Mr. Sun, Mr. Dong and Miss Dong successfully defended their Master theses

硕士生答辩:Mr. Sun, Mr. Dong and Miss Dong successfully defended their Master theses

On June 3, 2020, Mr. Jie Sun, Mr. Guo-hua Dong and Miss Qian Dong supervised by Prof. Zhen Fang, successfully defended their theses in A302 Huixia Building, Pukou Campus of Nanjing Agricultural University. The defending committee was composed of Prof. Chun-xia He (chair) from Nanjing Agricultural University, Prof. Hong-mei Jin from Jiangsu Provincial Academy of Agricultural Sciences, associate Prof. Xiao-yu Yong from Nanjing Technology University and associate Prof. Yu-tao Liu from Nanjing Agricultural University.

Mr. Sun, Mr. Dong and Miss Dong presented their research results for Master theses, the committee members raised relevant questions. Based on the replies and theses reviewed, the panel agreed that the three students had successfully completed their research and course requirements on agricultural bio-environment and energy engineering. Mr. Sun studied the hydrothermal gasification of agricultural wastes in subcritical water system with his thesis entitled “Catalytic gasification of lignocellulosic wastes with Ni-Co bimetallic catalysts in subcritical water”. Mr. Dong studied the gasification of cooking wastes with Ni-BN/Al2O3 in subcritical water to produce hydrogen with his thesis entitled “Subcritical hydrothermal gasification of cooking wastes with Ni-BN/Al2O3 catalyst to produce hydrogen rich gas”. He selected the process conditions for producing hydrogen from cooking waste and achieved the gasification of cooking wastes. Miss Dong studied the pretreatment of cotton stalk with ethylene glycol-chloride salts with her thesis of “Study on enzymatic hydrolysis and saccharification of cotton straw pretreated with ethylene glycol-chloride salts”. She optimized the pretreatment conditions and achieved the cotton stalk efficient saccharification. As first author, Mr. Sun published 1 Journal paper (Q1) and filed 1 invention patent. Mr. Dong co-authored 3 papers and Miss Dong co-authored 6 papers.

After the jury voted by secret ballot, the panel agree to confer Master of Science in Engineering Degree to Mr. Jie Sun, Master of Engineering Degrees to Mr. Guo-hua Dong and Miss Qian Dong, respectively.

Congratulations to Mr. Sun, Mr. Dong and Miss Dong!

2020年6月3日下午,南京农业大学生物能源组2017级工学硕士研究生孙杰(男),2018级工程硕士研究生董国华(男)和董倩(女)毕业答辩会在南京农业大学浦口校区汇贤楼A302举行。南京农业大学的何春霞教授担任答辩评审委员会主席,江苏省农科院的靳红梅研究员,南京工业大学的雍晓雨副教授和南京农业大学的刘玉涛副教授共三位专家担任评审委员。

答辩会上,孙杰,董国华和董倩三位同学分别对各自在校期间学位论文进行汇报,同时答辩委员会主席和各位评委提出了相关问题。根据三位同学问答问题以及学位论文评阅基础上,经过评审决议,专家组一致认为孙杰,董国华和董倩同学顺利完成了农业生物环境与能源方面的研究和学习要求。孙杰同学在毕业论文《亚临界水体系下Ni-Co双金属催化剂对木质纤维素废弃物催化气化研究》中研究了在亚临界水体系下Ni-Co双金属催化剂催化农业废弃物气化,并针对气化的工艺条件进行了筛选,可以达到气化农业废弃物的效果。董国华同学在毕业论文《Ni-BN/Al2O3催化餐厨垃圾亚临界水热制氢的研究》中研究了Ni-BN/Al2O3在亚临界水中催化餐厨垃圾制氢,针对餐厨垃圾在亚临界水中制氢的工艺条件进行了研究,实现了餐厨垃圾的气化。董倩同学在毕业论文《乙二醇-氯化盐预处理棉花秸秆促进酶解糖化的研究》中研究了乙二醇-氯化盐对棉杆的预处理工艺,针对乙二醇-氯化铁预处理条件进行了优化,实现了棉杆的高效酶解糖化。三位同学在校期间工作努力,其中孙杰同学以第一作者发表Q1区论文1篇,受理专利1项;董国华同学参与发表论文3篇;董倩同学参与发表论文6篇。经评委会无记名投票表决,一致同意通过毕业答辩。

祝贺孙杰、董国华、董倩同学!

Microbial Lipid Production from Both Rice Straw Hydrolysates and Recycled Pretreated Glycerol

Microbial Lipid Production from Both Rice Straw Hydrolysates and Recycled Pretreated Glycerol

Recently, PhD student Mr. Song Tang supervised by Prof. Zhen FANG produced microbial lipid from both rice straw hydrolysates and recycled pretreated glycerol. First, lipid fermentation of glucose via Cryptococcus curvatus was optimized by response surface methodology. Variables were selected by Plackett–Burman design, and optimized by central composite design, achieving 4.9 g/L total lipid and 0.16 g/g lipid yield, and increased further as glucose increased from 30 to 50 g/L. It was found that lipid content rapidly decreased from 44.5% to 6.4% as lignin (0.5 g/L) was added, which would inhibit lipid accumulation for hydrolysate and recycled glycerol. Secondly, these fermentation conditions were further used for rice straw hydrolysates. After glycerol-FeCl3 pretreatment (0.06 mol/L FeCl3, 150 °C and 20 min), 72% lignin of rice straw was removed with glucose yield increased by 2.4 times to 74.3% at 20% substrate loading and 3 FPU/g dry substrate. Its hydrolysates were separated for lipid fermentation, producing high total lipid (8.8 g/L) and lipid yield (0.17 g/g). Finally, recycled glycerol reached the maximum total lipid of 7.2 g/L and high lipid yield of 0.16 g/g. Based on the calculation, 2.9 g total lipid would be produced from 1 g rice straw and the recycled glycerol, with a similar composition to soybean oil.

The results were published:

S Tang, Q Dong, Zhen Fang*, WJ Cong, H Zhang, Microbial Lipid Production from Both Rice Straw Hydrolysates and Recycled Pretreated Glycerol, Bioresource Technology, 312, ​123580 (2020). https://doi.org/10.1016/j.biortech.2020.123580.

Microbial lipid production from both rice straw hydrolysates and recycled pretreated glycerol(水稻秸秆经甘油-氯化铁预处理后,酶水解,将秸秆水解产物和预处理液中纯化的甘油作为碳源,通过弯曲隐球菌高效生产油脂。)

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稻秆和废弃甘油发酵生产微生物油脂

 最近,博士生唐松(男)同学在方老师的指导下,利用稻秆水解液和预处理液中纯化的甘油发酵生产微生物油脂。首先,通过响应面优化弯曲隐球菌发酵葡萄糖产油脂,通过Plackett-Burman实验筛选出显著性因素,设计中心组合实验以优化油脂产量,在最佳发酵条件,总油脂量为4.9 g/L,油脂产率达到0.16 g/g,并通过增加葡萄糖浓度以进一步提高了其产油脂量。但在添加木质素(0.5 g/L)后,酵母胞内油脂含量从44.5%迅速降低至6.4%,这表明木质素会抑制胞内油脂的积累。此后,在优化的发酵条件下,利用稻秆水解产物发酵产微生物油脂。通过甘油-氯化铁预处理(150 °C 和 20 min),稻秆中72%木质素被去除,酶解率较未处理前提高了2.4倍。在3 FPU/g干基和20%基质浓度条件下,酶水解72 h后,预处理后稻秆的酶解率高达74.3%。基于响应面优化的最佳葡萄糖产油脂的发酵条件,在将分离的秸秆水解产物作为碳源,产出油脂8.8 g/L,同时油脂产率也达到了0.17 g/g。最后,利用预处理液中纯化的甘油发酵生产微生物油脂,总油脂量最高达到7.2 g/L,并获得了高水平的油脂产率(0.16 g/g)。通过物料质量平衡分析,1 g稻秆及其预处理中所用甘油将产出2​​.9 g油脂,其脂肪酸组成也相似于大豆油。

结果发表在Bioresource Technology:

S Tang, Q Dong, Zhen Fang*, WJ Cong, H Zhang, Microbial Lipid Production from Both Rice Straw Hydrolysates and Recycled Pretreated Glycerol, Bioresource Technology, 312, ​123580 (2020). https://doi.org/10.1016/j.biortech.2020.123580.