Bioconversion of 5-Hydroxymethylfurfural (HMF) to 2,5-Furandicarboxylic Acid (FDCA) by a Native Obligate Aerobic Bacterium, Acinetobacter calcoaceticus NL14

2020 ◽  
Vol 192 (2) ◽  
pp. 455-465 ◽  
Author(s):  
Yequan Sheng ◽  
Xin Tan ◽  
Xin Zhou ◽  
Yong Xu
Keyword(s):  
Acinetobacter Calcoaceticus ◽  
Aerobic Bacterium ◽  
Obligate Aerobic ◽  
Furandicarboxylic Acid

scholarly journals Flavobacterium glaciei sp. nov., a novel psychrophilic bacterium isolated from the China No.1 glacier

2006 ◽  
Vol 56 (12) ◽  
pp. 2921-2925 ◽  
Author(s):  
De-Chao Zhang ◽  
He-Xiang Wang ◽  
Hong-Can Liu ◽  
Xiu-Zhu Dong ◽  
Pei-Jin Zhou
Keyword(s):  
Phylogenetic Analysis ◽  
Sequence Similarity ◽  
Optimal Growth ◽  
Rrna Gene ◽  
Aerobic Bacterium ◽  
Psychrophilic Bacterium ◽  
Obligate Aerobic ◽  
Bacterium Strain ◽  
The Common ◽  
Sequence Similarities

A novel psychrophilic, yellow-pigmented and obligate aerobic bacterium, strain 0499T, was isolated from the China No.1 glacier. Strain 0499T displayed the common phenotypic and chemotaxonomic features of the genus Flavobacterium, containing menaquinone-6 (MK-6) as the major quinone and C15 : 0, iso-C15 : 0, C17 : 1 ω6c and summed feature 3 (C16 : 1 ω7c/iso-C15 : 0 2-OH) as the major fatty acids. Optimal growth occurred at 21 °C. The genomic DNA G+C content was 36.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequence similarity showed that strain 0499T was related to members of the genus Flavobacterium, sharing the highest sequence similarities with Flavobacterium succinicans (97.9 %), Flavobacterium granuli (97.4 %) and Flavobacterium hydatis (97.2 %). On the basis of phenotypic characteristics, phylogenetic analysis and DNA–DNA relatedness data, a novel species Flavobacterium glaciei is proposed with strain 0499T (=CGMCC 1.5380T=JCM 13953T) as the type strain.

Novel mechanisms of selenate and selenite reduction in the obligate aerobic bacterium Comamonas testosteroni S44

2018 ◽  
Vol 359 ◽  
pp. 129-138 ◽  
Author(s):  
Yuanqing Tan ◽  
Yuantao Wang ◽  
Yu Wang ◽  
Ding Xu ◽  
Yeting Huang ◽  
...  
Keyword(s):  
Aerobic Bacterium ◽  
Comamonas Testosteroni ◽  
Selenite Reduction ◽  
Obligate Aerobic

scholarly journals Engineering mediator-based electroactivity in the obligate aerobic bacterium Pseudomonas putida KT2440

2015 ◽  
Vol 6 ◽  
Author(s):  
Simone Schmitz ◽  
Salome Nies ◽  
Nick Wierckx ◽  
Lars M. Blank ◽  
Miriam A. Rosenbaum
Keyword(s):  
Pseudomonas Putida ◽  
Aerobic Bacterium ◽  
Pseudomonas Putida Kt2440 ◽  
Obligate Aerobic

scholarly journals Nitrous Oxide Reduction by an Obligate Aerobic Bacterium, Gemmatimonas aurantiaca Strain T-27

2017 ◽  
Vol 83 (12) ◽  
Author(s):  
Doyoung Park ◽  
Hayeon Kim ◽  
Sukhwan Yoon
Keyword(s):  
Nitrous Oxide ◽  
Large Fraction ◽  
Reduction Rate ◽  
Regulation Mechanism ◽  
Aerobic Bacterium ◽  
Content Type ◽  
Batch Cultures ◽  
Sources And Sinks ◽  
Reduction Activity ◽  
Obligate Aerobic

ABSTRACT N2O-reducing organisms with nitrous oxide reductases (NosZ) are known as the only biological sink of N2O in the environment. Among the most abundant nosZ genes found in the environment are nosZ genes affiliated with the understudied Gemmatimonadetes phylum. In this study, a unique regulatory mechanism of N2O reduction in Gemmatimonas aurantiaca strain T-27, an isolate affiliated with the Gemmatimonadetes phylum, was examined. Strain T-27 was incubated with N2O and/or O2 as the electron acceptor. Significant N2O reduction was observed only when O2 was initially present. When batch cultures of strain T-27 were amended with O2 and N2O, N2O reduction commenced after O2 was depleted. In a long-term incubation with the addition of N2O upon depletion, the N2O reduction rate decreased over time and came to an eventual stop. Spiking of the culture with O2 resulted in the resuscitation of N2O reduction activity, supporting the hypothesis that N2O reduction by strain T-27 required the transient presence of O2. The highest level of nosZ transcription (8.97 nosZ transcripts/recA transcript) was observed immediately after O2 depletion, and transcription decreased ∼25-fold within 85 h, supporting the observed phenotype. The observed difference between responses of strain T-27 cultures amended with and without N2O to O2 starvation suggested that N2O helped sustain the viability of strain T-27 during temporary anoxia, although N2O reduction was not coupled to growth. The findings in this study suggest that obligate aerobic microorganisms with nosZ genes may utilize N2O as a temporary surrogate for O2 to survive periodic anoxia. IMPORTANCE Emission of N2O, a potent greenhouse gas and ozone depletion agent, from the soil environment is largely determined by microbial sources and sinks. N2O reduction by organisms with N2O reductases (NosZ) is the only known biological sink of N2O at environmentally relevant concentrations (up to ∼1,000 parts per million by volume [ppmv]). Although a large fraction of nosZ genes recovered from soil is affiliated with nosZ found in the genomes of the obligate aerobic phylum Gemmatimonadetes, N2O reduction has not yet been confirmed in any of these organisms. This study demonstrates that N2O is reduced by an obligate aerobic bacterium, Gemmatimonas aurantiaca strain T-27, and suggests a novel regulation mechanism for N2O reduction in this organism, which may also be applicable to other obligate aerobic organisms possessing nosZ genes. We expect that these findings will significantly advance the understanding of N2O dynamics in environments with frequent transitions between oxic and anoxic conditions.

scholarly journals The ldhA Gene Encoding Fermentative L-Lactate Dehydrogenase in Corynebacterium glutamicum Is Positively Regulated by the Global Regulator GlxR

2021 ◽  
Vol 9 (3) ◽  
pp. 550
Author(s):  
Koichi Toyoda ◽  
Masayuki Inui
Keyword(s):  
Lactate Dehydrogenase ◽  
Binding Site ◽  
Corynebacterium Glutamicum ◽  
Lactate Production ◽  
Exponential Phase ◽  
Aerobic Bacterium ◽  
Global Regulator ◽  
Gene Encoding ◽  
Fermentation Products ◽  
Ldha Gene

Bacterial metabolism shifts from aerobic respiration to fermentation at the transition from exponential to stationary growth phases in response to limited oxygen availability. Corynebacterium glutamicum, a Gram-positive, facultative aerobic bacterium used for industrial amino acid production, excretes L-lactate, acetate, and succinate as fermentation products. The ldhA gene encoding L-lactate dehydrogenase is solely responsible for L-lactate production. Its expression is repressed at the exponential phase and prominently induced at the transition phase. ldhA is transcriptionally repressed by the sugar-phosphate-responsive regulator SugR and L-lactate-responsive regulator LldR. Although ldhA expression is derepressed even at the exponential phase in the sugR and lldR double deletion mutant, a further increase in its expression is still observed at the stationary phase, implicating the action of additional transcription regulators. In this study, involvement of the cAMP receptor protein-type global regulator GlxR in the regulation of ldhA expression was investigated. The GlxR-binding site found in the ldhA promoter was modified to inhibit or enhance binding of GlxR. The ldhA promoter activity and expression of ldhA were altered in proportion to the binding affinity of GlxR. Similarly, L-lactate production was also affected by the binding site modification. Thus, GlxR was demonstrated to act as a transcriptional activator of ldhA.

Sign in / Sign up

Export Citation Format

Share Document