变废为宝:利用活性污泥生产生物可降解塑料聚-3-羟基丁酸酯

From waste to treasure: turning activated sludge into bioplastic poly-3-hydroxybutyrate

活性污泥(简称污泥)是废水处理产生的副产物,量大而且难以处理。本研究通过对污泥的高温热裂解处理,获得可用于培养微生物的营养物质。实验发现污泥热裂解液可以取代培养嗜盐单胞菌Halomonas CJN的氮磷源、酵母膏和微量元素,来生产生物可降解塑料聚-3-羟基丁酸酯(PHB)。进一步发现厌氧发酵污泥热裂解液产生的乙酸可以取代葡萄糖来作为碳源支持微生物的生长。这样,可以实现利用污泥热裂解液来生产生物塑料PHB。通过进一步在Halomonas CJN中构建附加PHB合成路径,可以实现完全用污泥热裂解液来高效生产PHB,粗略估计使PHB的制造成本从30 000元/t下降到20 000元/t,实现污泥变废为宝的目标。

Large quantity of activated sludge is generated from wastewater treatment but without yet an appropriate deposition. High temperature can lyse the activate sludge so that nitrogen and phosphorus containing nutrients are released. Halomonas CJN was found to grow on the heat lysed activated sludge and glucose for production of bioplastic poly-3-hydroxybutyrate（PHB）in the absence of yeast extract,nitrogen and phosphorus sources as well as trace elements.This reduces the PHB production cost significantly.Furthermore,acetic acid formed from anaerobic fermentation of heat lysed activated sludge can be used to replace glucose for cell growth but not much for PHB production.After construction of an additional PHB synthesis pathway in Halomonas CJN,we can produce PHB entirely from heat lysed activated sludge,reducing production cost of PHB roughly from $30 000 Yuan/ton to $20 000 Yuan/ton,thus turning waste activated sludge to valuable raw material resource.