China 
Africa 
Explore chapters and articles related to this topic
Genetic Regulation of Principal Microorganisms (Yeast, Zymomonas mobilis, and Clostridium thermocellum) Producing Bioethanol/Biofuel
Published in Ayerim Y. Hernández Almanza, Nagamani Balagurusamy, Héctor Ruiz Leza, Cristóbal N. Aguilar, Bioethanol, 2023
Dania Sandoval-Nuñez, Teresa Romero-Gutiérrez, Melchor Arellano-Plaza, Anne Gschaedler, Lorena Amaya-Delgado
Different metabolic engineering experiments were performed to improve bioethanol production through the use of genetic tools such as heterologous expression systems, the silencing of specific genes, and mutagenesis, among others [73]. One example is a strain of Klebsiella oxytoca that was modified by metabolic engineering by inserting the PDC gene from Z. mobilis to increase its capacity for pyruvate decarboxylation, a key enzyme in the homoethanol pathway of Z. mobilis [74]. In recent years, next-generation sequencing (NGS) technologies have allowed the characterization of complete genomes from different microorganisms of industrial interest, including Z. mobilis. Knowledge of the genetic structure of these bacteria has allowed us to deeply study the production of metabolites with biotechnological applications and the adaptation mechanisms to environmental factors. The first genome of Z. mobilis was sequenced in 2005, with a circular chromosome with a length of 2,056,416 bp and 5 plasmids, and it was further annotated in 2009 [75, 76]. Subsequently, other genomes were also sequenced with an approximate length of 2.01 to 2.22 Mb including 2 to 6 plasmids [73].
Effect of continuous micro-aeration on hydrogen production by coal bio-fermentation
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Hongyu Guo, Saisai Li, Zhenwei Yang, Xianbo Su, Shufeng Zhao, Bo Song, Shangwei Shi
The technology of hydrogen production by dark fermentation mainly uses fermentation bacteria to degrade biomass in a dark environment to produce hydrogen. According to the metabolic characteristics of hydrogen production, there are two basic pathways for hydrogen production by fermentation bacteria: hydrogen production by pyruvate decarboxylation and hydrogen production by NADH+H+/NAD+ balance regulation (Lee, Show, and Su 2011; Yang and Wang 2017). Hydrogen production by pyruvate decarboxylation can be divided into two ways: hydrogen production by pyruvic acid decarboxylation-ferredoxin-hydrogenase pathway and hydrogen production by pyruvic acid decarboxylation-formic acid cleavage pathway (Fu et al. 2021). Hydrogen production from coal by anaerobic fermentation is mainly based on the secretion of extracellular enzymes by microbial flora in mine water, which hydrolyze carbohydrates, proteins and fats in coal into sugars, amino acids and glycerol, fatty acids, and then produces H2 through the acid-producing fermentation stage and hydrogen-producing acetic acid stage (Su et al. 2020), which can effectively reduce the environmental pollution caused by coal combustion and achieve carbon emission reduction at an early date, which has attracted the attention of researchers globally(Chen, Yin, and Wang 2020; Yan and Guo 2008)。