Creation of an Ethanol-Tolerant Yeast Strain by Genome Reconstruction Based on Chromosome Splitting Technology

Abstract

We sought to breed an industrially useful yeast strain, specifically an ethanol-tolerant yeast strain that would be optimal for ethanol production, using a novel breeding method, called genome reconstruction, based on chromosome splitting technology. To induce genome reconstruction, Saccharomyces cerevisiae strain SH6310, which contains 31 chromosomes including 12 artificial mini-chromosomes, was continuously cultivated in YPD medium containing 6% to 10% ethanol for 33 days. The 12 mini-chromosomes can be randomly or specifically lost because they do not contain any genes that are essential under high-level ethanol conditions. The strains selected by inducing genome reconstruction grew about ten times more than SH6310 in 8% ethanol. To determine the effect of minichromosome loss on the ethanol tolerance phenotype, PCR and Southern hybridization were performed to detect the remaining mini-chromosomes. These analyses revealed the loss of mini-chromosomes no. 11 and no. 12. Mini-chromosome no. 11 contains ten genes (YKL225W,

Quantitative iTRAQ LC–MS/MS Proteomics Reveals Metabolic Responses to Biofuel Ethanol in Cyanobacterial Synechocystis sp. PCC 6803

“…Ethanol is known to be highly toxic to their native producers (e.g., yeast and Z. mobiliz ) or engineered hosts (e.g., Escherichia coli ) . Application of ethanol-tolerant strains obtained from mutant selection has been demonstrated as a very efficient way to increase the ethanol production in industry. − More recently, based upon an increasing knowledge of ethanol tolerance mechanisms, successful studies employing more directed metabolic and genome engineering approaches were also conducted in yeast to improve its ethanol tolerance and production. − However, the tolerance level of cyanobacteria to ethanol is very low, far below those values calculated for cost- and energy-efficient distillation processes for product recovery, which is minimally about 40–50 g/L for ethanol . As such, it is difficult to produce ethanol in the photosynthetic cyanobacterial hosts at the titers needed for economic efficiency.…”

Research on the Factors Influencing of Chinese Female Consumers' Purchase Intention in Live Streaming E-commerce

“…Thirdly, For LSE "Products", this paper discusses the effect of products (brands) on the purchase intention of Chinese female consumers, and divides product attributes into general attributes and specific attributes in the context of LSE. Existing research have conducted a lot of research on offline product attributes (Dholakia, 2000;Lin and Chuang, 2005;Park et al, 2012;Chen,et al, 2019) proved the influence of general product attributes such as enjoyment, low price and ready-to-use on consumers' purchase Live Streaming E-commerce decisions (Kacen et al, 2012). In addition to these factors that have a general influence on products, this study also considers the role of product specific attributes in live streaming scenarios such as instant feedback of product information and perception of anchor product knowledge.…”

Manipulation of Mini-Yeast Artificial Chromosome Containing Xylan Metabolism Related Genes and Mitotic Stability Analysis in Yeast

“…따라서 S. cerevisiae 균주를 세포공장으로 효 율적인 염색체가공 및 다양한 기능적 연구를 위해 이전의 연 구에서 PCR-mediated chromosome splitting (PCS) 기술을 개발하였다 [6−8]. PCS법은 염색체 가공을 하고자 하는 염색 체부위의 표적서열(target)을 포함한 splitting fragment (DNA module)를 PCR을 통해 제작하고, 효모에 도입하여 인 공염색체의 구축 등 염색체 가공 및 특성분석을 용이하게 하 기 위해 개발된 염색체 분단(chromosome splitting) 기술이 다. PCS법을 통해 효모 12번 염색체의 rDNA cluster를 인 공염색체(artificial chromosome)화 하여 반복된 rDNA cluster 구조가 효모의 세포생리에 미치는 영향을 보고하였 으며 [9], 다수의 효모인공염색체(yeast artificial chromosome, YAC)를 가진 균주의 구축 및 게놈 재배열(genome rearrangement)을 통한 에탄올 내성균주의 제작 및 유전자 분석을 보고하였다 [10] In this study, yeast artificial chromosome Insert (YAC) harboring genes which related xylan metabolism was constructed by using chromosome manipulation technique. For efficient chromosome manipulation, each splitting fragment (DNA module) required for splitting process was prepared and these DNA modules were transformed into Saccharomyces cerevisiae strain YKY164.…”