The drug development scheme used by the National Cancer Institute begins with a drug discovery program (prescreen and screening phase). Since ascites (腹水) tumors are useful in identifing potentially active agents,a prescreening step using the P388mouse le...[继续阅读]

    In the production of L-glutamic acid,two enzymes have been shown to play important roles:phosphoenolpyruvate carboxylase (PC,磷酸烯醇丙酮酸羧化酶),which catalyzes carboxylation of phosphoenolpyruvate to form oxaloacetate,(草酰乙酸) and α-ketoglutarate dehydrogenase (KD...[继续阅读]

    White wine is the product of the fermentation of pure grape juice obtained from grapes by extraction from grapes. Macereation of the skins should be avoided and the must should be clarified by settling,One distinguishes two basic types,the dry,white wines...[继续阅读]

    Introduction There has been a world wide interest recently in the application of commercially available lipases for the hydrolysis of oils,(1,2)synthesis of esters,(3,4) interesterification of oils and fats,(5) production of biosurfactants,(6) and the res...[继续阅读]

    There are two basic types of Scotch whiskey,namely,malt whiskey and grain whiskey.Malt whiskey is made from peated barley malt as the only source of starch for the production of malt whiskey,the enzymes in the malt change the starch to sugar during the ma...[继续阅读]

    Between the traditional biotechnologies and the newer inovations lies a history of developments with a number of important milestones on the way.In any study of these developments it is clear that strategic and economic necessities as well as the inventiv...[继续阅读]

    In various traditional oriental foods (for example koji,miso) the nutrientional value of foodstuff is improved by microbial,usually fungal growth. Wheat or rice bran is a common starting material,and is rendered more digestible,more nutritious and more fl...[继续阅读]

    Suppose the aim of a process is to manufacture 1000 tonnes of phenylalanine per year.Phenylalanine concentrations of 20g/L can be expected and the yield of phenylalanine from glucose is 0.13 g phenylalanine per g glucose consumed.Tyrosine (酪氨酸) is require...[继续阅读]

    Horticultural (与园艺有有的,园艺学的) practice has long made use of vegetative cloning of plant parts (shoots,leaves,etc. ) for selective and rapid propagation of many plant species. Subsequently,plant tissues such as root tips,cambium (形成层) or plant tumours were f...[继续阅读]

    All matter is composed of basic substances called elements. An element cannot be broken down into esimpler units by chemical reactions;it contains only one kind of atom.An atom is the smallest characteristic unit of an element.A compound is a substance th...[继续阅读]