Exploiting membrane enzymes in biotechnology: Bioelectrocatalysis and fuel cells

越来越清楚的是，为了解决全球变暖问题，减少我们对化石燃料的依赖，需要采取各种办法，并需要将各种新技术结合起来付诸实践。许多形式的可再生能源，如太阳能电池和风车，提供间歇性的电力，因此重要的是这些能量可以储存在电池中或转化为燃料。这种存储需要从电能到化学能的转换，这是通过电催化剂进行的。能量转换中的许多重要反应需要昂贵的稀有金属催化剂。一个恰当的例子是氢转化。据估计，铂族金属的稀缺将严重限制（如果不是禁止的话）向氢经济的转化。生物学非常擅长能量转化，代谢和呼吸中的许多反应都转化能量。这些重要的反应，如氢气或二氧化碳转化，是由生物催化剂（即，酶）不依赖于昂贵或稀有金属。然而，这些酶中的一些存在于生物脂质膜中，这些生物脂质膜是疏水的（即防水的），这使得难以在能量转换技术中使用这些类型的生物催化剂。在这个项目中，我们的目标是开发使用膜酶的新型电催化剂。我们提出的技术是基于最近的结果，这表明膜酶可以用作电催化剂，如果沉积在导电（金属）表面。在这个项目中，膜酶将与特定类型的聚合物（塑料）混合，因为我们以前证明了这些聚合物可以大大延长膜生物催化剂的寿命。最后，从细菌中分离膜酶非常昂贵。因此，在本项目中，我们将不分离这些生物催化剂，而是研究如何使用细菌的粗提物，因为这将大大降低生物催化的成本。作为原理验证，我们将构建一个燃料电池，将氢气和氧气（空气中的氧气）转化为电能。这种氢燃料电池将来可能会为你的笔记本电脑、手机或其他移动的设备充电，甚至为你的汽车提供动力。

It is increasingly clear that to tackle global warming and reduce our reliance on fossil fuels, a variety of approaches are required and a combination of new technologies needs to be put into practice. Many forms of renewable energy, like solar cells and windmills, provide intermittent power and hence it is important that this energy can be stored, either in batteries or by conversion into fuels. Such storage requires conversion from electrical to chemical energy and back again, which is performed by electrocatalysts. Many important reactions in energy conversion require expensive, rare metal catalysts. A case in point is hydrogen conversion. It has been estimated that the scarcity of platinum group metals will severely limit, if not prohibit, a conversion to a hydrogen economy.Biology is very adept in energy conversion and many reactions in metabolism and respiration convert energy. These important reactions, like hydrogen or carbon dioxide conversions, are performed by biocatalysts (i.e., enzymes) that do not rely on expensive or rare metals. However, some of these enzymes reside in biological lipid membranes, which are hydrophobic (i.e. water repellent) and this makes it difficult to employ these types of biocatalysts in technologies for energy conversion. In this project we aim to develop new types of electrocatalysts that use membrane enzymes. Our proposed technology is based on recent results, which show that membrane enzymes could be employed as electrocatalyst if deposited on conducting (metallic) surfaces. In this project, membrane enzymes will be mixed with specific types of polymers (plastic) as we previously demonstrated that these polymers can vastly extend the lifetime of membrane biocatalysts. Finally, isolating membranes enzymes from bacteria is very expensive. Thus, in this project we will not isolate these biocatalyst, but study how crude extracts from bacteria can be used as this will greatly reduce the cost of biocatalysis.As a proof-of-principle, we will build a fuel cell that converts hydrogen and oxygen (oxygen from air) into electricity. Such hydrogen fuel cells might, in the future, recharge your laptop, phone or other mobile devices or even power your car.