Global Centre for Environmental Remediation (GCER), Faculty of Science, University of Newcastle, ATC Building, University Drive, Callaghan, NSW, 2308, Australia.
Cooperative Research Centre for Contamination Assessment and Remediation of Environment (CRC CARE), University of Newcastle, ATC Building, University Drive, Callaghan, NSW, 2308, Australia.
Appl Microbiol Biotechnol. 2018 Feb;102(3):1131-1144. doi: 10.1007/s00253-017-8693-7. Epub 2017 Dec 19.
Microalgae and bacteria offer a huge potential in delving interest to study and explore various mechanisms under extreme environments. Acid mine drainage (AMD) is one such environment which is extremely acidic containing copious amounts of heavy metals and poses a major threat to the ecosystem. Despite its extreme conditions, AMD is the habitat for several microbes and their activities. The use of various chemicals in prevention of AMD formation and conventional treatment in a larger scale is not feasible under different geological conditions. It implies that microbe-mediated approach is a viable and sustainable alternative technology for AMD remediation. Microalgae in biofilms play a pivotal role in such bioremediation as they maintain mutualism with heterotrophic bacteria. Synergistic approach of using microalgae-bacteria biofilms provides supportive metabolites from algal biomass for growth of bacteria and mediates remediation of AMD. However, by virtue of their physiology and capabilities of metal removal, non-acidophilic microalgae can be acclimated for use in AMD remediation. A combination of selective acidophilic and non-acidophilic microalgae together with bacteria, all in the form of biofilms, may be very effective for bioremediation of metal-contaminated waters. The present review critically examines the nature of mutualistic interactions established between microalgae and bacteria in biofilms and their role in removal of metals from AMDs, and consequent biomass production for the yield of biofuel. Integration of microalgal-bacterial consortia in fuel cells would be an attractive emerging approach of microbial biotechnology for AMD remediation.
微藻和细菌在探索极端环境下的各种机制方面具有巨大的潜力。酸性矿山排水（AMD）就是这样一种环境，它的酸度极高，含有大量重金属，对生态系统构成了重大威胁。尽管条件恶劣，AMD 却是许多微生物的栖息地，它们的活动在 AMD 中发挥了重要作用。在不同的地质条件下，使用各种化学物质来防止 AMD 的形成和常规的大规模处理是不可行的。这意味着微生物介导的方法是 AMD 修复的一种可行且可持续的替代技术。生物膜中的微藻在这种生物修复中起着关键作用，因为它们与异养细菌保持着共生关系。利用微藻-细菌生物膜的协同方法为细菌的生长提供了来自藻类生物质的支持代谢物，并介导了 AMD 的修复。然而，由于其生理学特性和去除金属的能力，非嗜酸微藻可以适应 AMD 的修复。选择性嗜酸和非嗜酸微藻与细菌的组合，以生物膜的形式存在，可能对受金属污染的水的生物修复非常有效。本综述批判性地考察了生物膜中微藻和细菌之间建立的共生相互作用的性质及其在从 AMD 中去除金属以及随后产生生物量以生产生物燃料方面的作用。将微藻-细菌联合体整合到燃料电池中是一种有吸引力的微生物生物技术新兴方法，可用于 AMD 修复。
