Lipid Production and Extraction for Biodiesel

PI：ChuProposal编号：1134488机构：德克萨斯工程实验站标题：生物柴油的油脂生产和提取生物柴油是一种清洁和可再生的生物燃料，与现有的能源基础设施和柴油发动机兼容。然而，在完全实现生物柴油的大规模、低成本生产之前，必须克服两个关键挑战。第一个挑战是生物柴油原料的廉价和可持续生产，第二个挑战是从原料中提取和回收生物柴油的前体--胞内脂肪的有效工艺。产油细菌是生产生物柴油的一种潜在的有吸引力的原料，因为它们积累高水平的三酰甘油(TAG)脂类(占干细胞重量的20%-75%)，生长迅速，在培养中达到高细胞密度，并利用多种碳源。这项拟议研究的总体目标是开发和研究从生物质衍生的水解液粗混合物中产生胞内脂类的细菌菌株，然后通过用噬菌体控制细菌的裂解来释放脂类。噬菌体是众所周知的在细菌培养物上增殖和裂解细菌的能力。这项拟议的研究将表征积累标签的细菌所特有的噬菌体，探索利用这些噬菌体或它们的溶菌基因来影响累积标签的释放，并表征这些过程的基本机制。拟议的研究有三个目标。第一个目标是确定积累标签的细菌是否可以在存在常见抑制化合物的情况下生长，例如在木质纤维素水解物中发现的呋喃和木质素衍生的酚类化合物，以及生物质碳水化合物。第二个目标是确定表达噬菌体裂解基因的噬菌体或细菌菌株是否能够有效地裂解积累标签的细菌并从宿主细胞中释放标签。第三个目标是通过应用噬菌体鸡尾酒或表达克隆的噬菌体裂解基因从积累标签的细菌模型中提取标签。广泛影响拟议的教育和外联活动侧重于学生和高中教师培训，指导来自代表性不足的少数族裔的学生，以及开发基于互联网的公共宣传和教学工具。两名博士生将接受环境工程、微生物学和病毒学方面的跨学科培训。预计两名本科生将在与德克萨斯农工大学(TAMU)噬菌体技术中心(TAMU)协调的PI实验室获得研究经验。本科生研究参与者将通过TAMU Louis Stokes少数群体参与联盟计划招募和指导。PI还将通过TAMU教师研究经验(RET)计划在暑期与两名高中教师密切合作。这项研究的结果将通过PIS网站、通过工程学院的“工程工作”服务的播客和YouTube视频发布。

PI: ChuProposal Number: 1134488Institution: Texas Engineering Experiment StationTitle: Lipid Production and Extraction for BiodieselIntellectual MeritBiodiesel is a clean and renewable biofuel that is compatible with existing energy infrastructure and diesel engines. However, before the large-scale, cost-effective production of biodiesel can be fully realized, two key challenges must be overcome. The first challenge is the inexpensive and sustainable production of the biodiesel feedstock, and the second challenge is an effective process for extraction for and recovery of the intracellular lipids, the precursors to biodiesel, from the feedstock. Oleaginous bacteria are a potentially attractive feedstock for biodiesel production, as they accumulate high levels triacylglycerol (TAG) lipids (20-75% of dry cell weight), grow rapidly, reach high cell densities in culture, and utilize diverse carbon sources. The overall goal of the proposed research is to develop and study bacterial strains that produce intracellular lipids from biomass-derived hydrolysate crude mixtures and then release the lipids through controlled lysis of the bacteria with bacteriophage. Bacteriophage (phage), are well known for their ability to proliferate on and lyse bacterial cultures. The proposed research will characterize phages specific for the TAG-accumulating bacteria, explore the use of these phages or their bacteriolytic genes to effect release of the accumulated TAG, and characterize the fundamental mechanisms underlying these processes. The proposed research has three objectives. The first objective is to determine if TAG-accumulating bacteria can grow in the presence of common inhibitory compounds, such as furaldehydes and lignin-derived phenolic compounds, found in lignocellulosic hydrolysates, in addition to the biomass carbohydrates. The second objective is to determine if phages or bacterial strains expressing phage lysis genes can effectively lyse TAG-accumulating bacteria and release TAGs from the host cells. The third objective is to extract TAGs from the model TAG-accumulating bacteria by application of a phage cocktail or expression of cloned phage lysis genes.Broader ImpactsThe proposed education and outreach activities focus on student and high school teacher training, mentoring of students from under-represented minorities, and development of internet-based public outreach and teaching tools. Two Ph.D. students will receive interdisciplinary training at the interface of environmental engineering, microbiology, and virology. It is also expected that two undergraduate students will be given research experiences in the PIs laboratory that are coordinated with the Center for Phage Technology at Texas A & M University (TAMU). The undergraduate student research participants will be recruited and mentored through the TAMU Louis Stokes Alliance for Minority Participation program. The PI will also work closely with two high school teachers during summers through the TAMU Research Experience for Teachers (RET) program. Outcomes of this study will communicated through the PIs web site, by podcasting through the College of Engineering's "Engineering Works" service, and by YouTube videos.