitable and economically viable than that of other treatments for shrimp farming.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

An experiment of 120 days of culture was conducted in brackishwater earthen ponds having an area of 0.2ha each. The hatchery produced shrimp (Penaeus monodon) post larvae were stocked in the 40m² fine meshed nylon net nursery enclosures were fed with commercial pellet feed. After two weeks of nursing, juveniles were allowed to spread in cultural pond by opening the fence. Fingerlings of three different strain of tilapia were stocked as shrimp and Strain-1 all male (monosex) (T1), shrimp and Strain-2 all male (T2), shrimp and Strain-3 mixed sex population (T3) @ 20.000/ha and 10.000/ha, respectively and shrimp only (monoculture) (T4) @ 20.000/ha. The shrimp and fish were fed with farm made feed consisting of a mixture of fishmeal 29%, MOC 15%, rice bran 30%, soybean meal 16%, wheat flour 9% and vitamin premix 0.1%. The average final weight of shrimp was 24.9±1.13g, 23.41±3.26g and 26.67±1.89g that stocked with tilapia in treatments T1, T2, and T3 respectively. The final average weight of shrimp in monoculture (T4) was 27.41±0.76g, apparently higher but insignificant in treatments. The survival of shrimp was 42.17%, 32.38%, 39.45% and 61.98% in treatments T1 T2, T3 and T4 respectively. The production of shrimp in concurrent culture was 193.67, 154.26 and 210.41kg/ha in T1, T2 and T3, respectively, while in monoculture (T4) was 339.77 kg/ha. The growth and survival of tilapia among the treatments was insignificant. The growth of monosex tilapia ranged 225.29 and 291.31g and survival 62.77 and 72.20% in T1 and T2, respectively, in mixed sex was 193.0g and 83.20% (T3). The production of tilapia monosex strains was 1676.69kg/ha (Strain-2 all male) and 1668.98 kg/ha (Strain-1 all male) while that of Strain-3 mixed sex population was 1622.92 kg/ha.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The present study aimed production of a new product with various texture and sensory properties in chase of the impetus for increasing human consumption considering suitable resources of Kilka fish in Caspian Sea. Following deheading, gutting, and brining, common Kilka were battered in two different formulations, i.e. simple batter and tempura batter, via automated predusting machinery and then, they were fried through flash frying for 30 seconds at 170°C in sunflower oil after they were breaded with bread crumbs flour. The products were subjected to continuous freezing at -40°C and were kept at -18°C in cold storage for four months once they were packed. Chemical composition (protein, fat, moisture, and ash), fatty acid profiles (29 fatty acids), chemical indices of spoilage (peroxide value, thiobarbituric acid, free fatty acids, and volatile nitrogen), and microbial properties (total bacteria count and coliform count) were compared in fresh and breaded Kilka at various times before frying (raw breaded Kilka), after frying (zero-phase), and in various months of frozen storage (phases 1, 2, 3, and 4). Organoleptic properties of breaded Kilka (i.e. odor, taste, texture, crispiness, cohesiveness of batter) and general acceptability in the phases 0, 1, 2, 3, and 4 were evaluated. The results obtained from chemical composition and fatty acid profiles in common Kilka denoted that MUFA, PUFA, and SFA were estimated to be 36.96, 32.85, and 29.12 g / 100g lipid, respectively. Levels of ù-3 and ù-6 were 7.6 and 1.12 g / 100 gr lipid, respectively. Docosahexaonoic acid (20.79%) was the highest fatty acid in PUFA group. ù-3/ù-6 and PUFA/SFA ratios were 7.6 and 1.12, respectively. The high rates of the indices and high percentage of ù-3 fatty acid in common Kilka showed that the fish can be considered as invaluable nutritional and fishery resources and commonsensical consumption of the species may reduce the risk of cardiovascular diseases. Frying breaded Kilka affected overall fat and moisture contents so that moisture content in fried breaded Kilka decreased significantly compared to raw breaded Kilka, while it was absolutely reverse for fat content. Overall fat content in tempura batter treatment was significantly lower than that of simple batter treatment (P≤0.05). Presence of hydrocolloids, namely proteins, starch, gum, and other polysaccharides, in tempura batter may prohibit moisture evaporation and placement with oil during frying process in addition to boosting water holding capacity through confining water molecules. During frying process, fatty acids composition of breaded Kilka with various batters changed so that rates of some fatty acids such as Palmitic acid (C16:0), Stearic acid (C18:0), Oleic acid (C18:1 ù-9cis), and linoleic acid (C18:3 ù-3) increased considerably following frying; however, ù-3/ù-6, PUFA/SFA, and EPA+DHA/C16:0 ratios (Polyan index) decreased significantly after frying. ù-3/ù-6, PUFA/SFA, and EPA+DHA/C16:0 ratios in tempura batter treatment were higher than those of simple batter treatment which is an indicator of higher nutritional value of breaded Kilka with tempura batter. Significant elevations were found in peroxide, thiobarbituric acid, and free fatty acids in fried breaded Kilka samples compared to raw samples which points to fat oxidation during cooking process. Overall microorganism count and coliform count decreased following heating process. Both breaded Kilka samples were of high sanitation quality at zero-phase according to ICMSF Standard. The results acquired from organoleptic evaluation declared that odor, cohesiveness, and general acceptability indices, among others, had significant differences between the treatments (P≤0.05). In all evaluated properties, breaded Kilka with tempura batter in different phases gained higher scores than breaded Kilka with simple batter. During cold storage of various treatments of breaded Kilka, total lipid content, PUFA, MUFA, ù-3, ù- 3/ù-6, PUFA/SFA, Polyen index decreased significantly. The mentioned reductions in addition to significant elevation of spoilage indices, namely peroxide, thiobarbituric acid, and free fatty acids, during frozen storage, indicate to oxidation and enzymatic mechanism activity during frozen storage of breaded Kilka. Considering sensory evaluation at the end of the fourth month and TVB-N contents exceeded eligible rate in the fourth month, shelf life of the products during frozen storage was set to be three months at -18°C. The results obtained from statistical tests indicate to better quality of breaded Kilka processed with tempura batter compared to simple batter in terms of organoleptic evaluation, spoilage indices, and high quality of fat in various sampling phases.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Aquaculture in Tanzania is still on a subsistence level and most of the ponds are maintained as part time job. The ponds are too small, shallow and over crowded with stunted Tilapia spp. In the present paper the results of experiments conducted in ponds at Nyegezi with T. esculenta and T. zillii are presented. This was part of an overall project of developing techniques of fish cultures with Tilapia under the limited existing conditions at Nyegezi. In a mono - species culture experiement with Tilapia zillii in nine month's time an average size of 172.8 mm/115.0 g was attained. In another experiment with T. zillii and T. esculenta in thirteen month's time, T. zillii attained an average size of 180.2mm/106.6 g and T. esculenta 193.6 mm/118.8 g. In another experiment with intensive feeding schedule an average size of 179.3 mm/126.6 g was attained by T. zillii and 191.0 mm/125.0 g by T. esculenta in four month's time. A locally prepared supplimentary feed with local Brewery Waste and Fish Meal (10:1) was readily accepted by both species of Tilapia. T. zillii voraciously fed on Cabbage leaves, Cauliflower leaves, Chinese cabbage leaves, Cassava leaves and on the common weed Comalina sp. Though all the items mentioned above were readily accepted by T. zillii feeding with Comaltna sp. was the easiest and most convenient because of its availability. In an intensive feeding experiment with vegetable leaves/Comalina sp. and the locally prepared supplimentary feed the fishes attained table size in four months time. Cement cistens of 5 X 3 X 1½ m size could be conveniently used for breeding both species of Tilapia. T. zillii had semi adhesive eggs and they were deposited on the sides of the cement wall. The number of young ones in a brood ranged from 160 to 314 in T. esculenta and 687 to 4,356 in T. zillii.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

青稞,是我国藏区居民对裸大麦的称谓,它不仅是藏民的主要食粮、燃料和牲畜饲料,而且也是啤酒、医药和保健品生产的原料;青稞不仅为藏区人民的健康和经济发展做出了很大的贡献,而且对人类健康和社会经济的可持续发展都有重要的意义。青藏高原是我国及世界上青稞分布和种植面积最大的地区,资源极其丰富。虽然从经典遗传直到分子标记对我国大麦遗传多样性都有研究,但研究手段、数量仍然不够深入,对我国大麦资源遗传多样性研究的信息非常有限,不能很好地满足大麦遗传研究和育种应用的需要,尤其是对西藏栽培大麦的遗传多样性的研究还只是刚刚开始,关于栽培青稞多态性的研究报道很少。本研究采用SSR标记和蛋白质电泳两类技术,从SSR标记位点、单体醇溶蛋白、B组醇溶蛋白和淀粉粒结合蛋白(SGP)等四个方面对我国青藏高原栽培青稞的遗传多样性进行了综合评价。 SSR标记具有基因组分布广泛、数量丰富、多态性高、容易检测、共显性、结果稳定可靠、实验重现性好、操作简单、经济、易于高通量分析等许多优点,被认为是用于遗传多样性、品种鉴定、物种的系统发育、亲缘关系及起源等研究的非常有效的分子标记。本研究采用SSR标记分析了64份青藏高原栽培青稞的遗传多样性,同时评估SSR标记在我国大麦育种和品种鉴定中的应用潜力。选择了30个已知作图位点SSR标记,其中25个标记与重要性状的控制位点连锁紧密。选择的30个SSR标记,5个未得到很好的扩增产物,3个无多态性。22个多态性SSR标记位点中,每位点检测出等位基因2~15个,共检测出等位基因132个,平均每位点6.0 个。各多态位点检测出基因型为2~11种,位点HVM33的基因型最多。各多态位点的多态信息指数为0.16~0.91, 平均为0.65。根据PIC值选择了13个SSR标记用于我国青藏高原栽培青稞基因型鉴定,这些标记的PIC值为0.6以上。结合PIC值和基因型差异,选择了8个多态信息含量高的SSR标记,构建了高效指纹图谱,此图谱能把64份材料完全区分。 贮藏蛋白电泳分析是研究相关编码蛋白基因多态性的非常有效的方法。大麦单体蛋白与小麦醇溶蛋白相对应,具有丰富的多态性,可用于大麦遗传多样性、品种鉴定和群体进化等研究。本研究通过A-PAGE电泳技术研究了84份青藏高原栽培青稞的单体醇溶蛋白多态性。大麦单体醇溶蛋白图谱与小麦醇溶蛋白电泳图谱类似,所分离的蛋白清晰地分为ω-,γ-,β-和α-四个部分。青藏高原栽培青稞单体醇溶蛋白具有丰富的多态性,84份青稞材料中存在43条不同的蛋白带,75种组合带谱;其中67种为单一材料所独有,另8种则分别包含了2-3份材料。每份材料中拥有醇溶蛋白带为6-16条,含有6-10条单体醇溶蛋白带材料较多。西藏和四川材料群体单体醇溶蛋白多态性不同,具有区域特异性。西藏材料中发现了40条不同蛋白带,3条特异带,46 种蛋白组合;四川材料中出现了40种不同蛋白带,26种条带组合, 3条特异带。基于单体蛋白多态性的聚类与材料的来源有一定的相关性。A-PAGE单体蛋白具有丰富的多态性,可作为遗传研究和品种鉴定的标记。 大麦醇溶蛋白(hordein)是大麦籽粒的主要贮藏蛋白,与大麦的营养品质和加工品质密切相关,而且具有丰富的多态性,广泛用于品种鉴定、种质筛选、遗传多样性和亲缘关系研究。B组醇溶蛋白是主要的醇溶蛋白组份,约占总醇溶蛋白的80%,而且具有丰富的多态性。本研究采用SDS-PAGE分析了72份青藏高原栽培青稞B组醇溶蛋白的遗传多样性。青藏高原栽培青稞B组醇溶蛋白具有丰富的多态性,72份青稞材料中存在15种蛋白带,30种组合带谱,其中15种为单一材料所独有,另15种则分别包含了2-10份材料。每份材料中B组醇溶蛋白条带数为4-8条,含5、6条的材料较常见。不同来源的群体材料间B组醇溶蛋白组成存在差异,西藏青稞含有26种蛋白组合带谱,其中有19种特异带谱;四川群体中共发现11种蛋白组合带型,其中有4种特有带谱。两群体中都存在稀有条带。聚类分析将材料分成三组,材料聚类与材料来源地没有明显的相关性。 淀粉粒蛋白(Starch granule proteins, SGPs)是一类与淀粉粒结合的微量蛋白,一些淀粉粒蛋白具有淀粉生化合成中主要的酶蛋白功能,其变异会影响淀粉含量和特性,从而影响淀粉的应用。关于我国大麦淀粉粒组成研究还未见报道。本实验首次开创了我国大麦淀粉粒结合蛋白的研究工作。采用SDS-PAGE电泳技术研究了青藏高原栽培青稞的SGP组成,并分析了不同SGP组合间淀粉含量的差异,初步探索了所分离的SGP蛋白与淀粉合成的关系。66份青稞材料中分离了10种主要的SGP,其表观分子量为40-100KD,低于60KD的SGP带有7条,共有16种组合带谱;各SGP蛋白和组合带谱出现的频率存在差异,青藏高原青稞的SGP组成存在多态性。西藏青稞和四川青稞的SGP组成有很大差异,SGP组成具有地域差异性,西藏青稞含有12种蛋白组合带谱,其中有9种特异带谱;四川群体中共发现7种蛋白组合带型,其中有4种特有带谱;两群体中仅有3种共同的蛋白组合带谱。SGP蛋白特性将66份青稞分为三组, 即Ⅰ、Ⅱ、Ⅲ,材料聚类与材料来源具有一定的相关性。不同组合带谱材料间淀粉含量差异显著性检验结果显示,不同带谱间材料的总淀粉含量、直链淀粉含量和支链淀粉含量有差异,带谱2(SGP1+3+7+9+10)和8(SGP1+2+4+6+8)的总淀粉含量及支链淀粉含量显著大于组合带谱3(SGP1+3+7+10)的总淀粉含量。组合带谱7(SGP1+2+6+8)的直链淀粉含量显著低于带谱11(SGP1+5+8)的直链淀粉。带谱SGP2、3、4、5、6、7、8、9、10可能参与淀粉合成,SGP9可能与高支链淀粉的合成相关。 SSR标记位点、单体醇溶蛋白、B组醇溶蛋白、淀粉结合蛋白等四个方面的研究结果表明青藏高原SSR标记多态性、单体醇溶蛋白多态性、B组醇溶蛋白多态性和SGP多态性都非常丰富,与青藏高原是栽培青稞的多样性分布中心的观点一致。 青藏高原栽培青稞的SSR标记、单体醇溶蛋白、B组醇溶蛋白和SGP多态性表现出很大差异。SSR标记覆盖了整个基因组,多态性非常高。单体蛋白、B组醇溶蛋白、SGP蛋白是育种中非常关注的性状,他们只是代表基因组中的某一区域或位点,多态性相对较低。但单体蛋白多态性很高,84份材料中检测出43条不同蛋白带,75种不同的组合带谱。SSR标记技术和单体蛋白技术都是遗传多样性研究的有力工具,但单体蛋白技术不仅多态性高,而且经济、操作简便,是种质鉴定的理想方法。 对不同标记的多态性材料数据进行聚类,聚类图能为我们提供各材料间的遗传相似信息,为材料选择提供参考。但材料聚类与材料来源的地理区域的相关性表现不一致。SSR聚类和B组醇溶蛋白聚类与材料的来源地无相关性,而单体醇溶蛋白和SGP聚类与材料来源地有一定相关性,即西藏群体和四川群体分别有集中类群,这可能是人为选择的附加效应。 不同来源的群体材料的遗传多样性不同,具有区域特异稀有基因,加强不同地区间资源的交换和配合使用,有利于增加群体遗传多样性和新品种培育。 青藏高原栽培青稞的麦芽浸提性状、淀粉性状、病虫及裸粒等重要农艺性状控制位点存在丰富的变异,遗传基础宽广,可能蕴藏着多种不同的等位基因,是研究重要性状遗传特性、基因资源挖掘和遗传育种的宝贵资源库。 Hulless barley, due to its favorable attributes such as high feed value, good human nutrition,rich dietary fiber and ease processing, attracts people,s attention . Hulless barley plays a very important role in Tibetan life, used as essential food crop, main animal feed and important fuel. In addition to tsampa (roasted barley flour), a main food for Tibetan, hulless barley is also made into cake, soup, porridge, recent naked barley liquor and cornmeal. Qinghai-Tibet Plateau is one of a few areas which plant naked barley widely in the world and also has a long growing history. Genetic diversity of the cultivated hulless barley in this region , however, has not been documented. The study of genetic diversity existing within this population is of particular interest in germplasm identification, preservation, and new cultivar development. This study analyzed the genetic diversity of the cultivated naked barley from Qinghai-Tibet plateau through the study of SSR marker loci and monomeric prolamins, B-horden and starch granule proteins. SSRs are present abundantly in genomes of higher organisms and have become a popular marker system in plant studies. SSRs offer a number of advantages, such as the high level of polymorphisms, locus specificity, co-dominance, reproducibility, ease of use through PCRand random distribution throughout the genome. In barley, several hundred SSRs have been developed and genetically mapped and can therefore be selected from specific genomic regions. The genetic diversity of 64 cultivated naked barley from Tibet and Sichuan was studied with 30 SSRs of known map location.Among the selected SSR markers, PCR products of 5 SSR markers were not obtained and 3 SSR marker loci were monomeric. A total of 132 alleles were identified at 22 polyomeric SSR loci. The number of alleles per locus ranged from 2 to 15, with an average of 6.0. The polymorphism information content values for the SSRs ranged from 0.08 to 0.94, with an average of 0.65. 13 SSR markers with the PIC value >0.6 have been selected for discrimination of Qinghai-Tibet naked barley genotypews. A finger Print map was developed through 7 SSR markers with the high PIC value. It could be used as an efficient tool for gene discovery and identification of gernplasm. Hordeins, the main storage proteins of the barley seed, are composed of momomeric and polymeric prolamins and divided into -A, B, C and D groups in order of decreasing electrophoretic mobility. Hordeins show high inter-genotypic variation and have been extensively used as markers for cultivar identification and analyzing the genetic diversity. This study analyzed the genetic diversity of B-hordein in 72 naked barley from Qinqhai-Tibet Plateau. Extensive diversity was observed. A total of 15 different bands and 30 distinct patterns were found. Jaccard's coefficient of similarity was calculated, and the accessions were divided into three main groups by cluster analysis using UPGMA. Differentiation among the populations from different collecting regions based on the polymorphism of B-hordein was investigated. Monomeric prolamins show high inter-genotypic variation and have been used as molecular markers for cultivar identification, analyzing the genetic diversity in collections and investigating the evolution processes and structure of populations However, the cultivated hulless accessions from Qinghai-Tibet Pateau in China have never been examined with respect to monomeric prolamins. This study analyzed the genetic diversity of monomeric prolamins (protein fraction corresponding to wheat gliadins) using the Acid -PAGE technique in eighty-four cultivated hulless barley from Qinqhai-Tibet Plateau in China. Extensive diversity was observed. A total of 43 different bands were found, of which 21 different bands were in the region of ω group, 8 in the region of γ, 8 in the region of β, and 6 in the region of α group. Among the 86 accessions, 75 distinct patterns were identified. The number of bands ranged from 6 to 16, depending on the variety. Jaccard’s coefficient of similarity was calculated, and the lines were grouped by cluster analysis using UPGMA. A dendrogram was obtained from the analysis of the groups and five main clusters were identified. No relationship between the distribution in the dendrogram and growth habits and origins of the cultivars could be detected. Starch is the major constituent of the cereal endosperm, comprising approximately 65% of the dry weight of the mature wheat grain. The starch formed in all organs of plants is packaged into starch granules, which vary widely between species and cultivars in size and shape. Wheat endosperm starch granules contain about corresponding to the main biosynthase of starch. This report firstly dealed with intraspecific variation of the major SGPs in cultivated naked barley from Qinghai-Tibet plateau. A total of 10 major SGPs were observed in the range of 40KD-100KD and 16 types of patterns were found. Based on the variation of SGPs, accessions studied were classified into 3 groups. A geographical cline of electrophoregram was observed. In addition, significance test of the difference of starch content among groups and types of patterns were done, and the results indicated those SGPs could be related to the content of starch. Diagram obtained through cluster analysis exhibited a structuration of diversity and genetic relationship among cultivated hulless accessions. In breeding program, parents with genetically distant relationship for hybridization will increase genetic diversity of progenies. In conclusion, cultivated naked barley from Qinghai-Tibet Plateau in China presents a high variability with respect to monomeric prolamins,SSR markers , B- hordeins and SGPs. The result of this study supports Qinghai-Tibet Plateau is the center of cultivated hulless barley and the cultivated naked barley is considered to be a gene pool with large diversity and could be applied to breeding for cereal.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

本文结合我国燃料乙醇发展的方针政策,以酿酒酵母和运动发酵单胞菌为菌种研究其在非粮能源作物木薯中乙醇发酵的情况,为木薯原料更好地应用于生产中提供了理论依据。 酿酒酵母木薯高浓度乙醇发酵的研究。实验采用的木薯干淀粉含量约70-75%。以酿酒酵母为菌种进行高浓度乙醇发酵的工艺条件研究,最佳条件为:木薯干粉碎细度为35目,料水比1:2,α-淀粉酶用量0.09 KNU/g淀粉,蒸煮温度85 ℃,蒸煮时间15 min。采用30 ℃同步糖化发酵工艺,糖化酶用量为3.4 AGU/g淀粉,发酵时间30 h。在10 L发酵罐中,乙醇质量比达127.88 g/kg,发酵效率为88.28%,发酵强度4.263 g/kg/h,100 L中试研究中乙醇浓度为127.75 g/kg,发酵强度4.258 g/kg/h。利用高效液相色谱对发酵液中残糖进行了分析,证明葡萄糖、果糖等单糖已完全被菌体利用,剩余糖为二糖,三糖等不可发酵的低聚糖。 运动发酵单胞菌快速乙醇发酵的研究。对实验室保藏的8株运动发酵单胞菌进行比较,选择发酵速度最快的Zymomonas mobilis232B进行研究。该菌在纯葡萄糖中的最佳发酵条件为:葡萄糖浓度18%,起始pH 6-7,发酵温度30 ℃,发酵时间18 h,乙醇浓度88 g/kg。在以木薯为底物同步糖化快速乙醇发酵中,采用Full Factorial设计和最速上升实验确定了培养基成分中的2个显著性因子及其最适浓度:酵母粉4 g/kg,硫酸铵0.8 g/kg。在最适培养基条件下,对木薯料水比和糖化酶用量进行了优化,得到Z.mobilis232B木薯乙醇发酵最佳料水比1:3,糖化酶浓度4 AGU/g淀粉,乙醇发酵4.915 g/kg/h。利用高效液相色谱对发酵液中残糖进行了分析,剩余糖为二糖,三糖等,但成分较酵母发酵后复杂。 According to the fuel ethanol development plans and policies in our country, the ethanol production from cassava by Saccharomyces cerevisiae and Zymomonas mobilis was studied. It provided theoretical basis for ethanol fermentation by cassava in industry. Part 1 is the study of VHG (very high gravity) ethanol fermentation by Saccharomyces cerevisiae. The content of starch in cassava was 70-75%. Compared with the performances under different experimental conditions, the following optimal conditions for VHG fermentation were obtained: Granule size of dry cassava 35 mashes, hydromodulus of cassava to water at 1:2, α-amylase enzyme dosage 0.09 KNU/g starch, cooking temperature 85 ℃ for 15 min, using the SSF process (simultaneous saccharification and fermentation) and the amount of glucoamylase 3.4 AGU/g starch. Accordingly, the final ethanol concentration was up to 127.88 g/kg; the ethanol yield reached 88.28%, and ethanol productivity was 4.263 g/kg/h after 30 h. When the fermentation scale expanded to 100 L, the final ethanol concentration was 127.75 g/kg, and the ethanol productivity was 4.258 g/kg/h in 30 h. The residual sugar was analyzed by high performance liquid chromatography, and proved that there was no glucose and fructose. The residual reducing sugar was some unfermentable oligosaccharide Part 2 is the study of the rapid ethanol production by Zymomonas mobilis. Compare with other seven stains, Zymomonas mobilis 232B was selected for research. The optimum condition in glucose medium was as follow: glucose concentration 18%, initial pH 6-7, and fermentation temperature 30 ℃. The ethanol concentration was 88g/kg in 18 h. After that, rapid ethanol production from cassava in SSF by Zymomonas mobilis 232B was studied. Through a series of experiments aided by Full Factorial Design and steepest ascent search, the optimal concentration yeast extract and ammonium sulfate were determined: 4 g/kg and 0.8 g/kg, each. Under optimum medium conditions, the optimal hydromodulus of cassava to water and glucoamylase dosages were obtained: hydromodulus of cassava to water at 1:3 and glucoamylase dosages 4 AGU/g starch. The ethanol production reached 4.915 g/kg/h. The residual sugar was analyzed by HPLC, and proved that the residual reducing sugar was some unfermentable oligosaccharide,but the components were more complex than that fermentation by Saccharomyces cerevisiae.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

生物质燃料乙醇是一种高度清洁的交通液体燃料,是减少温室气体排放,缓解大气污染的最佳技术选择。以非粮原料生产燃料乙醇可以在进行能源生产的同时保证粮食安全,有利于产业的可持续发展。在众多的非粮原料中,甘薯是我国开发潜力最大的生物质能源作物之一。我国占世界甘薯种植总面积和产量的90%。同时,甘薯的单位面积燃料乙醇产量远大于玉米和小麦。其成本是目前酒精中最低廉的,因此利用甘薯生产乙醇是发展生物质燃料乙醇的首要选择。目前采用薯类全原料主要采用分批发酵生产乙醇,其技术水平低,发酵强度低,一般在0.7-2.5g/(L•h),乙醇浓度低,甘薯发酵乙醇为6-8%(v/v),能耗高,环境负荷大,污染严重。针对上述问题,本文从菌株选育、原料预处理、中试放大、残糖成分分析等方面进行研究。 为了研究乙醇发酵生产规模扩大过程中,大型发酵罐底部高压条件下,CO2对酵母乙醇发酵的影响,我们通过CO2 加压的方法进行模拟试验,研究结果表明,发酵时间随压强的升高而逐渐延长,高压CO2 对乙醇发酵效率影响不大,在0.3 MPa 以下时,发酵效率均可达到90%以上。高压CO2 对发酵的抑制作用是高压和CO2 这两个因素联合作用的结果。高压CO2 条件下,酵母胞外酶和胞内重要酶类的酶活均表现出特征性。0.2 MPa 下,酶活性的变化趋势和0.1 MPa 条件下的较为一致。而0.3 MPa 下的酶活变化趋势与0.4 MPa 下的酶活更为接近。通过全基因表达分析发现在CO2 压力为0.3 MPa 下,乙醇发酵途径中多个基因表达量下调,同时海藻糖合成酶和热激蛋白基因表达量上调。 筛选耐高温的乙醇酵母菌株能够解决糖化温度和发酵温度不协调的矛盾,实现真正意义上的边糖化边发酵。高温发酵还能够降低发酵时的冷却成本,实现乙醇的周年生产。本研究筛选出一株高温发酵菌株Y-H1,进而我们对该菌株的胞外酶和胞内乙醇代谢重要酶类的酶活性进行了分析。结果表明Y-H1 能够在40 ℃条件下正常进行乙醇发酵,发酵33h,最终乙醇浓度达到10.7%(w/w),发酵效率达到90%以上。同时发酵液最终pH 在3.5 左右,显示菌株具有一定的耐酸性能力。同时观察到40 ℃下,菌株的胞外酶和胞内乙醇代谢重要酶类的酶活性发生了变化,乙醇发酵途径中关键酶基因表达下调,而海藻糖合成酶与热激蛋白基因表达量上调,这些结果为进一步研究酵母菌耐热调控机理提供了依据。 糖蜜是一种大规模工业生产乙醇的理想原料,本研究利用选育高浓度乙醇发酵菌株结合配套的发酵稳定剂,研究了糖蜜高浓度乙醇发酵情况。结果表明采用冷酸沉淀预处理糖蜜溶液,采用分批补料的发酵方式,乙醇浓度最高达到了10.26% (w/w),发酵时间为42 h。同时观察到在糖蜜发酵中,乙醛含量与乙醇浓度存在一定的相关性。 快速乙醇发酵对于缩短乙醇生产周期、降低乙醇生产成本、减少原料腐烂损失具有重要意义。本研究诱变和筛选得到了一株快速乙醇发酵菌株10232B。在优化后的发酵条件下,采用10L 发酵罐进行分批乙醇发酵,经过18h,乙醇的最终浓度达到88.5g/L,发酵效率93.6%,平均乙醇生产速度达到4.92 g/L/h。此菌株在保持较高乙醇生产浓度的同时,拥有快速生产乙醇的能力,适合作为快速乙醇发酵生产菌种。 由于鲜甘薯具有粘度大的特点,传统液化糖化处理很难在短时间内充分糖化原料;高粘度的醪液也难以进行管道输送,容易堵塞管路;同时,也会降低后续的乙醇发酵效率。 本文采用了快速粘度分析法对鲜甘薯糊化粘度特性进行了分析,进而对预处理条件进行了研究,在最佳预处理条件下,糖化2h 后,醪液葡萄糖值最高可达99.3,粘度4.5×104 mPa.s,而采用传统糖化工艺,醪液DE 值仅为85.8,粘度大于1.0×105 mPa.s。 此预处理方法也可用于快速糖化不加水的醪液。后续的乙醇发酵试验表明,通过此预处理方法获得的糖化醪液对乙醇发酵无负面影响。 在前期已实现了实验室水平的鲜甘薯燃料乙醇快速乙醇发酵基础上,进一步将发酵规模扩大到500L,在中试水平上对甘薯乙醇发酵进行了研究。结果表明在500L 中试规模,采用边糖化边发酵(SSF)工艺,在料液比为3∶1,发酵醪液最高粘度为6×104mPa.s 条件下,发酵37h,乙醇浓度达到了12.7%(v/v),发酵效率91%,发酵强度为2.7 g/(L•h)。与目前国内的薯类乙醇发酵生产技术水平具有明显的优越性。 为研究甘薯、木薯乙醇发酵中残糖的组成,采用了高效液相色谱—蒸发光散射检测法,对乙醇发酵残糖进行了分析。结果表明,甘薯、木薯乙醇发酵残糖均为寡聚糖,主要由葡萄糖、木糖、半乳糖、阿拉伯糖和甘露糖构成。随着发酵时间延长,寡聚糖中的葡萄糖、半乳糖、甘露糖可被缓慢的水解释放。提高糖化酶量仅在一定程度上降低残糖,过量的糖化酶反而会导致残糖增加。同时发现3, 5-二硝基水杨酸法不能准确测定甘薯、木薯乙醇发酵中的残总糖含量。进一步筛选了两株残糖降解菌株,对甘薯乙醇发酵残糖的降解利用率均达到了40%以上,而且还能显著降低发酵醪液粘度。经形态学和rRNA ITS 序列分析,确定这两株菌分别属于为木霉属和曲霉属黑曲霉组。 通过对以甘薯原料为代表的非粮原料发酵技术研究开发,以期形成乙醇转化率高,能耗低,生产效率高、季节适应性好,原料适应性广,经济性强,符合清洁生产机制的燃料乙醇高效转化技术,为具有我国特色的燃料乙醇发展模式提供技术支持。 Sweet potato is one of the major feedstock for the fuel ethanol production in China. The planting area and the yield in China take 90% of the world. Sweet potato is an efficient kind of energy crops. The energy outcome per area is higher than corn or wheat. And the manufacture cost of ethanol is the lowest, compared with corn and wheat. So sweet potato is the favorable crop for the bioethanol production in China. However, the low-level fermentation technology restricts the development of ethanol production by sweet potato, including slow ethanol production rate, low ethanol concentration and high energy cost. To solve these problems, we conducted research on the strain breeding, pretreatment, pilot fermentation test and residual saccharides analysis. To study the impact of hyperbaric condition at bottom of the large fermentor on yeast fermentation, high pressure carbon dioxide (CO2) was adopted to simulate the situation. The results showed that the fermentation was prolonged with the increasing pressure. The pressure of CO2 had little impact on the ethanol yield which could reach 90% under the pressure below 0.3 MPa. The inhibition was combined by the high pressure and CO2. Under the high CO2 pressure, the extracellular and important intracellular enzyme activities were different from those under normal state. The changes under 0.1 MPa and 0.2 MPa were similar. The changes under 0.3 MPa were closer to those under 0.4 MPa. The application of thermotolerance yeast could solve the problem of the inconsistent temperature between fermentation and saccharificaton and fulfill the real simultaneous saccharification and fermentation. And it could reduce the cooling cost. A thermotolerance strain Y-H1 was isolated in our research. It gave high ethanol concentration of 10.7%(w/w)at 40 ℃ for 33 h. The ethanol yield efficiency was over 90%. At 40 ℃, the extracellular and important intracellular enzyme activities of Y-H1 showed the difference with normal state, which may indicate its physiological changes at the high temperature. Molasses is another feedstock for industrial ethanol production. By our ethanol-tolerance strain and the regulation reagents, the fermentation with high ethanol concentration was investigated. In fed-batch mode combined with cold acid deposition, the highest ethanol concentration was 10.26% (w/w) for 42h. The aldehyde concentration in fermentation was found to be related to ethanol concentration. The development of a rapid ethanol fermentation strain of Zymomonas mobilis is essential for reducing the cost of ethanol production and for the timely utilization of fresh material that is easily decayed in the Chinese bioethanol industry. A mutant Z. mobilis strain, 10232B, was generated by UV mutagenesis. Under these optimized conditions, fermentation of the mutant Z. mobilis 10232B strain was completed in just 18 h with a high ethanol production rate, at an average of 4.92 gL-1h-1 per batch. The final maximum ethanol concentration was 88.5 gL-1, with an ethanol yield efficiency of 93.6%. This result illustrated the potential use of the mutant Z. mobilis 10232B strain in rapid ethanol fermentation in order to help reduce the cost of industrial ethanol production. As fresh sweet potato syrup shows high viscosity, it is hard to be fully converted to glucose by enzymes in the traditional saccharification process. The high-viscosity syrup is difficult to be transmitted in pipes, which may be easily blocked. Meanwhile it could also reduce the later ethanol fermentation efficiency. To solve these problems, effects of the pretreatment conditions were investigated. The highest dextrose equivalent value of 99.3 and the lowest viscosity of 4.5×104 mPa.s were obtained by the most favorable pretreatment conditions, while those of 85.8 and over 1.0×105 mPa.s was produced by traditional treatment conditions. The pretreatment could also be applied on the material syrup without adding water. The later experiments showed that the pretreated syrup had no negative effect on the ethanol fermentation and exhibited lower viscosity. The fuel ethanol rapid production from fresh sweet potato was enlarged in the 500L pilot scale after its fulfillment on the laboratory level. The optimal ratio of material to water was 3 to 1 in 500L fermentor. With low-temperature-cooking (85 ℃) using SSF, the Saccharomyces cerevisiae was able to produce ethanol 97.44 g/kg for 37h, which reached 92% of theoretical yield. The average ethanol production rate was 4.06 g/kg/h. And the maximum viscosity of syrup reached 6×104mPa.s. The results showed its superiority over current industrial ethanol fermentation. The compositions of the residual saccharides in the ethanol fermentation by sweet potato and cassava were analyzed by high performance liquid chromatography coupled with evaporative light-scattering detector. The results showed that all the residual saccharides were oligosaccharides, mainly composed of glucose, xylose, galactose, arabinose and mannose. The glucose, galactose and mannose could be slowly hydrolyzed from oligosaccharides in syrup during a long period. To increase the glucoamylase dosage could lower the residual saccharides to a certain extent. However, excess glucoamylase dosage led to more residual saccharides. And the method of 3, 5-dinitrosalicylic acid could not accurately quantify the residual total saccharides content. Two residual saccharides degrading strains were isolated, which could utilize 40% of total residual saccharide and lower the syrup viscosity. With the analysis of morphology and internal transcribed spacer sequence, they were finally identified as species of Trichoderma and Aspergillus niger.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Assessment of the potential CO2 emission reduction by development of non-grain-based ethanol in China is valuable for both setting up countermeasures against climate change and formulating bioethanol policies. Based on the land occupation property, feedstock classification and selection are conducted, identifying sweet sorghum, cassava, and sweet potato as plantation feedstocks cultivated from low-quality arable marginal land resources and molasses and agricultural straws as nonplantation feedstocks derived from agricultural by-products. The feedstock utilization degree, CO2 reduction coefficient of bioethanol, and assessment model of CO2 emission reduction potential of bioethanol are proposed and established to assess the potential CO2 emission reduction by development of non-grain-based bioethanol. The results show that China can obtain emission reduction potentials of 10.947 and 49.027 Mt CO2 with non-grain-based bioethanol in 2015 and 2030, which are much higher than the present capacity, calculated as 1.95 Mt. It is found that nonplantation feedstock can produce more bioethanol so as to obtain a higher potential than plantation feedstock in both 2015 and 2030. Another finding is that developing non-grain-based bioethanol can make only a limited contribution to China's greenhouse gas emission reduction. Moreover, this study reveals that the regions with low and very low potentials for emission reduction will dominate the spatial distribution in 2015, and regions with high and very high potentials will be the majority in 2030.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O melhoramento genético de plantas tem contribuído sobremaneira para o aumento da produção em diversas espécies de grande importância econômica e/ou social, beneficiando bilhões de pessoas, especialmente de menor poder aquisitivo, que vivem em países em desenvolvimento distribuídos por todo o mundo. Esses aumentos na produção resultam da obtenção de novos genótipos, que apresentam rendimentos mais elevados, adaptados a diversas condições ecológicas, muitas das vezes adversas, e resistentes a pragas e doenças. No entanto, para a geração desses materiais melhorados, torna-se necessário que características de interesse sejam incorporadas às novas cultivares, dentro de programas de melhoramento genético bem definidos, de forma que possam ser, ao final de todo o processo, exploradas comercialmente.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A mandioca (Manihot esculenta Crantz) é cultivada em todas as regiões do Brasil, desempenhando papel importante na alimentação humana e animal, como matéria-prima para vários produtos industriais e na geração de emprego e de renda. O Brasil ocupa a segunda posição na produção mundial de mandioca (12,7% do total), com área cultivada de cerca de 1,7 milhões de hectares, produção da ordem de 22,6 milhões de toneladas de raízes e produtividade média de 13,3 t/ha. Dentre os principais estados produtores destacam-se: Pará (18,0%), Bahia (16,3%), Paraná (12,5%), Rio Grande do Sul (5,0%) e Amazonas (4,3%), que respondem por 56,1% da produção do país. Estima-se que, nas fases de produção primária e no processamento de farinha e fécula, gera-se em torno de um milhão de empregos diretos e que a atividade mandioqueira proporciona receita bruta anual equivalente a 2,5 bilhões de dólares e uma contribuição tributária de 150 milhões de dólares; a produção que é transformada em farinha e fécula gera, respectivamente, receitas equivalentes a 600 milhões e 150 milhões de dólares. A Região Nordeste destaca-se com uma participação de 36,8% da produção nacional; as demais regiões participam com 28,7% (Norte), 19,7% (Sul), 8,8% (Sudeste) e 6,0% (Centro-Oeste).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A baixa taxa de multiplicação de mandioca é um dos obstáculos à sua propagação em larga escala. De cada planta de mandioca obtém-se de 5 a 10 manivas de 20 cm de comprimento, num período médio de 12 meses, o que equivale a dizer que a taxa de propagação de mandioca varia de 1:5 a 1:10. Embora produza sementes, comercialmente a mandioca é propagada vegetativamente por meio de pedaços de caule. A propagação vegetativa tem a desvantagem de permitir a transmissão de pragas e patógenos entre as gerações sucessivas de cultivo, caso não sejam tomados cuidados com relação à qualidade do material de propagação. Essa duas características, a baixa taxa de multiplicação e a degenerescência causada pelo acúmulo de pragas, contribuem para escassez de manivas de boa qualidade à disposição de agricultores. Um método simples e barato para aumento da taxa de multiplicação, da mandioca é a multiplicação rápida a qual consiste em cortar hastes da planta de mandioca em pedaços com duas ou três gemas, e plantá-los em canteiro cobertos com plásticos transparente, para reter o calor do sol. Esses canteiros são regados frequentemente, e assim, a umidade e a temperatura elevadas induzem as manivas a brotar. Ao atingir o tamanho de 10 a 15 cm, os brotos são cortados e posto em água, para enraizar. Por sua vez, as manivas de duas ou três gemas voltam a brotar, e nisso consiste a capacidade que essa técnica tem de aumentar a taxa de multiplicação da mandioca. As taxas de multiplicação obtidas nesse trabalho variaram entre 1:140 a 1:170, isto é, um aumento de 14 a 17 vezes em relação a taxa de multiplicação convencional da mandioca (1:10). Embora esses índices estejam abaixo do potencial máximo de multiplicação apresentado na literatura ( aumento de 60 vezes), demonstram o potencial da técnica da multiplicação rápida no aumento da taxa de multiplicação da mandioca, em razão da sua simplicidade e baixo custo.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O Maranhão é o quarto maior plantador de mandioca do Brasil, mas apresenta a menor produtividade de produto comercial, que é de 8,0 t de raízes por hectare. Dentre uma das causas para esse baixo rendimento é que o cultivo de mandioca ocorre em solos extremamente frágeis, de textura arenosa a média, com baixa retenção de umidade e com teores baixos de matéria orgânica, fósforo, cálcio, magnésio e potássio (Tabela 1), este último o nutriente mais absorvido e exportado pela cultura da mandioca.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Mandioca: Preços recuam após três meses de alta ? A oferta de mandioca seguiu elevada para a indústria de fécula das regiões acompanhadas pelo Cepea em março. Este quadro foi atribuído aos preços favoráveis da cultura e também pelo clima favorável ao longo do período. Por conta destes fatores, as cotações que vinham se valorizando expressivamente em meses anteriores, passaram a ter elevações menos intensas. Em março, a tonelada da raiz destinada às fecularias foi cotada à média de R$ 249,71 (R$ 0,4343/ grama de amido, considerando a balança hidrostática de 5 kg), subindo 5,4% frente à de fevereiro (R$ 236,89/t). Esta alta é pouco expressiva quando comparada com a de meses anteriores, que foi de até 15%. Comparando o preço médio de R$ 236,89/t da última semana de fevereiro com o de R$ 243,23 em igual período de março, a desvalorização é de 4,0% entre os períodos. Entre os estados acompanhados pelo Cepea, o maior preço foi registrado no Paraná, de R$ 269,13/t, aumento de 6,5% frente ao valor do mês anterior. No Mato Grosso do Sul, no mesmo período, houve valorização de 4,6%, com o produto cotado a R$ 231,48/t. O estado de São Paulo teve a variação mais expressiva, de 11,9%, com a mandioca comercializada a R$ 195,81/t (Figura 1). Em âmbito regional, os preços tiveram alta em todas as regiões em março. A mais expressiva ocorreu na região de Assis (SP), de 11,9%, porém a mesma área teve a menor média do período (R$ 195,81/t). Já o maior preço do mês ocorreu no noroeste paranaense (R$ 272,17/t), onde a valorização foi de 5,5%. A alta menos expressiva foi observada no sudeste do Mato Grosso do Sul, de 4,0%, com o produto cotado à média de R$ 234,06/t (Figura 2).