PEER-REVIEWED ARTICLE bioresources.com Du et al. (2011). “Reduce COD in CTMP Effluent,” BioResources 6(3), 3505-3514. 3505 REDUCING COD AND BOD, AS WELL AS PRODUCING TRIACYLGLYCEROL BY LDS5 GROWN IN CTMP EFFLUENT Yalan Du, a,b,# Yang Wang, b,c,# Gong Peng, b,c , Zhenhua Su, d Ming Xu, d Wenying Feng, d Shuyan Zhang, b Yunfeng Ding, b,c Degang Zhao, a and Pingsheng Liu b, * Both the energy shortage and pollution tend to slow down economic development and affect our daily lives. Some microorganisms not only can digest pollutants, but also can convert pollutant metabolites to triacylglycerol (TAG) that can be used to produce biodiesel. Here, we present results showing that the bacterium strain LDS5, a mutant of Rhodococcus sp. RHA1 (RHA1) generated in our lab, could grow well in chemithermomechanical pulping (CTMP) effluent, a type of paper mill wastewater, reduce chemical oxygen demand (COD Cr ) and biochemical oxygen demand (BOD 5 ) significantly, and produce TAG. Our data suggest that this strain has the potential to be used in paper mill wastewater treatment as well as in the development of biodiesel using biomass from paper mills. Key words: Rhodococcus sp. RHA1; LDS5; CTMP effluent; Triacylglycerol; Biodiesel Contact information: a: The Laboratory of Gene Engineering, College of life sciences, Guizhou University, Guiyang, Guizhou, China; b:National Laboratory of Biomacromolucules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; c: Graduate University of Chinese Academy of Sciences, Beijing, China; d: China National Pulp and Paper Research Institute, Beijing, China; The current address of Yalan Du is Department of Histology and Embryology, University of South China, Hengyang, Hunan, China; # These authors contributed equally to this work; * Corresponding author: pliu@ibp.ac.cn INTRODUCTION With the improvements in living standards, petroleum is playing a more and more important role in our daily lives. The increasing consumption of energy means that the world supply of such resources will more rapidly reach its limit, and the resulting prospect of an energy shortage becomes one of our most serious problems. According to the International Energy Agency (IEA) report, the world oil production demand is expected to increase 1.1% per year and will reach 105 million barrels per day (Mb/d) in 2030 (IEA 2008). Fossil fuels are non-renewable resources, and the remaining accessible reserves are consumed more rapidly each year. The decline of petroleum reserves is predicted at 2% to 3% per year from 2010 (Campbell 2006). Solving the energy shortage by finding some new energy resources is becoming a hot topic around the world. A consensus of opinion has grown favoring the development of bioenergy. Biofuel is one of the most widely used forms of transportable energy. Bioethanol and biodiesel currently make up about 90% of the biofuel market (Rottig et al. 2010). Biodiesel is composed of fatty acid alkyl esters and can be synthesized by chemical, biochemical, or other methods mainly from renewable resources. The raw material for biodiesel is triacylglycerol (TAG)